Abstract
Prior to 9 months of age, infants can discriminate between both own- and other-race faces using behavioral paradigms (e.g., Kelly, Quinn et al., 2007). However, the neural mechanisms underlying this early discrimination are not well understood. Here we examined adult and 6-month-olds infants' neural discrimination of faces within own- and other-race groups using steady state visual evoked potentials (ssVEP's). Continuous EEG was recorded in a group of Caucasian adults (preliminary n=4) and 6-month-old infants (n=10) while a single face from one of four racial groups (Caucasian, African American, Asian, or Hispanic) was presented at a frequency of 6Hz (the standard) for 20 second trials. Every 5th face was a different individual within the same race (the oddball). In general, a 6Hz response to faces was present for both adults and infants. For adults, an overall oddball response at 1.2Hz (6Hz/5) was also present indicating discrimination of exemplars within race. However, an analysis of the different face groups revealed a significant oddball response for Caucasian (p< 0.001) and African American (p< 0.001) faces but not for Asian or Hispanic faces (see Figure 1). We hypothesize that increased discrimination of faces within Caucasian and African American face groups are driven by different underlying mechanisms. Inspection of individual infant data revealed that the infants also exhibited an oddball (1.2Hz) response, however the topography of the response varied across infants with some showing peaks occurring over anterior electrode locations and others over posterior electrode locations. These results suggest increased neural variability across infants and within the infant brain and suggests that infants may recruit attentional (anterior) and/or perceptual (posterior) resources when learning to discriminate. Based on the findings with adults, we predict that the neural systems that underlie face discrimination stabilize to primarily posterior regions by adulthood.
Meeting abstract presented at VSS 2017