THE NEURAL DYNAMICS OF FAMILIAR FACE RECOGNITION
Recognizing individual faces is a challenging task for the visual system. Recently, fMRI decoding studies have revealed face identity representations in the occipitotemporal cortex. To uncover the temporal emergence of these representations, we used representational similarity analyses (RSA) of EEG responses for familiar faces. The participants viewed a set of ambient face images of four highly familiar celebrities (two male, two female), while performing an orthogonal task. While univariate analyses revealed a differentiation between male and female faces, they were not able to show a distinction between identities of the same sex, multivariate RSA, on the other hand, demonstrated a gradual emergence of face identity representations, with an increasing degree of invariance. We observed the rapid emergence of identity information, starting shortly after 100ms, modulated by sex differences and image similarities. From 400ms after onset and predominantly in the right hemisphere, we observed a high degree of discriminability between both opposite and within-sex stimuli, and a tolerance for image-dependent variations. As the appearance of a familiar person can vary drastically, these invariant representations may be a crucial prerequisite for successful face recognition in everyday situations.