No preference for direct versus averted gaze in autistic adults: a reinforced preferential looking paradigm

BACKGROUND: With the overarching objective to gain better insights into social attention in autistic adults, the present study addresses three outstanding issues about face processing in autism. First, do autistic adults display a preference for mouths over eyes; second, do they avoid direct gaze; third, is atypical visual exploration of faces in autism mediated by gender, social anxiety or alexithymia? METHODS: We used a novel reinforced preferential looking paradigm with a group of autistic adults (n = 43, 23 women) pairwise matched on age with neurotypical participants (n = 43, 21 women). Participants watched 28 different pairs of 5 s video recordings of a speaking person: the two videos, simultaneously displayed on the screen, were identical except that gaze was directed at the camera in one video and averted in the other. After a 680 ms transition phase, a short reinforcement animation appeared on the side that had displayed the direct gaze. RESULTS: None of the groups showed a preference for mouths over eyes. However, neurotypical participants fixated significantly more the stimuli with direct gaze, while no such preference emerged in autistic participants. As the experiment progressed, neurotypical participants also increasingly anticipated the appearance of the reinforcement, based on the location of the stimulus with the direct gaze, while no such anticipation emerged in autistic participants. LIMITATIONS: Our autistic participants scored higher on the social anxiety and alexithymia questionnaires than neurotypicals. Future studies should match neurotypical and autistic participants on social anxiety and alexithymia and complement questionnaires with physiological measures of anxiety. CONCLUSIONS: The absence of preference for direct versus averted gaze in the autistic group is probably due to difficulties in distinguishing eye gaze direction, potentially linked to a reduced spontaneous exploration or avoidance of the eye region. Social attention and preference for direct versus averted gaze correlated with alexithymia and social anxiety scores, but not gender.