Visual Attention Patterns in Toddlers with and without Autism

Background:  Eye-tracking studies have found that children with ASD show unique patterns of exploration, detail orientation, and perseveration in the Visual Exploration Task (VET), when compared to typically developing children. It is essential to use developmentally appropriate images and stimuli when designing the visual exploration task, as circumscribed interests may differ across different age groups. A toddler adaptation of VET (VET_T) was developed to capture the visual attention patterns of toddlers with ASD. However, VET_T needs to be validated as a reliable tool in capturing the differences in visual attention patterns between toddlers with and without ASD.

Objectives: This study compared the visual attention patterns of toddlers with and without ASD on the VET and VET_T, in an effort to: 1) examine differences in visual attention patterns of toddlers on the VET-T and on the original VET; and 2) compare differences in visual attention patterns between toddlers with and without ASD.

Methods: Thirty-nine toddlers with a diagnosis of ASD (17-35 months of age) and 21 without ASD (14-34 months of age) participated in this study. Each participant completed the VET and VET_T, which includes 12 VET arrays and 7 VET_T arrays. Randomized Arrays were organized to include high autism interest (HAI), low autism interest (LAI) and social items. Three major outcome variables representing visual exploration patterns were calculated: 1) Exploration: Number of images viewed per second onscreen, 2) Perseveration: Duration of fixation per image explored, and 3) Detail Orientation (DO): Number of discrete fixations per image explored. A series of repeated measures ANOVAs were conducted to test the differences in visual patterns of toddlers with and without ASD on the VET and VET_T.

Results: Toddlers with and without ASD showed different visual exploration patterns in the two tasks:

1) Both groups of toddlers were significantly more detail oriented in the VET_T (p<.05) and also showed significantly higher DO towards HAI items (p<.05) than toward social items and LAI items, especially in the VET_T (significant interaction effect, p<.001). There were no significant differences between toddlers with and without ASD;

2) No significant differences in exploration were found between tasks. However, both groups explored significantly more social items than LAI items. Also, the ASD group showed higher exploration during the tasks than the group without ASD (p<.05).

3) Toddlers showed significantly higher perseveration in VET_T (p<.05). No significant differences were found in stimulus types or between groups.

Conclusions: VET_T, which includes developmentally appropriate stimuli, is more effective at capturing the visual attention of when compared to the original VET. Thus, researchers should consider using this task when examining visual patterns in young children. Toddlers with ASD demonstrated different visual attention patterns across both tasks with higher exploration than toddlers without ASD. This finding indicated toddlers with ASD had visual exploration differences and this could be taken into consideration for intervention design. Further analysis will be done to explore the effects of autism symptoms and severity on toddler’s visual attention patterns towards different items in the ASD group.