The Social Feedback Hypothesis and Communicative Development in Autism Spectrum Disorder: A Response to Akhtar, Jaswal, Dinishak, and Stephan (2016).

Akhtar et al. (2016) suggest that individuals with autism spectrum disorder (ASD) often have motor difficulties and that such motor difficulties could reduce the ability of those individuals to produce speech or speech-related sounds. Akhtar et al. also indicate that it could be counterproductive to focus on social motivation to communicate as a factor underlying reduced volubility in this group. That some individuals with ASD have reduced motor and motor-learning abilities does not imply that their motor learning is not shaped in part by social feedback. Motor difficulties of children with ASD are entirely compatible with the our (Warlaumont, Richards, Gilkerson, & Oller, 2014) social-feedback-loop hypothesis. Motor-skill learning is influenced by reward (e.g., Buitrago, Ringer, Schulz, Dichgans, & Luft, 2004; Izawa & Shadmehr, 2011), so it is plausible that contingent social responses positively reinforce children both with and without ASD as they develop motor speech skills. Supporting this possibility, several computational models have shown how speech learning can be viewed as a type of motor learning that is influenced by reward (Howard & Messum, 2014; Miura, Yoshikawa, & Asada, 2012; Warlaumont & Finnegan, 2016; Warlaumont, Westermann, Buder, & Oller, 2013). At the same time, we do not reject the possibility that disruption in motivation to communicate might also play a role in the reduced numbers of vocalizations by some children with ASD. Some adults with ASD indicate that they have high motivation to communicate despite their limitations in motor speech skills, and these case reports demonstrate that not all cases of reduced volubility can be attributed to social motivation. However, such case reports cannot rule out the possibility that reduced social motivation to communicate plays a role for a significant contingent of autistic individuals. Our view on this question concerning the roles of social motivation, motor difficulty, and potentially other factors in reducing vocalization frequency and quality in children with ASD, and how motivation, motor ability, and communicative success dynamically influence each other, will be driven by empirical findings.