title: Dissimilar processing of emotional facial expressions in human and monkey temporal cortex.
abstract: Emotional facial expressions play an important role in social communication across primates. Despite major progress made in our understanding of categorical information processing such as for objects and faces, little is known, however, about how the primate brain evolved to process emotional cues. In this study, we used functional magnetic resonance imaging (fMRI) to compare the processing of emotional facial expressions between monkeys and humans. We used a 2×2×2 factorial design with species (human and monkey), expression (fear and chewing) and configuration (intact versus scrambled) as factors. At the whole brain level, neural responses to conspecific emotional expressions were anatomically confined to the superior temporal sulcus (STS) in humans. Within the human STS, we found functional subdivisions with a face-selective right posterior STS area that also responded to emotional expressions of other species and a more anterior area in the right middle STS that responded specifically to human emotions. Hence, we argue that the latter region does not show a mere emotion-dependent modulation of activity but is primarily driven by human emotional facial expressions. Conversely, in monkeys, emotional responses appeared in earlier visual cortex and outside face-selective regions in inferior temporal cortex that responded also to multiple visual categories. Within monkey IT, we also found areas that were more responsive to conspecific than to non-conspecific emotional expressions but these responses were not as specific as in human middle STS. Overall, our results indicate that human STS may have developed unique properties to deal with social cues such as emotional expressions.
authors.affiliation: Laboratory for Neuro- and Psychophysiology, KU Leuven, Leuven, Belgium.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: Laboratory for Neuro- and Psychophysiology, KU Leuven, Leuven, Belgium; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.
authors.forename: Koen
authors.initials: K
authors.lastname: Nelissen
authors.affiliation: Cognitive and Affective Neuroscience Laboratory, Tilburg University, Tilburg, The Netherlands; Brain and Emotion Laboratory Leuven (BELL), Division of Psychiatry, Department of Neuroscience, KU Leuven, Leuven, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Van den Stock
authors.affiliation: Brain and Emotion Laboratory Leuven (BELL), Division of Psychiatry, Department of Neuroscience, KU Leuven, Leuven, Belgium.
authors.forename: François-Laurent
authors.initials: FL
authors.lastname: De Winter
authors.affiliation: Laboratory for Neuro- and Psychophysiology, KU Leuven, Leuven, Belgium.
authors.forename: Karl
authors.initials: K
authors.lastname: Pauwels
authors.affiliation: Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA; Cognitive and Affective Neuroscience Laboratory, Tilburg University, Tilburg, The Netherlands; Brain and Emotion Laboratory Leuven (BELL), Division of Psychiatry, Department of Neuroscience, KU Leuven, Leuven, Belgium.
authors.forename: Beatrice
authors.initials: B
authors.lastname: de Gelder
authors.affiliation: Laboratory for Neuro- and Psychophysiology, KU Leuven, Leuven, Belgium; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. Electronic address: wim@nmr.mgh.harvard.edu.
authors.forename: Wim
authors.initials: W
authors.lastname: Vanduffel
authors.affiliation: Brain and Emotion Laboratory Leuven (BELL), Division of Psychiatry, Department of Neuroscience, KU Leuven, Leuven, Belgium.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Vandenbulcke
mesh_terms: D000328:Adult; D000818:Animals; D001931:Brain Mapping; D003463:Cues; D004644:Emotions / Q000502:physiology*; D005149:Facial Expression; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008253:Macaca mulatta; D008279:Magnetic Resonance Imaging; D008297:Male; D013702:Temporal Lobe / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: Emotions; Facial expressions; Human; Monkey; STS; fMRI