Open AccessTuning face perception with electrical stimulation of the fusiform gyrus
Author(s) -
Keller Corey J.,
Davidesco Ido,
Megevand Pierre,
Lado Fred A.,
Malach Rafael,
Mehta Ashesh D.
Publication year - 2017
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.23543
Subject(s) - fusiform gyrus , stimulus (psychology) , fusiform face area , psychology , neuroscience , perception , face perception , stimulation , electrophysiology , visual perception , visual cortex , electroencephalography , cognition , audiology , cognitive psychology , medicine
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. [[Parvizi J, 2012]]: 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.