EYE TRACKING USED TO EXAMINE VISUAL SALIENCY IN ASD

Written by: Dr. Signe Bray 

Eye-tracking technology lets us measure how people look at things. If I show you a scene with a football player about to kick a ball, do you look longer at the ball, the leg or the player’s face? People with autism spectrum disorder (ASD) tend to look longer at objects than they do at faces, but we don’t know why.

This study tried to understand what features in an image capture the attention of adults on the autism spectrum, more than typical adults. The hope is that if we can understand what captures the attention of people with ASD we can better understand why people on the spectrum have difficulty processing social information.

To do this, the researchers asked 20 adults with ASD and 20 matched healthy control adults to look at 700 different pictures, each for three seconds. They measured where people looked on the images. They then analyzed the images, decomposing them into features based on region (e.g. the center), color, properties of objects in the images such as size, and information about the type of objects (e.g. faces).

The researchers then asked which of these features predicted where a person would look, and which features predicted more strongly for people with ASD. The answer: all of the features they looked at had a different influence on the looking patterns of the adults with ASD. For example, people with ASD looked longer at the center of the screen, and their gaze was less influenced by the properties of objects in the images.

When they looked at object categories, they found a small difference in the importance of faces for capturing attention, but also differences in looking at objects that can move and that have a smell.  Differences between the ASD and typical adults became stronger the longer people looked at the images.

This study helps us to understand how people with ASD look at the world differently, and some tendencies they may have in their looking behavior. An interesting question is whether we can train people to adjust their looking behavior and whether this can help them better understand the social world. That is, because looking at objects and faces is how we get information about them, maybe people with ASD can get more information about the social world by looking at it differently?

 

Reference: 

Atypical visual saliency in Autism Spectrum Disorder quantified through model-based eye tracking (2015) Wang, Jiang, Morin Duchesne, Laugeson, Kennedy, Adolphs. Neuron. 88:1-13.