Respiratory Sinus Arrhythmia: A Moderator of Emotion Regulation and Social Motivation Deficits in ASD

Background: The social motivation theory of autismposits that the social deficits observed in autism spectrum disorder (ASD) may be attributed to dysfunctions in the social reinforcement mechanisms that are seen in typically developing individuals (Chevallier, Kohls, Troiani, Brodkin, & Schultz, 2012). Furthermore, individuals with ASD often have self-regulation difficulties, particularly in areas such as emotion regulation (ER; Samson, Huber, & Gross, 2012). Deficits in ER strategies are associated with social withdrawal and seem to contribute to the lack of social motivation observed in ASD (Laurent & Rubin, 2004). In typically developing populations, higher levels of respiratory sinus arrhythmia (RSA) are thought to promote flexible behavior necessary for navigating social interactions (Thayer & Friedman, 2004). Studies have similarly shown that higher baseline RSA is related to better social functioning in children with ASD (Patriquin, Scarpa, Friedman, & Porges, 2013). For this reason, higher baseline RSA may be a protective factor that moderates the relationship between emotion regulation deficits and social motivation in ASD. 

Objectives: The study aims to establish whether emotion regulation significantly predicts social motivation in children with ASD. We also assess baseline RSA as a moderator of this relationship.

Methods: Baseline RSA was collected for three minutes in 22 children (4-7 years old, 17 males, 5 females) with an ASD diagnosis. Parents completed the Social Responsiveness Scale (SRS; Constantino, 2002) and the emotion regulation (ER) subscale score from the Emotion Regulation Checklist (Shields & Cicchetti, 1997). Linear regression analysis was used to predict the influence of ER and baseline RSA on social motivation SRS subscale scores, and simple slopes were calculated to assess the moderating effect of baseline RSA.

Results: In a multiple regression equation where ER and baseline RSA were entered as predictors for social motivation, the main effect of ER approached significance, β = -1.297, t(21) = -1.997, p = 0.06. There was no main effect of baseline RSA on social motivation. A significant interaction effect of baseline RSA x ER was also present, β = 1.246, t(21) = 2.21, p = 0.04. Simple t-tests were performed to compare the slopes of ER onto social motivation regression lines at different levels baseline RSA. There was a negative relationship between ER and social motivation scores at lower levels of baseline RSA, t(20) = -3.71, p = 0.002. At higher levels of baseline RSA, ER did not significantly predict social motivation score.

Conclusions: Baseline RSA moderates the predictive ability of ER on social motivation in children with ASD. Higher baseline RSA levels act as a protective factor for the effect of ER on social motivation, such that poor ER did not significantly predict social motivation difficulties in ASD. However, at lower baseline RSA levels, poor ER significantly predicted more severe social motivation deficits. These findings suggest that children with ASD, who also have low baseline RSA, may benefit from emotion regulation interventions.