Physiological Responses to Social and Non-social Reward among Children with Autism

Abstract

Well-documented and widespread functional impairments among those with autism spectrum disorders (ASDs) are often construed as stemming from either reduced sensitivity to or aversion to stimuli that are social in nature. In fact, individuals with ASDs display altered patterns of neural responding to a variety of social stimuli, although familiarity may moderate such effects. Dawson and colleagues (Dawson et al., 2005; Dawson & Bernier, 2007) argue that reduced sensitivity to social stimuli reflects disrupted reward processing, reflected in behavioral and neurological impairments. In this study, I explored the effects of social and nonsocial reward on autonomic functioning among 8- to 12-year old boys with and without ASDs, with attention to the potential moderating effects of familiarity. During a simple matching task, participants with and without ASDs had slower reactions during social versus nonsocial reward, and boys with ASDs were less accurate than controls in their responses. Physiologically, the groups differed on baseline parasympathetic (respiratory sinus arrhythmia; RSA) functioning, but did not differ on baseline sympathetic (cardiac pre-ejection period; PEP) functioning, or on RSA or PEP reactivity. In addition, baseline RSA was correlated with parent-reported social behavior but not observational measures of social functioning. Finally, child RSA and PEP reactivity were not correlated with interaction partners' social behavior during a structured task. These findings may suggest a need to integrate relationship-based and reinforcement-based strategies in intervention, and to further explore relations between parasympathetic function and social behavior among individuals with ASDs.