Neural correlates of familiar and unfamiliar face processing in infants at risk for autism spectrum disorders.

Examining the neural correlates associated with processing social stimuli offers a viable option to the challenge of studying early social processing in infants at risk for autism spectrum disorders (ASDs). The present investigation included 32 12-month olds at high risk for ASD and 24 low-risk control infants, defined on the basis of family history. Infants were presented with familiar and unfamiliar faces, and three components of interest were explored for amplitude and latency differences. The anticipated developmental effects of emerging hemispheric asymmetry for face-sensitive components (the N290 and P400) were observed, as were familiarity effects for a component related to attention (the Nc). Although there were no striking group differences in the neural response to faces, there was some evidence for a developmental lag in an attentional component for the high-risk group. The infant ASD endophenotype, though elusive, may be better defined through expanding the age of study and addressing change over time in response to varied stimuli.