title: Fast recognition of social emotions takes the whole brain: interhemispheric cooperation in the absence of cerebral asymmetry.
abstract: Hemispheric asymmetry in emotional perception has been traditionally studied for basic emotions and very little is known about laterality for more complex social emotions. Here, we used the "redundant target paradigm" to investigate interhemispheric asymmetry and cooperation for two social emotions in healthy subjects. Facial expressions of flirtatiousness or arrogance were briefly presented either unilaterally in the left (LVF) or right visual field (RVF), or simultaneously to both visual fields (BVF) while participants responded to the target expression (flirtatious or arrogant, counterbalanced between blocks). In bilateral conditions the faces could show the same emotion (congruent condition) or two different expressions (incongruent condition). No difference between unilateral presentations was found, suggesting that the perception of social emotions is not hemispherically lateralized. Responses were faster and more accurate in bilateral displays with two emotionally congruent but physically different faces (i.e., a male and a female expressing the same emotion) than in unilateral conditions. This "redundant target effect" was consistent with a neural summation model, thereby showing that interhemispheric cooperation may occur for social emotions despite major perceptual differences between faces posing the same expression.
authors.affiliation: Department of Psychology and Center for Cognitive Science, University of Torino, via Po 14, 10123 Torino, Italy. tamietto@psych.unito.it
authors.forename: Marco
authors.initials: M
authors.lastname: Tamietto
authors.forename: Mauro
authors.initials: M
authors.lastname: Adenzato
authors.forename: Giuliano
authors.initials: G
authors.lastname: Geminiani
authors.forename: Beatrice
authors.initials: B
authors.lastname: de Gelder
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D003337:Corpus Callosum / Q000502:physiology; D004193:Discrimination Learning / Q000502:physiology; D004292:Dominance, Cerebral / Q000502:physiology*; D004644:Emotions / Q000502:physiology*; D005149:Facial Expression; D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D015348:Vision, Binocular / Q000502:physiology; D015349:Vision, Monocular / Q000502:physiology