BACKGROUND: Previous studies have documented atypicalities in face/object processing in children and adults with autism spectrum disorders (ASD). To investigate whether such atypicalities may reflect a genetically-mediated risk factor present early in development, we measured face/object processing in 10-month-old “High-Risk” infants, who carry some of the genes associated with ASD because they have an older sibling diagnosed with the disorder. METHODS: We employed event related potentials (ERPs) to measure cortical responses to pictures of faces and objects, the objects being pictures of toys. Latencies and amplitudes of four ERP components (P100, N290, P400 and Nc) were compared between 20 High-Risk infants and 20 Low-Risk controls (infants with no family history of ASD). RESULTS: Responses to faces vs. objects differed between High- and Low-Risk infants, for the latencies of the N290 and P400. Differences were driven by faster responses to faces than objects in Low-Risk, but not High-Risk, infants (P400), and conversely, faster responses to objects than faces in High-Risk, but not Low-Risk, infants (N290). And, object responses were faster in High-Risk than Low-Risk infants (both N290 and P400). Left vs. right hemisphere responses also differed between High- and Low-Risk infants, for the amplitudes of the P100, N290 and P400; collapsed across faces/objects, Low-Risk, but not High-Risk, infants exhibited hemisphere asymmetries. CONCLUSIONS: Genetic risk for ASD is associated with atypical face vs. object processing, and an atypical lack of hemispheric asymmetry, early in life. These atypicalities might contribute to development of the disorder
