Changes in EEG Asymmetry, ERP to Affective Stimuli, and Social Motivation and Cognition in Young Adults Completing PEERS® Intervention

Background:  Social challenges amongst adults with ASD lead to isolation, lack of friendships, and emotional difficulties (Venter, Lord, & Schopler, 1992). The Program for the Education and Enrichment of Relational Skills for Young Adults (PEERS®: Gantman, Kapp, Orenski, & Laugeson, 2012) teaches verbal young adults with ASD the social skills needed in order to make and keep friends. The program was based on PEERS® for adolescents (Laugeson & Frankel, 2010). One study (Van Hecke et al., 2013) found that adolescent PEERS® participants showed changes in EEG (electroencephalogram) asymmetry, indicative of more relative left hemisphere activation, that was also related to social contact gained from the program.

Objectives: No published studies have evaluated the effects of PEERS® for Young Adults on brain function. This study will examine how PEERS® affects measures of EEG asymmetry and ERP (evoked response potential). This study also seeks to understand whether behavioral improvements from the intervention are related to changes in EEG asymmetry and ERP.

Methods: The analysis included 32 young adults with ASD (18 to 26 years old), split evenly between the Experimental Immediate treatment (EXP), and the Waitlist Control (WL) group. All participants had a verbal IQ > 70 and diagnoses were confirmed with the ADOS. The intervention was a randomized controlled trial (RCT) of PEERS® for Young Adults. Measures were taken at pre- and post-intervention and included: (1) the Social Responsiveness Scale (caregiver report; SRS: Constantino, 2005); (2) a 3-minute resting state EEG, from which frontal and temporal-parietal alpha asymmetry were calculated, and (3) and an ERP paradigm utilizing positive and negative social/nonsocial IAPS (International Affective Picture System: Lang, Bradley, & Cuthbert, 2008).

Results: A significant time by group interaction for alpha asymmetry in the temporal-parietal region was found (F(1, 19) = 4.37, p < .05), indicating a relative increase in left-hemisphere activity in the EXP group, versus a decrease in the WL group. Higher relative activity in the left temporal-parietal region at post-treatment was significantly related to better SRS Social Cognition at post-treatment (r (21) = .49, p < .05) and improvements in SRS Social Motivation (r (21) = -.45, p< .05). Preliminary analysis of available ERP data indicated a significant time by group interaction on P300 responses to social, positive IAPS images, which was driven by an increase in P300 amplitude for the EXP group, vs. a decrease for the WL group. Planned analyses will include two additional cohorts of young adults to further assess PEERS®’ effects on caregiver-report on the SRS, as well as augment EEG asymmetry and ERP analyses.

Conclusions: Young adults receiving the PEERS® intervention demonstrated significant changes in EEG asymmetry and ERP to social, positive images, and levels of asymmetry after conclusion of the intervention were related to caregiver reports of social motivation and cognition. The results from this study corroborate neural outcomes of PEERS® reported on adolescents with ASD (Van Hecke et al., 2013).