From early markers to neuro-developmental mechanisms of autism

Highlights

• •

  Studies of infants at-risk could reveal the developmental origin of autism.

• •

  Behavioral and brain markers differentiate infants that develop autism symptoms from controls, during the first year of life.

• •

  Little evidence for decreased social orienting or social motivation.

• •

  Some evidence for multiple developmental pathways to autism.

Abstract

A fast growing field, the study of infants at risk because of having an older sibling with autism (i.e. infant sibs) aims to identify the earliest signs of this disorder, which would allow for earlier diagnosis and intervention. More importantly, we argue, these studies offer the opportunity to validate existing neuro-developmental models of autism against experimental evidence. Although autism is mainly seen as a disorder of social interaction and communication, emerging early markers do not exclusively reflect impairments of the “social brain”. Evidence for atypical development of sensory and attentional systems highlight the need to move away from localized deficits to models suggesting brain-wide involvement in autism pathology. We discuss the implications infant sibs findings have for future work into the biology of autism and the development of interventions.