Repetitive Stereotyped Behaviour Impacts Gesturing Behaviour Across Childhood in Children with ASD

Background:  

Children with ASD exhibit repetitive stereotyped behaviours (RSB), such as repeated involuntary arm, head and body movements. Research suggests a link between RSBs and impairments in IQ (Mirenda et al, 2010), but deficits in other domains have yet to be explored. The current study is a preliminary investigation into the impact of stereotyped behaviours on communicative gestures. 

Gestures require the coordination of the body to produce intentional and communicative actions. Thus, a deficit in motor control could potentially influence the ability to produce useful gestures. Furthermore, communicative gestures  (i.e. pointing,) are important because they are the precursors to the development of language (Iverson & Goldin-Meadows, 2005). Therefore, exploring the relationship between motor deficits, as exhibited through RSBs, and gesturing could add a critical component to the understanding of communicative development in children with ASD. Finally, research in this area can potentially inform interventions targeted to communicative development, especially for children with ASD with deviant motor behaviours.

Objectives:

This study investigates the relationship between stereotyped behaviours on gesturing skills in children with ASD. Specifically, we will examine the extent to which variations in motor skills (fine and gross motor), visual-motor coordination, and RSBs predict gesturing behaviour later in development, while accounting for cognitive scores (IQ).

Methods:  

The sample for analyses included 167 children diagnosed with ASD from the Pathways in ASD study who were assessed at ages 2 to 4 years and 11 months (T1) and 4 to 7 years (T2). Fine and gross motor scores were measured using the parental reports on the Vineland Adaptive Behavioural Scale. Standardized cognitive (IQ) and visual-motor scores were measured using the Merril-Palmer-Revised. RSBs were measured using a subscale of the parental report Repetitive Behaviour Scale-Revised and standardized before analysis. Finally, a gesture composite was abstracted from the non-verbal communication scores in the Autism Diagnostic Interview-Revised, reversed coded and standardized. Multiple regression and correlation analysis were used to test whether IQ, visual-motor, or RSBs predicted subsequent gesturing abilities later in childhood.

Results:  

RSBs predicted deficits in the presence of spontaneous gesturing behaviour across both time points, even after accounting for fine and gross motor skills, cognitive scores and visual-motor scores (F (1,7)=4.55, p<0.001). To further investigate this relationship and to control for the documented relationship between IQ and stereotyped behaviour, children were divided into two groups, low and high IQ as segregated by the median. Analysis revealed a significant negative correlation between RSBs and gesturing behaviour. However, this relationship was stronger in children with lower IQ (r= -0.35, p<0.01) than for those with higher IQ (r=-0.22, p < 0.05).

Conclusions:  

Study findings suggest that children with ASD who have elevated stereotyped behaviours may be at risk of using less spontaneous gestures during development, perhaps due to an inability to produce them. Future studies can identify whether this negatively impacts language development in later childhood.  Finally, interventions for children with stereotyped behaviours might benefit from inclusion of exercises that promote communicative gestures to circumvent the potential impact of a lack of motor control.