This project will examine the behavioral, attentional, and neural consequences of the bias that prioritizes nonsocial over social sources of stimulation that appears to be pathognomonic of autism. A primary consequence of this nonsocial bias may be both the development of circumscribed interests and the canalization of experience-dependent development away from social experience at a young age. If this is true, then nonsocial bias may constrain social learning and development in ASD. For this reason, isolation and measurement of nonsocial bias at an early age in ASD may assist in the design of novel forms of early intervention to help overcome the social cognitive and behavioral deficits of ASD. This project will: (1) Determine if circumscribed interests (CI) occur in toddlers with ASD and are associated with functional impairment, (2) Determine if visual attention in toddlers with ASD is biased toward nonsocial sources of information and if this attentional bias is associated with the expression of CI, and (3) Determine if toddlers with ASD demonstrate alterations in magnitude of the ERP/LPP component to nonsocial stimuli and if atypical neural responses to nonsocial stimuli are associated with CI.