Distinct face- and house-selective maps in the human ventral occipito-temporal cortex with intracerebral potentials and frequency-tagging
Résumé
Categorization of visual entities is thought to be supported by different neural circuits in the human ventral occipitotemporal cortex (VOTC). Here, we report a global mapping of the VOTC for selective responses to faces and houses with intracerebral EEG in a large population of human subjects. Participants viewed variable objects images presented periodically at 6 Hz with either variable face- or house-images interleaved as every fifth image (separate sequences). Face- and house-selective responses were objectively quantified at the face- or housestimulation frequency (6 Hz/5¼1.2 Hz) and harmonics. Face- and house-selective contacts (20.1% of recorded contacts) were spatially organized along the lateral-tomedial axis, consistent with neuroimaging studies. Importantly, both contact-types, with more face- than house-contacts, were found in the anterior temporal lobe (ATL), a region contaminated by large artifacts in neuroimaging. Moreover, a substantial portion of the ATL-contacts showed no response for other objects at 6 Hz. Finally, fewer contacts responded selectively to both faces and houses (12.2% of recorded contacts) and amplitudes to the two categories were not correlated, offering no evidence that they measure the same neural population for both categories. The results indicate that both posterior
and anterior VOTC contain distinct and distributed neural populations dedicated to categorization of face- and landmark-stimuli.