Effects of Joint Interaction on Pretend Play Abilities in Children with Prader-Willi Syndrome & Autism Spectrum Disorder

Background: The processes involved in pretend play are associated with positive skill development in children. Due to its importance, play deficits have been described in children with developmental disorders, including autism spectrum disorder (ASD). It is well established that children with ASD partake in rigid and stereotyped behaviors, which limit their symbolic play abilities. Current research also suggests that individuals with Prader-Willi Syndrome (PWS) have social deficits and repetitive behaviors similar to that of ASD. This link to ASD may result from the genetic underpinnings of PWS. Specifically, PWS is primarily caused by paternal deletions (DEL) of chromosome 15 (q11-13 region), where there is an absence of gene expression from the paternally inherited copy of chromosome 15 or maternal uniparental disomy (mUPD), where two copies of chromosome 15 are derived from the mother. Those with mUPD are at greater risk for ASD symptomatology and duplications of this same 15q11-13 region are strongly associated with autism, occurring in 3-5% of cases with idiopathic autism.

Objectives: The present study sought to further characterize the PWS social phenotype by examining play, and add to current ASD literature on the effects of joint interaction during play. We aimed to identify abilities of pretend play that may be impaired in these populations and determine if the addition of a play partner would increase play abilities in either population. 

Methods: 14 children with PWS (mean age = 10.27) and 10 children with ASD (mean age = 10.39), matched for age and IQ, underwent intelligence testing (WISC-IV) and the Autism Diagnostic Observation Schedule (ADOS) as part of a larger, ongoing research project. The ADOS sessions were recorded and play abilities were assessed through a modified Affect in Play Scale (APS; Russ, 2004). Specifically, the modified APS scored participants on scaled measures of comfort, imagination in play, organization of storyline, affective expression in play, frequency of symbolic, functional, and no play acts, and number of repetitive actions during both individual and joint play periods. Measures of intervention and responsiveness were also scored during joint play to assess if the child’s play ability benefited from the presence of an adult, who could scaffold the play for the child.

Results: Preliminary results show that both groups scored at least one standard deviation below normative scores on measure of imagination (ASD = 1.2; PWS = 1.15), organization (ASD = 1.2; PWS = 1.15), and affective frequency (ASD = 0.60; PWS = 0.46) during the individual play period. Results also indicate that the addition of a play partner during the joint play period increased all scaled scores on the APS. Within the ASD group, joint interaction increased the frequency of symbolic play. However, for the PWS group, joint play led to a frequency increase in all types of play. 

Conclusions: These results suggest that structured interventions targeting specific pretend play abilities (i.e. symbolic play, organization, and affect) for children with ASD and PWS may help increase this skill set and may help social and emotional development within these populations.