title: Functional mapping of face-selective regions in the extrastriate visual cortex of the marmoset.
abstract: The cerebral cortex of humans and macaques has specialized regions for processing faces and other visual stimulus categories. It is unknown whether a similar functional organization exists in New World monkeys, such as the common marmoset (Callithrix jacchus), a species of growing interest as a primate model in neuroscience. To address this question, we measured selective neural responses in the brain of four awake marmosets trained to fix their gaze upon images of faces, bodies, objects, and control patterns. In two of the subjects, we measured high gamma-range field potentials from electrocorticography arrays implanted over a large portion of the occipital and inferotemporal cortex. In the other two subjects, we measured BOLD fMRI responses across the entire brain. Both techniques revealed robust, regionally specific patterns of category-selective neural responses. We report that at least six face-selective patches mark the occipitotemporal pathway of the marmoset, with the most anterior patches showing the strongest preference for faces over other stimuli. The similar appearance of these patches to previous findings in macaques and humans, including their apparent arrangement in two parallel pathways, suggests that core elements of the face processing network were present in the common anthropoid primate ancestor living ∼35 million years ago. The findings also identify the marmoset as a viable animal model system for studying specialized neural mechanisms related to high-level social visual perception in humans.
authors.affiliation: Cerebral Microcirculation Section, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, Section on Cognitive Neurophysiology and Imaging, Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: Chia-Chun
authors.identifier: http://orcid.org/0000-0002-5264-9165
authors.initials: CC
authors.lastname: Hung
authors.affiliation: Cerebral Microcirculation Section, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: Cecil C
authors.initials: CC
authors.lastname: Yen
authors.affiliation: Cerebral Microcirculation Section, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Ciuchta
authors.affiliation: Cerebral Microcirculation Section, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: Daniel
authors.initials: D
authors.lastname: Papoti
authors.affiliation: Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada, and.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Bock
authors.affiliation: Section on Cognitive Neurophysiology and Imaging, Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, Neurophysiology Imaging Facility, National Institute of Mental Health, National Institute of Neurological Disorders and Stroke, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20182.
authors.forename: David A
authors.identifier: http://orcid.org/0000-0002-1345-6360
authors.initials: DA
authors.lastname: Leopold
authors.affiliation: Cerebral Microcirculation Section, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, SilvaA@ninds.nih.gov.
authors.forename: Afonso C
authors.identifier: http://orcid.org/0000-0002-6105-7567
authors.initials: AC
authors.lastname: Silva
mesh_terms: D000818:Animals; D001931:Brain Mapping; D002144:Callithrix; D005145:Face; D059907:Functional Neuroimaging; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010775:Photic Stimulation; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*
keywords: ECoG; evolution; fMRI; face; marmoset; visual cortex