Have It, Know It, but Do Not Show It: Examining Physiological Arousal, Anxiety, and Facial Expressions over the Course of a Social Skills Intervention for Autistic Adolescents

Facial expressions provide a nonverbal mechanism for social communication, a core challenge for autistic people. Little is known regarding the association between arousal, self-report of anxiety, and facial expressions among autistic adolescents. Therefore, this study investigated session-by-session facial expressions, self-report of anxiety, and physiological arousal via Electrodermal Activity (EDA), of 12 autistic male adolescents in a didactic social skills intervention setting. The goals of this study were threefold: 1) identify physiological arousal levels (\"have-it\"), 2) examine if autistic adolescents facial expressions indicated arousal (\"show-it\"), and 3) determine whether autistic adolescents were self-aware of their anxiety (\"know-it\"). Our results showed that autistic adolescents self-rated anxiety was significantly associated with peaks in EDA. Both machine learning algorithms and human participant-based methods, however, had low accuracy in predicting autistic adolescents arousal state from facial expressions, suggesting that autistic adolescents facial expressions did not coincide with their arousal. Implications for understanding social communication difficulties among autistic adolescents, as well as future targets for intervention, are discussed. This project is registered with ClinicalTrials.gov, Identifier: NCT02680015.