Frequency-tagged EEG Reveals Category-Selective Responses to Face Race.

Racial-category information in faces is visually and socially salient, and is rapidly extracted by the human brain. Yet, its electrophysiological encoding remains unclear. Event-related potentials findings are mixed, reporting contradictory effects of race on neural responses. To inform this debate, we used fast periodic visual stimulation (FPVS), an alternative objective and implicit method to measure neural face categorization. In Experiment 1, Western European participants viewed a 6 Hz stream of same- or other-race faces with periodic oddball faces from the alternate race. Results showed no above-noise-level race discrimination responses. In Experiment 2, oddball faces were embedded in object streams, presented upright or inverted, to test whether race modulates face categorization. Neural face categorization responses were above noise level for both same- and other-race faces. Importantly, while upright stimuli showed similar responses to both races, inversion selectively reduced responses to same-race faces, resulting in stronger neural responses to other-race faces. These findings suggest that face inversion affects neural responses based on visual expertise with face categories. Overall, our results demonstrate that racial-category information is robustly indexed by FPVS, highlighting this method as a powerful neurofunctional tool to study social vision.