title: Tuning face perception with electrical stimulation of the fusiform gyrus.
abstract: The fusiform gyrus (FG) is an important node in the face processing network, but knowledge of its causal role in face perception is currently limited. Recent work demonstrated that high frequency stimulation applied to the FG distorts the perception of faces in human subjects (Parvizi et al. []: J Neurosci 32:14915-14920). However, the timing of this process in the FG relative to stimulus onset and the spatial extent of FG's role in face perception are unknown. Here, we investigate the causal role of the FG in face perception by applying precise, event-related electrical stimulation (ES) to higher order visual areas including the FG in six human subjects undergoing intracranial monitoring for epilepsy. We compared the effects of single brief (100 μs) electrical pulses to the FG and non-face-selective visual areas on the speed and accuracy of detecting distorted faces. Brief ES applied to face-selective sites did not affect accuracy but significantly increased the reaction time (RT) of detecting face distortions. Importantly, RT was altered only when ES was applied 100ms after visual onset and in face-selective but not place-selective sites. Furthermore, ES applied to face-selective areas decreased the amplitude of visual evoked potentials and high gamma power over this time window. Together, these results suggest that ES of face-selective regions within a critical time window induces a delay in face perception. These findings support a temporally and spatially specific causal role of face-selective areas and signify an important link between electrophysiology and behavior in face perception. Hum Brain Mapp 38:2830-2842, 2017. © 2017 Wiley Periodicals, Inc.
authors.affiliation: Department of Neurosurgery, Hofstra Northwell School of Medicine, and Feinstein Institute for Medical Research, Manhasset, New York.|Departments of Neuroscience and Neurology, Albert Einstein College of Medicine, Bronx, New York.|Departments of Psychiatry and Behavioral Sciences and Stanford Neuroscience Institute, Stanford University School of Medicine, Stanford, California.
authors.forename: Corey J
authors.identifier: 0000-0003-0529-3490
authors.initials: CJ
authors.lastname: Keller
authors.affiliation: Department of Psychology, New York University.
authors.forename: Ido
authors.initials: I
authors.lastname: Davidesco
authors.affiliation: Department of Neurosurgery, Hofstra Northwell School of Medicine, and Feinstein Institute for Medical Research, Manhasset, New York.
authors.forename: Pierre
authors.initials: P
authors.lastname: Megevand
authors.affiliation: Departments of Neuroscience and Neurology, Albert Einstein College of Medicine, Bronx, New York.|Department of Neurology, Montefiore Medical Center, Bronx, New York.
authors.forename: Fred A
authors.initials: FA
authors.lastname: Lado
authors.affiliation: Weizmann Institute for Science, Rehovot, Israel.
authors.forename: Rafael
authors.initials: R
authors.lastname: Malach
authors.affiliation: Department of Neurosurgery, Hofstra Northwell School of Medicine, and Feinstein Institute for Medical Research, Manhasset, New York.
authors.forename: Ashesh D
authors.initials: AD
authors.lastname: Mehta
mesh_terms: D000328:Adult; D001931:Brain Mapping; D003198:Computer Simulation; D046690:Deep Brain Stimulation / Q000379:methods*; D000069279:Drug Resistant Epilepsy / Q000503:physiopathology* / Q000628:therapy*; D004567:Electrodes, Implanted; D005074:Evoked Potentials, Visual; D000066499:Facial Recognition / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D013702:Temporal Lobe / Q000502:physiology*; D055815:Young Adult
keywords: cortico-cortical evoked potentials; electrical stimulation; electrocorticography; fusiform gyrus; high gamma power