title: Optogenetic and pharmacological suppression of spatial clusters of face neurons reveal their causal role in face gender discrimination.
abstract: Neurons that respond more to images of faces over nonface objects were identified in the inferior temporal (IT) cortex of primates three decades ago. Although it is hypothesized that perceptual discrimination between faces depends on the neural activity of IT subregions enriched with "face neurons," such a causal link has not been directly established. Here, using optogenetic and pharmacological methods, we reversibly suppressed the neural activity in small subregions of IT cortex of macaque monkeys performing a facial gender-discrimination task. Each type of intervention independently demonstrated that suppression of IT subregions enriched in face neurons induced a contralateral deficit in face gender-discrimination behavior. The same neural suppression of other IT subregions produced no detectable change in behavior. These results establish a causal link between the neural activity in IT face neuron subregions and face gender-discrimination behavior. Also, the demonstration that brief neural suppression of specific spatial subregions of IT induces behavioral effects opens the door for applying the technical advantages of optogenetics to a systematic attack on the causal relationship between IT cortex and high-level visual perception.
authors.affiliation: Departments of Brain and Cognitive Sciences and McGovern Institute for Brain Research, and afraz@mit.edu.
authors.forename: Arash
authors.initials: A
authors.lastname: Afraz
authors.affiliation: Departments of Brain and Cognitive Sciences and McGovern Institute for Brain Research, and Biological Engineering, MIT Media Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139.
authors.forename: Edward S
authors.initials: ES
authors.lastname: Boyden
authors.affiliation: Departments of Brain and Cognitive Sciences and McGovern Institute for Brain Research, and.
authors.forename: James J
authors.initials: JJ
authors.lastname: DiCarlo
mesh_terms: D000818:Animals; D055724:Electrophysiological Phenomena; D005145:Face / Q000033:anatomy & histology*; D005260:Female; D058785:GABA-A Receptor Agonists / Q000008:administration & dosage; D008253:Macaca mulatta / Q000033:anatomy & histology* / Q000502:physiology*; D008297:Male; D009118:Muscimol / Q000008:administration & dosage; D062308:Optogenetics; D012727:Sex Characteristics; D013702:Temporal Lobe / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D014796:Visual Perception / Q000187:drug effects / Q000502:physiology
chemical_list: D058785:GABA-A Receptor Agonists; D009118:Muscimol
keywords: face; gender discrimination; inferior temporal cortex; object recognition; optogenetics