High-Atypicality Infant Siblings of Children with Autism: A Prospective Study of Mother-Infant Interaction

Background: Infant siblings of children with autism spectrum disorder (A-sibs) – who are themselves at genetic risk of autism –are more likely to exhibit early social and communicative difficulties than typically developing siblings (TD-sibs). Prospective observational studies, including our own, further show that mother-infant interactions in A-sibs show specific subtle but consistent differences in early-middle infancy from TD-sibs, which may exacerbate the infants’ social atypicalities through their experiencing or seeking of a less optimal early interactive environment. Little is known about the developmental trajectory of such mother-infant interactions through the first year.

Objectives: To compare mother-infant interaction characteristics between A-sib infants at 6-10 months and 12-15 months, with and without high phenotypic autism risk, and TD-sib controls.

Methods: Ninety 6-min mother-infant unstructured play interactions were videotaped within the British Autism Study for Infant Siblings (BASIS). The videotapes were rated, blind to dyad information, on a global rating scheme which involved 3 maternal, 3 infant and 2 dyadic dimensions. The rating scheme has been revised from previous presentations of our data, and was developed based on typical developmental, attachment, and autism literatures and previously validated scales.

Results: A preliminary analysis of N=55 at 6-10 months found that, as a group, the mothers of A-sib infants with high phenotypic atypicality were more likely to show lower sensitive responsiveness and low acceptance of infant behaviour. Here, we will present findings for the full sample across two time points in infancy.

Conclusions: Measures collected in this study reflect dyadic characteristics and hence neither maternal nor infant behavior could be described as causing the atypicality. The amelioration, stability or exacerbation of such interactional characteristics would have implications for early (prodromal) intervention.

* The BASIS Team in alphabetical order: S. Baron-Cohen^a, P. Bolton^b, T. Charman^c, H. Garwood^d, L. Tucker^d, and A. Volein^d
aUniversity of Cambridge, ^bInstitute of Psychiatry, ^cInstitute of Education, ^dBirkbeck, University of London