Exploring the Conditions of Typical and Atypical Social Attention in Autism: A Gaze Contingent Eye Tracking Study

Background:

Attending to faces is extremely important for understanding social cues and it is thought that atypical social attention may contribute to social difficulties in Autism Spectrum Disorder (ASD). However, research findings are mixed as to whether faces have the same special status in attention for people with ASD as in typical development. Methodological differences across studies make it hard to reach a consensus about social attention in ASD and why it may appear typical or atypical in experimental studies. Additionally, the Social Motivation Theory of autism predicts that individuals with ASD will attend to non-social objects of particular interest to them, rather than faces, and previous research has found that objects of Circumscribed Interest (CI) may disrupt social attention when co-occurring with people in a scene.

Objectives:

The present study employed visual scenes containing people and objects of CI to which adults with ASD have previously been found to attend atypically. A novel gaze contingent window technique explored the allocation of attention across these scenes among adults with and without ASD. This technique provides a measure of top down allocation of attention by removing opportunities for automatic attentional capture in peripheral vision.

Methods:

In Experiment 1, a gaze contingent window in a black screen revealed 4˚ visual angle around the point of fixation of a scene containing people and CI objects. Regions of interest (ROIs) corresponding to faces, bodies, CI objects, and background were defined. In Experiment 2, participants saw an array of gift boxes, which, upon fixation, revealed a different image of either a face, an object of CI, or a neutral object. Measures of fixation duration and number of fixations within each area were recorded. Participants also later rated how much they liked each image and how interesting they found it to explore explicit interest in the stimuli.

Results:

Experiment 1 found that all participants had longer fixations to face regions of scenes than any other region, with no group differences in the percentage of fixations in each ROI. However, in Experiment 2, whilst there were no group differences in mean fixation duration to each object category, participants in the TD group made a higher proportion of fixations to faces than the ASD group.

Conclusions:

Experiment 1 showed that when background information is removed from a scene, social attention appears typical in adults with ASD, with faces holding attention longer than other objects once fixated. However, Experiment 2 found suggested reduced social attention in participants with ASD. This could be because social cues are more important to establish context within natural scenes as in Experiment 1, than in Experiment 2 where images were displayed in isolation without context. Therefore, adults with ASD may be able to preferentially allocate information to social information when it may be informative, but lack the motivation to do so when it is not. Further time course analyses will help to elucidate these results.