Scanpath similarity measure reveals not only a decreased social preference, but also an increased nonsocial preference in individuals with autism.
Scanpath similarity shows both reduced social and heightened nonsocial attention bias in autism.
01Research in Context
What this study did
Król et al. (2020) used eye-tracking to watch how people with and without autism looked at pictures. They compared scanpaths, the exact trail of eye stops, for social and nonsocial images.
The team wanted to know if autistic viewers repeat the same looking pattern more on nonsocial scenes and less on social ones.
What they found
Autistic participants showed higher scanpath similarity to nonsocial images, meaning they looked at the same spots again and again. Their similarity to social images was lower than that of neurotypical controls.
In plain words, the data show both a weaker social pull and a stronger object pull in the same person.
How this fits with other research
Celani (2002) first showed kids with autism picking objects over people in a sorting game. Ewa et al. now capture the same object bias with eye trails, updating the finding with a fine-grain lens.
Waldron et al. (2023) extend the idea into real life: toddlers who looked longer at toys during eye-tracking later played less with caregivers. Together the three papers form a line, object gaze predicts lower social engagement.
Older oculomotor work by Gutierrez et al. (1998) and Caldani et al. (2020) noted extra or mistimed saccades in autism. Ewa’s scanpath metric adds a new layer, showing not just faster eyes but stuck-looking patterns on nonsocial content.
Why it matters
You can run a two-minute eye-tracking probe before treatment to see if a client shows the stuck-on-objects pattern. If they do, lead with object-based tokens first, then fade in social rewards. The metric also gives you an objective way to show parents why social praise alone may not work yet.
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02At a glance
03Original abstract
We compared scanpath similarity in response to repeated presentations of social and nonsocial images representing natural scenes in a sample of 30 participants with autism spectrum disorder and 32 matched typically developing individuals. We used scanpath similarity (calculated using ScanMatch) as a novel measure of attentional bias or preference, which constrains eye-movement patterns by directing attention to specific visual or semantic features of the image. We found that, compared with the control group, scanpath similarity of participants with autism was significantly higher in response to nonsocial images, and significantly lower in response to social images. Moreover, scanpaths of participants with autism were more similar to scanpaths of other participants with autism in response to nonsocial images, and less similar in response to social images. Finally, we also found that in response to nonsocial images, scanpath similarity of participants with autism did not decline with stimulus repetition to the same extent as in the control group, which suggests more perseverative attention in the autism spectrum disorder group. These results show a preferential fixation on certain elements of social stimuli in typically developing individuals compared with individuals with autism, and on certain elements of nonsocial stimuli in the autism spectrum disorder group, compared with the typically developing group.
Autism : the international journal of research and practice, 2020 · doi:10.1177/1362361319865809