Furl N, van Rijsbergen NJ, Kiebel SJ, Friston KJ, Treves A, Dolan RJ.
Cerebral Cortex, in press
People track facial expression dynamics with ease to accurately perceive distinct emotions. Although the superior temporal sulcus (STS) appears to possess mechanisms for perceiving changeable facial attributes such as expressions, the nature of the underlying neural computations is not known. Motivated by novel theoretical accounts, we hypothesized that visual and motor areas represent expressions as anticipated motion trajectories. Using magnetoencephalography, we show predictable transitions between fearful and neutral expressions (compared with scrambled and static presentations) heighten activity in visual cortex as quickly as 165 ms poststimulus onset and later (237 ms) engage fusiform gyrus, STS and premotor areas. Consistent with proposed models of biological motion representation, we suggest that visual areas predictively represent coherent facial trajectories. We show that such representations bias emotion perception of subsequent static faces, suggesting that facial movements elicit predictions that bias perception. Our findings reveal critical processes evoked in the perception of dynamic stimuli such as facial expressions, which can endow perception with temporal continuity.
Monday, July 27, 2009
ARTICLE UPDATE - Event-related potentials to task-irrelevant changes in facial expressions.
Astikainen P, Hietanen JK.
Behavioural Brain Function, in press
ABSTRACT: BACKGROUND: Numerous previous experiments have used oddball paradigm to study change detection. This paradigm is applied here to study change detection of facial expressions in a context which demands abstraction of the emotional expression-related facial features among other changing facial features. METHODS: Event-related potentials (ERPs) were recorded in adult humans engaged in a demanding auditory task. In an oddball paradigm, repeated pictures of faces with a neutral expression ('standard', p = .9) were rarely replaced by pictures with a fearful ('fearful deviant', p = .05) or happy ('happy deviant', p = .05) expression. Importantly, facial identities changed from picture to picture. Thus, change detection required abstraction of facial expression from changes in several low-level visual features. RESULTS: ERPs to both types of deviants differed from those to standards. At occipital electrode sites, ERPs to deviants were more negative than ERPs to standards at 150-180 ms and 280-320 ms post-stimulus. A positive shift to deviants at fronto-central electrode sites in the analysis window of 130-170 ms post-stimulus was also found. Waveform analysis computed as point-wise comparisons between the amplitudes elicited by standards and deviants revealed that the occipital negativity emerged earlier to happy deviants than to fearful deviants (after 140 ms versus 160 ms post-stimulus, respectively). In turn, the anterior positivity was earlier to fearful deviants than to happy deviants (110 ms versus 120 ms post-stimulus, respectively). CONCLUSION: ERP amplitude differences between emotional and neutral expressions indicated pre-attentive change detection of facial expressions among neutral faces. The posterior negative difference at 150-180 ms latency resembled visual mismatch negativity (vMMN) - an index of pre-attentive change detection previously studied only to changes in low-level features in vision. The positive anterior difference in ERPs at 130-170 ms post-stimulus probably indexed pre-attentive attention orienting towards emotionally significant changes. The results show that the human brain can abstract emotion related features of faces while engaged to a demanding task in another sensory modality.
Behavioural Brain Function, in press
ABSTRACT: BACKGROUND: Numerous previous experiments have used oddball paradigm to study change detection. This paradigm is applied here to study change detection of facial expressions in a context which demands abstraction of the emotional expression-related facial features among other changing facial features. METHODS: Event-related potentials (ERPs) were recorded in adult humans engaged in a demanding auditory task. In an oddball paradigm, repeated pictures of faces with a neutral expression ('standard', p = .9) were rarely replaced by pictures with a fearful ('fearful deviant', p = .05) or happy ('happy deviant', p = .05) expression. Importantly, facial identities changed from picture to picture. Thus, change detection required abstraction of facial expression from changes in several low-level visual features. RESULTS: ERPs to both types of deviants differed from those to standards. At occipital electrode sites, ERPs to deviants were more negative than ERPs to standards at 150-180 ms and 280-320 ms post-stimulus. A positive shift to deviants at fronto-central electrode sites in the analysis window of 130-170 ms post-stimulus was also found. Waveform analysis computed as point-wise comparisons between the amplitudes elicited by standards and deviants revealed that the occipital negativity emerged earlier to happy deviants than to fearful deviants (after 140 ms versus 160 ms post-stimulus, respectively). In turn, the anterior positivity was earlier to fearful deviants than to happy deviants (110 ms versus 120 ms post-stimulus, respectively). CONCLUSION: ERP amplitude differences between emotional and neutral expressions indicated pre-attentive change detection of facial expressions among neutral faces. The posterior negative difference at 150-180 ms latency resembled visual mismatch negativity (vMMN) - an index of pre-attentive change detection previously studied only to changes in low-level features in vision. The positive anterior difference in ERPs at 130-170 ms post-stimulus probably indexed pre-attentive attention orienting towards emotionally significant changes. The results show that the human brain can abstract emotion related features of faces while engaged to a demanding task in another sensory modality.
ARTICLE UPDATE - Evidence for mirror systems in emotions.
Bastiaansen JA, Thioux M, Keysers C.
Phil. Trans. R. Soc. B, 364, 2391 - 2404
Why do we feel tears well up when we see a loved one cry? Why do we wince when we see other people hurt themselves? This review addresses these questions from the perspective of embodied simulation: observing the actions and tactile sensations of others activates premotor, posterior parietal and somatosensory regions in the brain of the observer which are also active when performing similar movements and feeling similar sensations. We will show that seeing the emotions of others also recruits regions involved in experiencing similar emotions, although there does not seem to be a reliable mapping of particular emotions onto particular brain regions. Instead, emotion simulation seems to involve a mosaic of affective, motor and somatosensory components. The relative contributions of these components to a particular emotion and their interrelationship are largely unknown, although recent experimental evidence suggests that motor simulation may be a trigger for the simulation of associated feeling states. This mosaic of simulations may be necessary for generating the compelling insights we have into the feelings of others. Through their integration with, and modulation by, higher cognitive functions, they could be at the core of important social functions, including empathy, mind reading and social learning.
Phil. Trans. R. Soc. B, 364, 2391 - 2404
Why do we feel tears well up when we see a loved one cry? Why do we wince when we see other people hurt themselves? This review addresses these questions from the perspective of embodied simulation: observing the actions and tactile sensations of others activates premotor, posterior parietal and somatosensory regions in the brain of the observer which are also active when performing similar movements and feeling similar sensations. We will show that seeing the emotions of others also recruits regions involved in experiencing similar emotions, although there does not seem to be a reliable mapping of particular emotions onto particular brain regions. Instead, emotion simulation seems to involve a mosaic of affective, motor and somatosensory components. The relative contributions of these components to a particular emotion and their interrelationship are largely unknown, although recent experimental evidence suggests that motor simulation may be a trigger for the simulation of associated feeling states. This mosaic of simulations may be necessary for generating the compelling insights we have into the feelings of others. Through their integration with, and modulation by, higher cognitive functions, they could be at the core of important social functions, including empathy, mind reading and social learning.
ARTICLE UPDATE - N400 during recognition of voice identity and vocal affect.
Toivonen M, Rämä P.
Neuroreport, in press
This study explored whether neural processes underlying recognition of speaker's voice and vocal affect are dissociable by measuring event-related potentials. Individuals were asked to identify a target emotion, or a target (congruent) speaker among distracter (incongruent) emotions or speakers. The incongruent condition elicited more negative N400-like response during both tasks, but the distributions differed. Although the response in speaker task was more pronounced at frontal than posterior recording sites, in emotion task, the opposite was true. Furthermore, the response was more pronounced at the left recording sites for speaker task and more pronounced at the right recording sites for emotion task. The present results suggest that neural substrates involved in processing speaker identity are different from those responsible for processing vocal affect.
Neuroreport, in press
This study explored whether neural processes underlying recognition of speaker's voice and vocal affect are dissociable by measuring event-related potentials. Individuals were asked to identify a target emotion, or a target (congruent) speaker among distracter (incongruent) emotions or speakers. The incongruent condition elicited more negative N400-like response during both tasks, but the distributions differed. Although the response in speaker task was more pronounced at frontal than posterior recording sites, in emotion task, the opposite was true. Furthermore, the response was more pronounced at the left recording sites for speaker task and more pronounced at the right recording sites for emotion task. The present results suggest that neural substrates involved in processing speaker identity are different from those responsible for processing vocal affect.
Monday, July 20, 2009
ARTICLE UPDATE - Emotion words, regardless of polarity, have a processing advantage over neutral words.
Kousta ST, Vinson DP, Vigliocco G.
Cognition, in press
Despite increasing interest in the interface between emotion and cognition, the role of emotion in cognitive tasks is unclear. According to one hypothesis, negative valence is more relevant for survival and is associated with a general slowdown of the processing of stimuli, due to a defense mechanism that freezes activity in the face of threat. According to a different hypothesis which does not posit a privileged role for the aversive system, valence, regardless of polarity, facilitates processing due to the relevance of both negative and positive stimuli for survival and for the attainment of goals. Here, we present evidence that emotional valence has an overall facilitatory role in the processing of verbal stimuli, providing support for the latter hypothesis. We found no asymmetry between negative and positive words and suggest that previous findings of such an asymmetry can be attributed to failure to control for a number of critical lexical variables and to a sampling bias.
Cognition, in press
Despite increasing interest in the interface between emotion and cognition, the role of emotion in cognitive tasks is unclear. According to one hypothesis, negative valence is more relevant for survival and is associated with a general slowdown of the processing of stimuli, due to a defense mechanism that freezes activity in the face of threat. According to a different hypothesis which does not posit a privileged role for the aversive system, valence, regardless of polarity, facilitates processing due to the relevance of both negative and positive stimuli for survival and for the attainment of goals. Here, we present evidence that emotional valence has an overall facilitatory role in the processing of verbal stimuli, providing support for the latter hypothesis. We found no asymmetry between negative and positive words and suggest that previous findings of such an asymmetry can be attributed to failure to control for a number of critical lexical variables and to a sampling bias.
ARTICLE UPDATE - Amygdala activation predicts gaze toward fearful eyes.
Gamer M, Büchel C.
The Journal of Neuroscience, 29, 9123-9126
The human amygdala can be robustly activated by presenting fearful faces, and it has been speculated that this activation has functional relevance for redirecting the gaze toward the eye region. To clarify this relationship between amygdala activation and gaze-orienting behavior, functional magnetic resonance imaging data and eye movements were simultaneously acquired in the current study during the evaluation of facial expressions. Fearful, angry, happy, and neutral faces were briefly presented to healthy volunteers in an event-related manner. We controlled for the initial fixation by unpredictably shifting the faces downward or upward on each trial, such that the eyes or the mouth were presented at fixation. Across emotional expressions, participants showed a bias to shift their gaze toward the eyes, but the magnitude of this effect followed the distribution of diagnostically relevant regions in the face. Amygdala activity was specifically enhanced for fearful faces with the mouth aligned to fixation, and this differential activation predicted gazing behavior preferentially targeting the eye region. These results reveal a direct role of the amygdala in reflexive gaze initiation toward fearfully widened eyes. They mirror deficits observed in patients with amygdala lesions and open a window for future studies on patients with autism spectrum disorder, in which deficits in emotion recognition, probably related to atypical gaze patterns and abnormal amygdala activation, have been observed.
The Journal of Neuroscience, 29, 9123-9126
The human amygdala can be robustly activated by presenting fearful faces, and it has been speculated that this activation has functional relevance for redirecting the gaze toward the eye region. To clarify this relationship between amygdala activation and gaze-orienting behavior, functional magnetic resonance imaging data and eye movements were simultaneously acquired in the current study during the evaluation of facial expressions. Fearful, angry, happy, and neutral faces were briefly presented to healthy volunteers in an event-related manner. We controlled for the initial fixation by unpredictably shifting the faces downward or upward on each trial, such that the eyes or the mouth were presented at fixation. Across emotional expressions, participants showed a bias to shift their gaze toward the eyes, but the magnitude of this effect followed the distribution of diagnostically relevant regions in the face. Amygdala activity was specifically enhanced for fearful faces with the mouth aligned to fixation, and this differential activation predicted gazing behavior preferentially targeting the eye region. These results reveal a direct role of the amygdala in reflexive gaze initiation toward fearfully widened eyes. They mirror deficits observed in patients with amygdala lesions and open a window for future studies on patients with autism spectrum disorder, in which deficits in emotion recognition, probably related to atypical gaze patterns and abnormal amygdala activation, have been observed.
Monday, July 13, 2009
ARTICLE UPDATE - Short-term antidepressant treatment modulates amygdala response to happy faces.
Norbury R, Taylor MJ, Selvaraj S, Murphy SE, Harmer CJ, Cowen PJ.
Psychopharmacology, in press
RATIONALE: We have previously demonstrated that antidepressant medication facilitates the processing of positive affective stimuli in healthy volunteers. These early effects of antidepressants may be an important component in the therapeutic effects of antidepressant treatment in patients with depression and anxiety. OBJECTIVES: Here we used functional magnetic resonance imaging in a double-blind, randomised, placebo-controlled between-groups design to investigate the effects of short-term (7-10 days) treatment with the selective serotonin reuptake inhibitor, citalopram, on the amygdala response to positive and negative facial expressions in healthy volunteers. RESULTS: Citalopram was associated with increased amygdala activation to happy faces relative to placebo control, without changes in levels of mood or anxiety. CONCLUSIONS: These early, direct effects of antidepressant administration on emotional processing are consistent with a cognitive neuropsychological model of antidepressant action.
Psychopharmacology, in press
RATIONALE: We have previously demonstrated that antidepressant medication facilitates the processing of positive affective stimuli in healthy volunteers. These early effects of antidepressants may be an important component in the therapeutic effects of antidepressant treatment in patients with depression and anxiety. OBJECTIVES: Here we used functional magnetic resonance imaging in a double-blind, randomised, placebo-controlled between-groups design to investigate the effects of short-term (7-10 days) treatment with the selective serotonin reuptake inhibitor, citalopram, on the amygdala response to positive and negative facial expressions in healthy volunteers. RESULTS: Citalopram was associated with increased amygdala activation to happy faces relative to placebo control, without changes in levels of mood or anxiety. CONCLUSIONS: These early, direct effects of antidepressant administration on emotional processing are consistent with a cognitive neuropsychological model of antidepressant action.
Monday, July 06, 2009
ARTICLE UPDATE - Human brain responsivity to masked different intensities of fearful eye whites: An ERP study.
Feng W, Luo W, Liao Y, Wang N, Gan T, Luo Y.
Brain Research, in press
Previous studies have shown differential event-related potentials (ERPs) to intensities of fearful facial expressions. There are indications that the eyes may be particularly relevant for the recognition of fearful expressions, even the amount of white sclera exposed above and on sides of the dark pupil could activate the amygdala response. To investigate whether the ERP differences between intensities of fearful expressions are driven by the differential salience of the eyes in the fearful faces, ERPs were measured within a backward masking paradigm, where observers were asked to do a gender decision task with male and female neutral faces. The emotional stimuli used were low-intensity (50%), prototypical (100%), and caricatured (150%) fearful eye whites that were derived from corresponding intensities of fearful faces respectively. Three groups of white squares that have the same pixels as the eye whites were created as control conditions. Analysis of the ERP data showed a linear increase in amplitudes of the parietal-occipital P120 by three intensities of fearful eye whites. These ERP effects were proved sensitive to intensities of negative emotions but not to the simple physical features as the same patterns of differences were not observed on white squares. Larger parietal-occipital P250 amplitudes were observed for caricatured 150% than low-intensity 50% fearful eye-white. It might reflect the subcortical pathway of emotion-specific, fearful processing. The results demonstrate that the human brain is sensitive to intensities of fear, even if just shown intensities of fearful eye-white in the absence of awareness.
Brain Research, in press
Previous studies have shown differential event-related potentials (ERPs) to intensities of fearful facial expressions. There are indications that the eyes may be particularly relevant for the recognition of fearful expressions, even the amount of white sclera exposed above and on sides of the dark pupil could activate the amygdala response. To investigate whether the ERP differences between intensities of fearful expressions are driven by the differential salience of the eyes in the fearful faces, ERPs were measured within a backward masking paradigm, where observers were asked to do a gender decision task with male and female neutral faces. The emotional stimuli used were low-intensity (50%), prototypical (100%), and caricatured (150%) fearful eye whites that were derived from corresponding intensities of fearful faces respectively. Three groups of white squares that have the same pixels as the eye whites were created as control conditions. Analysis of the ERP data showed a linear increase in amplitudes of the parietal-occipital P120 by three intensities of fearful eye whites. These ERP effects were proved sensitive to intensities of negative emotions but not to the simple physical features as the same patterns of differences were not observed on white squares. Larger parietal-occipital P250 amplitudes were observed for caricatured 150% than low-intensity 50% fearful eye-white. It might reflect the subcortical pathway of emotion-specific, fearful processing. The results demonstrate that the human brain is sensitive to intensities of fear, even if just shown intensities of fearful eye-white in the absence of awareness.
ARTICLE UPDATE - Genetics of Emotion Regulation.
Canli T, Ferri J, Duman EA.
Neuroscience, in press
Emotions can be powerful drivers of behavior that may be adaptive or maladaptive for the individual. Thus, the ability to alter one's emotions, to regulate them, should be beneficial to an individual's success of survival and fitness. What is the biological basis of this ability? And what are the biological mechanisms that impart individual differences in the ability to regulate emotion? In this article, we will first introduce readers to the construct of emotion regulation, and the various strategies that individuals may utilize to regulate their emotions. We will then point to evidence that suggests genetic contributions (alongside environmental contributions) to individual differences in emotion regulation. To date, efforts to identify specific genetic mechanisms involved in emotion regulation have focused on common gene variants (i.e., variants that exist in > 1% of the population, referred to as polymorphisms) and their association with specific emotion regulation strategies or the neural substrate mediating these strategies. We will discuss these efforts, and conclude with a call to expand the set of experimental paradigms and putative molecular mechanisms, in order to significantly advance our understanding of the molecular mechanisms by which genes are involved in emotion regulation.
Neuroscience, in press
Emotions can be powerful drivers of behavior that may be adaptive or maladaptive for the individual. Thus, the ability to alter one's emotions, to regulate them, should be beneficial to an individual's success of survival and fitness. What is the biological basis of this ability? And what are the biological mechanisms that impart individual differences in the ability to regulate emotion? In this article, we will first introduce readers to the construct of emotion regulation, and the various strategies that individuals may utilize to regulate their emotions. We will then point to evidence that suggests genetic contributions (alongside environmental contributions) to individual differences in emotion regulation. To date, efforts to identify specific genetic mechanisms involved in emotion regulation have focused on common gene variants (i.e., variants that exist in > 1% of the population, referred to as polymorphisms) and their association with specific emotion regulation strategies or the neural substrate mediating these strategies. We will discuss these efforts, and conclude with a call to expand the set of experimental paradigms and putative molecular mechanisms, in order to significantly advance our understanding of the molecular mechanisms by which genes are involved in emotion regulation.
Saturday, June 27, 2009
ARTICLE UPDATE - Mirror of the soul: a cortical stimulation study on recognition of facial emotions.
Giussani C, Pirillo D, Roux FE.
Journal of Neurosurgery, in press
Object The capability of recognizing the expressions of facial emotions has been hypothesized to depend on a right hemispheric cortical-subcortical network. Its impairment deeply disturbs social relationships. To spare right hemispheric cortical areas involved in recognizing facial emotion, the authors used intraoperative cortical stimulation and the awake surgery technique in a consecutive series of patients. The feasibility and the interest to map them during brain mapping for neurosurgical procedures are discussed. Methods After a preoperative neuropsychological evaluation, 18 consecutive patients with right hemispheric lesions (5 metastases, 6 high-grade gliomas, 4 low-grade gliomas, 2 arteriovenous malformations, and 1 malignant meningioma) were tested by intraoperative cortical stimulation while performing a facial emotion recognition task along with sensorimotor and visuospatial tasks. Results Three hundred eighty-six cortical sites were studied. Five (1.30%) reproducible interference sites for facial emotion recognition were identified in 5 patients: 1 site in the medial segment of T1; 1 site in the posterior segment of T1; 1 site in the posterior segment of T2; and 2 sites in the supramarginal gyrus. No selective impairment was found regarding the emotion category. All facial emotion recognition sites were spared during surgery, and none of the patients experienced postoperative deficits in recognition of facial emotions. Conclusions The finding of interference sites in facial emotion recognition in the right posterior perisylvian area, independent to sensorimotor or visuospatial orientation processes, reinforces the theory about the role of anatomically and functionally segregated right hemisphere structures in this cognitive process. The authors advocate offering a brain mapping of facial emotion recognition to patients with right posterior perisylvian tumors.
Journal of Neurosurgery, in press
Object The capability of recognizing the expressions of facial emotions has been hypothesized to depend on a right hemispheric cortical-subcortical network. Its impairment deeply disturbs social relationships. To spare right hemispheric cortical areas involved in recognizing facial emotion, the authors used intraoperative cortical stimulation and the awake surgery technique in a consecutive series of patients. The feasibility and the interest to map them during brain mapping for neurosurgical procedures are discussed. Methods After a preoperative neuropsychological evaluation, 18 consecutive patients with right hemispheric lesions (5 metastases, 6 high-grade gliomas, 4 low-grade gliomas, 2 arteriovenous malformations, and 1 malignant meningioma) were tested by intraoperative cortical stimulation while performing a facial emotion recognition task along with sensorimotor and visuospatial tasks. Results Three hundred eighty-six cortical sites were studied. Five (1.30%) reproducible interference sites for facial emotion recognition were identified in 5 patients: 1 site in the medial segment of T1; 1 site in the posterior segment of T1; 1 site in the posterior segment of T2; and 2 sites in the supramarginal gyrus. No selective impairment was found regarding the emotion category. All facial emotion recognition sites were spared during surgery, and none of the patients experienced postoperative deficits in recognition of facial emotions. Conclusions The finding of interference sites in facial emotion recognition in the right posterior perisylvian area, independent to sensorimotor or visuospatial orientation processes, reinforces the theory about the role of anatomically and functionally segregated right hemisphere structures in this cognitive process. The authors advocate offering a brain mapping of facial emotion recognition to patients with right posterior perisylvian tumors.
ARTICLE UPDATE - Influence of attention to somatic information on emotional and autonomic responses.
Murakami H, Ohira H, Matsunaga M, Kimura K.
Perceptual Motor Skills, 108, 531-539
The present study aimed to investigate the dissociable effects of two forms of self-focus on emotional and autonomic responses. One form is suppression, which includes the suppression of heart rate and self-evaluation of performance. The other is observation, which includes attention to one's own heart rate with no suppression and no evaluation. 26 undergraduate and graduate students from the Nagoya University campus (13 men, 13 women), ages 18 to 24 years (M = 20.7, SD = 1.6) were recruited. Participants were provided with their own heart rate as feedback for 5 min., during which participants conducted a self-focus manipulation. Several days after the experimental session for one condition, the same participants conducted another experimental session for the other condition. Instruction to suppress enhanced physiological arousal and subsequent negative emotions; however, instruction to observe did not increase physiological arousal or negative emotions.
Perceptual Motor Skills, 108, 531-539
The present study aimed to investigate the dissociable effects of two forms of self-focus on emotional and autonomic responses. One form is suppression, which includes the suppression of heart rate and self-evaluation of performance. The other is observation, which includes attention to one's own heart rate with no suppression and no evaluation. 26 undergraduate and graduate students from the Nagoya University campus (13 men, 13 women), ages 18 to 24 years (M = 20.7, SD = 1.6) were recruited. Participants were provided with their own heart rate as feedback for 5 min., during which participants conducted a self-focus manipulation. Several days after the experimental session for one condition, the same participants conducted another experimental session for the other condition. Instruction to suppress enhanced physiological arousal and subsequent negative emotions; however, instruction to observe did not increase physiological arousal or negative emotions.
ARTICLE UPDATE - Worry tendencies predict brain activation during aversive imagery.
Schienle A, Schäfer A, Pignanelli R, Vaitl D.
Neuroscience Letters, in press
Because of its abstract nature, worrying might function as an avoidance response in order to cognitively disengage from fearful imagery. The present functional magnetic resonance imaging study investigated neural correlates of aversive imagery and their association with worry tendencies, as measured by the Penn State Worry Questionnaire (PSWQ). Nineteen healthy women first viewed, and subsequently imagined pictures from two categories, 'threat' and 'happiness'. Worry tendencies were negatively correlated with brain activation in the anterior cingulate cortex, the prefrontal cortex (dorsolateral, dorsomedial, ventrolateral), the parietal cortex and the insula. These negative correlations between PSWQ scores and localized brain activation were specific for aversive imagery. Moreover, activation in the abovementioned regions was positively associated with the experienced vividness of both pleasant and unpleasant mental pictures. As the identified brain regions are involved in emotion regulation, vivid imagery and memory retrieval, a lowered activity in high PSWQ scorers might be associated with cognitive disengagement from aversive imagery as well as insufficient refresh rates of mental pictures. Our preliminary findings encourage future imagery studies on generalized anxiety disorder patients, as one of the main symptoms of this disorder is excessive worrying.
Neuroscience Letters, in press
Because of its abstract nature, worrying might function as an avoidance response in order to cognitively disengage from fearful imagery. The present functional magnetic resonance imaging study investigated neural correlates of aversive imagery and their association with worry tendencies, as measured by the Penn State Worry Questionnaire (PSWQ). Nineteen healthy women first viewed, and subsequently imagined pictures from two categories, 'threat' and 'happiness'. Worry tendencies were negatively correlated with brain activation in the anterior cingulate cortex, the prefrontal cortex (dorsolateral, dorsomedial, ventrolateral), the parietal cortex and the insula. These negative correlations between PSWQ scores and localized brain activation were specific for aversive imagery. Moreover, activation in the abovementioned regions was positively associated with the experienced vividness of both pleasant and unpleasant mental pictures. As the identified brain regions are involved in emotion regulation, vivid imagery and memory retrieval, a lowered activity in high PSWQ scorers might be associated with cognitive disengagement from aversive imagery as well as insufficient refresh rates of mental pictures. Our preliminary findings encourage future imagery studies on generalized anxiety disorder patients, as one of the main symptoms of this disorder is excessive worrying.
Friday, June 19, 2009
ARTICLE UPDATE - In search of specificity: functional MRI in the study of emotional experience.
Schienle A, Schäfer A.
International Journal of Psychophysiology, 73, 22-26.
The growing availability of functional magnetic resonance imaging (fMRI) with its property of high spatial resolution has energized the search for specific neural substrates of basic emotions and their feeling components. In the present article, we address the question as to whether recent fMRI studies on primary affective experiences have truly helped to pinpoint emotion-specific areas in the human brain or whether these studies are afflicted with methodological problems which make such inferences difficult. As one approach for improvement, we suggest the combination of fMRI with methods characterized by high temporal resolution, such as electroencephalography (EEG). Simultaneous recoding allows the correlation of temporally specific EEG components (e.g., the late positive potential) with regional blood-oxygen-level-dependent (BOLD) signals during affective experiences. Combined information on the source as well as the exact temporal pattern of a neural affective response will help to improve our understanding of emotion-specific brain activation.
International Journal of Psychophysiology, 73, 22-26.
The growing availability of functional magnetic resonance imaging (fMRI) with its property of high spatial resolution has energized the search for specific neural substrates of basic emotions and their feeling components. In the present article, we address the question as to whether recent fMRI studies on primary affective experiences have truly helped to pinpoint emotion-specific areas in the human brain or whether these studies are afflicted with methodological problems which make such inferences difficult. As one approach for improvement, we suggest the combination of fMRI with methods characterized by high temporal resolution, such as electroencephalography (EEG). Simultaneous recoding allows the correlation of temporally specific EEG components (e.g., the late positive potential) with regional blood-oxygen-level-dependent (BOLD) signals during affective experiences. Combined information on the source as well as the exact temporal pattern of a neural affective response will help to improve our understanding of emotion-specific brain activation.
Saturday, June 13, 2009
ARTICLE UPDATE - Emotions in motion: Dynamic compared to static facial expressions of disgust and happiness reveal more widespread emotion-specific ac
Emotions in motion: Dynamic compared to static facial expressions of disgust and happiness reveal more widespread emotion-specific activations.
Brain Research, in press
In social contexts, facial expressions are dynamic in nature and vary rapidly in relation to situational requirements. However, there are very few fMRI studies using dynamic emotional stimuli. The aim of this study was (1) to introduce and evaluate a new stimulus database of static and dynamic emotional facial expressions according to arousal and recognizability investigated by a rating by both participants of the present fMRI study and by an external sample of 30 healthy women, (2) to examine the neural networks involved in emotion perception of static and dynamic facial stimuli separately, and (3) to examine the impact of motion on the emotional processing of dynamic compared to static face stimuli. A total of 16 females participated in the present fMRI study performing a passive emotion perception task including static and dynamic faces of neutral, happy and disgusted expressions. Comparing dynamic stimuli to static faces indicated enhanced emotion-specific brain activation patterns in the parahippocampal gyrus (PHG) including the amygdala (AMG), fusiform gyrus (FG), superior temporal gyrus (STG), inferior frontal gyrus (IFG), and occipital and orbitofrontal cortex (OFC). These regions have been discussed to be associated with emotional memory encoding, the perception of threat, facial identity, biological motion, the mirror neuron system, an increase of emotional arousal, and reward processing, respectively. Post hoc ratings of the dynamic stimuli revealed a better recognizability in comparison to the static stimuli. In conclusion, dynamic facial expressions might provide a more appropriate approach to examine the processing of emotional face perception than static stimuli.
Brain Research, in press
In social contexts, facial expressions are dynamic in nature and vary rapidly in relation to situational requirements. However, there are very few fMRI studies using dynamic emotional stimuli. The aim of this study was (1) to introduce and evaluate a new stimulus database of static and dynamic emotional facial expressions according to arousal and recognizability investigated by a rating by both participants of the present fMRI study and by an external sample of 30 healthy women, (2) to examine the neural networks involved in emotion perception of static and dynamic facial stimuli separately, and (3) to examine the impact of motion on the emotional processing of dynamic compared to static face stimuli. A total of 16 females participated in the present fMRI study performing a passive emotion perception task including static and dynamic faces of neutral, happy and disgusted expressions. Comparing dynamic stimuli to static faces indicated enhanced emotion-specific brain activation patterns in the parahippocampal gyrus (PHG) including the amygdala (AMG), fusiform gyrus (FG), superior temporal gyrus (STG), inferior frontal gyrus (IFG), and occipital and orbitofrontal cortex (OFC). These regions have been discussed to be associated with emotional memory encoding, the perception of threat, facial identity, biological motion, the mirror neuron system, an increase of emotional arousal, and reward processing, respectively. Post hoc ratings of the dynamic stimuli revealed a better recognizability in comparison to the static stimuli. In conclusion, dynamic facial expressions might provide a more appropriate approach to examine the processing of emotional face perception than static stimuli.
ARTICLE UPDATE - Emotion and space. Lateralized emotional word detection depends on line bisection bias.
Tamagni C, Mantei T, Brugger P.
Neuroscience, in press
There is converging evidence, from various independent areas of neuroscience, for a functional specialization of the left and right cerebral hemispheres for positive and negative emotions, respectively ("valence theory" of emotional processing). One subfield, however, has produced mixed results, i.e. work on the detection of parafoveally presented positively or negatively emotional words by healthy subjects. Right or left visual field advantages were described and interpreted as reflecting the superiority of either the left hemisphere (LH) for linguistic material, or of the right hemisphere (RH) for highly emotional stimuli. Here we show that 48 healthy, right-handed participants' performance on a lateralized lexical decision task depends on their individual inclination to bisect a line to the left or right of the objective center. Only those with a bisection bias to the right showed the LH advantage for word detection known from the neuropsychological literature. Negative emotional words were processed with comparable accuracy in the two visual fields. However, a recognition advantage for negative over positive emotional words was found exclusively for those participants with a leftward line bisection bias. These results suggest that in work on functional hemispheric differences state variables like stimulus lateralization and word emotionality may be less decisive than the trait variable of lateral hemispatial attention. We propose a cautious reconsideration of the concept of "hemisphericity", which once emphasized individual differences in baseline hemispheric arousal, but was later dismissed in a reaction to oversimplifications in popular science accounts.
Neuroscience, in press
There is converging evidence, from various independent areas of neuroscience, for a functional specialization of the left and right cerebral hemispheres for positive and negative emotions, respectively ("valence theory" of emotional processing). One subfield, however, has produced mixed results, i.e. work on the detection of parafoveally presented positively or negatively emotional words by healthy subjects. Right or left visual field advantages were described and interpreted as reflecting the superiority of either the left hemisphere (LH) for linguistic material, or of the right hemisphere (RH) for highly emotional stimuli. Here we show that 48 healthy, right-handed participants' performance on a lateralized lexical decision task depends on their individual inclination to bisect a line to the left or right of the objective center. Only those with a bisection bias to the right showed the LH advantage for word detection known from the neuropsychological literature. Negative emotional words were processed with comparable accuracy in the two visual fields. However, a recognition advantage for negative over positive emotional words was found exclusively for those participants with a leftward line bisection bias. These results suggest that in work on functional hemispheric differences state variables like stimulus lateralization and word emotionality may be less decisive than the trait variable of lateral hemispatial attention. We propose a cautious reconsideration of the concept of "hemisphericity", which once emphasized individual differences in baseline hemispheric arousal, but was later dismissed in a reaction to oversimplifications in popular science accounts.
ARTICLE UPDATE - EEG coherence in humans: relationship with success in recognizing emotions in the voice.
Kislova OO, Rusalova MN.
Neuroscience and Behavioral Physiology, in press
EEG recordings from two groups of subjects - with high and low levels of recognition of emotions from voices were made. Comparisons were performed of the numbers of pairs of leads with different levels of coherence in baseline conditions and on recognition of emotions in six standard frequency ranges and in individual bands with 1-Hz steps. Significant differences were seen between groups 1 and 2 both in baseline conditions and during recognition of emotions: in most cases, coherence was greater in subjects with poor recognition of emotions from voices.
Neuroscience and Behavioral Physiology, in press
EEG recordings from two groups of subjects - with high and low levels of recognition of emotions from voices were made. Comparisons were performed of the numbers of pairs of leads with different levels of coherence in baseline conditions and on recognition of emotions in six standard frequency ranges and in individual bands with 1-Hz steps. Significant differences were seen between groups 1 and 2 both in baseline conditions and during recognition of emotions: in most cases, coherence was greater in subjects with poor recognition of emotions from voices.
Saturday, June 06, 2009
ARTICLE UPDATE - Prolonged reduction of electrocortical activity predicts correct performance during rapid serial visual processing.
Keil A, Heim S.
Psychophysiology, in press
Abstract When two targets are shown in a rapid temporal stream of distractors, performance for the second target (T2) is typically reduced when presented between 200 and 500 ms after the first (T1). The present study used the steady-state visual evoked potential (ssVEP), a continuous index of electrocortical facilitation, to compare brain responses in trials with correct versus incorrect T2 responses. We found a reduction of the electrocortical response following T1 in trials with correct T2 identification. By contrast, incorrect T2 trials were characterized by enhanced electrocortical amplitude. Amplitude attenuation predictive of successful T2 report was sustained over time, suggesting a reduction of resources allocated to the distractor stream in correct trials. Across intertarget intervals, T2 performance was a linear function of the ssVEP amplitude reduction in correct trials, weighted by the stimulus onset asynchrony.
Psychophysiology, in press
Abstract When two targets are shown in a rapid temporal stream of distractors, performance for the second target (T2) is typically reduced when presented between 200 and 500 ms after the first (T1). The present study used the steady-state visual evoked potential (ssVEP), a continuous index of electrocortical facilitation, to compare brain responses in trials with correct versus incorrect T2 responses. We found a reduction of the electrocortical response following T1 in trials with correct T2 identification. By contrast, incorrect T2 trials were characterized by enhanced electrocortical amplitude. Amplitude attenuation predictive of successful T2 report was sustained over time, suggesting a reduction of resources allocated to the distractor stream in correct trials. Across intertarget intervals, T2 performance was a linear function of the ssVEP amplitude reduction in correct trials, weighted by the stimulus onset asynchrony.
Saturday, May 30, 2009
PUBLICATION - Affective learning enhances activity and functional connectivity in early visual cortex.
Damaraju E, Huang YM, Barrett LF, Pessoa L.
Neuropsychologia, in press
This study examined the impact of task-irrelevant affective information on early visual processing regions V1-V4. Fearful and neutral faces presented with rings of different colors were used as stimuli. During the conditioning phase, fearful faces presented with a certain ring color (e.g., black) were paired with mild electrical stimulation. Neutral faces shown with rings of that color, as well as fearful or neutral faces shown with another ring color (e.g., white), were never paired with shock. Our findings revealed that fearful faces evoked enhanced blood oxygen level dependent (BOLD) responses in V1 and V4 compared to neutral faces. Faces embedded in a color ring that was paired with shock (e.g., black) evoked greater BOLD responses in V1-V4 compared to a ring color that was never paired with shock (e.g., white). Finally, BOLD responses in early visual cortex were tightly interrelated (i.e., correlated) during an affectively potent context (i.e., ring color) but not during a neutral one, suggesting that increased functional integration was present with affective learning. Taken together, the results suggest that task-irrelevant affective information not only influences evoked responses in early, retinotopically organized visual cortex, but also determines the pattern of responses across early visual cortex.
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Neuropsychologia, in press
This study examined the impact of task-irrelevant affective information on early visual processing regions V1-V4. Fearful and neutral faces presented with rings of different colors were used as stimuli. During the conditioning phase, fearful faces presented with a certain ring color (e.g., black) were paired with mild electrical stimulation. Neutral faces shown with rings of that color, as well as fearful or neutral faces shown with another ring color (e.g., white), were never paired with shock. Our findings revealed that fearful faces evoked enhanced blood oxygen level dependent (BOLD) responses in V1 and V4 compared to neutral faces. Faces embedded in a color ring that was paired with shock (e.g., black) evoked greater BOLD responses in V1-V4 compared to a ring color that was never paired with shock (e.g., white). Finally, BOLD responses in early visual cortex were tightly interrelated (i.e., correlated) during an affectively potent context (i.e., ring color) but not during a neutral one, suggesting that increased functional integration was present with affective learning. Taken together, the results suggest that task-irrelevant affective information not only influences evoked responses in early, retinotopically organized visual cortex, but also determines the pattern of responses across early visual cortex.
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ARTICLE UPDATE - Embodiment of emotion concepts.
Niedenthal PM, Winkielman P, Mondillon L, Vermeulen N.
Journal of Personality and Social Psychology, 96, 1120-1136
Theories of embodied cognition hold that higher cognitive processes operate on perceptual symbols and that concept use involves partial reactivations of the sensory-motor states that occur during experience with the world. On this view, the processing of emotion knowledge involves a (partial) reexperience of an emotion, but only when access to the sensory basis of emotion knowledge is required by the task. In 2 experiments, participants judged emotional and neutral concepts corresponding to concrete objects (Experiment 1) and abstract states (Experiment 2) while facial electromyographic activity was recorded from the cheek, brow, eye, and nose regions. Results of both studies show embodiment of specific emotions in an emotion-focused but not a perceptual-focused processing task on the same words. A follow up in Experiment 3, which blocked selective facial expressions, suggests a causal, rather than simply a correlational, role for embodiment in emotion word processing. Experiment 4, using a property generation task, provided support for the conclusion that emotions embodied in conceptual tasks are context-dependent situated simulations rather than associated emotional reactions. Implications for theories of embodied simulation and for emotion theories are discussed.
Journal of Personality and Social Psychology, 96, 1120-1136
Theories of embodied cognition hold that higher cognitive processes operate on perceptual symbols and that concept use involves partial reactivations of the sensory-motor states that occur during experience with the world. On this view, the processing of emotion knowledge involves a (partial) reexperience of an emotion, but only when access to the sensory basis of emotion knowledge is required by the task. In 2 experiments, participants judged emotional and neutral concepts corresponding to concrete objects (Experiment 1) and abstract states (Experiment 2) while facial electromyographic activity was recorded from the cheek, brow, eye, and nose regions. Results of both studies show embodiment of specific emotions in an emotion-focused but not a perceptual-focused processing task on the same words. A follow up in Experiment 3, which blocked selective facial expressions, suggests a causal, rather than simply a correlational, role for embodiment in emotion word processing. Experiment 4, using a property generation task, provided support for the conclusion that emotions embodied in conceptual tasks are context-dependent situated simulations rather than associated emotional reactions. Implications for theories of embodied simulation and for emotion theories are discussed.
ARTICLE UPDATE - Early and late temporo-spatial effects of contextual interference during perception of facial affect.
Frühholz S, Fehr T, Herrmann M.
International Journal of Psychophysiology, in press
Contextual features during recognition of facial affect are assumed to modulate the temporal course of emotional face processing. Here, we simultaneously presented colored backgrounds during valence categorizations of facial expressions. Subjects incidentally learned to perceive negative, neutral and positive expressions within a specific colored context. Subsequently, subjects made fast valence judgments while presented with the same face-color-combinations as in the first run (congruent trials) or with different face-color-combinations (incongruent trials). Incongruent trials induced significantly increased response latencies and significantly decreased performance accuracy. Contextual incongruent information during processing of neutral expressions modulated the P1 and the early posterior negativity (EPN) both localized in occipito-temporal areas. Contextual congruent information during emotional face perception revealed an emotion-related modulation of the P1 for positive expressions and of the N170 and the EPN for negative expressions. Highest amplitude of the N170 was found for negative expressions in a negatively associated context and the N170 amplitude varied with the amount of overall negative information. Incongruent trials with negative expressions elicited a parietal negativity which was localized to superior parietal cortex and which most likely represents a posterior manifestation of the N450 as an indicator of conflict processing. A sustained activation of the late LPP over parietal cortex for all incongruent trials might reflect enhanced engagement with facial expression during task conditions of contextual interference. In conclusion, whereas early components seem to be sensitive to the emotional valence of facial expression in specific contexts, late components seem to subserve interference resolution during emotional face processing.
International Journal of Psychophysiology, in press
Contextual features during recognition of facial affect are assumed to modulate the temporal course of emotional face processing. Here, we simultaneously presented colored backgrounds during valence categorizations of facial expressions. Subjects incidentally learned to perceive negative, neutral and positive expressions within a specific colored context. Subsequently, subjects made fast valence judgments while presented with the same face-color-combinations as in the first run (congruent trials) or with different face-color-combinations (incongruent trials). Incongruent trials induced significantly increased response latencies and significantly decreased performance accuracy. Contextual incongruent information during processing of neutral expressions modulated the P1 and the early posterior negativity (EPN) both localized in occipito-temporal areas. Contextual congruent information during emotional face perception revealed an emotion-related modulation of the P1 for positive expressions and of the N170 and the EPN for negative expressions. Highest amplitude of the N170 was found for negative expressions in a negatively associated context and the N170 amplitude varied with the amount of overall negative information. Incongruent trials with negative expressions elicited a parietal negativity which was localized to superior parietal cortex and which most likely represents a posterior manifestation of the N450 as an indicator of conflict processing. A sustained activation of the late LPP over parietal cortex for all incongruent trials might reflect enhanced engagement with facial expression during task conditions of contextual interference. In conclusion, whereas early components seem to be sensitive to the emotional valence of facial expression in specific contexts, late components seem to subserve interference resolution during emotional face processing.
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