Abstract
The present study examined the extent to which visual attention and perceptual discrimination of faces from familiar and unfamiliar race groups differs in two longitudinal cohorts of infants (6 to 9 months of age (n=14) and 9 to 12 months of age (n=18). Infants within each cohort completed a Fast Periodic Visual Stimulation (FPVS) EEG task designed to index attention and individuation of familiar race and unfamiliar race (1 of 3 races) faces. For FPVS, separate blocks of familiar and unfamiliar race faces were presented at a rate of 6 Hz and every 5th face was a different individual (1.2 Hz). Data was analyzed using a novel moving-window technique (Figueira et al, under review) designed for use with infants or other populations which may exhibit increased noise. The moving-window analysis amplifies any oscillation that is time and phase-locked to the driving stimulus and attenuates oscillations that vary in terms of their phase or frequency. As expected, the 6Hz response was present over middle occipital brain regions, but it did not differ for familiar and unfamiliar races. Preliminary results showed that the 1.2Hz individuation response was significant for all ages and both cohorts with a more lateralized topographic distribution. In addition, infants in the younger cohort showed a marginally greater 1.2 Hz response for the familiar race faces at 6 months of age relative to 9 months of age over left occipital brain regions. Like previous work (Barry-Anwar et al., 2018) the present results suggest that infants as young as 6 months of age individuate own- and other- race faces, however the response decreases from 6 to 9 months of age for familiar race faces suggesting that experience may impact this response.