The face-sensitive N170 encodes social category information.

Prominent models of face perception posit that the encoding of social categories begins after initial structural encoding has completed. In contrast, we hypothesized that social category encoding may occur simultaneously with structural encoding. While event-related potentials were recorded, participants categorized the sex of sex-typical and sex-atypical faces. Results indicated that the face-sensitive right N170, a component involved in structural encoding, was larger for sex-typical relative to sex-atypical faces. Moreover, its amplitude predicted the efficiency of sex-category judgments. The right P1 component also peaked earlier for sex-typical faces. These findings show that social category encoding and the extraction of lower-level face information operate in parallel, suggesting that they may be accomplished by a single dynamic process rather than two separate mechanisms.