Valeriani M, Betti V, Le Pera D, De Armas L, Miliucci R, Restuccia D, Avenanti A, Aglioti SM.
Neuroimage, in press
Seeing actions, emotions and feelings of other individuals may activate resonant mechanisms that allow the empathic understanding of others' states. Being crucial for implementing pro-social behaviors, empathy is considered as inherently altruistic. Here we explored whether the personal experience of pain make individuals less inclined to share others' pain. We used laser-evoked potentials (LEPs) to explore whether observation of painful or non-noxious stimuli delivered to a stranger model induced any modulation in the pain system of onlookers who were suffering from pain induced by the laser stimuli. After LEPs recording, participants rated intensity and unpleasantness of the laser pain, and of the pain induced by the movie in themselves and in the model. Mere observation of needles penetrating the model's hand brought about a specific reduction of the N1/P1 LEP component, related to the activation of somatic nodes of the pain matrix. Such reduction is stronger in onlookers who rated the pain intensity induced by the pain movie as higher in themselves and lower in the model. Conversely, the N2a-P2 component, supposedly associated to affective pain qualities, did not show any specific modulation during observation of others' pain. Thus, viewing 'flesh and bone' pain in others specifically modulates neural activity in the pain matrix sensory node. Moreover, this socially-derived inhibitory effect is correlated with the intensity of the pain attributed to self rather than to others suggesting that being in pain may bias the empathic relation with stranger models towards self-centred instead than other-related stances.
Friday, February 29, 2008
ARTICLE UPDATE - Understanding the Role of Emotion in Sense-making. A Semiotic Psychoanalytic Oriented Perspective.
Salvatore S, Venuleo C.
Integrative Psychological and Behavioral Science, 42, 32-46
We propose a model of emotion grounded on Ignacio Matte Blanco's theory of the unconscious. According to this conceptualization, emotion is a generalized representation of the social context actors are involved in. We discuss how this model can help to better understand the sensemaking processes. For this purpose we present a hierarchical model of sensemaking based on the distinction between significance-the content of the sign-and sense-the psychological value of the act of producing the sign in the given contingence of the social exchange. According to this model, emotion categorization produces the frame of sense regulating the interpretation of the sense of the signs, therefore creating the psychological value of the sensemaking.
Integrative Psychological and Behavioral Science, 42, 32-46
We propose a model of emotion grounded on Ignacio Matte Blanco's theory of the unconscious. According to this conceptualization, emotion is a generalized representation of the social context actors are involved in. We discuss how this model can help to better understand the sensemaking processes. For this purpose we present a hierarchical model of sensemaking based on the distinction between significance-the content of the sign-and sense-the psychological value of the act of producing the sign in the given contingence of the social exchange. According to this model, emotion categorization produces the frame of sense regulating the interpretation of the sense of the signs, therefore creating the psychological value of the sensemaking.
ARTICLE UPDATE - The power of the word may reside in the power of affect.
Panksepp J.
Integrative Psychological and Behavioral Science, 42, 47-55
This commentary on Dan Shanahan's, A New View of Language, Emotion and the Brain, basically agrees with an emotion-based view of the evolutionary and developmental basis of language acquisition. It provides a supplementary neuroscience perspective that is more deeply affective and epigenetic in the sense that all claims about neocortically-based language modules need to be tempered by the existing genetic evidence as well as the robust neuroscience evidence that the cortex resembles random-access-memory space, a tabula rasa upon which epigenetic and learning processes create functional networks. The transition from non-linguistic creatures to linguistic ones may have required the conjunction of social-affective brain mechanisms, morphological changes in the articulatory apparatus, an abundance of cross-modal cortical processing ability, and the initial urge to communicate in coordinate prosodic gestural and vocal ways, which may have been more poetic and musical than current propositional language. There may be no language instinct that is independent of these evolutionary pre-adaptations.
Integrative Psychological and Behavioral Science, 42, 47-55
This commentary on Dan Shanahan's, A New View of Language, Emotion and the Brain, basically agrees with an emotion-based view of the evolutionary and developmental basis of language acquisition. It provides a supplementary neuroscience perspective that is more deeply affective and epigenetic in the sense that all claims about neocortically-based language modules need to be tempered by the existing genetic evidence as well as the robust neuroscience evidence that the cortex resembles random-access-memory space, a tabula rasa upon which epigenetic and learning processes create functional networks. The transition from non-linguistic creatures to linguistic ones may have required the conjunction of social-affective brain mechanisms, morphological changes in the articulatory apparatus, an abundance of cross-modal cortical processing ability, and the initial urge to communicate in coordinate prosodic gestural and vocal ways, which may have been more poetic and musical than current propositional language. There may be no language instinct that is independent of these evolutionary pre-adaptations.
ARTICLE UPDATE - Differential effects of object-based attention on evoked potentials to fearful and disgusted faces.
Isabel M. Santos, Jaime Iglesias, Ela I. Olivares and Andrew W. Young
Neuropsychologia, in press
Event-related potentials (ERPs) were used to investigate the role of attention on the processing of facial expressions of fear and disgust. Stimuli consisted of overlapping pictures of a face and a house. Participants had to monitor repetitions of faces or houses, in separate blocks of trials, so that object-based attention was manipulated while spatial attention was kept constant. Faces varied in expression and could be either fearful or neutral (in the fear condition) or disgusted or neutral (in the disgust condition). When attending to faces, participants were required to signal repetitions of the same person, with the facial expressions being completely irrelevant to the task. Different effects of selective attention and different patterns of brain activity were observed for faces with fear and disgust expressions. Results indicated that the perception of fear from faces is gated by selective attention at early latencies, whereas a sustained positivity for fearful faces compared to neutral faces emerged around 160ms at central-parietal sites, independent of selective attention. In the case of disgust, ERP differences began only around 160ms after stimulus onset, and only after 480ms was the perception of disgust modulated by attention allocation. Results are interpreted in terms of different neural mechanisms for the perception of fear and disgust and related to the functional significance of these two emotions for the survival of the organism.
Neuropsychologia, in press
Event-related potentials (ERPs) were used to investigate the role of attention on the processing of facial expressions of fear and disgust. Stimuli consisted of overlapping pictures of a face and a house. Participants had to monitor repetitions of faces or houses, in separate blocks of trials, so that object-based attention was manipulated while spatial attention was kept constant. Faces varied in expression and could be either fearful or neutral (in the fear condition) or disgusted or neutral (in the disgust condition). When attending to faces, participants were required to signal repetitions of the same person, with the facial expressions being completely irrelevant to the task. Different effects of selective attention and different patterns of brain activity were observed for faces with fear and disgust expressions. Results indicated that the perception of fear from faces is gated by selective attention at early latencies, whereas a sustained positivity for fearful faces compared to neutral faces emerged around 160ms at central-parietal sites, independent of selective attention. In the case of disgust, ERP differences began only around 160ms after stimulus onset, and only after 480ms was the perception of disgust modulated by attention allocation. Results are interpreted in terms of different neural mechanisms for the perception of fear and disgust and related to the functional significance of these two emotions for the survival of the organism.
Thursday, February 21, 2008
ARTICLE UPDATE - Emotional scenes in peripheral vision: Selective orienting and gist processing, but not content identification.
Calvo MG, Nummenmaa L, Hyönä J.
Emotion, 8, 68-80
Emotional-neutral pairs of visual scenes were presented peripherally (with their inner edges 5.2 degrees away from fixation) as primes for 150 to 900 ms, followed by a centrally presented recognition probe scene, which was either identical in specific content to one of the primes or related in general content and affective valence. Results indicated that (a) if no foveal fixations on the primes were allowed, the false alarm rate for emotional probes was increased; (b) hit rate and sensitivity (A') were higher for emotional than for neutral probes only when a fixation was possible on only one prime; and (c) emotional scenes were more likely to attract the first fixation than neutral scenes. It is concluded that the specific content of emotional or neutral scenes is not processed in peripheral vision. Nevertheless, a coarse impression of emotional scenes may be extracted, which then leads to selective attentional orienting or--in the absence of overt attention--causes false alarms for related probes.
Emotion, 8, 68-80
Emotional-neutral pairs of visual scenes were presented peripherally (with their inner edges 5.2 degrees away from fixation) as primes for 150 to 900 ms, followed by a centrally presented recognition probe scene, which was either identical in specific content to one of the primes or related in general content and affective valence. Results indicated that (a) if no foveal fixations on the primes were allowed, the false alarm rate for emotional probes was increased; (b) hit rate and sensitivity (A') were higher for emotional than for neutral probes only when a fixation was possible on only one prime; and (c) emotional scenes were more likely to attract the first fixation than neutral scenes. It is concluded that the specific content of emotional or neutral scenes is not processed in peripheral vision. Nevertheless, a coarse impression of emotional scenes may be extracted, which then leads to selective attentional orienting or--in the absence of overt attention--causes false alarms for related probes.
ARTICLE UPDATE - Affective learning increases sensitivity to graded emotional faces.
Lim SL, Pessoa L.
Emotion, 8, 96-103
How does the affective significance of emotional faces affect perceptual decisions? We manipulated affective significance by pairing 100% fearful faces with aversive electrical stimulation and hypothesized that increasing the significance of a stimulus via its prior history would lead to enhanced processing. After fear conditioning, participants viewed graded emotional faces that ranged from neutral to fearful. Faces were shown either in a color that was previously paired with shock or a color not paired with shock during conditioning. Increases in the frequency of "fearful" responses for faces shown in the shock-paired color were most robust for faces at intermediate intensity levels (40-60% fearful). Psychometric fits to the data revealed significant increased sensitivity for shock-paired relative to unpaired faces. Thus, despite identical physical features for shock-paired and unpaired stimuli (aside from the color, which was counterbalanced), more frequent (and faster) "fearful" responses were made when participants viewed affectively significant stimuli.
Emotion, 8, 96-103
How does the affective significance of emotional faces affect perceptual decisions? We manipulated affective significance by pairing 100% fearful faces with aversive electrical stimulation and hypothesized that increasing the significance of a stimulus via its prior history would lead to enhanced processing. After fear conditioning, participants viewed graded emotional faces that ranged from neutral to fearful. Faces were shown either in a color that was previously paired with shock or a color not paired with shock during conditioning. Increases in the frequency of "fearful" responses for faces shown in the shock-paired color were most robust for faces at intermediate intensity levels (40-60% fearful). Psychometric fits to the data revealed significant increased sensitivity for shock-paired relative to unpaired faces. Thus, despite identical physical features for shock-paired and unpaired stimuli (aside from the color, which was counterbalanced), more frequent (and faster) "fearful" responses were made when participants viewed affectively significant stimuli.
ARTICLE UPDATE - Affective flexibility: evaluative processing goals shape amygdala activity.
Cunningham WA, Van Bavel JJ, Johnsen IR.
Psychological Science, 19, 152-160
Although early research implicated the amygdala in automatic processing of negative information, more recent research suggests that it plays a more general role in processing the motivational relevance of various stimuli, suggesting that the relation between valence and amygdala activation may depend on contextual goals. This study provides experimental evidence that the relation between valence and amygdala activity is dynamically modulated by evaluative goals. During functional magnetic resonance imaging, participants evaluated the positive, negative, or overall (positive plus negative) aspects of famous people. When participants were providing overall evaluations, both positive and negative names were associated with amygdala activation. When they were evaluating positivity, positive names were associated with amygdala activity, and when they were evaluating negativity, negative names were associated with amygdala activity. Evidence for a negativity bias was found; modulation was more pronounced for positive than for negative information. These data suggest that the amygdala flexibly processes motivationally relevant evaluative information in accordance with current processing goals, but processes negative information less flexibly than positive information.
Psychological Science, 19, 152-160
Although early research implicated the amygdala in automatic processing of negative information, more recent research suggests that it plays a more general role in processing the motivational relevance of various stimuli, suggesting that the relation between valence and amygdala activation may depend on contextual goals. This study provides experimental evidence that the relation between valence and amygdala activity is dynamically modulated by evaluative goals. During functional magnetic resonance imaging, participants evaluated the positive, negative, or overall (positive plus negative) aspects of famous people. When participants were providing overall evaluations, both positive and negative names were associated with amygdala activation. When they were evaluating positivity, positive names were associated with amygdala activity, and when they were evaluating negativity, negative names were associated with amygdala activity. Evidence for a negativity bias was found; modulation was more pronounced for positive than for negative information. These data suggest that the amygdala flexibly processes motivationally relevant evaluative information in accordance with current processing goals, but processes negative information less flexibly than positive information.
ARTICLE UPDATE - Neural activities for negative priming with affective stimuli: An fMRI study.
Leung KK, Lee TM, Xiao Z, Wang Z, Zhang JX, Yip PS, Li LS.
Neuropsychology, in press
Negative priming refers to the slowing down in reaction time to a stimulus that is either the same as, or related to, a distracting stimulus that has been ignored by people in an immediately preceding trial. It can be used as an index to examine the extent to which people are able to disengage attention or even ignore a distracting stimulus. In this fMRI study, with healthy Mandarin-speaking Chinese participants, we replicated the basic negative priming effect with affectively neutral words. Negative priming was associated with increased activities in the anterior cingulate cortex and the insula, a result that supports the inhibition account of negative priming. We observed that the negative priming effect was attenuated by negative affective words, relative to neutral words, suggesting that subjects' inhibition of negative information was compromised. Such attenuation of negative priming by negative affective words was associated with increased activities in the ventrolateral and medial frontal regions, the hippocampus, and supplementary motor areas. These observations indicate that specific frontal and subcortical regions take part in attention orientation toward negative-affect information.
Neuropsychology, in press
Negative priming refers to the slowing down in reaction time to a stimulus that is either the same as, or related to, a distracting stimulus that has been ignored by people in an immediately preceding trial. It can be used as an index to examine the extent to which people are able to disengage attention or even ignore a distracting stimulus. In this fMRI study, with healthy Mandarin-speaking Chinese participants, we replicated the basic negative priming effect with affectively neutral words. Negative priming was associated with increased activities in the anterior cingulate cortex and the insula, a result that supports the inhibition account of negative priming. We observed that the negative priming effect was attenuated by negative affective words, relative to neutral words, suggesting that subjects' inhibition of negative information was compromised. Such attenuation of negative priming by negative affective words was associated with increased activities in the ventrolateral and medial frontal regions, the hippocampus, and supplementary motor areas. These observations indicate that specific frontal and subcortical regions take part in attention orientation toward negative-affect information.
ARTICLE UPDATE - The pupil as a measure of emotional arousal and autonomic activation.
Bradley MM, Miccoli L, Escrig MA, Lang PJ.
Psychophysiology, in press
Pupil diameter was monitored during picture viewing to assess effects of hedonic valence and emotional arousal on pupillary responses. Autonomic activity (heart rate and skin conductance) was concurrently measured to determine whether pupillary changes are mediated by parasympathetic or sympathetic activation. Following an initial light reflex, pupillary changes were larger when viewing emotionally arousing pictures, regardless of whether these were pleasant or unpleasant. Pupillary changes during picture viewing covaried with skin conductance change, supporting the interpretation that sympathetic nervous system activity modulates these changes in the context of affective picture viewing. Taken together, the data provide strong support for the hypothesis that the pupil's response during affective picture viewing reflects emotional arousal associated with increased sympathetic activity.
Psychophysiology, in press
Pupil diameter was monitored during picture viewing to assess effects of hedonic valence and emotional arousal on pupillary responses. Autonomic activity (heart rate and skin conductance) was concurrently measured to determine whether pupillary changes are mediated by parasympathetic or sympathetic activation. Following an initial light reflex, pupillary changes were larger when viewing emotionally arousing pictures, regardless of whether these were pleasant or unpleasant. Pupillary changes during picture viewing covaried with skin conductance change, supporting the interpretation that sympathetic nervous system activity modulates these changes in the context of affective picture viewing. Taken together, the data provide strong support for the hypothesis that the pupil's response during affective picture viewing reflects emotional arousal associated with increased sympathetic activity.
ARTICLE UPDATE - The use of aftereffects in the study of relationships among emotion categories.
Rutherford MD, Chattha HM, Krysko KM.
Journal of Experimental Psychology: Human Perception & Performance, 34, 27-40
The perception of visual aftereffects has been long recognized, and these aftereffects reveal a relationship between perceptual categories. Thus, emotional expression aftereffects can be used to map the categorical relationships among emotion percepts. One might expect a symmetric relationship among categories, but an evolutionary, functional perspective predicts an asymmetrical relationship. In a series of 7 experiments, the authors tested these predictions. Participants fixated on a facial expression, then briefly viewed a neutral expression, then reported the apparent facial expression of the 2nd image. Experiment 1 revealed that happy and sad are opposites of one another; each evokes the other as an aftereffect. The 2nd and 3rd experiments reveal that fixating on any negative emotions yields an aftereffect perceived as happy, whereas fixating on a happy face results in the perception of a sad aftereffect. This suggests an asymmetric relationship among categories. Experiments 4-7 explored the mechanism driving this effect. The evolutionary and functional explanations for the category asymmetry are discussed.
Journal of Experimental Psychology: Human Perception & Performance, 34, 27-40
The perception of visual aftereffects has been long recognized, and these aftereffects reveal a relationship between perceptual categories. Thus, emotional expression aftereffects can be used to map the categorical relationships among emotion percepts. One might expect a symmetric relationship among categories, but an evolutionary, functional perspective predicts an asymmetrical relationship. In a series of 7 experiments, the authors tested these predictions. Participants fixated on a facial expression, then briefly viewed a neutral expression, then reported the apparent facial expression of the 2nd image. Experiment 1 revealed that happy and sad are opposites of one another; each evokes the other as an aftereffect. The 2nd and 3rd experiments reveal that fixating on any negative emotions yields an aftereffect perceived as happy, whereas fixating on a happy face results in the perception of a sad aftereffect. This suggests an asymmetric relationship among categories. Experiments 4-7 explored the mechanism driving this effect. The evolutionary and functional explanations for the category asymmetry are discussed.
ARTICLE UPDATE - The emotional memory effect: differential processing or item distinctiveness?
Schmidt SR, Saari B.
Memory & Cognition, 35, 1905-1916
A color-naming task was followed by incidental free recall to investigate how emotional words affect attention and memory. We compared taboo, nonthreatening negative-affect, and neutral words across three experiments. As compared with neutral words, taboo words led to longer color-naming times and better memory in both within- and between-subjects designs. Color naming of negative-emotion nontaboo words was slower than color naming of neutral words only during block presentation and at relatively short interstimulus intervals (ISIs). The nontaboo emotion words were remembered better than neutral words following blocked and random presentation and at both long and short ISIs, but only in mixed-list designs. Our results support multifactor theories of the effects of emotion on attention and memory. As compared with neutral words, threatening stimuli received increased attention, poststimulus elaboration, and benefit from item distinctiveness, whereas nonthreatening emotional stimuli benefited only from increased item distinctiveness.
Memory & Cognition, 35, 1905-1916
A color-naming task was followed by incidental free recall to investigate how emotional words affect attention and memory. We compared taboo, nonthreatening negative-affect, and neutral words across three experiments. As compared with neutral words, taboo words led to longer color-naming times and better memory in both within- and between-subjects designs. Color naming of negative-emotion nontaboo words was slower than color naming of neutral words only during block presentation and at relatively short interstimulus intervals (ISIs). The nontaboo emotion words were remembered better than neutral words following blocked and random presentation and at both long and short ISIs, but only in mixed-list designs. Our results support multifactor theories of the effects of emotion on attention and memory. As compared with neutral words, threatening stimuli received increased attention, poststimulus elaboration, and benefit from item distinctiveness, whereas nonthreatening emotional stimuli benefited only from increased item distinctiveness.
ARTICLE UPDATE - The automaticity of emotion recognition.
Tracy JL, Robins RW.
Emotion, 8, 81-95
Evolutionary accounts of emotion typically assume that humans evolved to quickly and efficiently recognize emotion expressions because these expressions convey fitness-enhancing messages. The present research tested this assumption in 2 studies. Specifically, the authors examined (a) how quickly perceivers could recognize expressions of anger, contempt, disgust, embarrassment, fear, happiness, pride, sadness, shame, and surprise; (b) whether accuracy is improved when perceivers deliberate about each expression's meaning (vs. respond as quickly as possible); and (c) whether accurate recognition can occur under cognitive load. Across both studies, perceivers quickly and efficiently (i.e., under cognitive load) recognized most emotion expressions, including the self-conscious emotions of pride, embarrassment, and shame. Deliberation improved accuracy in some cases, but these improvements were relatively small. Discussion focuses on the implications of these findings for the cognitive processes underlying emotion recognition.
Emotion, 8, 81-95
Evolutionary accounts of emotion typically assume that humans evolved to quickly and efficiently recognize emotion expressions because these expressions convey fitness-enhancing messages. The present research tested this assumption in 2 studies. Specifically, the authors examined (a) how quickly perceivers could recognize expressions of anger, contempt, disgust, embarrassment, fear, happiness, pride, sadness, shame, and surprise; (b) whether accuracy is improved when perceivers deliberate about each expression's meaning (vs. respond as quickly as possible); and (c) whether accurate recognition can occur under cognitive load. Across both studies, perceivers quickly and efficiently (i.e., under cognitive load) recognized most emotion expressions, including the self-conscious emotions of pride, embarrassment, and shame. Deliberation improved accuracy in some cases, but these improvements were relatively small. Discussion focuses on the implications of these findings for the cognitive processes underlying emotion recognition.
ARTICLE UPDATE - Modulations of the electrophysiological response to pleasant stimuli by cognitive reappraisal.
Krompinger JW, Moser JS, Simons RF.
Emotion, 8, 132-137
Research indicates that individuals successfully regulate their emotions to negatively valenced stimuli using cognitive, antecedent-focused techniques (cf. Gross, 1998). Event-related potential studies have elucidated candidate neural correlates, particularly modulations of the late positive potential (LPP) to index emotion regulation processes. The present study attempted to extend prior demonstrations of emotion regulation effects on the LPP to the domain of positively valenced stimuli. Twenty participants completed a blocked emotion regulation task: The first block consisted of passively viewing pleasant and neutral pictures, whereas the last two blocks consisted of either decreasing or increasing emotions to pleasant pictures. Results replicated our previous findings with negatively valenced stimuli, demonstrating an attenuated LPP during decrease instructions and no effect of increase instructions. Modulation of the ERP as a function of instruction was most prominent during the positive-going slow-wave time window of the LPP, indicating that attentional resources allocated to the perceptual processing of pleasant stimuli may be manipulated using emotion regulation strategies.
Emotion, 8, 132-137
Research indicates that individuals successfully regulate their emotions to negatively valenced stimuli using cognitive, antecedent-focused techniques (cf. Gross, 1998). Event-related potential studies have elucidated candidate neural correlates, particularly modulations of the late positive potential (LPP) to index emotion regulation processes. The present study attempted to extend prior demonstrations of emotion regulation effects on the LPP to the domain of positively valenced stimuli. Twenty participants completed a blocked emotion regulation task: The first block consisted of passively viewing pleasant and neutral pictures, whereas the last two blocks consisted of either decreasing or increasing emotions to pleasant pictures. Results replicated our previous findings with negatively valenced stimuli, demonstrating an attenuated LPP during decrease instructions and no effect of increase instructions. Modulation of the ERP as a function of instruction was most prominent during the positive-going slow-wave time window of the LPP, indicating that attentional resources allocated to the perceptual processing of pleasant stimuli may be manipulated using emotion regulation strategies.
Tuesday, February 12, 2008
ARTICLE UPDATE - Learning affective values for faces is expressed in amygdala and fusiform gyrus
Predrag Petrovic, Raffael Kalisch, Mathias Pessiglione, Tania Singer and Raymond J. Dolan
Social Cognitive and Affective Neuroscience, in press
To monitor the environment for social threat humans must build affective evaluations of others. These evaluations are malleable and to a high degree shaped by responses engendered by specific social encounters. The precise neuronal mechanism by which these evaluations are constructed is poorly understood. We tested a hypothesis that conjoint activity in amygdala and fusiform gyrus would correlate with acquisition of social stimulus value. We tested this using a reinforcement learning algorithm, Q-learning, that assigned values to faces as a function of a history of pairing, or not pairing, with aversive shocks. Behaviourally, we observed a correlation between conditioning induced changes in skin conductance response (SCR) and subjective ratings for likeability of faces. Activity in both amygdala and fusiform gyrus (FG) correlated with the output of the reinforcement learning algorithm parameterized by these ratings. In amygdala, this effect was greater for averted than direct gaze faces. Furthermore, learning-related activity change in these regions correlated with SCR and subjective ratings. We conclude that amygdala and fusiform encode affective value in a manner that closely approximates a standard computational solution to learning.
Social Cognitive and Affective Neuroscience, in press
To monitor the environment for social threat humans must build affective evaluations of others. These evaluations are malleable and to a high degree shaped by responses engendered by specific social encounters. The precise neuronal mechanism by which these evaluations are constructed is poorly understood. We tested a hypothesis that conjoint activity in amygdala and fusiform gyrus would correlate with acquisition of social stimulus value. We tested this using a reinforcement learning algorithm, Q-learning, that assigned values to faces as a function of a history of pairing, or not pairing, with aversive shocks. Behaviourally, we observed a correlation between conditioning induced changes in skin conductance response (SCR) and subjective ratings for likeability of faces. Activity in both amygdala and fusiform gyrus (FG) correlated with the output of the reinforcement learning algorithm parameterized by these ratings. In amygdala, this effect was greater for averted than direct gaze faces. Furthermore, learning-related activity change in these regions correlated with SCR and subjective ratings. We conclude that amygdala and fusiform encode affective value in a manner that closely approximates a standard computational solution to learning.
ARTICLE UPDATE - Electrophysiological correlates of spatial orienting towards angry faces: A source localization study
Diane L. Santesso, Alicia E. Meuret, Stefan G. Hofmann, Erik M. Mueller, Kyle G. Ratner, Etienne B. Roesch and Diego A. Pizzagalli
Neuropsychologia, in press
The goal of this study was to examine behavioral and electrophysiological correlates of involuntary orienting toward rapidly presented angry faces in non-anxious, healthy adults using a dot-probe task in conjunction with high-density event-related potentials and a distributed source localization technique. Consistent with previous studies, participants showed hypervigilance toward angry faces, as indexed by facilitated response time for validly cued probes following angry faces and an enhanced P1 component. An opposite pattern was found for happy faces suggesting that attention was directed toward the relatively more threatening stimuli within the visual field (neutral faces). Source localization of the P1 effect for angry faces indicated increased activity within the anterior cingulate cortex, possibly reflecting conflict experienced during invalidly cued trials. No modulation of the early C1 component was found for affect or spatial attention. Furthermore, the face-sensitive N170 was not modulated by emotional expression. Results suggest that the earliest modulation of spatial attention by face stimuli is manifested in the P1 component, and provide insights about mechanisms underlying attentional orienting toward cues of threat and social disapproval.
Neuropsychologia, in press
The goal of this study was to examine behavioral and electrophysiological correlates of involuntary orienting toward rapidly presented angry faces in non-anxious, healthy adults using a dot-probe task in conjunction with high-density event-related potentials and a distributed source localization technique. Consistent with previous studies, participants showed hypervigilance toward angry faces, as indexed by facilitated response time for validly cued probes following angry faces and an enhanced P1 component. An opposite pattern was found for happy faces suggesting that attention was directed toward the relatively more threatening stimuli within the visual field (neutral faces). Source localization of the P1 effect for angry faces indicated increased activity within the anterior cingulate cortex, possibly reflecting conflict experienced during invalidly cued trials. No modulation of the early C1 component was found for affect or spatial attention. Furthermore, the face-sensitive N170 was not modulated by emotional expression. Results suggest that the earliest modulation of spatial attention by face stimuli is manifested in the P1 component, and provide insights about mechanisms underlying attentional orienting toward cues of threat and social disapproval.
Tuesday, February 05, 2008
ARTICLE UPDATE - Does it look painful or disgusting? Ask your parietal and cingulate cortex.
Benuzzi F, Lui F, Duzzi D, Nichelli PF, Porro CA.
The Journal of Neuroscience, 28, 923-931
Looking at still images of body parts in situations that are likely to cause pain has been shown to be associated with activation in some brain areas involved in pain processing. Because pain involves both sensory components and negative affect, it is of interest to explore whether the visually evoked representations of pain and of other negative emotions overlap. By means of event-related functional magnetic resonance imaging, here we compare the brain areas recruited, in female volunteers, by the observation of painful, disgusting, or neutral stimuli delivered to one hand or foot. Several cortical foci were activated by the observation of both painful and disgusting video clips, including portions of the medial prefrontal cortex, anterior, mid-, and posterior cingulate cortex, left posterior insula, and right parietal operculum. Signal changes in perigenual cingulate and left anterior insula were linearly related to the perceived unpleasantness, when the individual differences in susceptibility to aversive stimuli were taken into account. Painful scenes selectively induced activation of left parietal foci, including the parietal operculum, the postcentral gyrus, and adjacent portions of the posterior parietal cortex. In contrast, brain foci specific for disgusting scenes were found in the posterior cingulate cortex. These data show both similarities and differences between the brain patterns of activity related to the observation of noxious or disgusting stimuli. Namely, the parietal cortex appears to be particularly involved in the recognition of noxious environmental stimuli, suggesting that areas involved in sensory aspects of pain are specifically triggered by observing noxious events.
The Journal of Neuroscience, 28, 923-931
Looking at still images of body parts in situations that are likely to cause pain has been shown to be associated with activation in some brain areas involved in pain processing. Because pain involves both sensory components and negative affect, it is of interest to explore whether the visually evoked representations of pain and of other negative emotions overlap. By means of event-related functional magnetic resonance imaging, here we compare the brain areas recruited, in female volunteers, by the observation of painful, disgusting, or neutral stimuli delivered to one hand or foot. Several cortical foci were activated by the observation of both painful and disgusting video clips, including portions of the medial prefrontal cortex, anterior, mid-, and posterior cingulate cortex, left posterior insula, and right parietal operculum. Signal changes in perigenual cingulate and left anterior insula were linearly related to the perceived unpleasantness, when the individual differences in susceptibility to aversive stimuli were taken into account. Painful scenes selectively induced activation of left parietal foci, including the parietal operculum, the postcentral gyrus, and adjacent portions of the posterior parietal cortex. In contrast, brain foci specific for disgusting scenes were found in the posterior cingulate cortex. These data show both similarities and differences between the brain patterns of activity related to the observation of noxious or disgusting stimuli. Namely, the parietal cortex appears to be particularly involved in the recognition of noxious environmental stimuli, suggesting that areas involved in sensory aspects of pain are specifically triggered by observing noxious events.
ARTICLE UPDATE - The cognitive consequences of emotion regulation: An ERP investigation.
Deveney CM, Pizzagalli DA.
Psychophysiology, in press
Increasing evidence suggests that emotion regulation (ER) strategies modulate encoding of information presented during regulation; however, no studies have assessed the impact of cognitive reappraisal ER strategies on the processing of stimuli presented after the ER period. Participants in the present study regulated emotions to unpleasant pictures and then judged whether a word was negative or neutral. Electromyographic measures (corrugator supercilli) confirmed that individuals increased and decreased negative affect according to ER condition. Event-related potential analyses revealed smallest N400 amplitudes to negative and neutral words presented after decreasing unpleasant emotions and smallest P300 amplitudes to words presented after increasing unpleasant emotions whereas reaction time data failed to show ER modulations. Results are discussed in the context of the developing ER literature, as well as theories of emotional incongruity (N400) and resource allocation (P300).
Psychophysiology, in press
Increasing evidence suggests that emotion regulation (ER) strategies modulate encoding of information presented during regulation; however, no studies have assessed the impact of cognitive reappraisal ER strategies on the processing of stimuli presented after the ER period. Participants in the present study regulated emotions to unpleasant pictures and then judged whether a word was negative or neutral. Electromyographic measures (corrugator supercilli) confirmed that individuals increased and decreased negative affect according to ER condition. Event-related potential analyses revealed smallest N400 amplitudes to negative and neutral words presented after decreasing unpleasant emotions and smallest P300 amplitudes to words presented after increasing unpleasant emotions whereas reaction time data failed to show ER modulations. Results are discussed in the context of the developing ER literature, as well as theories of emotional incongruity (N400) and resource allocation (P300).
ARTICLE UPDATE - Fearful faces selectively increase corticospinal motor tract excitability: A transcranial magnetic stimulation study.
Schutter DJ, Hofman D, Van Honk J.
Psychophysiology, in press
Fearful facial expressions are danger signals that rapidly trigger a cascade of neurobiological processes defensibly associated with action preparation. However, direct evidence for the activating effects of fearful facial expressions on the motor system is absent. The current transcranial magnetic stimulation (TMS) study investigated whether fearful facial expressions selectively increase corticospinal motor tract (CST) excitability. Focal TMS was applied over the left primary motor cortex during the exposure of fearful, happy, and neutral facial expressions in 12 healthy right-handed volunteers. Changes in CST excitability using the motor evoked potential (MEP) were recorded. Results showed significant selective increases in MEP to fearful facial expressions. These findings provide the first direct evidence for selective increases in CST excitability to threat and contribute to evolutionary views on emotion and action preparedness.
Psychophysiology, in press
Fearful facial expressions are danger signals that rapidly trigger a cascade of neurobiological processes defensibly associated with action preparation. However, direct evidence for the activating effects of fearful facial expressions on the motor system is absent. The current transcranial magnetic stimulation (TMS) study investigated whether fearful facial expressions selectively increase corticospinal motor tract (CST) excitability. Focal TMS was applied over the left primary motor cortex during the exposure of fearful, happy, and neutral facial expressions in 12 healthy right-handed volunteers. Changes in CST excitability using the motor evoked potential (MEP) were recorded. Results showed significant selective increases in MEP to fearful facial expressions. These findings provide the first direct evidence for selective increases in CST excitability to threat and contribute to evolutionary views on emotion and action preparedness.
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