Early Joint Attention Behaviors in Infants at High Familial Risk for Autism Spectrum Disorder: association with cortical development

Joint attention is the ability to follow the gaze of others, which allows infants to share a common focus on individuals or objects. Impairments in initiating and responding to joint attention are some of the earliest indicators of Autism Spectrum Disorder (ASD). Subcortical brain areas are implicated in joint attention, but less is known about cortical regions and joint attention behaviours in infancy. In this longitudinal study, 101 high-risk infants (64% males) with an older biological sibling with ASD underwent MRI scanning at 4 or 6 months of age and were assessed for joint attention behaviours at 2 years of age. Brain volumes were automatically extracted. High-risk infants with ASD demonstrated atypical initiating and responding joint attention behaviours compared to those who did not. When examining cortical regions in relation to initiating and responding to joint attention behaviours, significant associations were found between the left posterior cingulate gyrus and impaired initiating joint attention in infants who developed ASD. Additionally, the right cuneus was associated with impaired initiating joint attention in this group. Better characterization of the neural mechanisms underlying initiating joint attention can help identify biomarkers to assess the efficacy of therapies to promote improved social and behavioural outcomes.