Association Between Brain Function Measures and Parent-Child Interactions in the Autism Phenotype

Background: Evidence suggests that autism emerges in toddlerhood as a result of early subtle differences in brain function within the first year that become compounded and amplified due to atypical interactions within developing brain systems and with the external environment (Elsabbagh and Johnson, 2010). Such dynamic and complex developmental pathways are difficult to test empirically. One approach is to explore links between brain function measures collected under controlled laboratory conditions and more naturalistic measures such as of parent-child interactions. Such associations may help clarify how atypical development of brain systems manifest at the behavioral level.

Objectives:  We explored links between brain function measures in response to gaze stimuli and patterns of parent-child interactions in a group of 104 infants with and without a family history of autism in the first year of life.

Methods:   Participants were drawn from the British Autism Study of Infant Siblings (BASIS) and included 104 families recruited sequentially into the study. Within this group, there were 54 at-risk infants (21 male, 33 female) and 50 control infants (21 male, 29 female). The infants were on average 7-months at the time of the study (mean = 238.3 days, SD= 37.2). Approximately 30% of the infants in the at-risk group received an autism diagnosis as toddlers. Data from two tasks were used for the current study. In the first task, ERPs were recorder while infants were seated on their parents' lap and facing a computer screen on which were images of female faces with gaze directed either towards or away from the infant. The second task was a Parent-child interaction (PCI) assessment, where a 6-min episode of unstructured play was videotaped during which the parent-infant dyad was seated on a floor mat in a room with a small set of toys.

Results:  After initial exploration of factor structure within each task using Principal Component Analysis, variables which explained most of the variance were retained from the ERP (P100 latency and P400 amplitude and latency) and PCI (Infant positive affect, attentiveness and liveliness; Parent sensitive responsiveness, and Dyadic mutuality) tasks. Our findings suggest an association between ERP responses to eye gaze and parent-infant interaction measures. In both groups, infants with more positive affect exhibit stronger differentiation to gaze stimuli. This association was observed with the earlier P100 waveform component in the control group but with the later P400 component in infants at-risk. These findings held across the entire group and were not driven by the subgroup of infants who developed autism in toddlerhood.

Conclusions:  These findings suggest that variability in functional brain development is associated with infants’ overt behavior when examined within naturalistic interaction contexts. The results are critical in paving the way for a better understanding of how infant laboratory measures may relate to overt behavior and how both can be combined in the context of predicting risk or clinical diagnosis in toddlerhood.