Imitation of Socially Rewarding and Non-Socially Rewarding Actions in Preschoolers with ASD

Background: While imitation difficulties and atypical reward processing have been documented in preschoolers with ASD, the link between these phenomena is poorly understood. As imitation is a common treatment target and provision of contingent rewards is a common treatment procedure in ASD early intervention, a fine-grained understanding of how imitative responses in ASD are modulated by reward has the potential to provide critical insight on both mechanisms of impairment and mechanisms of treatment response in this population.

Objectives:  We investigated how young children with ASD imitated actions that were either instrumental to achieve a non-social reward or a social reward compared to typically developing children and children with Williams Syndrome (WS). The aim was to identify whether putative imitation differences between the groups were (1) modulated by the social versus non-social nature of the demonstrated actions and (2) linked to learning outcomes in response to early intervention in ASD.

Methods:  Participants were 35 preschoolers with ASD and 20 peers with WS, matched for age, cognitive, verbal and motor functioning as well as 20 typically developing peers matched for chronological age. We tested participants’ spontaneous imitation performance in response to a series of novel eye-tracking-based imitation tasks, in which the to-be-imitated actions achieved either a non-social reward (obtaining a desired toy from a container) or a social reward (shared enjoyment between the demonstrator and the imitator). In the ASD group, we also examined the extent to which individual differences in imitation were correlated to intervention gains occurring in the 12 months following the test.

Results:  We found that children in the ASD group imitated actions that were instrumental to achieving non-social rewards as frequently as participants in the TD and WS groups. Conversely, imitation performance was lower in ASD compared to the control groups in response to the demonstration of actions accomplishing social rewards (F (2, 67)= 9.87; p< .01). Similarly, eye-tracking patterns were similar across groups in response the demonstration of actions achieving non-social rewards, while children in the ASD group were less focused on the model’s face during the observation of actions achieving a social reward (p<.05). Imitative response to socially rewarding actions was associated with response to early intervention outcomes (r=.7, p<.005).

Conclusions: Atypical reward processing modulates imitation performance in ASD. Imitation of socially rewarding actions is distinctively impaired in young children with ASD and sensitivity to the socially rewarding nature of demonstrated actions is linked to early intervention outcomes.