Visual attention in infants at-risk for autism

Background: Recent studies of infant siblings of children diagnosed with autism have allowed for a prospective approach to examine the emergence of symptoms and revealed behavioural differences in the broader autism phenotype within the early years. In the current study we focused on a set of functions associated with visual attention, previously reported to be atypical in autism.

Objectives: The aim was to assess whether visual attention functions differ in infants at-risk relative to a matched control group.

Methods: We compared performance of a group of 40 6-10-month-old infant siblings of children with autism (sib-ASD) to a control group with no family history of autism on the “gap-overlap task”, which measures the cost of disengaging from a central stimulus in order to fixate a peripheral stimulus. Two measures were derived on the basis of infants’ saccadic reaction times. The first is the Disengagement effect, which measures the efficiency of disengaging from a central stimulus to orient to a peripheral one. The second was a Facilitation effect, which arises when the infant is cued by a temporal gap preceding the onset of the peripheral stimulus, and would orient faster after its onset.

Results: The sib-ASD group showed longer Disengagement latency as well as less Facilitation relative to the control group.

Conclusions: These differences indicate that certain characteristics of the broader autism phenotype are present in infancy and may relate to differences in scanning both social and non-social stimuli.