Gaze-Contingent Event Triggering in the Social and Nonsocial Conditions

Background: Eye movement is more than passive viewing of the world and retrieval of visual input. Particularly in social scenarios, eye movements are important social cues that communicate emotion and shared attention. Most eye-tracking experiments in studies of autism spectrum disorder (ASD) are designed to explore the looking behavior of participants, but fail to consider eye movements as an interactive way for a participant to communicate shared attention.

Objectives: To create a gaze-contingent (GC) paradigm to provide opportunities for participants to trigger an event with their eye movement. To explore the differences in triggering time and looking duration in Social and Nonsocial conditions for children with ASD and typical development (TD).

Methods: Participants included TD children (n = 12 , Age = 38.3 ± 17.34 months) and children with ASD (n = 6, Age = 33.5 ± 8.55 months). Both groups completed 16 trials of Social and 16 trials of Nonsocial GC trials. In the Social condition, an actress sat in the center of the screen with an empty circular area on either side of her. Each condition started with a greeting, after which the trial began. Within each trial, the actress used escalating directional cues consisting of a Gaze Shift, Head Turn, Finger Point to one of the areas, with the last escalation involving a Flashing Red strobe in the target area. Once the participant looked at the target after one of the cues, the appearance of an animated toy in the target area was triggered as a visual reward. If the participant did not respond to any of the cues, the animated toy would appear after a delay. Each of the five steps took 2 seconds, for a maximum of 10 seconds per trial. The Nonsocial condition was constructed by scrambling the image of the actress in the Social condition, controlling for movement duration, motion, and size of moving area. We compared time required for the toddlers to follow the cue and move their gaze to the target area (Triggering time) and total looking duration on the screen (Looking duration).

Results: A Diagnosis x Condition linear mixed model on Triggering time revealed a significant effect of condition (p < .001) and diagnosis (p = 0.02). Triggering time was shorter in the Social (M = 2.9 s, SD = 0.44) versus the Nonsocial condition (M = 5.1 s, SD = 0.45) and TD children responded faster to the cues than children with ASD. Analysis of looking duration indicated a significant interaction effect (p < 0.05). Toddlers with ASD looked significantly longer at the Nonsocial cues compared to the Social cues (p < 0.001), but this was not the case for TD toddlers (p = .502).

Conclusions: Our preliminary results indicate that children with ASD have a preference for looking at nonsocial compared to social information. Children with ASD evidenced slower responses to directional cues in both conditions compared to typical peers, suggesting that they may need more cueing steps in both the social and nonsocial conditions.