Interacting with autistic virtual characters: Intrapersonal synchrony of nonverbal behavior influences participants' perception

Abstract

Temporal coordination of communicative behavior is not only located between but also within interaction partners (e.g., gaze and gestures). This intrapersonal synchrony (IaPS) is assumed to constitute interpersonal alignment. Gaze-gesture delays have been shown to be particularly enlarged and more variable in interactants with autism spectrum disorder (ASD) compared to non-autistic interactants. In the current study, we reversed the approach and mapped the measured behavior of interactants with and without ASD from a previous study onto virtual characters to study the effects of the differential communicative behavior on observers (N = 68), both with and without ASD (crossed design). During an interaction task with both characters, who indicated targets with gaze and delayed pointing gestures, we measured response times, gaze behavior, and post-hoc impression formation.Results show that character behavior indicative of ASD resulted in overall enlarged decoding times in observers and this effect was even pronounced in observers with ASD. A classification of observer’s gaze types indicated differentiated decoding strategies: Whereas non-autistic observers presented with a rather consistent eyes-focused strategy associated with efficient and fast responses, observers with ASD presented with highly variable decoding strategies. In contrast to communication efficiency, impression formation was not influenced by IaPS. The results underline the importance of timing differences in both production and perception processes during multimodal nonverbal communication in interactants with and without ASD. In essence, the current findings locate the manifestation of reduced reciprocity in autism not merely in the person, but in the interactional dynamics of dyads.