Visual Search and Attention in Children with Autism Spectrum Disorders--- an Eye-Tracking Study

Background:  

Abnormalities of visual attention or perception have been reported to appear inherent in a number of behaviors observed in ASD. Individuals with ASD often show enhanced performance relative to non-ASD individuals, for example, individuals with ASD have been found to excel in the Embedded Figures Task (Joliffe & Baron-Cohen, 1997; Shah & Frith, 1983) and visual search (Kemner, van Ewijk, van Engeland & Hooge, 2008; O’Riordan & Plaisted, 2001; Joseph, Keehn, Connolly, Wolfe & Horowitz, 2009), but there has been relatively little attention paid to their cognitive mechanism and memory.

 Objectives:  

The objective of the study is to examine the contributions of both memory and enhanced perceptual processing to visual search and attention in children with ASD and typically developed (TD) children when they are identifying neutral faces.

Methods:  

Participants attended two tests. Short-term memory test: In this test, 18 children with ASD and 22 age matched TD children were asked to watch 5 target pictures (5 neutral expression of 5 main characters) and 14 distractor pictures (14 strangers' neutral expression). 5 target pictures successively appeared three times, and 14 distractor pictures appeared only once, so there would be 29 pictures displaying in total. The playback order of pictures would be random. Participants' responses on these pictures were recorded by Tobii TX300. Long-term memory test: One week later after the short-term memory test, the two groups were tested again in the same way.

Results:  

The results showed significant differences between ASD and TD groups on the fixation duration in the area of interest (AOI) on faces of characters. It was found that ASD and TD children have significant differences on face memory. There are also significant differences in AOIs in short-term memory test between the two groups. It was also found that children with ASD showed superior visual search skills than TD children.

Conclusions:  

In summary, ASD search superiority may from anomalously enhanced perception of stimulus features, which was also associated with autism symptom severity.