Dynamics of Social Movement Coordination As a Pathway to Understanding ASD-Specific Social Deficits

Background:  The processes underlying the social deficits of individuals with Autism Spectrum Disorder (ASD) are not fully understood. When human beings interact with others, we implicitly coordinate our bodies and this has been found to facilitate interpersonal connections (e.g., Lakin & Chartrand, 2003). It is possible that such social movement coordination may be an important key for increasing understanding of ASD-specific social deficits (Fitzpatrick et al., 2013).  Research that provides finer grained measures of mechanisms underlying social deficits in ASD may help elucidate the contradictory research and shed light on how it is that individuals with ASD can have very real problems in naturalistic social situations even though they are able to successfully perform social experimental tasks (e.g., Klin, 2000). 

Objectives:  This research evaluates whether fine-grained dynamical social movement coordination measures can provide insight into understanding ASD-specific social deficits.  In particular, we tested whether dynamical measures of social movement coordination differentiate those with ASD, whether those differences were due solely to motor control problems, and explored the relationship between social movement measures and clinical assessments of social skill. 

Methods:  47 typically developing children and 35 age-matched children with autism (M = 101.34; SD = 16.85, Range 72 -131 months) completed a series of clinical assessments and social cognitive tasks (theory of mind (ToM), joint attention, cooperation tasks).  Social movement coordination was evaluated through an imitation and synchrony battery as well as an interpersonal game of pat-a-cake. Motor coordination was measured during in-phase and anti-phase drumming.  The movements of the participants and the experimenter were recorded with a Polhemus and the time-series underwent cross-spectral coherence analysis to measure the correlation between the two time-series and the degree of co-occurrence of the interpersonal movements. 

Results:  Children with ASD had significantly lower coherence scores than TD children in imitation and synchrony (p < .001) and pat-a-cake (p = .003).  In addition, coherence was lower for imitation than synchrony (p < .001) for both groups.   Children with ASD had lower coherence scores during drumming (p < .001) and coherence was lower for anti-phase than in-phase drumming (p < .001).  Significant group differences were found on some social cognitive measures (responding to joint attention, visual perspective taking, behavioral interruption) but not others (ToM, behavioral reenactment, or initiating joint attention).   There were significant correlations between social movement coordination and VABS social domain, and CBCL attention, social problems, and thought problems.  Social movement coordination was not correlated with in-phase or anti-phase drumming.

Conclusions:  Our findings suggest that children with ASD have difficulty synchronizing their movements with another person.  Although children with ASD also exhibited poorer motor coordination, the social movement problems do not appear to be simply a motor control deficit as these measures were not related.  Social movement measures were related, however, to clinical assessments of social deficits. While coordinating ones movements with another person typically helps to facilitate social connection, these findings suggest that children with ASD have disruptions in social movement coordination that may interfere with the formation of social bonds.