Cano ME, Class QA, Polich J.
International Journal of Psychophysiology, in press
Pictures from the International Affective Picture System (IAPS) were selected to manipulate affective valence (unpleasant, neutral, pleasant) while keeping arousal level the same. The pictures were presented in an oddball paradigm, with a visual pattern used as the standard stimulus. Subjects pressed a button whenever a target was detected. Experiment 1 presented normal pictures in color and black/white. Control stimuli were constructed for both the color and black/white conditions by randomly rearranging 1 cm square fragments of each original picture to produce a "scrambled" image. Experiment 2 presented the same normal color pictures with large, medium, and small scrambled condition (2, 1, and 0.5 cm squares). The P300 event-related brain potential demonstrated larger amplitudes over frontal areas for positive compared to negative or neutral images for normal color pictures in both experiments. Attenuated and nonsignificant valence effects were obtained for black/white images. Scrambled stimuli in each study yielded no valence effects but demonstrated typical P300 topography that increased from frontal to parietal areas. The findings suggest that P300 amplitude is sensitive to affective picture valence in the absence of stimulus arousal differences, and that stimulus color contributes to ERP valence effects.
Sunday, August 24, 2008
ARTICLE UPDATE - Visual search is not blind to emotion.
Gerritsen C, Frischen A, Blake A, Smilek D, Eastwood JD.
Perception and Psychophysics, 70, 1047-1059
A series of three visual search tasks revealed more efficient search for hostile than for peaceful faces among neutral face distractors. Given that this effect has been observed inconsistently in prior literature, meta-analytic methods were employed for evaluating data across three experiments in order to develop a more valid estimate of the potentially small effect size. Furthermore, in the present experiments, different emotional meanings were conditioned to identical faces across observers, thus eliminating confounds between the physical characteristics and the emotional valences of the face stimuli. On the basis of the present findings, we argue that the visual system is capable of determining a face's emotional valence before the face becomes the focus of attention, and that emotional valence can be used by the visual system to determine subsequent attention allocation. However, meta-analytic results indicate that emotional valence makes a relatively small contribution to search efficiency in the present search context.
Perception and Psychophysics, 70, 1047-1059
A series of three visual search tasks revealed more efficient search for hostile than for peaceful faces among neutral face distractors. Given that this effect has been observed inconsistently in prior literature, meta-analytic methods were employed for evaluating data across three experiments in order to develop a more valid estimate of the potentially small effect size. Furthermore, in the present experiments, different emotional meanings were conditioned to identical faces across observers, thus eliminating confounds between the physical characteristics and the emotional valences of the face stimuli. On the basis of the present findings, we argue that the visual system is capable of determining a face's emotional valence before the face becomes the focus of attention, and that emotional valence can be used by the visual system to determine subsequent attention allocation. However, meta-analytic results indicate that emotional valence makes a relatively small contribution to search efficiency in the present search context.
Saturday, August 16, 2008
ARTICLE UPDATE - Integration of cross-modal emotional information in the human brain: An fMRI study.
Park JY, Gu BM, Kang DH, Shin YW, Choi CH, Lee JM, Kwon JS.
Cortex, in press
The interaction of information derived from the voice and facial expression of a speaker contributes to the interpretation of the emotional state of the speaker and to the formation of inferences about information that may have been merely implied in the verbal communication. Therefore, we investigated the brain processes responsible for the integration of emotional information originating from different sources. Although several studies have reported possible sites for integration, further investigation using a neutral emotional condition is required to locate emotion-specific networks. Using functional magnetic resonance imaging (fMRI), we explored the brain regions involved in the integration of emotional information from different modalities in comparison to those involved in integrating emotionally neutral information. There was significant activation in the superior temporal gyrus (STG); inferior frontal gyrus (IFG); and parahippocampal gyrus, including the amygdala, under the bimodal versus the unimodal condition, irrespective of the emotional content. We confirmed the results of previous studies by finding that the bimodal emotional condition elicited strong activation in the left middle temporal gyrus (MTG), and we extended this finding to locate the effects of emotional factors by using a neutral condition in the experimental design. We found anger-specific activation in the posterior cingulate, fusiform gyrus, and cerebellum, whereas we found happiness-specific activation in the MTG, parahippocampal gyrus, hippocampus, claustrum, inferior parietal lobule, cuneus, middle frontal gyrus (MFG), IFG, and anterior cingulate. These emotion-specific activations suggest that each emotion uses a separate network to integrate bimodal information and shares a common network for cross-modal integration.
Cortex, in press
The interaction of information derived from the voice and facial expression of a speaker contributes to the interpretation of the emotional state of the speaker and to the formation of inferences about information that may have been merely implied in the verbal communication. Therefore, we investigated the brain processes responsible for the integration of emotional information originating from different sources. Although several studies have reported possible sites for integration, further investigation using a neutral emotional condition is required to locate emotion-specific networks. Using functional magnetic resonance imaging (fMRI), we explored the brain regions involved in the integration of emotional information from different modalities in comparison to those involved in integrating emotionally neutral information. There was significant activation in the superior temporal gyrus (STG); inferior frontal gyrus (IFG); and parahippocampal gyrus, including the amygdala, under the bimodal versus the unimodal condition, irrespective of the emotional content. We confirmed the results of previous studies by finding that the bimodal emotional condition elicited strong activation in the left middle temporal gyrus (MTG), and we extended this finding to locate the effects of emotional factors by using a neutral condition in the experimental design. We found anger-specific activation in the posterior cingulate, fusiform gyrus, and cerebellum, whereas we found happiness-specific activation in the MTG, parahippocampal gyrus, hippocampus, claustrum, inferior parietal lobule, cuneus, middle frontal gyrus (MFG), IFG, and anterior cingulate. These emotion-specific activations suggest that each emotion uses a separate network to integrate bimodal information and shares a common network for cross-modal integration.
ARTICLE UPDATE - I feel how you feel but not always: the empathic brain and its modulation.
Hein G, Singer T.
Current Opinions in Neurobiology, in press
The ability to share the other's feelings, known as empathy, has recently become the focus of social neuroscience studies. We review converging evidence that empathy with, for example, the pain of another person, activates part of the neural pain network of the empathizer, without first hand pain stimulation to the empathizer's body. The amplitude of empathic brain responses is modulated by the intensity of the displayed emotion, the appraisal of the situation, characteristics of the suffering person such as perceived fairness, and features of the empathizer such as gender or previous experience with pain-inflicting situations. Future studies in the field should address inter-individual differences in empathy, development and plasticity of the empathic brain over the life span, and the link between empathy, compassionate motivation, and prosocial behavior.
Current Opinions in Neurobiology, in press
The ability to share the other's feelings, known as empathy, has recently become the focus of social neuroscience studies. We review converging evidence that empathy with, for example, the pain of another person, activates part of the neural pain network of the empathizer, without first hand pain stimulation to the empathizer's body. The amplitude of empathic brain responses is modulated by the intensity of the displayed emotion, the appraisal of the situation, characteristics of the suffering person such as perceived fairness, and features of the empathizer such as gender or previous experience with pain-inflicting situations. Future studies in the field should address inter-individual differences in empathy, development and plasticity of the empathic brain over the life span, and the link between empathy, compassionate motivation, and prosocial behavior.
ARTICLE UPDATE - How emotional arousal and valence influence access to awareness.
Sheth BR, Pham T.
Vision Research, in press
Volume 8, Number 6, Abstract 248, Page 248a doi:10.1167/8.6.248 http://journalofvision.org/8/6/248/ ISSN 1534-7362
How emotional arousal and affect influence access to visual awareness
Bruno Breitmeyer
Department of Psychology, University of Houston, and Center for NeuroEngineering and Cognitive Science, University of Houston
[e-mail]
Thuan Pham
University of Houston
Bhavin Sheth
Department of Electrical and Computer Engineering, University of Houston, and Center for NeuroEngineering and Cognitive Science, University of Houston
Abstract
Emotional stimuli attract attention and potentiate the effect of attention on contrast sensitivity, a feature of early vision. The amygdala, a key structure in emotional processing, responds to emotional content prior to awareness and projects to visual cortex. In light of evidence that the primary visual cortex does not have direct access to awareness, we hypothesize that emotion can affect the processing of a visual stimulus even before awareness. Moreover, emotion varies along at least two dimensions: arousal and affect (valence). Dissociating their effects is important to understanding the link between emotion and perception. We examined these effects in binocular rivalry. Pairs of images (54 total) were selected from a known database of natural images (IAPS). Pictures of a pair differed significantly along only one emotional dimension, creating two types – iso-valence and iso-arousal pairs. Pictures of a given pair were presented side by side in a rivalry setup for trials lasting 1 min. each. The duration for which each eye's image was dominant in a trial (dominant phase duration) was obtained from 12 observers. Our results showed: –A main effect of arousal: The dominant phase durations for more arousing pictures of the iso-valence pairs were significantly longer than those for the less arousing pictures. –No main effect of affect: The dominant phase durations of pleasant and unpleasant pictures of iso-arousal pairs did not differ significantly. –An interaction between arousal and affect: For low arousal-level stimuli, the more pleasant image of the pair dominated significantly. In contrast, for high arousal-level stimuli, the more unpleasant image dominated significantly. Our findings suggest that the limbic system acts on visual signals early in processing. While emotional arousal and valence interactively affect access to visual awareness, only arousal exerts an independent control of such access.
Vision Research, in press
Volume 8, Number 6, Abstract 248, Page 248a doi:10.1167/8.6.248 http://journalofvision.org/8/6/248/ ISSN 1534-7362
How emotional arousal and affect influence access to visual awareness
Bruno Breitmeyer
Department of Psychology, University of Houston, and Center for NeuroEngineering and Cognitive Science, University of Houston
[e-mail]
Thuan Pham
University of Houston
Bhavin Sheth
Department of Electrical and Computer Engineering, University of Houston, and Center for NeuroEngineering and Cognitive Science, University of Houston
Abstract
Emotional stimuli attract attention and potentiate the effect of attention on contrast sensitivity, a feature of early vision. The amygdala, a key structure in emotional processing, responds to emotional content prior to awareness and projects to visual cortex. In light of evidence that the primary visual cortex does not have direct access to awareness, we hypothesize that emotion can affect the processing of a visual stimulus even before awareness. Moreover, emotion varies along at least two dimensions: arousal and affect (valence). Dissociating their effects is important to understanding the link between emotion and perception. We examined these effects in binocular rivalry. Pairs of images (54 total) were selected from a known database of natural images (IAPS). Pictures of a pair differed significantly along only one emotional dimension, creating two types – iso-valence and iso-arousal pairs. Pictures of a given pair were presented side by side in a rivalry setup for trials lasting 1 min. each. The duration for which each eye's image was dominant in a trial (dominant phase duration) was obtained from 12 observers. Our results showed: –A main effect of arousal: The dominant phase durations for more arousing pictures of the iso-valence pairs were significantly longer than those for the less arousing pictures. –No main effect of affect: The dominant phase durations of pleasant and unpleasant pictures of iso-arousal pairs did not differ significantly. –An interaction between arousal and affect: For low arousal-level stimuli, the more pleasant image of the pair dominated significantly. In contrast, for high arousal-level stimuli, the more unpleasant image dominated significantly. Our findings suggest that the limbic system acts on visual signals early in processing. While emotional arousal and valence interactively affect access to visual awareness, only arousal exerts an independent control of such access.
ARTICLE UPDATE - A common anterior insula representation of disgust observation, experience and imagination shows divergent functional connectivity pa
Jabbi M, Bastiaansen J, Keysers C.
PLoS
Similar brain regions are involved when we imagine, observe and execute an action. Is the same true for emotions? Here, the same subjects were scanned while they (a) experience, (b) view someone else experiencing and (c) imagine experiencing gustatory emotions (through script-driven imagery). Capitalizing on the fact that disgust is repeatedly inducible within the scanner environment, we scanned the same participants while they (a) view actors taste the content of a cup and look disgusted (b) tasted unpleasant bitter liquids to induce disgust, and (c) read and imagine scenarios involving disgust and their neutral counterparts. To reduce habituation, we inter-mixed trials of positive emotions in all three scanning experiments. We found voxels in the anterior Insula and adjacent frontal operculum to be involved in all three modalities of disgust, suggesting that simulation in the context of social perception and mental imagery of disgust share a common neural substrates. Using effective connectivity, this shared region however was found to be embedded in distinct functional circuits during the three modalities, suggesting why observing, imagining and experiencing an emotion feels so different
PLoS
Similar brain regions are involved when we imagine, observe and execute an action. Is the same true for emotions? Here, the same subjects were scanned while they (a) experience, (b) view someone else experiencing and (c) imagine experiencing gustatory emotions (through script-driven imagery). Capitalizing on the fact that disgust is repeatedly inducible within the scanner environment, we scanned the same participants while they (a) view actors taste the content of a cup and look disgusted (b) tasted unpleasant bitter liquids to induce disgust, and (c) read and imagine scenarios involving disgust and their neutral counterparts. To reduce habituation, we inter-mixed trials of positive emotions in all three scanning experiments. We found voxels in the anterior Insula and adjacent frontal operculum to be involved in all three modalities of disgust, suggesting that simulation in the context of social perception and mental imagery of disgust share a common neural substrates. Using effective connectivity, this shared region however was found to be embedded in distinct functional circuits during the three modalities, suggesting why observing, imagining and experiencing an emotion feels so different
Wednesday, August 13, 2008
ARTICLE UPDATE - The human amygdala is sensitive to the valence of pictures and sounds irrespective of arousal: an fMRI study
Silke Anders, Falk Eippert, Nikolaus Weiskopf and Ralf Veit
Social Cognitive and Affective Neuroscience, in press
With the advent of studies showing that amygdala responses are not limited to fear-related or highly unpleasant stimuli, studies began to focus on stimulus valence and stimulus-related arousal as predictors of amygdala activity. Recent studies in the chemosensory domain found amygdala activity to increase with the intensity of negative and positive chemosensory stimuli. This has led to the proposal that amygdala activity might be an indicator of emotional arousal, at least in the chemosensory domain. The present study investigated amygdala activity in response to visual and auditory stimuli. By selecting stimuli based on individual valence and arousal ratings, we were able to dissociate stimulus valence and stimulus-related arousal, both on the verbal and the peripheral physiological level. We found that the amygdala was sensitive to stimulus valence even when arousal was controlled for, and that increased amygdala activity was better explained by valence than by arousal. The proposed difference in the relation between amygdala activity and stimulus-related arousal between the chemosensory and the audiovisual domain is discussed in terms of the amygdala's embedding within these sensory systems and the processes by which emotional meaning is derived.
Social Cognitive and Affective Neuroscience, in press
With the advent of studies showing that amygdala responses are not limited to fear-related or highly unpleasant stimuli, studies began to focus on stimulus valence and stimulus-related arousal as predictors of amygdala activity. Recent studies in the chemosensory domain found amygdala activity to increase with the intensity of negative and positive chemosensory stimuli. This has led to the proposal that amygdala activity might be an indicator of emotional arousal, at least in the chemosensory domain. The present study investigated amygdala activity in response to visual and auditory stimuli. By selecting stimuli based on individual valence and arousal ratings, we were able to dissociate stimulus valence and stimulus-related arousal, both on the verbal and the peripheral physiological level. We found that the amygdala was sensitive to stimulus valence even when arousal was controlled for, and that increased amygdala activity was better explained by valence than by arousal. The proposed difference in the relation between amygdala activity and stimulus-related arousal between the chemosensory and the audiovisual domain is discussed in terms of the amygdala's embedding within these sensory systems and the processes by which emotional meaning is derived.
Saturday, August 09, 2008
ARTICLE UPDATE - Emotional experience modulates brain activity during fixation periods between tasks.Emotional experience modulates brain activity dur
Pitroda S, Angstadt M, McCloskey MS, Coccaro EF, Phan KL.
Neuroscience Letters, in press
Functional imaging studies have begun to identify a set of brain regions whose brain activity is greater during 'rest' (e.g., fixation) states than during cognitive tasks. It has been posited that these regions constitute a network that supports the brain's default mode, which is temporarily suspended during specific goal-directed behaviors. Exogenous tasks that require cognitive effort are thought to command reallocation of resources away from the brain's default state. However, it remains unknown if brain activity during fixation periods between active task periods is influenced by previous task-related emotional content. We examined brain activity during periods of FIXATION (viewing and rating gray-scale images) interspersed among periods of viewing and rating complex images ('PICTURE') with positive, negative, and neutral affective content. We show that a selected group of brain regions (PCC, precuneus, IPL, vACC) do exhibit activity that is greater during FIXATION (>PICTURE); these regions have previously been implicated in the "default brain network". In addition, we report that activity within precuneus and IPL in the FIXATION period is attenuated by the precedent processing of images with positive and negative emotional content, relative to non-emotional content. These data suggest that the activity within regions implicated in the default network is modulated by the presence of environmental stimuli with motivational salience and, thus, adds to our understanding of the brain function during periods of low cognitive, emotional, or sensory demand.
Neuroscience Letters, in press
Functional imaging studies have begun to identify a set of brain regions whose brain activity is greater during 'rest' (e.g., fixation) states than during cognitive tasks. It has been posited that these regions constitute a network that supports the brain's default mode, which is temporarily suspended during specific goal-directed behaviors. Exogenous tasks that require cognitive effort are thought to command reallocation of resources away from the brain's default state. However, it remains unknown if brain activity during fixation periods between active task periods is influenced by previous task-related emotional content. We examined brain activity during periods of FIXATION (viewing and rating gray-scale images) interspersed among periods of viewing and rating complex images ('PICTURE') with positive, negative, and neutral affective content. We show that a selected group of brain regions (PCC, precuneus, IPL, vACC) do exhibit activity that is greater during FIXATION (>PICTURE); these regions have previously been implicated in the "default brain network". In addition, we report that activity within precuneus and IPL in the FIXATION period is attenuated by the precedent processing of images with positive and negative emotional content, relative to non-emotional content. These data suggest that the activity within regions implicated in the default network is modulated by the presence of environmental stimuli with motivational salience and, thus, adds to our understanding of the brain function during periods of low cognitive, emotional, or sensory demand.
ARTICLE UPDATE - Functional neuroimaging of reward processing and decision-making: A review of aberrant motivational and affective processing in addic
Diekhof EK, Falkai P, Gruber O.
Brain Research Review, in press
The adequate integration of reward- and decision-related information provided by the environment is critical for behavioral success and subjective well being in everyday life. Functional neuroimaging research has already presented a comprehensive picture on affective and motivational processing in the healthy human brain and has recently also turned its interest to the assessment of impaired brain function in psychiatric patients. This article presents an overview on neuroimaging studies dealing with reward processing and decision-making by combining most recent findings from fundamental and clinical research. It provides an outline on the neural mechanisms guiding context-adequate reward processing and decision-making processes in the healthy brain, and also addresses pathophysiological alterations in the brain's reward system that have been observed in substance abuse and mood disorders, two highly prevalent classes of psychiatric disorders. The overall goal is to critically evaluate the specificity of neurophysiological alterations identified in these psychiatric disorders and associated symptoms, and to make suggestions concerning future research.
Brain Research Review, in press
The adequate integration of reward- and decision-related information provided by the environment is critical for behavioral success and subjective well being in everyday life. Functional neuroimaging research has already presented a comprehensive picture on affective and motivational processing in the healthy human brain and has recently also turned its interest to the assessment of impaired brain function in psychiatric patients. This article presents an overview on neuroimaging studies dealing with reward processing and decision-making by combining most recent findings from fundamental and clinical research. It provides an outline on the neural mechanisms guiding context-adequate reward processing and decision-making processes in the healthy brain, and also addresses pathophysiological alterations in the brain's reward system that have been observed in substance abuse and mood disorders, two highly prevalent classes of psychiatric disorders. The overall goal is to critically evaluate the specificity of neurophysiological alterations identified in these psychiatric disorders and associated symptoms, and to make suggestions concerning future research.
Saturday, August 02, 2008
ARTICLE UPDATE - The selective processing of emotional visual stimuli while detecting auditory targets: An ERP analysis.
Schupp HT, Stockburger J, Bublatzky F, Junghöfer M, Weike AI, Hamm AO.
Brain Research, in press
Event-related potential studies revealed an early posterior negativity (EPN) for emotional compared to neutral pictures. Exploring the emotion-attention relationship, a previous study observed that a primary visual discrimination task interfered with the emotional modulation of the EPN component. To specify the locus of interference, the present study assessed the fate of selective visual emotion processing while attention is directed towards the auditory modality. While simply viewing a rapid and continuous stream of pleasant, neutral, and unpleasant pictures in one experimental condition, processing demands of a concurrent auditory target discrimination task were systematically varied in three further experimental conditions. Participants successfully performed the auditory task as revealed by behavioral performance and selected event-related potential components. Replicating previous results, emotional pictures were associated with a larger posterior negativity compared to neutral pictures. Of main interest, increasing demands of the auditory task did not modulate the selective processing of emotional visual stimuli. With regard to the locus of interference, selective emotion processing as indexed by the EPN does not seem to reflect shared processing resources of visual and auditory modality.
Brain Research, in press
Event-related potential studies revealed an early posterior negativity (EPN) for emotional compared to neutral pictures. Exploring the emotion-attention relationship, a previous study observed that a primary visual discrimination task interfered with the emotional modulation of the EPN component. To specify the locus of interference, the present study assessed the fate of selective visual emotion processing while attention is directed towards the auditory modality. While simply viewing a rapid and continuous stream of pleasant, neutral, and unpleasant pictures in one experimental condition, processing demands of a concurrent auditory target discrimination task were systematically varied in three further experimental conditions. Participants successfully performed the auditory task as revealed by behavioral performance and selected event-related potential components. Replicating previous results, emotional pictures were associated with a larger posterior negativity compared to neutral pictures. Of main interest, increasing demands of the auditory task did not modulate the selective processing of emotional visual stimuli. With regard to the locus of interference, selective emotion processing as indexed by the EPN does not seem to reflect shared processing resources of visual and auditory modality.
ARTICLE UPDATE - Communicating emotion: Linking affective prosody and word meaning.
Nygaard LC, Queen JS.
Journal of Experimental Psychology: Human Perception & Performance, 34, 1017-1030
The present study investigated the role of emotional tone of voice in the perception of spoken words. Listeners were presented with words that had either a happy, sad, or neutral meaning. Each word was spoken in a tone of voice (happy, sad, or neutral) that was congruent, incongruent, or neutral with respect to affective meaning, and naming latencies were collected. Across experiments, tone of voice was either blocked or mixed with respect to emotional meaning. The results suggest that emotional tone of voice facilitated linguistic processing of emotional words in an emotion-congruent fashion. These findings suggest that information about emotional tone is used in the processing of linguistic content influencing the recognition and naming of spoken words in an emotion-congruent manner.
Journal of Experimental Psychology: Human Perception & Performance, 34, 1017-1030
The present study investigated the role of emotional tone of voice in the perception of spoken words. Listeners were presented with words that had either a happy, sad, or neutral meaning. Each word was spoken in a tone of voice (happy, sad, or neutral) that was congruent, incongruent, or neutral with respect to affective meaning, and naming latencies were collected. Across experiments, tone of voice was either blocked or mixed with respect to emotional meaning. The results suggest that emotional tone of voice facilitated linguistic processing of emotional words in an emotion-congruent fashion. These findings suggest that information about emotional tone is used in the processing of linguistic content influencing the recognition and naming of spoken words in an emotion-congruent manner.
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