Hofer A, Siedentopf CM, Ischebeck A, Rettenbacher MA, Verius M, Felber S, Wolfgang Fleischhacker W.
Psychological Medicine, in press
Background. Previous studies have suggested that men and women process emotional stimuli differently. In this study, we used event-related functional magnetic resonance imaging (fMRI) to investigate gender differences in regional cerebral activity during the perception of positive or negative emotions.
Method. The experiment comprised two emotional conditions (positively/negatively valenced words) during which fMRI data were acquired.
Results. Thirty-eight healthy volunteers (19 males, 19 females) were investigated. A direct comparison of brain activation between men and women revealed differential activation in the right putamen, the right superior temporal gyrus, and the left supramarginal gyrus during processing of positively valenced words versus non-words for women versus men. By contrast, during processing of negatively valenced words versus non-words, relatively greater activation was seen in the left perirhinal cortex and hippocampus for women versus men, and in the right supramarginal gyrus for men versus women.
Conclusions. Our findings suggest gender-related neural responses to emotional stimuli and could contribute to the understanding of mechanisms underlying the gender disparity of neuropsychiatric diseases such as mood disorders.
Friday, October 20, 2006
ARTICLE UPDATE - Preferential responses in amygdala and insula during presentation of facial contempt and disgust.
Fabio Sambataro, Savino Dimalta, Annabella Di Giorgio, Paolo Taurisano, Giuseppe Blasi, Tommaso Scarabino, Giuseppe Giannatempo, Marcello Nardini and Alessandro Bertolino
European Journal of Neuroscience, in press
Some authors consider contempt to be a basic emotion while others consider it a variant of disgust. The neural correlates of contempt have not so far been specifically contrasted with disgust. Using functional magnetic resonance imaging (fMRI), we investigated the neural networks involved in the processing of facial contempt and disgust in 24 healthy subjects. Facial recognition of contempt was lower than that of disgust and of neutral faces. The imaging data indicated significant activity in the amygdala and in globus pallidus and putamen during processing of contemptuous faces. Bilateral insula and caudate nuclei and left as well as right inferior frontal gyrus were engaged during processing of disgusted faces. Moreover, direct comparisons of contempt vs. disgust yielded significantly different activations in the amygdala. On the other hand, disgusted faces elicited greater activation than contemptuous faces in the right insula and caudate. Our findings suggest preferential involvement of different neural substrates in the processing of facial emotional expressions of contempt and disgust.
European Journal of Neuroscience, in press
Some authors consider contempt to be a basic emotion while others consider it a variant of disgust. The neural correlates of contempt have not so far been specifically contrasted with disgust. Using functional magnetic resonance imaging (fMRI), we investigated the neural networks involved in the processing of facial contempt and disgust in 24 healthy subjects. Facial recognition of contempt was lower than that of disgust and of neutral faces. The imaging data indicated significant activity in the amygdala and in globus pallidus and putamen during processing of contemptuous faces. Bilateral insula and caudate nuclei and left as well as right inferior frontal gyrus were engaged during processing of disgusted faces. Moreover, direct comparisons of contempt vs. disgust yielded significantly different activations in the amygdala. On the other hand, disgusted faces elicited greater activation than contemptuous faces in the right insula and caudate. Our findings suggest preferential involvement of different neural substrates in the processing of facial emotional expressions of contempt and disgust.
Friday, October 13, 2006
ARTICLE UPDATE - Individual differences in amygdala activity predict response speed during working memory.
Schaefer A, Braver TS, Reynolds JR, Burgess GC, Yarkoni T, Gray JR.
The Journal of Neuroscience, 26, 12120-12128
The human amygdala has classically been viewed as a brain structure primarily related to emotions and dissociated from higher cognition. We report here findings suggesting that the human amygdala also has a role in supporting working memory (WM), a canonical higher cognitive function. In a first functional magnetic resonance imaging (fMRI) study (n = 53), individual differences in amygdala activity predicted behavioral performance in a 3-back WM task. Specifically, higher event-related amygdala amplitude predicted faster response time (RT; r = -0.64), with no loss of accuracy. This relationship was not contingent on mood state, task content, or personality variables. In a second fMRI study (n = 21), we replicated the key finding (r = -0.47) and further showed that the correlation between the amygdala and faster RT was specific to a high working memory load condition (3-back) compared with a low working memory load condition (1-back). These results support models of amygdala function that can account for its involvement not only in emotion but also higher cognition.
The Journal of Neuroscience, 26, 12120-12128
The human amygdala has classically been viewed as a brain structure primarily related to emotions and dissociated from higher cognition. We report here findings suggesting that the human amygdala also has a role in supporting working memory (WM), a canonical higher cognitive function. In a first functional magnetic resonance imaging (fMRI) study (n = 53), individual differences in amygdala activity predicted behavioral performance in a 3-back WM task. Specifically, higher event-related amygdala amplitude predicted faster response time (RT; r = -0.64), with no loss of accuracy. This relationship was not contingent on mood state, task content, or personality variables. In a second fMRI study (n = 21), we replicated the key finding (r = -0.47) and further showed that the correlation between the amygdala and faster RT was specific to a high working memory load condition (3-back) compared with a low working memory load condition (1-back). These results support models of amygdala function that can account for its involvement not only in emotion but also higher cognition.
Tuesday, October 03, 2006
ARTICLE UPDATE - Effects of emotional arousal on multiple memory systems: Evidence from declarative and procedural learning
Stephan Steidl, Salwa Mohi-uddin and Adam K. Anderson
Learning and Memory, in press
Extensive evidence documents emotional modulation of hippocampus-dependent declarative memory in humans. However, little is known about the emotional modulation of striatum-dependent procedural memory. To address how emotional arousal influences declarative and procedural memory, the current study utilized (1) a picture recognition and (2) a weather prediction (WP) task (a probabilistic classification learning task), which have been shown to rely on hippocampal- and striatum-based memory systems, respectively. Observers viewed arousing or neutral pictures after (Experiment 1) or during (Experiment 2) WP training trials. A 1-wk delayed picture recognition memory test revealed enhanced declarative memory for arousing compared with neutral pictures. Arousal during encoding impaired initial WP acquisition but did not influence retention when tested after a 1-wk delay. Data from a subsequent 3-mo delayed test, however, suggested that arousal during acquisition may enhance remote WP retention. These results suggest a potential dissociation between how readily emotional arousal influences hippocampus-dependent and striatum-dependent memory systems in humans.
Learning and Memory, in press
Extensive evidence documents emotional modulation of hippocampus-dependent declarative memory in humans. However, little is known about the emotional modulation of striatum-dependent procedural memory. To address how emotional arousal influences declarative and procedural memory, the current study utilized (1) a picture recognition and (2) a weather prediction (WP) task (a probabilistic classification learning task), which have been shown to rely on hippocampal- and striatum-based memory systems, respectively. Observers viewed arousing or neutral pictures after (Experiment 1) or during (Experiment 2) WP training trials. A 1-wk delayed picture recognition memory test revealed enhanced declarative memory for arousing compared with neutral pictures. Arousal during encoding impaired initial WP acquisition but did not influence retention when tested after a 1-wk delay. Data from a subsequent 3-mo delayed test, however, suggested that arousal during acquisition may enhance remote WP retention. These results suggest a potential dissociation between how readily emotional arousal influences hippocampus-dependent and striatum-dependent memory systems in humans.
ARTICLE UPDATE - Progress in Brain Research Volume 156
This issue is a special issue about understanding emotions.
Section I Attention and Motivation in Emotional Decoding
Chapter 1 Emotion, motivation, and the brain: Reflex foundations in animal and human research.
Peter J. Lang and Michael Davis
Chapter 2 Emotion and attention: event-related brain potential studies.
Harald T. Schupp, Tobias Flaisch, Jessica Stockburger and Markus Junghöfer
Chapter 3 Implicit and explicit categorization of natural scenes.
Maurizio Codispoti, Vera Ferrari, Andrea De Cesarei and Rossella Cardinale
Chapter 4 Dynamics of emotional effects on spatial attention in the human visual cortex.
Gilles Pourtois and Patrik Vuilleumier
Chapter 5 The neural basis of narrative imagery: emotion and action.
Dean Sabatinelli, Peter J. Lang, Margaret M. Bradley and Tobias Flaisch
Chapter 6 Subliminal emotion perception in brain imaging: findings, issues, and recommendations.
Stefan Wiens
Chapter 7 Neuroimaging methods in affective neuroscience: Selected methodological issues.
Markus Junghöfer, Peter Peyk, Tobias Flaisch and Harald T. Schupp
Section II Understanding Emotional Language Content
Chapter 8 Emotional and semantic networks in visual word processing: insights from ERP studies.
Johanna Kissler, Ramin Assadollahi and Cornelia Herbert
Chapter 9 Event-related potential studies of language and emotion: words, phrases, and task effects.
Ira Fischler and Margaret Bradley
Chapter 10 Emotional connotation of words: role of emotion in distributed semantic systems.
M. Allison Cato Jackson and Bruce Crosson
Chapter 11 Macroscopic brain dynamics during verbal and pictorial processing of affective stimuli.
Andreas Keil
Section III Understanding Emotional Intonation
Chapter 12 Intonation as an interface between language and affect.
Didier Grandjean, Tanja Bänziger and Klaus R. Scherer
Chapter 13 Cerebral processing of linguistic and emotional prosody: fMRI studies.
D. Wildgruber, H. Ackermann, B. Kreifelts and T. Ethofer
Chapter 14 Affective and linguistic processing of speech prosody: DC potential studies.
Hans Pihan
Chapter 15 Lateralization of emotional prosody in the brain: an overview and synopsis on the impact of study design.
Sonja A. Kotz, Martin Meyer and Silke Paulmann
Chapter 16 Psychoacoustic studies on the processing of vocal interjections: how to disentangle lexical and prosodic information?
Susanne Dietrich, Hermann Ackermann, Diana P. Szameitat and Kai Alter
Chapter 17 Judging emotion and attitudes from prosody following brain damage.
Marc D. Pell
Section IV Integrating Social Information
Chapter 18 Processing of facial identity and expression: a psychophysical, physiological, and computational perspective.
Adrian Schwaninger, Christian Wallraven, Douglas W. Cunningham and Sarah D. Chiller-Glaus
Chapter 19 Investigating audiovisual integration of emotional signals in the human brain.
Thomas Ethofer, Gilles Pourtois and Dirk Wildgruber
Chapter 20 Role of the amygdala in processing visual social stimuli.
Ralph Adolphs and Michael Spezio
Chapter 21 Towards a unifying neural theory of social cognition.
Christian Keysers and Valeria Gazzola
Chapter 22 Empathizing: neurocognitive developmental mechanisms and individual differences.
Bhismadev Chakrabarti and Simon Baron-Cohen
Chapter 23 The multiple facets of empathy: a survey of theory and evidence.
Susanne Leiberg and Silke Anders
Section V Understanding Emotional Disorders
Chapter 24 Partly dissociable neural substrates for recognizing basic emotions: a critical review.
Andreas Hennenlotter and Ulrike Schroeder
Chapter 25 Integration of emotion and cognition in patients with psychopathy.
Monika Sommer, Göran Hajak, Katrin Döhnel, Johannes Schwerdtner, Jörg Meinhardt and Jürgen L. Müller
Chapter 26 Disordered emotional processing in schizophrenia and one-sided brain damage.
Katarzyna Kucharska-Pietura
Chapter 27 The biochemistry of dysfunctional emotions: proton MR spectroscopic findings in major depressive disorder.
Gabriele Ende, Traute Demirakca and Heike Tost
Section I Attention and Motivation in Emotional Decoding
Chapter 1 Emotion, motivation, and the brain: Reflex foundations in animal and human research.
Peter J. Lang and Michael Davis
Chapter 2 Emotion and attention: event-related brain potential studies.
Harald T. Schupp, Tobias Flaisch, Jessica Stockburger and Markus Junghöfer
Chapter 3 Implicit and explicit categorization of natural scenes.
Maurizio Codispoti, Vera Ferrari, Andrea De Cesarei and Rossella Cardinale
Chapter 4 Dynamics of emotional effects on spatial attention in the human visual cortex.
Gilles Pourtois and Patrik Vuilleumier
Chapter 5 The neural basis of narrative imagery: emotion and action.
Dean Sabatinelli, Peter J. Lang, Margaret M. Bradley and Tobias Flaisch
Chapter 6 Subliminal emotion perception in brain imaging: findings, issues, and recommendations.
Stefan Wiens
Chapter 7 Neuroimaging methods in affective neuroscience: Selected methodological issues.
Markus Junghöfer, Peter Peyk, Tobias Flaisch and Harald T. Schupp
Section II Understanding Emotional Language Content
Chapter 8 Emotional and semantic networks in visual word processing: insights from ERP studies.
Johanna Kissler, Ramin Assadollahi and Cornelia Herbert
Chapter 9 Event-related potential studies of language and emotion: words, phrases, and task effects.
Ira Fischler and Margaret Bradley
Chapter 10 Emotional connotation of words: role of emotion in distributed semantic systems.
M. Allison Cato Jackson and Bruce Crosson
Chapter 11 Macroscopic brain dynamics during verbal and pictorial processing of affective stimuli.
Andreas Keil
Section III Understanding Emotional Intonation
Chapter 12 Intonation as an interface between language and affect.
Didier Grandjean, Tanja Bänziger and Klaus R. Scherer
Chapter 13 Cerebral processing of linguistic and emotional prosody: fMRI studies.
D. Wildgruber, H. Ackermann, B. Kreifelts and T. Ethofer
Chapter 14 Affective and linguistic processing of speech prosody: DC potential studies.
Hans Pihan
Chapter 15 Lateralization of emotional prosody in the brain: an overview and synopsis on the impact of study design.
Sonja A. Kotz, Martin Meyer and Silke Paulmann
Chapter 16 Psychoacoustic studies on the processing of vocal interjections: how to disentangle lexical and prosodic information?
Susanne Dietrich, Hermann Ackermann, Diana P. Szameitat and Kai Alter
Chapter 17 Judging emotion and attitudes from prosody following brain damage.
Marc D. Pell
Section IV Integrating Social Information
Chapter 18 Processing of facial identity and expression: a psychophysical, physiological, and computational perspective.
Adrian Schwaninger, Christian Wallraven, Douglas W. Cunningham and Sarah D. Chiller-Glaus
Chapter 19 Investigating audiovisual integration of emotional signals in the human brain.
Thomas Ethofer, Gilles Pourtois and Dirk Wildgruber
Chapter 20 Role of the amygdala in processing visual social stimuli.
Ralph Adolphs and Michael Spezio
Chapter 21 Towards a unifying neural theory of social cognition.
Christian Keysers and Valeria Gazzola
Chapter 22 Empathizing: neurocognitive developmental mechanisms and individual differences.
Bhismadev Chakrabarti and Simon Baron-Cohen
Chapter 23 The multiple facets of empathy: a survey of theory and evidence.
Susanne Leiberg and Silke Anders
Section V Understanding Emotional Disorders
Chapter 24 Partly dissociable neural substrates for recognizing basic emotions: a critical review.
Andreas Hennenlotter and Ulrike Schroeder
Chapter 25 Integration of emotion and cognition in patients with psychopathy.
Monika Sommer, Göran Hajak, Katrin Döhnel, Johannes Schwerdtner, Jörg Meinhardt and Jürgen L. Müller
Chapter 26 Disordered emotional processing in schizophrenia and one-sided brain damage.
Katarzyna Kucharska-Pietura
Chapter 27 The biochemistry of dysfunctional emotions: proton MR spectroscopic findings in major depressive disorder.
Gabriele Ende, Traute Demirakca and Heike Tost
ARTICLE UPDATE - “Did you see him in the newspaper?” Electrophysiological correlates of context and valence in face processing
Giulia Galli, Matteo Feurra and Maria Pia Viggiano
Brain Research, in press
Face recognition emerges from an interaction between bottom-up and top-down processing. Specifically, it relies on complex associations between the visual representation of a given face and previously stored knowledge about that face (e.g. biographical details). In the present experiment, the time-course of the interaction between bottom-up and top-down processing was investigated using event-related potentials (ERPs) and manipulating realistic, ecological contextual information. In the study phase, half of the faces (context faces) were framed in a newspaper page entitled with an action committed by the person depicted; these actions could have a positive or a negative value, so in this way emotional valence could be manipulated. The other half was presented on a neutral background (no-context faces). In the test phase, previously presented faces and new ones were presented on neutral backgrounds and an old/new discrimination was requested. The N170 component was modulated by both context (presence/absence at encoding) and valence (positive/negative). A reduction in amplitude was found for context faces as opposed to no-context faces. The same pattern was observed for negative faces compared to positive ones. Moreover, later activations associated with context and valence were differentially distributed over the scalp: context effects were prominent in left frontal areas, traditionally linked to person-specific information retrieval, whereas valence effects were broadly distributed over the scalp. In relation to recent neuroimaging findings on the neural basis of top-down modulations, present findings indicate that the information flow from higher-order areas might have modulated the N170 component and mediated the retrieval of semantic information pertaining to the study episode.
Brain Research, in press
Face recognition emerges from an interaction between bottom-up and top-down processing. Specifically, it relies on complex associations between the visual representation of a given face and previously stored knowledge about that face (e.g. biographical details). In the present experiment, the time-course of the interaction between bottom-up and top-down processing was investigated using event-related potentials (ERPs) and manipulating realistic, ecological contextual information. In the study phase, half of the faces (context faces) were framed in a newspaper page entitled with an action committed by the person depicted; these actions could have a positive or a negative value, so in this way emotional valence could be manipulated. The other half was presented on a neutral background (no-context faces). In the test phase, previously presented faces and new ones were presented on neutral backgrounds and an old/new discrimination was requested. The N170 component was modulated by both context (presence/absence at encoding) and valence (positive/negative). A reduction in amplitude was found for context faces as opposed to no-context faces. The same pattern was observed for negative faces compared to positive ones. Moreover, later activations associated with context and valence were differentially distributed over the scalp: context effects were prominent in left frontal areas, traditionally linked to person-specific information retrieval, whereas valence effects were broadly distributed over the scalp. In relation to recent neuroimaging findings on the neural basis of top-down modulations, present findings indicate that the information flow from higher-order areas might have modulated the N170 component and mediated the retrieval of semantic information pertaining to the study episode.
Monday, October 02, 2006
ARTICLE UPDATE - Neural Processing of Fearful Faces: Effects of Anxiety are Gated by Perceptual Capacity Limitations
Sonia J. Bishop, Rob Jenkins, and Andrew D. Lawrence
Cerebral Cortex, in press
Debate continues as to the automaticity of the amygdala's response to threat. Accounts taking a strong automaticity line suggest that the amygdala's response to threat is both involuntary and independent of attentional resources. Building on these accounts, prominent models have suggested that anxiety modulates the output of an amygdala-based preattentive threat evaluation system. Here, we argue for a modification of these models. Functional magnetic resonance imaging data were collected while volunteers performed a letter search task of high or low perceptual load superimposed on fearful or neutral face distractors. Neither high- nor low-anxious volunteers showed an increased amygdala response to threat distractors under high perceptual load, contrary to a strong automaticity account of amygdala function. Under low perceptual load, elevated state anxiety was associated with a heightened response to threat distractors in the amygdala and superior temporal sulcus, whereas individuals high in trait anxiety showed a reduced prefrontal response to these stimuli, consistent with weakened recruitment of control mechanisms used to prevent the further processing of salient distractors. These findings suggest that anxiety modulates processing subsequent to competition for perceptual processing resources, with state and trait anxiety having distinguishable influences upon the neural mechanisms underlying threat evaluation and "top-down" control.
Cerebral Cortex, in press
Debate continues as to the automaticity of the amygdala's response to threat. Accounts taking a strong automaticity line suggest that the amygdala's response to threat is both involuntary and independent of attentional resources. Building on these accounts, prominent models have suggested that anxiety modulates the output of an amygdala-based preattentive threat evaluation system. Here, we argue for a modification of these models. Functional magnetic resonance imaging data were collected while volunteers performed a letter search task of high or low perceptual load superimposed on fearful or neutral face distractors. Neither high- nor low-anxious volunteers showed an increased amygdala response to threat distractors under high perceptual load, contrary to a strong automaticity account of amygdala function. Under low perceptual load, elevated state anxiety was associated with a heightened response to threat distractors in the amygdala and superior temporal sulcus, whereas individuals high in trait anxiety showed a reduced prefrontal response to these stimuli, consistent with weakened recruitment of control mechanisms used to prevent the further processing of salient distractors. These findings suggest that anxiety modulates processing subsequent to competition for perceptual processing resources, with state and trait anxiety having distinguishable influences upon the neural mechanisms underlying threat evaluation and "top-down" control.
ARTICLE UPDATE - Resolving Emotional Conflict: A Role for the Rostral Anterior Cingulate Cortex in Modulating Activity in the Amygdala
Amit Etkin, Tobias Egner, Daniel M. Peraza, Eric R. Kandel and Joy Hirsch
Neuron, 51, 871-882
Effective mental functioning requires that cognition be protected from emotional conflict due to interference by task-irrelevant emotionally salient stimuli. The neural mechanisms by which the brain detects and resolves emotional conflict are still largely unknown, however. Drawing on the classic Stroop conflict task, we developed a protocol that allowed us to dissociate the generation and monitoring of emotional conflict from its resolution. Using functional magnetic resonance imaging (fMRI), we find that activity in the amygdala and dorsomedial and dorsolateral prefrontal cortices reflects the amount of emotional conflict. By contrast, the resolution of emotional conflict is associated with activation of the rostral anterior cingulate cortex. Activation of the rostral cingulate is predicted by the amount of previous-trial conflict-related neural activity and is accompanied by a simultaneous and correlated reduction of amygdalar activity. These data suggest that emotional conflict is resolved through top-down inhibition of amygdalar activity by the rostral cingulate cortex.
Neuron, 51, 871-882
Effective mental functioning requires that cognition be protected from emotional conflict due to interference by task-irrelevant emotionally salient stimuli. The neural mechanisms by which the brain detects and resolves emotional conflict are still largely unknown, however. Drawing on the classic Stroop conflict task, we developed a protocol that allowed us to dissociate the generation and monitoring of emotional conflict from its resolution. Using functional magnetic resonance imaging (fMRI), we find that activity in the amygdala and dorsomedial and dorsolateral prefrontal cortices reflects the amount of emotional conflict. By contrast, the resolution of emotional conflict is associated with activation of the rostral anterior cingulate cortex. Activation of the rostral cingulate is predicted by the amount of previous-trial conflict-related neural activity and is accompanied by a simultaneous and correlated reduction of amygdalar activity. These data suggest that emotional conflict is resolved through top-down inhibition of amygdalar activity by the rostral cingulate cortex.
ARTICLE UPDATE - Fast recognition of social emotions takes the whole brain: Interhemispheric cooperation in the absence of cerebral asymmetry
Marco Tamietto, Mauro Adenzato, Giuliano Geminiani and Beatrice de Gelder
Neuropsychologia, in press
Hemispheric asymmetry in emotional perception has been traditionally studied for basic emotions and very little is known about laterality for more complex social emotions. Here, we used the “redundant target paradigm” to investigate interhemispheric asymmetry and cooperation for two social emotions in healthy subjects. Facial expressions of flirtatiousness or arrogance were briefly presented either unilaterally in the left (LVF) or right visual field (RVF), or simultaneously to both visual fields (BVF) while participants responded to the target expression (flirtatious or arrogant, counterbalanced between blocks). In bilateral conditions the faces could show the same emotion (congruent condition) or two different expressions (incongruent condition). No difference between unilateral presentations was found, suggesting that the perception of social emotions is not hemispherically lateralized. Responses were faster and more accurate in bilateral displays with two emotionally congruent but physically different faces (i.e., a male and a female expressing the same emotion) than in unilateral conditions. This “redundant target effect” was consistent with a neural summation model, thereby showing that interhemispheric cooperation may occur for social emotions despite major perceptual differences between faces posing the same expression.
Neuropsychologia, in press
Hemispheric asymmetry in emotional perception has been traditionally studied for basic emotions and very little is known about laterality for more complex social emotions. Here, we used the “redundant target paradigm” to investigate interhemispheric asymmetry and cooperation for two social emotions in healthy subjects. Facial expressions of flirtatiousness or arrogance were briefly presented either unilaterally in the left (LVF) or right visual field (RVF), or simultaneously to both visual fields (BVF) while participants responded to the target expression (flirtatious or arrogant, counterbalanced between blocks). In bilateral conditions the faces could show the same emotion (congruent condition) or two different expressions (incongruent condition). No difference between unilateral presentations was found, suggesting that the perception of social emotions is not hemispherically lateralized. Responses were faster and more accurate in bilateral displays with two emotionally congruent but physically different faces (i.e., a male and a female expressing the same emotion) than in unilateral conditions. This “redundant target effect” was consistent with a neural summation model, thereby showing that interhemispheric cooperation may occur for social emotions despite major perceptual differences between faces posing the same expression.
ARTICLE UPDATE - Affective evaluations of objects are influenced by observed gaze direction and emotional expression
Andrew P. Bayliss, Alexandra Frischen, Mark J. Fenske and Steven P. Tipper
Cognition, in press
Gaze direction signals another person’s focus of interest. Facial expressions convey information about their mental state. Appropriate responses to these signals should reflect their combined influence, yet current evidence suggests that gaze-cueing effects for objects near an observed face are not modulated by its emotional expression. Here, we extend the investigation of perceived gaze direction and emotional expression by considering their combined influence on affective judgments. While traditional response-time measures revealed equal gaze-cueing effects for happy and disgust faces, affective evaluations critically depended on the combined product of gaze and emotion. Target objects looked at with a happy expression were liked more than objects looked at with a disgust expression. Objects not looked at were rated equally for both expressions. Our results demonstrate that facial expression does modulate the way that observers utilize gaze cues: Objects attended by others are evaluated according to the valence of their facial expression.
Cognition, in press
Gaze direction signals another person’s focus of interest. Facial expressions convey information about their mental state. Appropriate responses to these signals should reflect their combined influence, yet current evidence suggests that gaze-cueing effects for objects near an observed face are not modulated by its emotional expression. Here, we extend the investigation of perceived gaze direction and emotional expression by considering their combined influence on affective judgments. While traditional response-time measures revealed equal gaze-cueing effects for happy and disgust faces, affective evaluations critically depended on the combined product of gaze and emotion. Target objects looked at with a happy expression were liked more than objects looked at with a disgust expression. Objects not looked at were rated equally for both expressions. Our results demonstrate that facial expression does modulate the way that observers utilize gaze cues: Objects attended by others are evaluated according to the valence of their facial expression.
ARTICLE UPDATE - The influence of current mood on affective startle modulation.
Sabine M. Grüsser, Klaus Wölfling, Chantal P. Mörsen, Norbert Kathmann and Herta Flor
Experimental Brain Research, in press
The affect-modulated startle response is a reliable indicator of the affective processing of stimuli. It may be influenced by trait and state affective variables as well as psychopathological status. The aim of the present study was to determine the influence of the current mood state on startle modulation. Forty-five healthy volunteers viewed affective stimuli while eye blink responses and subjective emotional ratings were assessed. In addition, the current state of mood was assessed, pre and post the experimental procedure. Subjects were divided into those that were in a more positive and those that were in a more negative mood based on a median split. Compared to subjects in a positive mood those in a more negative mood showed significantly reduced startle amplitudes after viewing the negative and neutral stimuli. The results of the present study show that changes in startle responses are not only related to the current state of psychopathology but also to the general affective state of the participants during the assessments.
Experimental Brain Research, in press
The affect-modulated startle response is a reliable indicator of the affective processing of stimuli. It may be influenced by trait and state affective variables as well as psychopathological status. The aim of the present study was to determine the influence of the current mood state on startle modulation. Forty-five healthy volunteers viewed affective stimuli while eye blink responses and subjective emotional ratings were assessed. In addition, the current state of mood was assessed, pre and post the experimental procedure. Subjects were divided into those that were in a more positive and those that were in a more negative mood based on a median split. Compared to subjects in a positive mood those in a more negative mood showed significantly reduced startle amplitudes after viewing the negative and neutral stimuli. The results of the present study show that changes in startle responses are not only related to the current state of psychopathology but also to the general affective state of the participants during the assessments.
ARTICLE UPDATE - The Experience of Emotion.
Barrett LF, Mesquita B, Ochsner KN, Gross JJ.
Annual Review of Psychology, in press
Experiences of emotion are content-rich events that emerge at the level of psychological description, but must be causally constituted by neurobiological processes. This chapter outlines an emerging scientific agenda for understanding what these experiences feel like and how they arise. We review the available answers to what is felt (i.e., the content that makes up an experience of emotion) and how neurobiological processes instantiate these properties of experience. These answers are then integrated into a broad framework that describes, in psychological terms, how the experience of emotion emerges from more basic processes. We then discuss the role of such experiences in the economy of the mind and behavior.
Annual Review of Psychology, in press
Experiences of emotion are content-rich events that emerge at the level of psychological description, but must be causally constituted by neurobiological processes. This chapter outlines an emerging scientific agenda for understanding what these experiences feel like and how they arise. We review the available answers to what is felt (i.e., the content that makes up an experience of emotion) and how neurobiological processes instantiate these properties of experience. These answers are then integrated into a broad framework that describes, in psychological terms, how the experience of emotion emerges from more basic processes. We then discuss the role of such experiences in the economy of the mind and behavior.
Wednesday, September 20, 2006
ARTICLE UPDATE - The psychological, neurochemical and functional neuroanatomical mediators of the effects of positive and negative mood on executive f
Rachel L.C. Mitchell and Louise H. Phillips
Neuropsychologia, in press
In this review we evaluate the cognitive and neural effects of positive and negative mood on executive function. Mild manipulations of negative mood appear to have little effect on cognitive control processes, whereas positive mood impairs aspects of updating, planning and switching. These cognitive effects may be linked to neurochemistry: with positive mood effects mediated by dopamine while negative mood effects may be mediated by serotonin levels. Current evidence on the effects of mood on regional brain activity during executive functions, indicates that the prefrontal cortex is a recurrent site of integration between mood and cognition. We conclude that there is a disparity between the importance of this topic and awareness of how mood affects, executive functions in the brain. Most behavioural and neuroimaging studies of executive function in normal samples do not explore the potential role of variations in mood, yet the evidence we outline indicates that even mild fluctuations in mood can have a significant influence on neural activation and cognition.
Neuropsychologia, in press
In this review we evaluate the cognitive and neural effects of positive and negative mood on executive function. Mild manipulations of negative mood appear to have little effect on cognitive control processes, whereas positive mood impairs aspects of updating, planning and switching. These cognitive effects may be linked to neurochemistry: with positive mood effects mediated by dopamine while negative mood effects may be mediated by serotonin levels. Current evidence on the effects of mood on regional brain activity during executive functions, indicates that the prefrontal cortex is a recurrent site of integration between mood and cognition. We conclude that there is a disparity between the importance of this topic and awareness of how mood affects, executive functions in the brain. Most behavioural and neuroimaging studies of executive function in normal samples do not explore the potential role of variations in mood, yet the evidence we outline indicates that even mild fluctuations in mood can have a significant influence on neural activation and cognition.
ARTICLE UPDATE - Separating subjective emotion from the perception of emotion-inducing stimuli: An fMRI study
Amy S. Garrett and Richard J. Maddock
NeuroImage, in press
fMRI was used to dissociate neural responses temporally associated with the subjective experience of emotion from those associated with the perception of emotion-inducing stimuli in order to better define the emotion-related functions of the amygdala, lateral orbital frontal cortex (OFC), and hippocampus. Subjects viewed aversive pictures followed by an extended post-stimulus period of sustained subjective emotion. Brain regions showing activation paralleling the period of sustained subjective emotion were distinguished from those showing activation limited to the period of aversive picture presentation. Behavioral results showed that subjective ratings of emotion remained elevated for 20 s after offset of the aversive pictures. fMRI results showed that viewing aversive pictures activated the amygdala, lateral OFC, and hippocampus. Subjective emotion (present both during and after aversive pictures) was temporally associated with activation in the right lateral OFC and left hippocampus but not the amygdala. Ratings of subjective emotion were correlated with activation in the right lateral OFC and left hippocampus. The results support direct amygdala involvement in emotion perception but suggest that amygdala activation is not temporally associated with subjective emotion that occurs after the offset of emotion-related stimuli. The results are consistent with a general role for the lateral OFC in monitoring or reflecting on internal experience and show that hippocampal activation is sustained during a period of subjective emotion, possibly related to enhanced memory encoding for the aversive pictures.
NeuroImage, in press
fMRI was used to dissociate neural responses temporally associated with the subjective experience of emotion from those associated with the perception of emotion-inducing stimuli in order to better define the emotion-related functions of the amygdala, lateral orbital frontal cortex (OFC), and hippocampus. Subjects viewed aversive pictures followed by an extended post-stimulus period of sustained subjective emotion. Brain regions showing activation paralleling the period of sustained subjective emotion were distinguished from those showing activation limited to the period of aversive picture presentation. Behavioral results showed that subjective ratings of emotion remained elevated for 20 s after offset of the aversive pictures. fMRI results showed that viewing aversive pictures activated the amygdala, lateral OFC, and hippocampus. Subjective emotion (present both during and after aversive pictures) was temporally associated with activation in the right lateral OFC and left hippocampus but not the amygdala. Ratings of subjective emotion were correlated with activation in the right lateral OFC and left hippocampus. The results support direct amygdala involvement in emotion perception but suggest that amygdala activation is not temporally associated with subjective emotion that occurs after the offset of emotion-related stimuli. The results are consistent with a general role for the lateral OFC in monitoring or reflecting on internal experience and show that hippocampal activation is sustained during a period of subjective emotion, possibly related to enhanced memory encoding for the aversive pictures.
ARTICLE UPDATE - The role of awareness in delay and trace fear conditioning in humans
Knight, David C.; Nguyen, Hanh T.; Bandettini, Peter A.
Cognitive, Affective, & Behavioral Neuroscience, 6, 157-162
Expression of conditional fear without awareness has been previously demonstrated during delay conditioning, a procedure in which the conditioned stimulus (CS) and unconditioned stimulus (UCS) overlap. However, less is known about the role of awareness in trace fear conditioning, where an interval of time separates the CS and UCS. The present study assessed skin conductance response (SCR) and UCS expectancy during delay and trace conditioning. UCS predictability was varied on a trial-by-trial basis by presenting perithreshold auditory CSs. Differential UCS expectancies were demonstrated only on perceived delay and trace trials. Learning-related SCRs were observed during both perceived and unperceived delay CSs. In contrast, differential SCRs were demonstrated only for perceived trace CSs. These data suggest that awareness is necessary for conditional responding during trace, but not delay, fear conditioning.
Cognitive, Affective, & Behavioral Neuroscience, 6, 157-162
Expression of conditional fear without awareness has been previously demonstrated during delay conditioning, a procedure in which the conditioned stimulus (CS) and unconditioned stimulus (UCS) overlap. However, less is known about the role of awareness in trace fear conditioning, where an interval of time separates the CS and UCS. The present study assessed skin conductance response (SCR) and UCS expectancy during delay and trace conditioning. UCS predictability was varied on a trial-by-trial basis by presenting perithreshold auditory CSs. Differential UCS expectancies were demonstrated only on perceived delay and trace trials. Learning-related SCRs were observed during both perceived and unperceived delay CSs. In contrast, differential SCRs were demonstrated only for perceived trace CSs. These data suggest that awareness is necessary for conditional responding during trace, but not delay, fear conditioning.
ARTICLE UPDATE - Interference produced by emotional conflict associated with anterior cingulate activation
Haas, Brian W.; Omura, Kazufumi; Constable, R. Todd; Canli, Turhan
Cognitive, Affective, & Behavioral Neuroscience, 6, 152-156
The anterior cingulate cortex (ACC) is involved in cognition and emotion. In the classic stroop task, presentation of stimuli that are in response conflict with one another produces activation in the caudal ACC. In the emotional stroop task, presentation of emotionally salient stimuli produces activation in the rostral ACC. Presentation of stimuli that are emotionally conflicting should activate the caudal ACC; stimuli that are emotionally salient should activate the rostral ACC. We tested this prediction using functional magnetic resonance imaging while subjects made emotional valence judgments of words overlaid on emotional faces (word-face stroop task). Emotionally incongruent pairs were responded to more slowly than emotionally congruent pairs. Emotionally incongruent trials were associated with increased activation within the caudal ACC, whereas no ACC activation was found in response to emotional saliency. These results support the conflict-monitoring model of caudal ACC and extend this function to conflict within the domain of emotional stimuli.
Cognitive, Affective, & Behavioral Neuroscience, 6, 152-156
The anterior cingulate cortex (ACC) is involved in cognition and emotion. In the classic stroop task, presentation of stimuli that are in response conflict with one another produces activation in the caudal ACC. In the emotional stroop task, presentation of emotionally salient stimuli produces activation in the rostral ACC. Presentation of stimuli that are emotionally conflicting should activate the caudal ACC; stimuli that are emotionally salient should activate the rostral ACC. We tested this prediction using functional magnetic resonance imaging while subjects made emotional valence judgments of words overlaid on emotional faces (word-face stroop task). Emotionally incongruent pairs were responded to more slowly than emotionally congruent pairs. Emotionally incongruent trials were associated with increased activation within the caudal ACC, whereas no ACC activation was found in response to emotional saliency. These results support the conflict-monitoring model of caudal ACC and extend this function to conflict within the domain of emotional stimuli.
ARTICLE UPDATE - Processing emotional pictures and words: Effects of valence and arousal
Kensinger, Elizabeth A.; Schacter, Daniel L.
Cognitive, Affective, & Behavioral Neuroscience, 6, 110-126
There is considerable debate regarding the extent to which limbic regions respond differentially to items with different valences (positive or negative) or to different stimulus types (pictures or words). In the present event-related fMRI study, 21 participants viewed words and pictures that were neutral, negative, or positive. Negative and positive items were equated on arousal. The participants rated each item for whether it depicted or described something animate or inanimate or something common or uncommon. For both pictures and words, the amygdala, dorsomedial prefrontal cortex (PFC), and ventromedial PFC responded equally to all high-arousal items, regardless of valence. Laterality effects in the amygdala were based on the stimulus type (word = left, picture = bilateral). Valence effects were most apparent when the individuals processed pictures, and the results revealed a lateral/medial distinction within the PFC: the lateral PFC responded differentially to negative items, whereas the medial PFC was more engaged during the processing of positive pictures.
Cognitive, Affective, & Behavioral Neuroscience, 6, 110-126
There is considerable debate regarding the extent to which limbic regions respond differentially to items with different valences (positive or negative) or to different stimulus types (pictures or words). In the present event-related fMRI study, 21 participants viewed words and pictures that were neutral, negative, or positive. Negative and positive items were equated on arousal. The participants rated each item for whether it depicted or described something animate or inanimate or something common or uncommon. For both pictures and words, the amygdala, dorsomedial prefrontal cortex (PFC), and ventromedial PFC responded equally to all high-arousal items, regardless of valence. Laterality effects in the amygdala were based on the stimulus type (word = left, picture = bilateral). Valence effects were most apparent when the individuals processed pictures, and the results revealed a lateral/medial distinction within the PFC: the lateral PFC responded differentially to negative items, whereas the medial PFC was more engaged during the processing of positive pictures.
ARTICLE UPDATE - Emotional constraints on intentional forgetting
B. Keith Payne and Elizabeth Corrigan
Journal of Experimental Social Psychology, in press
One way people control the contents of their minds is intentional forgetting—voluntarily forgetting events after they have happened. The events people would most like to forget are unpleasant and emotional. This study used a directed forgetting procedure with emotional and neutral pictures to examine whether people can intentionally forget emotional events as easily as mundane ones. When the to-be-forgotten list was neutral, participants showed successful intentional forgetting. But when the to-be-forgotten list was emotional, directed forgetting failed. Results contribute to understanding the ways that emotion constrains mental control by capturing mental processes including memory retrieval. Emotion may short-circuit attempts to forget those parts of the past people would most like to forget.
Journal of Experimental Social Psychology, in press
One way people control the contents of their minds is intentional forgetting—voluntarily forgetting events after they have happened. The events people would most like to forget are unpleasant and emotional. This study used a directed forgetting procedure with emotional and neutral pictures to examine whether people can intentionally forget emotional events as easily as mundane ones. When the to-be-forgotten list was neutral, participants showed successful intentional forgetting. But when the to-be-forgotten list was emotional, directed forgetting failed. Results contribute to understanding the ways that emotion constrains mental control by capturing mental processes including memory retrieval. Emotion may short-circuit attempts to forget those parts of the past people would most like to forget.
ARTICLE UPDATE - A neural network reflecting individual differences in cognitive processing of emotions during perceptual decision making
Katja Mériau, Isabell Wartenburger, Philipp Kazzer, Kristin Prehn, Claas-Hinrich Lammers, Elke van der Meer, Arno Villringer and Hauke R. Heekeren
NeuorImage, 33, 1016-1027
Even simple perceptual decisions are influenced by the emotional content of a stimulus. Recent neuroimaging studies provide evidence about the neural mechanisms of perceptual decision making on emotional stimuli. However, the effect of individual differences in cognitive processing of emotions on perceptual decision making remains poorly understood. Here, we investigated how changes in the fMRI signal during perceptual decision making on facial stimuli covaried with individual differences in the ability to identify and communicate one’s emotional state. Although this personality trait covaried with changes in activity in the dorsal anterior cingulate cortex (dACC) during gender decisions on facial expressions, there was no correlation during emotion decisions. Further, we investigated whether individual differences in the ability to cognitively process emotions depend on differences in the functional integration of emotional and cognitive brain regions. We therefore compared task-dependent changes in effective connectivity of dACC in individuals with good and with poor ability to cognitively process emotions using a psychophysiological interaction analysis. We found greater coupling of dACC with prefrontal regions in individuals with good ability to identify and communicate their emotional state. Conversely, individuals with poor ability in this domain showed greater coupling of dACC with the amygdala. Our data indicate that individual differences in the ability to identify and communicate one’s emotional state are reflected by altered effective connectivity of the dACC with prefrontal and limbic regions. Thus, we provide neurophysiological evidence for a theoretical model that posits that a discommunication between limbic areas and the neocortex impairs cognitive processing of emotions.
NeuorImage, 33, 1016-1027
Even simple perceptual decisions are influenced by the emotional content of a stimulus. Recent neuroimaging studies provide evidence about the neural mechanisms of perceptual decision making on emotional stimuli. However, the effect of individual differences in cognitive processing of emotions on perceptual decision making remains poorly understood. Here, we investigated how changes in the fMRI signal during perceptual decision making on facial stimuli covaried with individual differences in the ability to identify and communicate one’s emotional state. Although this personality trait covaried with changes in activity in the dorsal anterior cingulate cortex (dACC) during gender decisions on facial expressions, there was no correlation during emotion decisions. Further, we investigated whether individual differences in the ability to cognitively process emotions depend on differences in the functional integration of emotional and cognitive brain regions. We therefore compared task-dependent changes in effective connectivity of dACC in individuals with good and with poor ability to cognitively process emotions using a psychophysiological interaction analysis. We found greater coupling of dACC with prefrontal regions in individuals with good ability to identify and communicate their emotional state. Conversely, individuals with poor ability in this domain showed greater coupling of dACC with the amygdala. Our data indicate that individual differences in the ability to identify and communicate one’s emotional state are reflected by altered effective connectivity of the dACC with prefrontal and limbic regions. Thus, we provide neurophysiological evidence for a theoretical model that posits that a discommunication between limbic areas and the neocortex impairs cognitive processing of emotions.
ARTICLE UPDATE - The effect of anticipation and the specificity of sex differences for amygdala and hippocampus function in emotional memory
Kristen L. Mackiewicz, Issidoros Sarinopoulos, Krystal L. Cleven, and Jack B. Nitschke
PNAS, 103, 14200-14205
Prior research has shown memory is enhanced for emotional events. Key brain areas involved in emotional memory are the amygdala and hippocampus, which are also recruited during aversion and its anticipation. This study investigated whether anticipatory processes signaling an upcoming aversive event contribute to emotional memory. In an event-related functional MRI paradigm, 40 healthy participants viewed aversive and neutral pictures preceded by predictive warning cues. Participants completed a surprise recognition task directly after functional MRI scanning or 2 weeks later. In anticipation of aversive pictures, bilateral dorsal amygdala and anterior hippocampus activations were associated with better immediate recognition memory. Similar associations with memory were observed for activation of those areas in response to aversive pictures. Anticipatory activation predicted immediate memory over and above these associations for picture viewing. Bilateral ventral amygdala activations in response to aversive pictures predicted delayed memory only. We found that previously reported sex differences of memory associations with left amygdala for women and with right amygdala for men were confined to the ventral amygdala during picture viewing and delayed memory. Results support an established animal model elucidating the functional neuroanatomy of the amygdala and hippocampus in emotional memory, highlight the importance of anticipatory processes in such memory for aversive events, and extend neuroanatomical evidence of sex differences for emotional memory.
PNAS, 103, 14200-14205
Prior research has shown memory is enhanced for emotional events. Key brain areas involved in emotional memory are the amygdala and hippocampus, which are also recruited during aversion and its anticipation. This study investigated whether anticipatory processes signaling an upcoming aversive event contribute to emotional memory. In an event-related functional MRI paradigm, 40 healthy participants viewed aversive and neutral pictures preceded by predictive warning cues. Participants completed a surprise recognition task directly after functional MRI scanning or 2 weeks later. In anticipation of aversive pictures, bilateral dorsal amygdala and anterior hippocampus activations were associated with better immediate recognition memory. Similar associations with memory were observed for activation of those areas in response to aversive pictures. Anticipatory activation predicted immediate memory over and above these associations for picture viewing. Bilateral ventral amygdala activations in response to aversive pictures predicted delayed memory only. We found that previously reported sex differences of memory associations with left amygdala for women and with right amygdala for men were confined to the ventral amygdala during picture viewing and delayed memory. Results support an established animal model elucidating the functional neuroanatomy of the amygdala and hippocampus in emotional memory, highlight the importance of anticipatory processes in such memory for aversive events, and extend neuroanatomical evidence of sex differences for emotional memory.
Friday, September 01, 2006
ARTICLE UPDATE - Left hemisphere specialization for response to positive emotional expressions: a divided output methodology.
Root JC, Wong PS, Kinsbourne M.
Emotion, 6, 473-483
An extensive literature credits the right hemisphere with dominance for processing emotion. Conflicting literature finds left hemisphere dominance for positive emotions. This conflict may be resolved by attending to processing stage. A divided output (bimanual) reaction time paradigm in which response hand was varied for emotion (angry; happy) in Experiments 1 and 2 and for gender (male; female) in Experiment 3 focused on response to emotion rather than perception. In Experiments 1 and 2, reaction time was shorter when right-hand responses indicated a happy face and left-hand responses an angry face, as compared to reversed assignment. This dissociation did not obtain with incidental emotion (Experiment 3). Results support the view that response preparation to positive emotional stimuli is left lateralized.
Emotion, 6, 473-483
An extensive literature credits the right hemisphere with dominance for processing emotion. Conflicting literature finds left hemisphere dominance for positive emotions. This conflict may be resolved by attending to processing stage. A divided output (bimanual) reaction time paradigm in which response hand was varied for emotion (angry; happy) in Experiments 1 and 2 and for gender (male; female) in Experiment 3 focused on response to emotion rather than perception. In Experiments 1 and 2, reaction time was shorter when right-hand responses indicated a happy face and left-hand responses an angry face, as compared to reversed assignment. This dissociation did not obtain with incidental emotion (Experiment 3). Results support the view that response preparation to positive emotional stimuli is left lateralized.
ARTICLE UPDATE - Attending to affect: appraisal strategies modulate the electrocortical response to arousing pictures
Hajcak G, Moser JS, Simons RF.
Emotion, 6, 517-522.
Arousing (unpleasant and pleasant) pictures elicit increased neurophysiological measures of perceptual processing. In particular, the electrocortical late positive potential (LPP) is enhanced for arousing, compared with neutral, pictures. To determine whether the magnitude of the LPP is sensitive to the way stimuli are appraised, 16 participants viewed both pleasant and unpleasant pictures and categorized them along an affective or nonaffective dimension. Results indicate that the LPP was reduced for both pleasant and unpleasant pictures when participants made nonaffective, compared with affective, judgments. These results are consistent with previous studies that have used functional neuroimaging to investigate the role of appraisal on emotional processing. The results are further discussed in terms of the utility of using the LPP to study emotion regulation.
Emotion, 6, 517-522.
Arousing (unpleasant and pleasant) pictures elicit increased neurophysiological measures of perceptual processing. In particular, the electrocortical late positive potential (LPP) is enhanced for arousing, compared with neutral, pictures. To determine whether the magnitude of the LPP is sensitive to the way stimuli are appraised, 16 participants viewed both pleasant and unpleasant pictures and categorized them along an affective or nonaffective dimension. Results indicate that the LPP was reduced for both pleasant and unpleasant pictures when participants made nonaffective, compared with affective, judgments. These results are consistent with previous studies that have used functional neuroimaging to investigate the role of appraisal on emotional processing. The results are further discussed in terms of the utility of using the LPP to study emotion regulation.
ARTICLE UPDATE - An emotion-induced attentional blink elicited by aversively conditioned stimuli.
Smith SD, Most SB, Newsome LA, Zald DH.
Emotion, 6, 523-527
The current study examines whether aversively conditioned stimuli can modulate attention to such a degree that they impair the perception of subsequently presented nonemotional targets. In the initial phase of this study, participants viewed 3 categories of photographs, 1 of which was paired with an aversive noise. Following conditioning, participants searched for a target embedded within a series of 17 rapidly presented images on each trial. Critically, a conditioned or unconditioned item from the initial phase appeared 200 ms or 800 ms before the target. At 200-ms lags but not 800-ms lags, the conditioned images impaired target detection relative to the other distractors. Thus, temporary visual deficits can be induced by otherwise neutral distractors whose aversive associations have only recently been learned.
Emotion, 6, 523-527
The current study examines whether aversively conditioned stimuli can modulate attention to such a degree that they impair the perception of subsequently presented nonemotional targets. In the initial phase of this study, participants viewed 3 categories of photographs, 1 of which was paired with an aversive noise. Following conditioning, participants searched for a target embedded within a series of 17 rapidly presented images on each trial. Critically, a conditioned or unconditioned item from the initial phase appeared 200 ms or 800 ms before the target. At 200-ms lags but not 800-ms lags, the conditioned images impaired target detection relative to the other distractors. Thus, temporary visual deficits can be induced by otherwise neutral distractors whose aversive associations have only recently been learned.
ARTICLE UPDATE - EEG phase synchronization during emotional response to positive and negative film stimuli.
Costa T, Rognoni E, Galati D.
Neuroscience Letter, in press
In the present study the patterns of interdependency between different brain regions were investigated as volunteers looked at emotional and non-emotional film stimuli. The main goal was to evaluate the emotion-related differences and to check their consistency during the elaboration of the same type of stimuli in repeated presentations. A measure called synchronization index (SI) was used to detect interdependencies in EEG signals. The hypotheses were that emotional-information processing could involve variation in synchronized activity and that two valence-specific emotions - happiness and sadness - differ from each other. The SI obtained was compared among the various experimental conditions and significant changes were found. The results demonstrated an overall increase of SI during emotional stimulation and, in particular, during sadness, which yielded a pattern involving a large exchange of information among frontal channels. On the other hand, happiness was associated with a wider synchronization among frontal and occipital sites, although happiness itself was less synchronized. We conclude that the SI can be successfully applied for studying the dynamic cooperation between cortical areas during emotion responses.
Neuroscience Letter, in press
In the present study the patterns of interdependency between different brain regions were investigated as volunteers looked at emotional and non-emotional film stimuli. The main goal was to evaluate the emotion-related differences and to check their consistency during the elaboration of the same type of stimuli in repeated presentations. A measure called synchronization index (SI) was used to detect interdependencies in EEG signals. The hypotheses were that emotional-information processing could involve variation in synchronized activity and that two valence-specific emotions - happiness and sadness - differ from each other. The SI obtained was compared among the various experimental conditions and significant changes were found. The results demonstrated an overall increase of SI during emotional stimulation and, in particular, during sadness, which yielded a pattern involving a large exchange of information among frontal channels. On the other hand, happiness was associated with a wider synchronization among frontal and occipital sites, although happiness itself was less synchronized. We conclude that the SI can be successfully applied for studying the dynamic cooperation between cortical areas during emotion responses.
ARTICLE UPDATE - Amygdala response to facial expressions reflects emotional learning.
Hooker CI, Germine LT, Knight RT, D'Esposito M.
Journal of Neuroscience, 26,8915-8922
The functional role of the human amygdala in the evaluation of emotional facial expressions is unclear. Previous animal and human research shows that the amygdala participates in processing positive and negative reinforcement as well as in learning predictive associations between stimuli and subsequent reinforcement. Thus, amygdala response to facial expressions could reflect the processing of primary reinforcement or emotional learning. Here, using functional magnetic resonance imaging, we tested the hypothesis that amygdala response to facial expressions is driven by emotional association learning. We show that the amygdala is more responsive to learning object-emotion associations from happy and fearful facial expressions than it is to the presentation of happy and fearful facial expressions alone. The results provide evidence that the amygdala uses social signals to rapidly and flexibly learn threatening and rewarding associations that ultimately serve to enhance survival.
Journal of Neuroscience, 26,8915-8922
The functional role of the human amygdala in the evaluation of emotional facial expressions is unclear. Previous animal and human research shows that the amygdala participates in processing positive and negative reinforcement as well as in learning predictive associations between stimuli and subsequent reinforcement. Thus, amygdala response to facial expressions could reflect the processing of primary reinforcement or emotional learning. Here, using functional magnetic resonance imaging, we tested the hypothesis that amygdala response to facial expressions is driven by emotional association learning. We show that the amygdala is more responsive to learning object-emotion associations from happy and fearful facial expressions than it is to the presentation of happy and fearful facial expressions alone. The results provide evidence that the amygdala uses social signals to rapidly and flexibly learn threatening and rewarding associations that ultimately serve to enhance survival.
Friday, August 25, 2006
ARTICLE UPDATE - Feature binding and affect: Emotional modulation of visuo-motor integration
Lorenza S. Colzato, Nelleke C. van Wouwe and Bernhard Hommel
Neuropsychologia, in press
The primate cortex represents the external world in a distributed fashion, which calls for a mechanism that integrates and binds the features of a perceived or processed event. Animal and patients studies provide evidence that feature binding in the visual cortex is driven by the muscarinic–cholinergic system, whereas visuo-motor integration may be under dopaminergic control. Consistent with this scenario, we present indication that the binding of visual and action features is modulated by emotions through the probable stimulation of the dopaminergic system. Interestingly, the impact of emotions on binding was restricted to tasks in which shape was task-relevant, suggesting that extracting affective information is not automatic but requires attention to shape.
Neuropsychologia, in press
The primate cortex represents the external world in a distributed fashion, which calls for a mechanism that integrates and binds the features of a perceived or processed event. Animal and patients studies provide evidence that feature binding in the visual cortex is driven by the muscarinic–cholinergic system, whereas visuo-motor integration may be under dopaminergic control. Consistent with this scenario, we present indication that the binding of visual and action features is modulated by emotions through the probable stimulation of the dopaminergic system. Interestingly, the impact of emotions on binding was restricted to tasks in which shape was task-relevant, suggesting that extracting affective information is not automatic but requires attention to shape.
Friday, August 18, 2006
ARTICLE UPDATE - Separating subjective emotion from the perception of emotion-inducing stimuli: An fMRI study.
Garrett AS, Maddock RJ.
NeuroImage, in press
fMRI was used to dissociate neural responses temporally associated with the subjective experience of emotion from those associated with the perception of emotion-inducing stimuli in order to better define the emotion-related functions of the amygdala, lateral orbital frontal cortex (OFC), and hippocampus. Subjects viewed aversive pictures followed by an extended post-stimulus period of sustained subjective emotion. Brain regions showing activation paralleling the period of sustained subjective emotion were distinguished from those showing activation limited to the period of aversive picture presentation. Behavioral results showed that subjective ratings of emotion remained elevated for 20 s after offset of the aversive pictures. fMRI results showed that viewing aversive pictures activated the amygdala, lateral OFC, and hippocampus. Subjective emotion (present both during and after aversive pictures) was temporally associated with activation in the right lateral OFC and left hippocampus but not the amygdala. Ratings of subjective emotion were correlated with activation in the right lateral OFC and left hippocampus. The results support direct amygdala involvement in emotion perception but suggest that amygdala activation is not temporally associated with subjective emotion that occurs after the offset of emotion-related stimuli. The results are consistent with a general role for the lateral OFC in monitoring or reflecting on internal experience and show that hippocampal activation is sustained during a period of subjective emotion, possibly related to enhanced memory encoding for the aversive pictures.
NeuroImage, in press
fMRI was used to dissociate neural responses temporally associated with the subjective experience of emotion from those associated with the perception of emotion-inducing stimuli in order to better define the emotion-related functions of the amygdala, lateral orbital frontal cortex (OFC), and hippocampus. Subjects viewed aversive pictures followed by an extended post-stimulus period of sustained subjective emotion. Brain regions showing activation paralleling the period of sustained subjective emotion were distinguished from those showing activation limited to the period of aversive picture presentation. Behavioral results showed that subjective ratings of emotion remained elevated for 20 s after offset of the aversive pictures. fMRI results showed that viewing aversive pictures activated the amygdala, lateral OFC, and hippocampus. Subjective emotion (present both during and after aversive pictures) was temporally associated with activation in the right lateral OFC and left hippocampus but not the amygdala. Ratings of subjective emotion were correlated with activation in the right lateral OFC and left hippocampus. The results support direct amygdala involvement in emotion perception but suggest that amygdala activation is not temporally associated with subjective emotion that occurs after the offset of emotion-related stimuli. The results are consistent with a general role for the lateral OFC in monitoring or reflecting on internal experience and show that hippocampal activation is sustained during a period of subjective emotion, possibly related to enhanced memory encoding for the aversive pictures.
ARTICLE UPDATE - How do emotion and gaze direction interfere with overt orienting of visual attention?
Bonifacci P, Ricciardelli P, Lugli L, Chitti F, Nicoletti R.
Cognitive Proceedings, 7 (supp 5), 155
BACKGROUND: Several studies using spatial cueing paradigms have demonstrated that observing gaze direction may trigger a reflexive visual orienting in the direction of the other person's gaze. Recently, it has been reported that facial expression may enhance the reflexive orienting of attention to gaze stimuli. However, some researchers have also suggested that, rather than facilitating attentional orienting away from the face, emotional expressions may, in fact, delay or prevent orienting. In the present study we investigated the effects of facial expression and gaze direction on a visual orienting oculomotor task to test whether an angry face may or may not interfere with visual orienting. METHOD: Participants performed an oculomotor task in which they had to make a saccade towards one of two lateral targets, depending upon the colour of the fixation dot which appeared at the centre of the computer screen. The instruction dot remained visible for 50 ms and then disappeared. At different time intervals (stimulus onset asynchronies, SOAs: 50, 100, 150 ms) following the onset of the instruction cue, a real face (gazing either to the right or to the left) was presented at the centre of the monitor. Gaze direction could be congruent or incongruent with respect to the instruction and target location. Facial expression was also manipulated. In half of the trials the diverted gaze (i.e., congruent or incongruent) appeared with an angry expression, whereas in the other half the face had a neutral expression. Participants were instructed to saccade either to the target on the left or to the target on the right (the targets were visible throughout the trial), as indicated by the instruction dot, while completely disregarding the face because it was irrelevant for the task. RESULTS: Eye movement recordings on correct trials showed that saccades congruent with the direction of the distracting gaze had shorter latencies than incongruent ones. However, the time-course of this effect varied depending on the facial expression. With a neutral expression, the congruency effect was found only at the shortest SOA (50 ms). On the contrary, for the angry face the congruency effect occurred at the longer SOAs. These findings suggest that gaze direction (even when task-irrelevant) is capable of interfering with the orienting of visual attention, and that faces with an angry expression may hold attention and affect its orienting longer than a neutral expression.
Cognitive Proceedings, 7 (supp 5), 155
BACKGROUND: Several studies using spatial cueing paradigms have demonstrated that observing gaze direction may trigger a reflexive visual orienting in the direction of the other person's gaze. Recently, it has been reported that facial expression may enhance the reflexive orienting of attention to gaze stimuli. However, some researchers have also suggested that, rather than facilitating attentional orienting away from the face, emotional expressions may, in fact, delay or prevent orienting. In the present study we investigated the effects of facial expression and gaze direction on a visual orienting oculomotor task to test whether an angry face may or may not interfere with visual orienting. METHOD: Participants performed an oculomotor task in which they had to make a saccade towards one of two lateral targets, depending upon the colour of the fixation dot which appeared at the centre of the computer screen. The instruction dot remained visible for 50 ms and then disappeared. At different time intervals (stimulus onset asynchronies, SOAs: 50, 100, 150 ms) following the onset of the instruction cue, a real face (gazing either to the right or to the left) was presented at the centre of the monitor. Gaze direction could be congruent or incongruent with respect to the instruction and target location. Facial expression was also manipulated. In half of the trials the diverted gaze (i.e., congruent or incongruent) appeared with an angry expression, whereas in the other half the face had a neutral expression. Participants were instructed to saccade either to the target on the left or to the target on the right (the targets were visible throughout the trial), as indicated by the instruction dot, while completely disregarding the face because it was irrelevant for the task. RESULTS: Eye movement recordings on correct trials showed that saccades congruent with the direction of the distracting gaze had shorter latencies than incongruent ones. However, the time-course of this effect varied depending on the facial expression. With a neutral expression, the congruency effect was found only at the shortest SOA (50 ms). On the contrary, for the angry face the congruency effect occurred at the longer SOAs. These findings suggest that gaze direction (even when task-irrelevant) is capable of interfering with the orienting of visual attention, and that faces with an angry expression may hold attention and affect its orienting longer than a neutral expression.
Wednesday, August 16, 2006
ARTICLE UPDATE - Attentional capture by task-irrelevant fearful faces is revealed by the N2pc component
Martin Eimer and Monika Kissa
Biological Psychology, in press
We measured the N2pc component as an electrophysiological indicator of attentional selection to investigate whether fearful faces can attract attention even when they are entirely task-irrelevant and attention is focused on another demanding visual monitoring task. Participants had to detect infrequent luminance changes of the fixation cross, while ignoring stimulus arrays containing a face singleton (a fearful face among neutral faces, or neutral face among fearful faces) to the left or right of fixation. On trials without a target luminance change, an N2pc was elicited by fearful faces presented next to fixation, irrespective of whether they were singletons or not, demonstrating that irrelevant fearful faces can bias the spatial distribution of attention. The N2pc to fearful faces was attenuated when face arrays were presented simultaneously with a target luminance change, suggesting that concurrent target processing reduces attentional capture by emotional salient events.
Biological Psychology, in press
We measured the N2pc component as an electrophysiological indicator of attentional selection to investigate whether fearful faces can attract attention even when they are entirely task-irrelevant and attention is focused on another demanding visual monitoring task. Participants had to detect infrequent luminance changes of the fixation cross, while ignoring stimulus arrays containing a face singleton (a fearful face among neutral faces, or neutral face among fearful faces) to the left or right of fixation. On trials without a target luminance change, an N2pc was elicited by fearful faces presented next to fixation, irrespective of whether they were singletons or not, demonstrating that irrelevant fearful faces can bias the spatial distribution of attention. The N2pc to fearful faces was attenuated when face arrays were presented simultaneously with a target luminance change, suggesting that concurrent target processing reduces attentional capture by emotional salient events.
Friday, August 11, 2006
ARTICLE UPDATE - Neuroimaging Studies of Emotional Responses in PTSD.
Liberzon I, Martis B.
Annuals of the New York Academy of Sciences, 1071, 87-109
Neuroimaging research offers a powerful and noninvasive means to understand healthy as well as dysregulated emotional processing in healthy subjects and PTSD patients. Functional neuroimaging findings suggest specific roles for subregions of the medial prefrontal (mPFC), orbito frontal (OFC), anterior cingulate (ACC), and insular cortices as well as the sublenticular extended amygdala (SLEA) and hippocampus in various components of emotional processing. Some of the same regions appear to be associated with emotional response to trauma, and with symptom formation in PTSD. Neuroimaging findings of emotional processing in healthy subjects and PTSD patients are discussed, addressing the specific roles of cortical regions like mPFC, ACC, and insula, and their potential contribution to PTSD pathophysiology. Processes of cognitive-emotional interactions and social emotions are discussed in an attempt to synthesize the prefrontal findings in healthy subjects and PTSD patients. Further links between functional neuroanatomy of emotional responses and neuroendocrine stress regulation are proposed.
Annuals of the New York Academy of Sciences, 1071, 87-109
Neuroimaging research offers a powerful and noninvasive means to understand healthy as well as dysregulated emotional processing in healthy subjects and PTSD patients. Functional neuroimaging findings suggest specific roles for subregions of the medial prefrontal (mPFC), orbito frontal (OFC), anterior cingulate (ACC), and insular cortices as well as the sublenticular extended amygdala (SLEA) and hippocampus in various components of emotional processing. Some of the same regions appear to be associated with emotional response to trauma, and with symptom formation in PTSD. Neuroimaging findings of emotional processing in healthy subjects and PTSD patients are discussed, addressing the specific roles of cortical regions like mPFC, ACC, and insula, and their potential contribution to PTSD pathophysiology. Processes of cognitive-emotional interactions and social emotions are discussed in an attempt to synthesize the prefrontal findings in healthy subjects and PTSD patients. Further links between functional neuroanatomy of emotional responses and neuroendocrine stress regulation are proposed.
ARTICLE UPDATE - Right hemispheric dominance in processing of unconscious negative emotion.
Sato W, Aoki S.
Brain and Cognition, in press
Right hemispheric dominance in unconscious emotional processing has been suggested, but remains controversial. This issue was investigated using the subliminal affective priming paradigm combined with unilateral visual presentation in 40 normal subjects. In either left or right visual fields, angry facial expressions, happy facial expressions, or plain gray images were briefly presented as negative, positive, and control primes, followed by a mosaic mask. Then nonsense target ideographs were presented, and the subjects evaluated their partiality toward the targets. When the stimuli were presented in the left, but not the right, visual fields, the negative primes reduced the subjects' liking for the targets, relative to the case of the positive or control primes. These results provided behavioral evidence supporting the hypothesis that the right hemisphere is dominant for unconscious negative emotional processing.
Brain and Cognition, in press
Right hemispheric dominance in unconscious emotional processing has been suggested, but remains controversial. This issue was investigated using the subliminal affective priming paradigm combined with unilateral visual presentation in 40 normal subjects. In either left or right visual fields, angry facial expressions, happy facial expressions, or plain gray images were briefly presented as negative, positive, and control primes, followed by a mosaic mask. Then nonsense target ideographs were presented, and the subjects evaluated their partiality toward the targets. When the stimuli were presented in the left, but not the right, visual fields, the negative primes reduced the subjects' liking for the targets, relative to the case of the positive or control primes. These results provided behavioral evidence supporting the hypothesis that the right hemisphere is dominant for unconscious negative emotional processing.
Friday, July 21, 2006
ARTICLE UPDATE - Neural substrates associated with evaluative processing during co-activation of positivity and negativity: A PET investigation.
Jung YC, An SK, Seok JH, Kim JS, Oh SJ, Moon DH, Kim JJ.
Biological Psychology, in press,
Affective symmetries, such as the positivity offset and negativity bias, have been postulated to be attributable to distinct activation functions of the positive and negative affect systems. We investigated the neural substrates that are engaged when the positive and negative affect systems undergo parallel and integrative processing. Eleven subjects were scanned using H(2)(15)O PET during choosing the subjective feeling produced by a stimulation pair of pictures or words. Four different conditions were designed for contrast: pure positivity, pure negativity, positivity offset, and negativity bias. The dorsolateral prefrontal activation was associated with positivity offset and negativity bias condition, whereas the ventromedial prefrontal activation, together with limbic and subcortical activations, was associated with pure positivity and pure negativity condition. The results indicated that positivity offset and negativity bias are not merely due to asymmetric activations of the positive and negative systems, but integrative processing of higher neocortical levels is involved.
Biological Psychology, in press,
Affective symmetries, such as the positivity offset and negativity bias, have been postulated to be attributable to distinct activation functions of the positive and negative affect systems. We investigated the neural substrates that are engaged when the positive and negative affect systems undergo parallel and integrative processing. Eleven subjects were scanned using H(2)(15)O PET during choosing the subjective feeling produced by a stimulation pair of pictures or words. Four different conditions were designed for contrast: pure positivity, pure negativity, positivity offset, and negativity bias. The dorsolateral prefrontal activation was associated with positivity offset and negativity bias condition, whereas the ventromedial prefrontal activation, together with limbic and subcortical activations, was associated with pure positivity and pure negativity condition. The results indicated that positivity offset and negativity bias are not merely due to asymmetric activations of the positive and negative systems, but integrative processing of higher neocortical levels is involved.
ARTICLE UPDATE - Anticipation of affective image modulates visual evoked magnetic fields (VEF).
Onoda K, Okamoto Y, Shishida K, Hashizume A, Ueda K, Kinoshita A, Yamashita H, Yamawaki S.
Experimental Brain Research, in press
We investigated the interaction between anticipation of positive and negative affective images and visual evoked magnetic fields (VEF). Participants (n = 13) were presented emotionally positive or negative images under different anticipatory conditions, and their subsequent brain responses were recorded by magnetoencephalography (MEG). In the Affective Cue conditions, the cue stimulus indicated the emotional valence of the image, which followed 2 s later. In the Null Cue conditions, the cue stimulus did not include any information about the valence of the image. In the No Cue conditions, the affective image was suddenly presented, without a cue stimulus. The VEF amplitude for the negative image in the Affective Cue condition was smaller than that of the positive image in the Affective Cue condition and that of the negative image in the Null Cue condition. This result suggests that anticipation of the valence of affective images modulates the processes of the visual cortex.
Experimental Brain Research, in press
We investigated the interaction between anticipation of positive and negative affective images and visual evoked magnetic fields (VEF). Participants (n = 13) were presented emotionally positive or negative images under different anticipatory conditions, and their subsequent brain responses were recorded by magnetoencephalography (MEG). In the Affective Cue conditions, the cue stimulus indicated the emotional valence of the image, which followed 2 s later. In the Null Cue conditions, the cue stimulus did not include any information about the valence of the image. In the No Cue conditions, the affective image was suddenly presented, without a cue stimulus. The VEF amplitude for the negative image in the Affective Cue condition was smaller than that of the positive image in the Affective Cue condition and that of the negative image in the Null Cue condition. This result suggests that anticipation of the valence of affective images modulates the processes of the visual cortex.
ARTICLE UPDATE - The locus ceruleus is involved in the successful retrieval of emotional memories in humans.
Sterpenich V, D'Argembeau A, Desseilles M, Balteau E, Albouy G, Vandewalle G, Degueldre C, Luxen A, Collette F, Maquet P.
Journal of Neuroscience, 26, 7416-7423.
Emotional memories are better remembered than neutral ones. The amygdala is involved in this enhancement not only by modulating the hippocampal activity, but possibly also by modulating central arousal. Using functional magnetic resonance imaging, we analyzed the retrieval of neutral faces encoded in emotional or neutral contexts. The pupillary size measured during encoding was used as a modulator of brain responses during retrieval. The interaction between emotion and memory showed significant responses in a set of areas, including the amygdala and parahippocampal gyrus. These areas responded significantly more for correctly remembered faces encoded in an emotional, compared with neutral, context. The same interaction conducted on responses modulated by the pupillary size revealed an area of the dorsal tegmentum of the ponto-mesencephalic region, consistent with the locus ceruleus. Moreover, a psychophysiological interaction showed that amygdalar responses were more tightly related to those of the locus ceruleus when remembering faces that had been encoded in an emotional, rather than neutral, context. These findings suggest that the restoration of a central arousal similar to encoding takes part in the successful retrieval of neutral events learned in an emotional context.
Journal of Neuroscience, 26, 7416-7423.
Emotional memories are better remembered than neutral ones. The amygdala is involved in this enhancement not only by modulating the hippocampal activity, but possibly also by modulating central arousal. Using functional magnetic resonance imaging, we analyzed the retrieval of neutral faces encoded in emotional or neutral contexts. The pupillary size measured during encoding was used as a modulator of brain responses during retrieval. The interaction between emotion and memory showed significant responses in a set of areas, including the amygdala and parahippocampal gyrus. These areas responded significantly more for correctly remembered faces encoded in an emotional, compared with neutral, context. The same interaction conducted on responses modulated by the pupillary size revealed an area of the dorsal tegmentum of the ponto-mesencephalic region, consistent with the locus ceruleus. Moreover, a psychophysiological interaction showed that amygdalar responses were more tightly related to those of the locus ceruleus when remembering faces that had been encoded in an emotional, rather than neutral, context. These findings suggest that the restoration of a central arousal similar to encoding takes part in the successful retrieval of neutral events learned in an emotional context.
ARTICLE UPDATE - Distributed and interactive brain mechanisms during emotion face perception: Evidence from functional neuroimaging.
Vuilleumier P, Pourtois G.
Neuropsychologia, in press
Brain imaging studies in humans have shown that face processing in several areas is modulated by the affective significance of faces, particularly with fearful expressions, but also with other social signals such gaze direction. Here we review haemodynamic and electrical neuroimaging results indicating that activity in the face-selective fusiform cortex may be enhanced by emotional (fearful) expressions, without explicit voluntary control, and presumably through direct feedback connections from the amygdala. fMRI studies show that these increased responses in fusiform cortex to fearful faces are abolished by amygdala damage in the ipsilateral hemisphere, despite preserved effects of voluntary attention on fusiform; whereas emotional increases can still arise despite deficits in attention or awareness following parietal damage, and appear relatively unaffected by pharmacological increases in cholinergic stimulation. Fear-related modulations of face processing driven by amygdala signals may implicate not only fusiform cortex, but also earlier visual areas in occipital cortex (e.g., V1) and other distant regions involved in social, cognitive, or somatic responses (e.g., superior temporal sulcus, cingulate, or parietal areas). In the temporal domain, evoked-potentials show a widespread time-course of emotional face perception, with some increases in the amplitude of responses recorded over both occipital and frontal regions for fearful relative to neutral faces (as well as in the amygdala and orbitofrontal cortex, when using intracranial recordings), but with different latencies post-stimulus onset. Early emotional responses may arise around 120ms, prior to a full visual categorization stage indexed by the face-selective N170 component, possibly reflecting rapid emotion processing based on crude visual cues in faces. Other electrical components arise at later latencies and involve more sustained activities, probably generated in associative or supramodal brain areas, and resulting in part from the modulatory signals received from amygdala. Altogether, these fMRI and ERP results demonstrate that emotion face perception is a complex process that cannot be related to a single neural event taking place in a single brain regions, but rather implicates an interactive network with distributed activity in time and space. Moreover, although traditional models in cognitive neuropsychology have often considered that facial expression and facial identity are processed along two separate pathways, evidence from fMRI and ERPs suggests instead that emotional processing can strongly affect brain systems responsible for face recognition and memory. The functional implications of these interactions remain to be fully explored, but might play an important role in the normal development of face processing skills and in some neuropsychiatric disorders.
Neuropsychologia, in press
Brain imaging studies in humans have shown that face processing in several areas is modulated by the affective significance of faces, particularly with fearful expressions, but also with other social signals such gaze direction. Here we review haemodynamic and electrical neuroimaging results indicating that activity in the face-selective fusiform cortex may be enhanced by emotional (fearful) expressions, without explicit voluntary control, and presumably through direct feedback connections from the amygdala. fMRI studies show that these increased responses in fusiform cortex to fearful faces are abolished by amygdala damage in the ipsilateral hemisphere, despite preserved effects of voluntary attention on fusiform; whereas emotional increases can still arise despite deficits in attention or awareness following parietal damage, and appear relatively unaffected by pharmacological increases in cholinergic stimulation. Fear-related modulations of face processing driven by amygdala signals may implicate not only fusiform cortex, but also earlier visual areas in occipital cortex (e.g., V1) and other distant regions involved in social, cognitive, or somatic responses (e.g., superior temporal sulcus, cingulate, or parietal areas). In the temporal domain, evoked-potentials show a widespread time-course of emotional face perception, with some increases in the amplitude of responses recorded over both occipital and frontal regions for fearful relative to neutral faces (as well as in the amygdala and orbitofrontal cortex, when using intracranial recordings), but with different latencies post-stimulus onset. Early emotional responses may arise around 120ms, prior to a full visual categorization stage indexed by the face-selective N170 component, possibly reflecting rapid emotion processing based on crude visual cues in faces. Other electrical components arise at later latencies and involve more sustained activities, probably generated in associative or supramodal brain areas, and resulting in part from the modulatory signals received from amygdala. Altogether, these fMRI and ERP results demonstrate that emotion face perception is a complex process that cannot be related to a single neural event taking place in a single brain regions, but rather implicates an interactive network with distributed activity in time and space. Moreover, although traditional models in cognitive neuropsychology have often considered that facial expression and facial identity are processed along two separate pathways, evidence from fMRI and ERPs suggests instead that emotional processing can strongly affect brain systems responsible for face recognition and memory. The functional implications of these interactions remain to be fully explored, but might play an important role in the normal development of face processing skills and in some neuropsychiatric disorders.
Friday, July 14, 2006
ARTICLE UPDATE - On rejecting emotional lures created by phonological neighborhood activation.
Starns JJ, Cook GI, Hicks JL, Marsh RL.
Journal of Experimental Psychology: Learning, Memory and Cognition, 32, 847-853.
The authors conducted 2 experiments to assess how phonologically related lures are rejected in a false memory paradigm. Some phonological lures were emotional (i.e., taboo) words, and others were not. The authors manipulated the presence of taboo items on the study list and reduced the ability to use controlled rejection strategies by dividing attention and forcing a short response deadline. The results converge on the idea that participants reduce false alarms to emotional lures by setting more stringent recognition criteria for these items based on their expected memorability. Additionally, emotional lures are less familiar than nonemotional lures because emotional lures have affective and semantic features that mismatch studied nonemotional items.
Journal of Experimental Psychology: Learning, Memory and Cognition, 32, 847-853.
The authors conducted 2 experiments to assess how phonologically related lures are rejected in a false memory paradigm. Some phonological lures were emotional (i.e., taboo) words, and others were not. The authors manipulated the presence of taboo items on the study list and reduced the ability to use controlled rejection strategies by dividing attention and forcing a short response deadline. The results converge on the idea that participants reduce false alarms to emotional lures by setting more stringent recognition criteria for these items based on their expected memorability. Additionally, emotional lures are less familiar than nonemotional lures because emotional lures have affective and semantic features that mismatch studied nonemotional items.
Monday, July 03, 2006
ARTICLE UPDATE - Temporal dynamics of face repetition suppression
Alumit Ishai, Philip C. Bikle and Leslie G. Ungerleider
Brain Research Bulletin, in press
Single-unit recordings and functional brain imaging studies have shown reduced neural responses to repeated stimuli in the visual cortex. Using MEG, we compared responses evoked by repetitions of neutral faces to those evoked by fearful faces, which were either task relevant (targets) or irrelevant (distracters). Faces evoked a bi-phasic response in extrastriate cortex, peaking at 160–185 ms and at 220–250 ms, with stronger responses to neutral faces at the earlier interval and stronger responses to fearful faces at the later interval. At both latencies, repetitions of neutral and fearful targets resulted in reduced amplitude of the MEG signal. Additionally, we found that the context in which targets were presented affected their processing: fearful distracters increased the responses evoked by both neutral and fearful targets. Our data indicate that valence enhancement and context effects can be detected in extrastriate visual cortex within 250 ms and that these processes likely reflect feedback from other regions.
Brain Research Bulletin, in press
Single-unit recordings and functional brain imaging studies have shown reduced neural responses to repeated stimuli in the visual cortex. Using MEG, we compared responses evoked by repetitions of neutral faces to those evoked by fearful faces, which were either task relevant (targets) or irrelevant (distracters). Faces evoked a bi-phasic response in extrastriate cortex, peaking at 160–185 ms and at 220–250 ms, with stronger responses to neutral faces at the earlier interval and stronger responses to fearful faces at the later interval. At both latencies, repetitions of neutral and fearful targets resulted in reduced amplitude of the MEG signal. Additionally, we found that the context in which targets were presented affected their processing: fearful distracters increased the responses evoked by both neutral and fearful targets. Our data indicate that valence enhancement and context effects can be detected in extrastriate visual cortex within 250 ms and that these processes likely reflect feedback from other regions.
Friday, June 30, 2006
ARTICLE UPDATE - Intentional modulation of emotional responding to unpleasant pictures: An ERP study.
Moser JS, Hajcak G, Bukay E, Simons RF.
Psychophysiology, 43, 292-296.
Intentionally altering responses to unpleasant stimuli affects physiological and hemodynamic activity associated with emotional and cognitive processing. In the present experiment, we measured the late-positive potential (LPP) of the visually evoked event-related brain potential to examine the effects of intentional emotion modulation on electrophysiological correlates of emotional and cognitive processing. Seventeen participants received instructions to view, suppress, and enhance emotional responses to unpleasant stimuli. Results revealed significantly decreased electrophysiological activity during suppression of emotional responses beginning around 250 ms poststimulus and lasting several hundred milliseconds. These data suggest that ERPs are sensitive to emotion modulation/regulation processes.
Psychophysiology, 43, 292-296.
Intentionally altering responses to unpleasant stimuli affects physiological and hemodynamic activity associated with emotional and cognitive processing. In the present experiment, we measured the late-positive potential (LPP) of the visually evoked event-related brain potential to examine the effects of intentional emotion modulation on electrophysiological correlates of emotional and cognitive processing. Seventeen participants received instructions to view, suppress, and enhance emotional responses to unpleasant stimuli. Results revealed significantly decreased electrophysiological activity during suppression of emotional responses beginning around 250 ms poststimulus and lasting several hundred milliseconds. These data suggest that ERPs are sensitive to emotion modulation/regulation processes.
Wednesday, June 28, 2006
ARTICLE UPDATE - Event-related brain potential correlates of emotional face processing
Martin Eimer and Amanda Holmes
Neuropsychologia, in press
Results from recent event-related brain potential (ERP) studies investigating brain processes involved in the detection and analysis of emotional facial expression are reviewed. In all experiments, emotional faces were found to trigger an increased ERP positivity relative to neutral faces. The onset of this emotional expression effect was remarkably early, ranging from 120 to 180 ms post-stimulus in different experiments where faces were either presented at fixation or laterally, and with or without non-face distractor stimuli. While broadly distributed positive deflections beyond 250 ms post-stimulus have been found in previous studies for non-face stimuli, the early frontocentrally distributed phase of this emotional positivity is most likely face-specific. Similar emotional expression effects were found for six basic emotions, suggesting that these effects are not primarily generated within neural structures specialised for the automatic detection of specific emotions. Expression effects were eliminated when attention was directed away from the location of peripherally presented emotional faces, indicating that they are not linked to pre-attentive emotional processing. When foveal faces were unattended, expression effects were attenuated, but not completely eliminated. It is suggested that these ERP correlates of emotional face processing reflect activity within a neocortical system where representations of emotional content are generated in a task-dependent fashion for the adaptive intentional control of behaviour. Given the early onset of the emotion-specific effects reviewed here, it is likely that this system is activated in parallel with the ongoing evaluation of emotional content in the amygdala and related subcortical brain circuits.
Neuropsychologia, in press
Results from recent event-related brain potential (ERP) studies investigating brain processes involved in the detection and analysis of emotional facial expression are reviewed. In all experiments, emotional faces were found to trigger an increased ERP positivity relative to neutral faces. The onset of this emotional expression effect was remarkably early, ranging from 120 to 180 ms post-stimulus in different experiments where faces were either presented at fixation or laterally, and with or without non-face distractor stimuli. While broadly distributed positive deflections beyond 250 ms post-stimulus have been found in previous studies for non-face stimuli, the early frontocentrally distributed phase of this emotional positivity is most likely face-specific. Similar emotional expression effects were found for six basic emotions, suggesting that these effects are not primarily generated within neural structures specialised for the automatic detection of specific emotions. Expression effects were eliminated when attention was directed away from the location of peripherally presented emotional faces, indicating that they are not linked to pre-attentive emotional processing. When foveal faces were unattended, expression effects were attenuated, but not completely eliminated. It is suggested that these ERP correlates of emotional face processing reflect activity within a neocortical system where representations of emotional content are generated in a task-dependent fashion for the adaptive intentional control of behaviour. Given the early onset of the emotion-specific effects reviewed here, it is likely that this system is activated in parallel with the ongoing evaluation of emotional content in the amygdala and related subcortical brain circuits.
ARTICLE UPDATE - Are you always on my mind? A review of how face perception and attention interact
Romina Palermo and Gillian Rhodes
Neuropsychologia, in press,
In this review we examine how attention is involved in detecting faces, recognizing facial identity and registering and discriminating between facial expressions of emotion. The first section examines whether these aspects of face perception are “automatic”, in that they are especially rapid, non-conscious, mandatory and capacity-free. The second section discusses whether limited-capacity selective attention mechanisms are preferentially recruited by faces and facial expressions. Evidence from behavioral, neuropsychological, neuroimaging and psychophysiological studies from humans and single-unit recordings from primates is examined and the neural systems involved in processing faces, emotion and attention are highlighted. Avenues for further research are identified.
Neuropsychologia, in press,
In this review we examine how attention is involved in detecting faces, recognizing facial identity and registering and discriminating between facial expressions of emotion. The first section examines whether these aspects of face perception are “automatic”, in that they are especially rapid, non-conscious, mandatory and capacity-free. The second section discusses whether limited-capacity selective attention mechanisms are preferentially recruited by faces and facial expressions. Evidence from behavioral, neuropsychological, neuroimaging and psychophysiological studies from humans and single-unit recordings from primates is examined and the neural systems involved in processing faces, emotion and attention are highlighted. Avenues for further research are identified.
Friday, June 16, 2006
ARTICLE UPDATE - The influence of nonremembered affective associations on preference.
Ghuman AS, Bar M.
Emotion, 6, 215-223.
An important influence on our preference toward a specific object is its associations with affective information. Here, the authors concentrate on the role of memory on shaping such preferences. Specifically, the authors used a multistage behavioral paradigm that fostered associations between neutral shapes and affective images. Participants that explicitly remembered these affective associations preferred neutral shapes associated with positive images. Counterintuitively, participants who could not explicitly remember the associations preferred neutral shapes that were associated with negative images. Generally, the difference in preference between participants who could and could not remember the affective associations demonstrates a critical link between memory and preference formation. The authors propose that the preference for negatively associated items is a manifestation of a mechanism that produces an inherent incentive for rapidly assessing potentially threatening aspects in the environment.
Emotion, 6, 215-223.
An important influence on our preference toward a specific object is its associations with affective information. Here, the authors concentrate on the role of memory on shaping such preferences. Specifically, the authors used a multistage behavioral paradigm that fostered associations between neutral shapes and affective images. Participants that explicitly remembered these affective associations preferred neutral shapes associated with positive images. Counterintuitively, participants who could not explicitly remember the associations preferred neutral shapes that were associated with negative images. Generally, the difference in preference between participants who could and could not remember the affective associations demonstrates a critical link between memory and preference formation. The authors propose that the preference for negatively associated items is a manifestation of a mechanism that produces an inherent incentive for rapidly assessing potentially threatening aspects in the environment.
ARTICLE UPDATE - Rapid picture presentation and affective engagement.
Smith JC, Low A, Bradley MM, Lang PJ.
Emotion, 6, 208-214.
Emotional reactions were assessed to pictorial stimuli presented in a continuous stream at rapid speeds that compromise conceptual memory and the processing of specific picture content. Blocks of unpleasant, neutral, or pleasant pictures were presented at the rate of either three pictures per second or seven pictures per second. Even with rapid presentation rates, startle reflexes, corrugator muscle activity, and skin conductance responses were heightened when viewing unpleasant pictures. These effects were stronger later in the aversive block, suggesting that cumulative exposure increasingly activates the defense system. The findings suggest that, despite conceptual masking inherent in rapid serial visual presentation, affective pictures prompt measurable emotional engagement.
Emotion, 6, 208-214.
Emotional reactions were assessed to pictorial stimuli presented in a continuous stream at rapid speeds that compromise conceptual memory and the processing of specific picture content. Blocks of unpleasant, neutral, or pleasant pictures were presented at the rate of either three pictures per second or seven pictures per second. Even with rapid presentation rates, startle reflexes, corrugator muscle activity, and skin conductance responses were heightened when viewing unpleasant pictures. These effects were stronger later in the aversive block, suggesting that cumulative exposure increasingly activates the defense system. The findings suggest that, despite conceptual masking inherent in rapid serial visual presentation, affective pictures prompt measurable emotional engagement.
ARTICLE UPDATE - Spontaneous retrieval of affective person knowledge in face perception.
Todorov A, Gobbini MI, Evans KK, Haxby JV.
Neuropsychologia, in press
In a functional magnetic resonance imaging experiment, we explored whether affective person knowledge based on memories formed from minimal information is spontaneously retrieved in face perception. In the first stage of the experiment, participants were presented with 120 unfamiliar faces. Each face was presented with a description of one of four types of behaviors: aggressive, disgusting, neutral, and nice. In the second stage, participants were scanned while engaged in a one-back recognition task in which they saw the faces that were associated with behaviors and 30 novel faces. Although this task is a simple perceptual task that neither demands person evaluation nor retrieval of person knowledge, neural responses to faces differed as a function of the behaviors. Faces associated with behaviors evoked stronger activity than did novel faces in regions implicated in social cognition-anterior paracingulate cortex and superior temporal sulcus. Explicit memory for the behaviors enhanced the neural response in these regions. Faces associated with disgusting behaviors evoked stronger activity in left anterior insula than did faces associated with aggressive behaviors. This effect was equally strong for faces associated with explicitly recalled behaviors and faces associated with non-recalled behaviors. The findings suggest that affective person knowledge acquired from minimal information is spontaneously retrieved in face perception, engaging neural systems for analysis of social cognition and emotions.
Neuropsychologia, in press
In a functional magnetic resonance imaging experiment, we explored whether affective person knowledge based on memories formed from minimal information is spontaneously retrieved in face perception. In the first stage of the experiment, participants were presented with 120 unfamiliar faces. Each face was presented with a description of one of four types of behaviors: aggressive, disgusting, neutral, and nice. In the second stage, participants were scanned while engaged in a one-back recognition task in which they saw the faces that were associated with behaviors and 30 novel faces. Although this task is a simple perceptual task that neither demands person evaluation nor retrieval of person knowledge, neural responses to faces differed as a function of the behaviors. Faces associated with behaviors evoked stronger activity than did novel faces in regions implicated in social cognition-anterior paracingulate cortex and superior temporal sulcus. Explicit memory for the behaviors enhanced the neural response in these regions. Faces associated with disgusting behaviors evoked stronger activity in left anterior insula than did faces associated with aggressive behaviors. This effect was equally strong for faces associated with explicitly recalled behaviors and faces associated with non-recalled behaviors. The findings suggest that affective person knowledge acquired from minimal information is spontaneously retrieved in face perception, engaging neural systems for analysis of social cognition and emotions.
ARTICLE UPDATE - Human and computer recognition of facial expressions of emotion.
Susskind JM, Littlewort G, Bartlett MS, Movellan J, Anderson AK.
Neuropsychologia, in press
Neuropsychological and neuroimaging evidence suggests that the human brain contains facial expression recognition detectors specialized for specific discrete emotions. However, some human behavioral data suggest that humans recognize expressions as similar and not discrete entities. This latter observation has been taken to indicate that internal representations of facial expressions may be best characterized as varying along continuous underlying dimensions. To examine the potential compatibility of these two views, the present study compared human and support vector machine (SVM) facial expression recognition performance. Separate SVMs were trained to develop fully automatic optimal recognition of one of six basic emotional expressions in real-time with no explicit training on expression similarity. Performance revealed high recognition accuracy for expression prototypes. Without explicit training of similarity detection, magnitude of activation across each emotion-specific SVM captured human judgments of expression similarity. This evidence suggests that combinations of expert classifiers from separate internal neural representations result in similarity judgments between expressions, supporting the appearance of a continuous underlying dimensionality. Further, these data suggest similarity in expression meaning is supported by superficial similarities in expression appearance.
Neuropsychologia, in press
Neuropsychological and neuroimaging evidence suggests that the human brain contains facial expression recognition detectors specialized for specific discrete emotions. However, some human behavioral data suggest that humans recognize expressions as similar and not discrete entities. This latter observation has been taken to indicate that internal representations of facial expressions may be best characterized as varying along continuous underlying dimensions. To examine the potential compatibility of these two views, the present study compared human and support vector machine (SVM) facial expression recognition performance. Separate SVMs were trained to develop fully automatic optimal recognition of one of six basic emotional expressions in real-time with no explicit training on expression similarity. Performance revealed high recognition accuracy for expression prototypes. Without explicit training of similarity detection, magnitude of activation across each emotion-specific SVM captured human judgments of expression similarity. This evidence suggests that combinations of expert classifiers from separate internal neural representations result in similarity judgments between expressions, supporting the appearance of a continuous underlying dimensionality. Further, these data suggest similarity in expression meaning is supported by superficial similarities in expression appearance.
Monday, June 12, 2006
ARTICLE UPDATE - Semantic Processing Precedes Affect Retrieval: The Neurological Case for Cognitive Primacy in Visual Processing
Justin Storbeck, Michael D. Robinson and Mark E. McCourt
Review of General Psychology, 10, 41-55.
According to the affective primacy hypothesis, visual stimuli can be evaluated prior to and independent of object identification and semantic analysis (Zajonc, 1980, 2000). Our review concludes that the affective primacy hypothesis is, from the available evidence, not likely correct. Although people can react to objects that they cannot consciously identify, such affective reactions are dependent upon prior semantic analysis within the visual cortex. The authors propose that the features of objects must first be integrated, and then the objects themselves must be categorized and identified, all prior to affective analysis. Additionally, the authors offer a preliminary neurological analysis of the mere exposure and affective priming effects that is consistent with the claim that semantic analysis is needed to elicit these effects. In sum, the authors conclude that the brain must know what something is in order to know whether it is good or bad.
Review of General Psychology, 10, 41-55.
According to the affective primacy hypothesis, visual stimuli can be evaluated prior to and independent of object identification and semantic analysis (Zajonc, 1980, 2000). Our review concludes that the affective primacy hypothesis is, from the available evidence, not likely correct. Although people can react to objects that they cannot consciously identify, such affective reactions are dependent upon prior semantic analysis within the visual cortex. The authors propose that the features of objects must first be integrated, and then the objects themselves must be categorized and identified, all prior to affective analysis. Additionally, the authors offer a preliminary neurological analysis of the mere exposure and affective priming effects that is consistent with the claim that semantic analysis is needed to elicit these effects. In sum, the authors conclude that the brain must know what something is in order to know whether it is good or bad.
Saturday, June 10, 2006
ARTICLE UPDATE - Functional neuroimaging of emotional learning and autonomic reactions
Martin Peper, Martin Herpers, Joachim Spreer, Jürgen Hennig and Josef Zentner
Journal of Psysiology - Paris, in press
This article provides a selective overview of the functional neuroimaging literature with an emphasis on emotional activation processes. Emotions are fast and flexible response systems that provide basic tendencies for adaptive action. From the range of involved component functions, we first discuss selected automatic mechanisms that control basic adaptational changes. Second, we illustrate how neuroimaging work has contributed to the mapping of the network components associated with basic emotion families (fear, anger, disgust, happiness), and secondary dimensional concepts that organise the meaning space for subjective experience and verbal labels (emotional valence, activity/intensity, approach/withdrawal, etc.). Third, results and methodological difficulties are discussed in view of own neuroimaging experiments that investigated the component functions involved in emotional learning. The amygdala, prefrontal cortex, and striatum form a network of reciprocal connections that show topographically distinct patterns of activity as a correlate of up and down regulation processes during an emotional episode. Emotional modulations of other brain systems have attracted recent research interests. Emotional neuroimaging calls for more representative designs that highlight the modulatory influences of regulation strategies and socio-cultural factors responsible for inhibitory control and extinction. We conclude by emphasising the relevance of the temporal process dynamics of emotional activations that may provide improved prediction of individual differences in emotionality.
Journal of Psysiology - Paris, in press
This article provides a selective overview of the functional neuroimaging literature with an emphasis on emotional activation processes. Emotions are fast and flexible response systems that provide basic tendencies for adaptive action. From the range of involved component functions, we first discuss selected automatic mechanisms that control basic adaptational changes. Second, we illustrate how neuroimaging work has contributed to the mapping of the network components associated with basic emotion families (fear, anger, disgust, happiness), and secondary dimensional concepts that organise the meaning space for subjective experience and verbal labels (emotional valence, activity/intensity, approach/withdrawal, etc.). Third, results and methodological difficulties are discussed in view of own neuroimaging experiments that investigated the component functions involved in emotional learning. The amygdala, prefrontal cortex, and striatum form a network of reciprocal connections that show topographically distinct patterns of activity as a correlate of up and down regulation processes during an emotional episode. Emotional modulations of other brain systems have attracted recent research interests. Emotional neuroimaging calls for more representative designs that highlight the modulatory influences of regulation strategies and socio-cultural factors responsible for inhibitory control and extinction. We conclude by emphasising the relevance of the temporal process dynamics of emotional activations that may provide improved prediction of individual differences in emotionality.
Friday, June 09, 2006
ARTICLE UPDATE - Fear Recognition Ability Predicts Differences in Social Cognitive and Neural Functioning in Men
Ben Corden, Hugo D. Critchley, David Skuse and Raymond J. Dolan
Journal of Cognitive Neuroscience, 18, 889-897.
By testing the facial fear-recognition ability of 341 men in the general population, we show that 8.8% have deficits akin to those seen with acquired amygdala damage. Using psychological tests and functional magnetic resonance imaging (fMRI) we tested the hypothesis that poor fear recognition would predict deficits in other domains of social cognition and, in response to socially relevant stimuli, abnormal activation in brain regions that putatively reflect engagement of the "social brain." On tests of "theory of mind" ability, 25 "low fear scorers" (LFS) performed significantly worse than 25 age- and IQ-matched "normal (good) fear scorers" (NFS). In fMRI, we compared evoked activity during a gender judgement task to neutral faces portraying different head and eye gaze orientations in 12 NFS and 12 LFS subjects. Despite identical between-group accuracy in gender discrimination, LFS demonstrated significantly reduced activation in amygdala, fusiform gyrus, and anterior superior temporal cortices when viewing faces with direct versus averted gaze. In a functional connectivity analysis, NFS show enhanced connectivity between the amygdala and anterior temporal cortex in the context of direct gaze; this enhanced coupling is absent in LFS. We suggest that important individual differences in social cognitive skills are expressed within the healthy male population, which appear to have a basis in a compromised neural system that underpins social information processing.
Journal of Cognitive Neuroscience, 18, 889-897.
By testing the facial fear-recognition ability of 341 men in the general population, we show that 8.8% have deficits akin to those seen with acquired amygdala damage. Using psychological tests and functional magnetic resonance imaging (fMRI) we tested the hypothesis that poor fear recognition would predict deficits in other domains of social cognition and, in response to socially relevant stimuli, abnormal activation in brain regions that putatively reflect engagement of the "social brain." On tests of "theory of mind" ability, 25 "low fear scorers" (LFS) performed significantly worse than 25 age- and IQ-matched "normal (good) fear scorers" (NFS). In fMRI, we compared evoked activity during a gender judgement task to neutral faces portraying different head and eye gaze orientations in 12 NFS and 12 LFS subjects. Despite identical between-group accuracy in gender discrimination, LFS demonstrated significantly reduced activation in amygdala, fusiform gyrus, and anterior superior temporal cortices when viewing faces with direct versus averted gaze. In a functional connectivity analysis, NFS show enhanced connectivity between the amygdala and anterior temporal cortex in the context of direct gaze; this enhanced coupling is absent in LFS. We suggest that important individual differences in social cognitive skills are expressed within the healthy male population, which appear to have a basis in a compromised neural system that underpins social information processing.
ARTICLE UPDATE - Orbitofrontal Cortex and Social Behavior: Integrating Self-monitoring and Emotion–Cognition Interactions
Jennifer S. Beer, Oliver P. John, Donatella Scabini and Robert T. Knight
Journal of Cognitive Neuroscience, 18, 871-879.
The role of the orbitofrontal cortex in social behavior remains a puzzle. Various theories of the social functions of the orbitofrontal cortex focus on the role of this area in either emotional processing or its involvement in online monitoring of behavior (i.e., self-monitoring). The present research attempts to integrate these two theories by examining whether improving the self-monitoring of patients with orbitofrontal damage is associated with the generation of emotions needed to guide interpersonal behavior. Patients with orbitofrontal damage, patients with lateral prefrontal damage, and healthy controls took part in an interpersonal task. After completing the task, participants' self-monitoring was increased by showing them a videotape of their task performance. In comparison to healthy controls and patients with lateral prefrontal damage, orbitofrontal damage was associated with objectively inappropriate social behavior. Although patients with orbitofrontal damage were aware of social norms of intimacy, they were unaware that their task performance violated these norms. The embarrassment typically associated with inappropriate social behavior was elicited in these patients only after their self-monitoring increased from viewing their videotaped performance. These findings suggest that damage to the orbitofrontal cortex impairs self-insight that may preclude the generation of helpful emotional information. The results highlight the role of the orbitofrontal cortex in the interplay of self-monitoring and emotional processing and suggest avenues for neurorehabilitation of patients with social deficits subsequent to orbitofrontal damage.
Journal of Cognitive Neuroscience, 18, 871-879.
The role of the orbitofrontal cortex in social behavior remains a puzzle. Various theories of the social functions of the orbitofrontal cortex focus on the role of this area in either emotional processing or its involvement in online monitoring of behavior (i.e., self-monitoring). The present research attempts to integrate these two theories by examining whether improving the self-monitoring of patients with orbitofrontal damage is associated with the generation of emotions needed to guide interpersonal behavior. Patients with orbitofrontal damage, patients with lateral prefrontal damage, and healthy controls took part in an interpersonal task. After completing the task, participants' self-monitoring was increased by showing them a videotape of their task performance. In comparison to healthy controls and patients with lateral prefrontal damage, orbitofrontal damage was associated with objectively inappropriate social behavior. Although patients with orbitofrontal damage were aware of social norms of intimacy, they were unaware that their task performance violated these norms. The embarrassment typically associated with inappropriate social behavior was elicited in these patients only after their self-monitoring increased from viewing their videotaped performance. These findings suggest that damage to the orbitofrontal cortex impairs self-insight that may preclude the generation of helpful emotional information. The results highlight the role of the orbitofrontal cortex in the interplay of self-monitoring and emotional processing and suggest avenues for neurorehabilitation of patients with social deficits subsequent to orbitofrontal damage.
ARTICLE UPDATE - Neural systems connecting interoceptive awareness and feelings.
Pollatos O, Gramann K, Schandry R.
Human Brain Mapping, in press
In many theories of emotions the representations of bodily responses play an important role for subjective feelings. We tested the hypothesis that the perception of bodily states is positively related to the experienced intensity of feelings as well as to the activity of first-order and second-order brain structures involved in the processing of feelings. Using a heartbeat perception task, subjects were separated into groups with either high or poor interoceptive awareness. During emotional picture presentation we measured high-density EEG and used spatiotemporal current density reconstruction to identify regions involved in both interoceptive awareness and emotion processing. We observed a positive relation between interoceptive awareness and the experienced intensity of emotions. Furthermore, the P300 amplitudes to pleasant and unpleasant pictures were enhanced for subjects with high interoceptive awareness. The source reconstruction revealed that interoceptive awareness is related to an enhanced activation in both first-order structures (insula, somatosensory cortices) and second-order structures (anterior cingulate, prefrontal cortices). We conclude that the perception of bodily states is a crucial determinant for the processing and the subjective experience of feelings.
Human Brain Mapping, in press
In many theories of emotions the representations of bodily responses play an important role for subjective feelings. We tested the hypothesis that the perception of bodily states is positively related to the experienced intensity of feelings as well as to the activity of first-order and second-order brain structures involved in the processing of feelings. Using a heartbeat perception task, subjects were separated into groups with either high or poor interoceptive awareness. During emotional picture presentation we measured high-density EEG and used spatiotemporal current density reconstruction to identify regions involved in both interoceptive awareness and emotion processing. We observed a positive relation between interoceptive awareness and the experienced intensity of emotions. Furthermore, the P300 amplitudes to pleasant and unpleasant pictures were enhanced for subjects with high interoceptive awareness. The source reconstruction revealed that interoceptive awareness is related to an enhanced activation in both first-order structures (insula, somatosensory cortices) and second-order structures (anterior cingulate, prefrontal cortices). We conclude that the perception of bodily states is a crucial determinant for the processing and the subjective experience of feelings.
ARTICLE UPDATE - Hemispheric asymmetries for the conscious and unconscious perception of emotional words
Smith SD, Bulman-Fleming MB.
Laterality, 11, 304-330.
The current research examines the interactions between hemispheric asymmetries for visual perception and emotion. In a series of four experiments, participants completed tasks measuring both conscious and unconscious perception of linguistic stimuli. In these studies, stimulus-presentation parameters (brief exposure duration vs masking) and the emotional valence of the test stimuli (negative vs positive) were manipulated in order to create studies in which the visual and emotional asymmetries were congruent (favoured the same hemispheres) or were incongruent (favoured opposing hemispheres). The results demonstrated that negative emotional stimuli led to a right-hemisphere advantage for conscious perception only when stimuli were shown for brief exposures (17 ms). Positive emotional words did not elicit hemispheric asymmetries. The results are discussed in terms of their relevance for theories of emotional lateralisation.
Laterality, 11, 304-330.
The current research examines the interactions between hemispheric asymmetries for visual perception and emotion. In a series of four experiments, participants completed tasks measuring both conscious and unconscious perception of linguistic stimuli. In these studies, stimulus-presentation parameters (brief exposure duration vs masking) and the emotional valence of the test stimuli (negative vs positive) were manipulated in order to create studies in which the visual and emotional asymmetries were congruent (favoured the same hemispheres) or were incongruent (favoured opposing hemispheres). The results demonstrated that negative emotional stimuli led to a right-hemisphere advantage for conscious perception only when stimuli were shown for brief exposures (17 ms). Positive emotional words did not elicit hemispheric asymmetries. The results are discussed in terms of their relevance for theories of emotional lateralisation.
Thursday, May 25, 2006
ARTICLE UPDATE - Neural response to sustained affective visual stimulation using an indirect task
Carretie L, Hinojosa JA, Albert J, Mercado F.
Experimental Brain Research, in press
Event-related potentials were recorded from 30 subjects using sustained stimulation and an indirect task, two strategies which facilitate affective responses that are complete and free of cognitive interference. Stimuli were of three types: pleasant, unpleasant and neutral. A three-phase pattern was found. The first phase, an amplitude increase in response to negative stimuli higher than to neutral and pleasant stimuli, was produced at 160 ms after stimulus onset, the prefrontal cortex being the origin of this phase. The second phase, characterized by maximal amplitudes in response to positive stimuli, was produced at 400 ms, originating in the visual cortex. Finally, the third phase, another amplitude increase in response to negative stimuli, was produced at 680 ms, and its source was located in the left precentral gyrus. Present data show that the cortical response to sustained emotional visual stimulation presented within indirect tasks provides information on attention-, motivation- and motor-related biases that complement information obtained under other experimental conditions.
Experimental Brain Research, in press
Event-related potentials were recorded from 30 subjects using sustained stimulation and an indirect task, two strategies which facilitate affective responses that are complete and free of cognitive interference. Stimuli were of three types: pleasant, unpleasant and neutral. A three-phase pattern was found. The first phase, an amplitude increase in response to negative stimuli higher than to neutral and pleasant stimuli, was produced at 160 ms after stimulus onset, the prefrontal cortex being the origin of this phase. The second phase, characterized by maximal amplitudes in response to positive stimuli, was produced at 400 ms, originating in the visual cortex. Finally, the third phase, another amplitude increase in response to negative stimuli, was produced at 680 ms, and its source was located in the left precentral gyrus. Present data show that the cortical response to sustained emotional visual stimulation presented within indirect tasks provides information on attention-, motivation- and motor-related biases that complement information obtained under other experimental conditions.
ARTICLE UPDATE - Processing of emotional adjectives: Evidence from startle EMG and ERPs.
Herbert C, Kissler J, Junghofer M, Peyk P, Rockstroh B.
Psychophysiology, 43, 197-206
Affective startle modulation in the electromyographic (EMG), auditory startle evoked potentials, and visually evoked potentials (VEPs) were assessed while subjects evaluated pleasant, unpleasant, and neutral adjectives. Acoustic startle probes were presented at random time points 2.5-4.0 s after word onset. The visual P2 and P3 potentials were generally larger during processing of emotional than of neutral adjectives. In contrast, the late positive component was enhanced and was correlated with larger EMG startle responses and auditory startle evoked potential P3 amplitudes for pleasant words only. During internal cognitive activity, the startle reflex represents a measure of "processing interrupt." Thus the startle tone interrupted processing of particularly pleasant adjectives and caused re-alerting to environmental stimuli. Specific effects for pleasant material may arise from a "positivity offset," favoring responses to pleasant material at lower arousal levels.
Psychophysiology, 43, 197-206
Affective startle modulation in the electromyographic (EMG), auditory startle evoked potentials, and visually evoked potentials (VEPs) were assessed while subjects evaluated pleasant, unpleasant, and neutral adjectives. Acoustic startle probes were presented at random time points 2.5-4.0 s after word onset. The visual P2 and P3 potentials were generally larger during processing of emotional than of neutral adjectives. In contrast, the late positive component was enhanced and was correlated with larger EMG startle responses and auditory startle evoked potential P3 amplitudes for pleasant words only. During internal cognitive activity, the startle reflex represents a measure of "processing interrupt." Thus the startle tone interrupted processing of particularly pleasant adjectives and caused re-alerting to environmental stimuli. Specific effects for pleasant material may arise from a "positivity offset," favoring responses to pleasant material at lower arousal levels.
ARTICLE UPDATE - When does size not matter? Effects of stimulus size on affective modulation.
De Cesarei A, Codispoti M.
Psychophysiology, 43, 207-215.
Motivationally relevant stimuli have been shown to receive prioritized processing compared to neutral stimuli at distinct processing stages. This effect has been related to the evolutionary importance of rapidly detecting dangers and potential rewards and has been shown to be modulated by the distance between an organism and a faced stimulus. Similarly, recent studies showed degrees of emotional modulation of autonomic responses and subjective arousal ratings depending on stimulus size. In the present study, affective modulation of pictures presented in different sizes was investigated by measuring event-related potentials during a two-choice categorization task. Results showed significant emotional modulation across all sizes at both earlier and later stages of processing. Moreover, affective modulation of earlier processes was reduced in smaller compared to larger sizes, whereas no changes in affective modulation were observed at later stages.
Psychophysiology, 43, 207-215.
Motivationally relevant stimuli have been shown to receive prioritized processing compared to neutral stimuli at distinct processing stages. This effect has been related to the evolutionary importance of rapidly detecting dangers and potential rewards and has been shown to be modulated by the distance between an organism and a faced stimulus. Similarly, recent studies showed degrees of emotional modulation of autonomic responses and subjective arousal ratings depending on stimulus size. In the present study, affective modulation of pictures presented in different sizes was investigated by measuring event-related potentials during a two-choice categorization task. Results showed significant emotional modulation across all sizes at both earlier and later stages of processing. Moreover, affective modulation of earlier processes was reduced in smaller compared to larger sizes, whereas no changes in affective modulation were observed at later stages.
ARTICLE UPDATE - Differential time course and intensity of PFC activation for men and women in response to emotional stimuli: A functional near-infrar
Leon-Carrion J, Damas J, Izzetoglu K, Pourrezai K, Martin-Rodriguez JF, Martin JM, Dominguez-Morales MR.
Neuroscience Letters, in press
Using functional near-infrared spectroscopy (fNIRS) we recorded prefrontal cortex (PFC) activation during positive, negative and neutral film clips, based on affective ratings according to their valence and arousal, to assess gender differences in cerebral activation in 15 male and 15 female volunteers. To record PFC activation, five movie clips were presented on a 17-in. TFT screen. The recordings included a pre-stimulus 5-s local baseline and "on" and "off" segments of data, referring to fNIRS Oxy-Hb levels while stimulation (movie clip) was present and during an inter-stimulus blank screen. Our data showed gender differences in the delay period to initial PFC activation and in the course and intensity of activation produced by affective visual stimuli. During the exposure or "on" period of the stimuli we observed more pronounced overshoot and undershoot in men versus women across the range of emotions elicited. This effect was even more pronounced following stimulus cessation ("off" period). The results indicate that gender and the duration of recordings may affect the results of emotional neuroimaging studies
Neuroscience Letters, in press
Using functional near-infrared spectroscopy (fNIRS) we recorded prefrontal cortex (PFC) activation during positive, negative and neutral film clips, based on affective ratings according to their valence and arousal, to assess gender differences in cerebral activation in 15 male and 15 female volunteers. To record PFC activation, five movie clips were presented on a 17-in. TFT screen. The recordings included a pre-stimulus 5-s local baseline and "on" and "off" segments of data, referring to fNIRS Oxy-Hb levels while stimulation (movie clip) was present and during an inter-stimulus blank screen. Our data showed gender differences in the delay period to initial PFC activation and in the course and intensity of activation produced by affective visual stimuli. During the exposure or "on" period of the stimuli we observed more pronounced overshoot and undershoot in men versus women across the range of emotions elicited. This effect was even more pronounced following stimulus cessation ("off" period). The results indicate that gender and the duration of recordings may affect the results of emotional neuroimaging studies
ARTICLE UPDATE - A novel set-shifting modification of the iowa gambling task: flexible emotion-based learning in schizophrenia.
Turnbull OH, Evans CE, Kemish K, Park S, Bowman CH.
Neuropsychology, 20, 290-298.
Although it might seem that people with schizophrenia would perform poorly on measures of emotion-based learning, several studies have shown normal levels of performance on the Iowa Gambling Task (IGT; C. E. Y. Evans, C. H. Bowman, & O. H. Turnbull, 2005; L. M. Ritter, J. H. Meador-Woodruff, & G. W. Dalack, 2004; B. Shurman, W. P. Horan, & K. H. Nuechterlein, 2005; K. E. Wilder, D. R. Weinberger, & T. E. Goldberg, 1998). The present article describes a newly developed modification of the IGT involving initial familiarization with the basic contingency pattern then 3 periods of contingency shift. Control participants showed substantial gains during the later trials of each shift period. Analyzed in terms of positive symptoms, those with schizophrenia were little different from control participants. Those high in negative symptoms could perform the basic task but showed remarkably poor performances (no better than chance) in the shift phases, retaining a preference for decks that had previously been "good," even when they experienced substantial losses.
Neuropsychology, 20, 290-298.
Although it might seem that people with schizophrenia would perform poorly on measures of emotion-based learning, several studies have shown normal levels of performance on the Iowa Gambling Task (IGT; C. E. Y. Evans, C. H. Bowman, & O. H. Turnbull, 2005; L. M. Ritter, J. H. Meador-Woodruff, & G. W. Dalack, 2004; B. Shurman, W. P. Horan, & K. H. Nuechterlein, 2005; K. E. Wilder, D. R. Weinberger, & T. E. Goldberg, 1998). The present article describes a newly developed modification of the IGT involving initial familiarization with the basic contingency pattern then 3 periods of contingency shift. Control participants showed substantial gains during the later trials of each shift period. Analyzed in terms of positive symptoms, those with schizophrenia were little different from control participants. Those high in negative symptoms could perform the basic task but showed remarkably poor performances (no better than chance) in the shift phases, retaining a preference for decks that had previously been "good," even when they experienced substantial losses.
Friday, May 12, 2006
ARTICLE UPDATE - Enhanced perceptual priming for neutral stimuli occurring in a traumatic context: Two experimental investigations
T. Michael and A. Ehlers
Brain Research and Therapy, in press
Intrusive memories in posttraumatic stress disorder are often triggered by stimuli that are perceptually similar to those present shortly before or during the trauma. The present study aims to examine the possible role of perceptual priming in this phenomenon. It further investigates whether the degree of perceptual priming is associated with dissociation and whether both perceptual priming and intrusive memories can be reduced through elaboration.
Two experiments measured perceptual priming for neutral stimuli that immediately preceded a “traumatic” event. Volunteers (N=46, 92) watched a series of “traumatic” and neutral picture stories, and completed a blurred object identification (perceptual priming) memory task, and a recognition memory task. Participants in Experiment 1 were selected to score either high or low on the Trait Dissociation Questionnaire [Murray, Ehlers, & Mayou (2002). Dissociation and posttraumatic stress disorder: Two prospective studies of motor vehicle accident survivors. British Journal of Psychiatry, 180, 363–368]. They also completed a state dissociation measure in the session. Experiment 2 randomly allocated participants to an experimental condition designed to increase elaboration or to a control condition. This experiment also included a measure of intrusive memories.
Both experiments found enhanced perceptual priming for the stimuli that immediately preceded the “traumatic” stories compared to those preceding neutral stories. Participants with high trait dissociation showed relatively stronger perceptual perceptual priming. The degree of perceptual priming for stimuli from the “traumatic” stories also correlated with state dissociation (Experiment 1). Experimental manipulation of the elaboration of the stories showed that elaboration reduced the enhanced perceptual priming effect and the relative probability of reexperiencing symptoms (Experiment 2). The results support the role of perceptual priming in intrusions after traumatic events.
Brain Research and Therapy, in press
Intrusive memories in posttraumatic stress disorder are often triggered by stimuli that are perceptually similar to those present shortly before or during the trauma. The present study aims to examine the possible role of perceptual priming in this phenomenon. It further investigates whether the degree of perceptual priming is associated with dissociation and whether both perceptual priming and intrusive memories can be reduced through elaboration.
Two experiments measured perceptual priming for neutral stimuli that immediately preceded a “traumatic” event. Volunteers (N=46, 92) watched a series of “traumatic” and neutral picture stories, and completed a blurred object identification (perceptual priming) memory task, and a recognition memory task. Participants in Experiment 1 were selected to score either high or low on the Trait Dissociation Questionnaire [Murray, Ehlers, & Mayou (2002). Dissociation and posttraumatic stress disorder: Two prospective studies of motor vehicle accident survivors. British Journal of Psychiatry, 180, 363–368]. They also completed a state dissociation measure in the session. Experiment 2 randomly allocated participants to an experimental condition designed to increase elaboration or to a control condition. This experiment also included a measure of intrusive memories.
Both experiments found enhanced perceptual priming for the stimuli that immediately preceded the “traumatic” stories compared to those preceding neutral stories. Participants with high trait dissociation showed relatively stronger perceptual perceptual priming. The degree of perceptual priming for stimuli from the “traumatic” stories also correlated with state dissociation (Experiment 1). Experimental manipulation of the elaboration of the stories showed that elaboration reduced the enhanced perceptual priming effect and the relative probability of reexperiencing symptoms (Experiment 2). The results support the role of perceptual priming in intrusions after traumatic events.
ARTICLE UPDATE - Simultaneous masking in a dichotic emotion detection task
Daniel Voyer, Mariana Soraggi, Brandy Brake and Heather-Dawn Wood
Brain and Cognition, in press
The present study investigated the possible role of ceiling effects in producing laterality effects of small magnitude in dichotic emotion detection. Twenty two right-handed undergraduate students participated in the present experiment. They were required to detect the presence of a target emotion in the expressions tones of happiness, sadness, anger, and neutrality presented dichotically. Stimuli were adjusted to 70 dB and occurred simultaneously with a white noise mask that had an intensity of 65, 70, 80, or 85 dB. Results showed a left ear advantage (LEA) for the 65 dB mask and a right ear advantage for the 85 dB mask, but only after two testing sessions. The possible existence of a generalized right ear bias that might affect the observed LEA for non-verbal tasks is discussed. Alternative explanations and limitations of the present experiment are also presented.
Brain and Cognition, in press
The present study investigated the possible role of ceiling effects in producing laterality effects of small magnitude in dichotic emotion detection. Twenty two right-handed undergraduate students participated in the present experiment. They were required to detect the presence of a target emotion in the expressions tones of happiness, sadness, anger, and neutrality presented dichotically. Stimuli were adjusted to 70 dB and occurred simultaneously with a white noise mask that had an intensity of 65, 70, 80, or 85 dB. Results showed a left ear advantage (LEA) for the 65 dB mask and a right ear advantage for the 85 dB mask, but only after two testing sessions. The possible existence of a generalized right ear bias that might affect the observed LEA for non-verbal tasks is discussed. Alternative explanations and limitations of the present experiment are also presented.
ARTICLE UPDATE - Amygdala activation during masked presentation of emotional faces predicts conscious detection of threat-related faces
Thomas Suslow, Patricia Ohrmann, Jochen Bauer, Astrid Veronika Rauch, Wolfram Schwindt, Volker Arolt, Walter Heindel and Harald Kugel
Brain and Cognition, in press
It has been argued that critical functions of the human amygdala are to modulate the moment-to-moment vigilance level and to enhance the processing and the consolidation of memories of emotionally arousing material. In this functional magnetic resonance study, pictures of human faces bearing fearful, angry, and happy expressions were presented to nine healthy volunteers using a backward masking procedure based on neutral facial expression. Activation of the left and right amygdala in response to the masked fearful faces (compared to neutral faces) was significantly correlated with the number of fearful faces detected. In addition, right but not left amygdala activation in response to the masked angry faces was significantly related to the number of angry faces detected. The present findings underscore the role of the amygdala in the detection and consolidation of memory for marginally perceptible threatening facial expression.
Brain and Cognition, in press
It has been argued that critical functions of the human amygdala are to modulate the moment-to-moment vigilance level and to enhance the processing and the consolidation of memories of emotionally arousing material. In this functional magnetic resonance study, pictures of human faces bearing fearful, angry, and happy expressions were presented to nine healthy volunteers using a backward masking procedure based on neutral facial expression. Activation of the left and right amygdala in response to the masked fearful faces (compared to neutral faces) was significantly correlated with the number of fearful faces detected. In addition, right but not left amygdala activation in response to the masked angry faces was significantly related to the number of angry faces detected. The present findings underscore the role of the amygdala in the detection and consolidation of memory for marginally perceptible threatening facial expression.
ARTICLE UPDATE - Controlling the integration of emotion and cognition.
Beer JS, Knight RT, D'Esposito M.
Psychological Science, 17, 448-453.
Emotion has been both lauded and vilified for its role in decision making. How are people able to ensure that helpful emotions guide decision making and irrelevant emotions are kept out of decision making? The orbitofrontal cortex has been identified as a neural area involved in incorporating emotion into decision making. Is this area's function specific to the integration of emotion and cognition, or does it more broadly govern whether emotional information should be integrated into cognition? The present research examined the role of orbitofrontal cortex when it was appropriate to control (i.e., prevent) the influence of emotion in decision making (Experiment 1) and to incorporate the influence of emotion in decision making (Experiment 2). Together, the two studies suggest that activity in lateral orbitofrontal cortex is associated with evaluating the contextual relevance of emotional information for decision making.
Psychological Science, 17, 448-453.
Emotion has been both lauded and vilified for its role in decision making. How are people able to ensure that helpful emotions guide decision making and irrelevant emotions are kept out of decision making? The orbitofrontal cortex has been identified as a neural area involved in incorporating emotion into decision making. Is this area's function specific to the integration of emotion and cognition, or does it more broadly govern whether emotional information should be integrated into cognition? The present research examined the role of orbitofrontal cortex when it was appropriate to control (i.e., prevent) the influence of emotion in decision making (Experiment 1) and to incorporate the influence of emotion in decision making (Experiment 2). Together, the two studies suggest that activity in lateral orbitofrontal cortex is associated with evaluating the contextual relevance of emotional information for decision making.
Tuesday, May 09, 2006
ARTICLE UPDATE - Nonconscious semantic processing of emotional words modulates conscious access
Raphaël Gaillard, Antoine Del Cul, Lionel Naccache, Fabien Vinckier, Laurent Cohen, and Stanislas Dehaene
PNAS, 103, 7524-7529
Whether masked words can be processed at a semantic level remains a controversial issue in cognitive psychology. Although recent behavioral studies have demonstrated masked semantic priming for number words, attempts to generalize this finding to other categories of words have failed. Here, as an alternative to subliminal priming, we introduce a sensitive behavioral method to detect nonconscious semantic processing of words. The logic of this method consists of presenting words close to the threshold for conscious perception and examining whether their semantic content modulates performance in objective and subjective tasks. Our results disclose two independent sources of modulation of the threshold for access to consciousness. First, prior conscious perception of words increases the detection rate of the same words when they are subsequently presented with stronger masking. Second, the threshold for conscious access is lower for emotional words than for neutral ones, even for words that have not been previously consciously perceived, thus implying that written words can receive nonconscious semantic processing.
PNAS, 103, 7524-7529
Whether masked words can be processed at a semantic level remains a controversial issue in cognitive psychology. Although recent behavioral studies have demonstrated masked semantic priming for number words, attempts to generalize this finding to other categories of words have failed. Here, as an alternative to subliminal priming, we introduce a sensitive behavioral method to detect nonconscious semantic processing of words. The logic of this method consists of presenting words close to the threshold for conscious perception and examining whether their semantic content modulates performance in objective and subjective tasks. Our results disclose two independent sources of modulation of the threshold for access to consciousness. First, prior conscious perception of words increases the detection rate of the same words when they are subsequently presented with stronger masking. Second, the threshold for conscious access is lower for emotional words than for neutral ones, even for words that have not been previously consciously perceived, thus implying that written words can receive nonconscious semantic processing.
ARTICLE UPDATE - Mood-congruent free recall bias in anxious individuals is not a consequence of response bias
Russo, Riccardo, Whittuck, Dora, Roberson, Debi, Dutton, Kevin, Georgiou, George, Fox, Elaine
Memory, 14, 393-399.
The status of mood-congruent free recall bias in anxious individuals was evaluated following incidental encoding of target words. Individuals with high and low levels of trait anxiety completed a modified Stroop task, which revealed an attentional bias for threat-related stimuli in anxious individuals. This group was significantly slower in naming the colour in which threat-related words were displayed compared to neutral words. In a subsequent free recall test for the words used in the modified Stroop task, anxious individuals recalled more threat-related words compared to low-anxious people. This difference was significant even when controlling for the false recall of items that had not been presented during study. These results support the view put forward by Russo, Fox, Bellinger, and Nguyen-Van-Tam (2001) that mood-congruent free recall bias in anxious individuals can be observed if the target material is encoded at a relatively shallow level. Moreover, contrary to Dowens and Calvo (2003), the current results show that the memory advantage for threat-related information in anxious individuals is not a consequence of response bias.
Memory, 14, 393-399.
The status of mood-congruent free recall bias in anxious individuals was evaluated following incidental encoding of target words. Individuals with high and low levels of trait anxiety completed a modified Stroop task, which revealed an attentional bias for threat-related stimuli in anxious individuals. This group was significantly slower in naming the colour in which threat-related words were displayed compared to neutral words. In a subsequent free recall test for the words used in the modified Stroop task, anxious individuals recalled more threat-related words compared to low-anxious people. This difference was significant even when controlling for the false recall of items that had not been presented during study. These results support the view put forward by Russo, Fox, Bellinger, and Nguyen-Van-Tam (2001) that mood-congruent free recall bias in anxious individuals can be observed if the target material is encoded at a relatively shallow level. Moreover, contrary to Dowens and Calvo (2003), the current results show that the memory advantage for threat-related information in anxious individuals is not a consequence of response bias.
ARTICLE UPDATE - Modulation of the C1 Visual Event-related Component by Conditioned Stimuli: Evidence for Sensory Plasticity in Early Affective Percep
Margarita Stolarova, Andreas Keil and Stephan Moratti
Cerebral Cortex, 16, 876-887
Previous research has demonstrated optimized processing of motivationally significant stimuli early in perception. In the present study, the time course and underlying mechanisms for such fast differentiation are of interest. We investigated the involvement of the primary visual cortex in affective evaluation of conditioned stimuli (CSs). In order to elicit learning within the visual system we chose affective pictures as unconditioned stimuli and used laterally presented gratings as CSs. Using high-density electroencephalography, we demonstrated modulation of the C1 visual event-related component for threat-related stimuli versus neutral stimuli, which increased with continuing acquisition of affective meaning. The differentiation between aversive and neutral visual stimuli occurred as early as 65–90 ms after stimulus onset and suggested involvement of the primary visual areas in affective evaluation. As an underlying mechanism, we discuss short-term reorganization in visual cortex, enabling sensory amplification of specific visual features that are related to motivationally relevant information.
Cerebral Cortex, 16, 876-887
Previous research has demonstrated optimized processing of motivationally significant stimuli early in perception. In the present study, the time course and underlying mechanisms for such fast differentiation are of interest. We investigated the involvement of the primary visual cortex in affective evaluation of conditioned stimuli (CSs). In order to elicit learning within the visual system we chose affective pictures as unconditioned stimuli and used laterally presented gratings as CSs. Using high-density electroencephalography, we demonstrated modulation of the C1 visual event-related component for threat-related stimuli versus neutral stimuli, which increased with continuing acquisition of affective meaning. The differentiation between aversive and neutral visual stimuli occurred as early as 65–90 ms after stimulus onset and suggested involvement of the primary visual areas in affective evaluation. As an underlying mechanism, we discuss short-term reorganization in visual cortex, enabling sensory amplification of specific visual features that are related to motivationally relevant information.
Monday, May 08, 2006
ARTICLE UPDATE - Dissociation of event-related potentials indexing arousal and semantic cohesion during emotional word encoding
Daniel G. Dillon, Julie J. Cooper, Tineke Grent-‘t-Jong, Marty G. Woldorff and Kevin S. LaBar
Brain and Cognition, in press
Event-related potential (ERP) studies have shown that emotional stimuli elicit greater amplitude late positive-polarity potentials (LPPs) than neutral stimuli. This effect has been attributed to arousal, but emotional stimuli are also more semantically coherent than uncategorized neutral stimuli. ERPs were recorded during encoding of positive, negative, uncategorized neutral, and categorized neutral words. Differences in LPP amplitude elicited by emotional versus uncategorized neutral stimuli were evident from 450 to 1000 ms. From 450 to 700 ms, LPP effects at midline and right hemisphere frontal electrodes indexed arousal, whereas LPP effects at left hemisphere centro-parietal electrodes indexed semantic cohesion. This dissociation helps specify the processes underlying emotional stimulus encoding, and suggests the need to control for semantic cohesion in emotional information processing studies.
Brain and Cognition, in press
Event-related potential (ERP) studies have shown that emotional stimuli elicit greater amplitude late positive-polarity potentials (LPPs) than neutral stimuli. This effect has been attributed to arousal, but emotional stimuli are also more semantically coherent than uncategorized neutral stimuli. ERPs were recorded during encoding of positive, negative, uncategorized neutral, and categorized neutral words. Differences in LPP amplitude elicited by emotional versus uncategorized neutral stimuli were evident from 450 to 1000 ms. From 450 to 700 ms, LPP effects at midline and right hemisphere frontal electrodes indexed arousal, whereas LPP effects at left hemisphere centro-parietal electrodes indexed semantic cohesion. This dissociation helps specify the processes underlying emotional stimulus encoding, and suggests the need to control for semantic cohesion in emotional information processing studies.
Friday, May 05, 2006
ARTICLE UPDATE - Effects of picture content and intensity on affective physiological response.
Bernat E, Patrick CJ, Benning SD, Tellegen A.
Psychophysiology, 43, 93-103
Abstract This study evaluated the effects of affective intensity and thematic content of foreground photographic stimuli on various physiological response systems. This was accomplished by assessing responses to pictures that varied systematically in these parameters. Along with overall effects of picture valence reported in previous work, we found effects of thematic content (i.e., specific nature of objects/events depicted) for all measures except heart rate. In addition, we found that the magnitude of startle blink, skin conductance, and corrugator muscle reactions increased with increasing affective intensity of pictures. Additionally, for these three measures, intensity effects also interacted with effects of picture content. These results indicate that stimulus parameters of intensity and thematic content exert separate-and in some cases interactive-modulatory effects on physiological reactions to emotional pictures.
Psychophysiology, 43, 93-103
Abstract This study evaluated the effects of affective intensity and thematic content of foreground photographic stimuli on various physiological response systems. This was accomplished by assessing responses to pictures that varied systematically in these parameters. Along with overall effects of picture valence reported in previous work, we found effects of thematic content (i.e., specific nature of objects/events depicted) for all measures except heart rate. In addition, we found that the magnitude of startle blink, skin conductance, and corrugator muscle reactions increased with increasing affective intensity of pictures. Additionally, for these three measures, intensity effects also interacted with effects of picture content. These results indicate that stimulus parameters of intensity and thematic content exert separate-and in some cases interactive-modulatory effects on physiological reactions to emotional pictures.
ARTICLE UPDATE - Flanker effects with faces may depend on perceptual as well as emotional differences.
Horstmann G, Borgstedt K, Heumann M.
Emotion, 6, 28-39
Do threatening or negative faces capture attention? The authors argue that evidence from visual search, spatial cuing, and flanker tasks is equivocal and that perceptual differences may account for effects attributed to emotional categories. Empirically, the authors examine the flanker task. Although they replicate previous results in which a positive face flanked by negative faces suffers more interference than a negative face flanked by positive faces, further results indicate that face perception is not necessary for the flanker-effect asymmetry and that the asymmetry also occurs with nonemotional stimuli. The authors conclude that the flanker-effect asymmetry with affective faces cannot be unambiguously attributed to emotional differences and may well be due to purely perceptual differences between the stimuli.
Emotion, 6, 28-39
Do threatening or negative faces capture attention? The authors argue that evidence from visual search, spatial cuing, and flanker tasks is equivocal and that perceptual differences may account for effects attributed to emotional categories. Empirically, the authors examine the flanker task. Although they replicate previous results in which a positive face flanked by negative faces suffers more interference than a negative face flanked by positive faces, further results indicate that face perception is not necessary for the flanker-effect asymmetry and that the asymmetry also occurs with nonemotional stimuli. The authors conclude that the flanker-effect asymmetry with affective faces cannot be unambiguously attributed to emotional differences and may well be due to purely perceptual differences between the stimuli.
ARTICLE UPDATE - Anxiety meets fear in perception of dynamic expressive gaze.
Putman P, Hermans E, van Honk J.
Emotion, 6, 94-102
This study investigated in 2 experiments whether reflexive cuing of attention that occurs after perception of a gaze cue is greater for fearful than for happy faces in normal participants, as hypothesized from a social neuroscience perspective. To increase neuroecological validity, dynamic stimulus presentation was used to display faces that simultaneously morphed from a neutral expression into a happy or fearful one and shifted eye gaze from the center to the periphery. Shifts of attention resulting from a natural fearful gaze were expected to be related to participants' anxiety traits, in agreement with the often found increased selective attention to threat in anxious participants. Both hypotheses were confirmed: Fearful faces induced stronger gaze cuing than happy faces, and the strength of this cuing effect was correlated to participants' anxiety levels. These results suggest a neural network, which integrates the processing of gaze, expression, and emotional states to adaptively prime vigilance under threatening circumstances.
Emotion, 6, 94-102
This study investigated in 2 experiments whether reflexive cuing of attention that occurs after perception of a gaze cue is greater for fearful than for happy faces in normal participants, as hypothesized from a social neuroscience perspective. To increase neuroecological validity, dynamic stimulus presentation was used to display faces that simultaneously morphed from a neutral expression into a happy or fearful one and shifted eye gaze from the center to the periphery. Shifts of attention resulting from a natural fearful gaze were expected to be related to participants' anxiety traits, in agreement with the often found increased selective attention to threat in anxious participants. Both hypotheses were confirmed: Fearful faces induced stronger gaze cuing than happy faces, and the strength of this cuing effect was correlated to participants' anxiety levels. These results suggest a neural network, which integrates the processing of gaze, expression, and emotional states to adaptively prime vigilance under threatening circumstances.
ARTICLE UPDATE - Anxiety selectively disrupts visuospatial working memory.
Shackman AJ, Sarinopoulos I, Maxwell JS, Pizzagalli DA, Lavric A, Davidson RJ.
Emotion, 6, 40-61
On the basis of a review of the extant literature describing emotion-cognition interactions, the authors propose 4 methodological desiderata for studying how task-irrelevant affect modulates cognition and present data from an experiment satisfying them. Consistent with accounts of the hemispheric asymmetries characterizing withdrawal-related negative affect and visuospatial working memory (WM) in prefrontal and parietal cortices, threat-induced anxiety selectively disrupted accuracy of spatial but not verbal WM performance. Furthermore, individual differences in physiological measures of anxiety statistically mediated the degree of disruption. A second experiment revealed that individuals characterized by high levels of behavioral inhibition exhibited more intense anxiety and relatively worse spatial WM performance in the absence of threat, solidifying the authors' inference that anxiety causally mediates disruption. These observations suggest a revision of extant models of how anxiety sculpts cognition and underscore the utility of the desiderata.
Emotion, 6, 40-61
On the basis of a review of the extant literature describing emotion-cognition interactions, the authors propose 4 methodological desiderata for studying how task-irrelevant affect modulates cognition and present data from an experiment satisfying them. Consistent with accounts of the hemispheric asymmetries characterizing withdrawal-related negative affect and visuospatial working memory (WM) in prefrontal and parietal cortices, threat-induced anxiety selectively disrupted accuracy of spatial but not verbal WM performance. Furthermore, individual differences in physiological measures of anxiety statistically mediated the degree of disruption. A second experiment revealed that individuals characterized by high levels of behavioral inhibition exhibited more intense anxiety and relatively worse spatial WM performance in the absence of threat, solidifying the authors' inference that anxiety causally mediates disruption. These observations suggest a revision of extant models of how anxiety sculpts cognition and underscore the utility of the desiderata.
ARTICLE UPDATE - Lexical characteristics of words used in emotional Stroop experiments.
Larsen RJ, Mercer KA, Balota DA.
Emotion, 6, 62-72.
Validity of the emotional Stroop task hinges on equivalence between the emotion and the control words in terms of lexical features related to word recognition. The authors evaluated the lexical features of 1,033 words used in 32 published emotional Stroop studies. Emotion words were significantly lower in frequency of use, longer in length, and had smaller orthographic neighborhoods than words used as controls. These lexical features contribute to slower word recognition and hence are likely to contribute to delayed latencies in color naming. The often-replicated slowdown in color naming of emotion words may be due, in part, to lexical differences between the emotion and control words used in the majority of such studies to date.
Emotion, 6, 62-72.
Validity of the emotional Stroop task hinges on equivalence between the emotion and the control words in terms of lexical features related to word recognition. The authors evaluated the lexical features of 1,033 words used in 32 published emotional Stroop studies. Emotion words were significantly lower in frequency of use, longer in length, and had smaller orthographic neighborhoods than words used as controls. These lexical features contribute to slower word recognition and hence are likely to contribute to delayed latencies in color naming. The often-replicated slowdown in color naming of emotion words may be due, in part, to lexical differences between the emotion and control words used in the majority of such studies to date.
ARTICLE UPDATE - The impact of affect and frequency on lexical decision: The role of the amygdala and inferior frontal cortex.
Nakic M, Smith BW, Busis S, Vythilingam M, Blair RJ.
NeuroImage, in press
The current study used event-related fMRI to examine BOLD responses associated with two factors that behaviorally determine speed of lexical decision: frequency and emotion. Thirteen healthy adults performed a visual lexical decision task, discriminating between words and orthographically and phonologically legal nonwords. The study involved a 2 (Frequency: high and low) x 3 (Emotional arousal: highly negative, mildly negative, and neutral words) design with word categories matched for number of letters and concreteness. There were significant main effects for both frequency and emotion in lexical decision reaction times but no significant interaction. Negative word lexical decisions were associated with increased activation in bilateral amygdala and middle temporal cortex as well as rostral anterior and posterior cingulate cortex. Low-frequency word lexical decisions, relative to high-frequency word lexical decisions, were associated with increased bilateral activity in inferior frontal cortex. Inferior frontal cortex activation was particularly low during lexical decision for high-frequency emotional words but significant for high-frequency neutral emotional words. We suggest that this is because the semantic representation of high-frequency emotional words may receive sufficient additional augmentation via the reciprocal activation from the amygdala such that selective augmentation by inferior frontal cortex to achieve lexical decision is unnecessary.
NeuroImage, in press
The current study used event-related fMRI to examine BOLD responses associated with two factors that behaviorally determine speed of lexical decision: frequency and emotion. Thirteen healthy adults performed a visual lexical decision task, discriminating between words and orthographically and phonologically legal nonwords. The study involved a 2 (Frequency: high and low) x 3 (Emotional arousal: highly negative, mildly negative, and neutral words) design with word categories matched for number of letters and concreteness. There were significant main effects for both frequency and emotion in lexical decision reaction times but no significant interaction. Negative word lexical decisions were associated with increased activation in bilateral amygdala and middle temporal cortex as well as rostral anterior and posterior cingulate cortex. Low-frequency word lexical decisions, relative to high-frequency word lexical decisions, were associated with increased bilateral activity in inferior frontal cortex. Inferior frontal cortex activation was particularly low during lexical decision for high-frequency emotional words but significant for high-frequency neutral emotional words. We suggest that this is because the semantic representation of high-frequency emotional words may receive sufficient additional augmentation via the reciprocal activation from the amygdala such that selective augmentation by inferior frontal cortex to achieve lexical decision is unnecessary.
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