Difficulties in facial identity recognition are commonly reported in autism spectrum disorder (ASD), although factors contributing to this are unclear. One possibility is that atypical visual scanning strategies could underlie this impairment. Previous studies have reported that children with ASD differ from typically developing children with respect to: a) how they visually scan people and non-people in the environment; and b) how they scan face stimuli. The hypothetical link between scanning strategies and face recognition skills has yet to be directly tested.
Objectives:
This research has three aims. First, to measure face and object recognition ability in ASD and typically developing children. Second, to investigate differences between the way ASD and typically developing children view visual scenes and face stimuli. Third, to directly test associations between face and object recognition abilities, and measures on the visual scanning tasks.
Methods:
12 ASD children and 12 age-matched typically developing controls completed 2 alternative forced choice matching tasks for faces and objects. Scores were standardized according to age. Next, we recorded eye-movements whilst the children viewed visual scenes containing People and Objects. Finally, eye-movements were recorded during a 2-alternative forced choice recognition memory test for faces. Associations between performance on behavioural tests, and visual scanning measures were analyzed.
Results:
Wide heterogeneity was evident within the ASD group on all behavioural tasks, with some children performing as well as typically developing children, and others exhibiting severe impairments. As a group, ASD children were worse than typically developing children on the face-matching, but not the object-matching test. Age-standardized scores on the face-matching test were associated with the percentage of times ASD children fixated on the People before the Objects in visual scenes. In the recognition memory test for faces, the ASD group performed significantly worse than the typically developing group. Here, age-standardized scores were strongly associated with the number of times the participant shifted eye-gaze between facial features. This association was significant in both participant groups, and was not accounted for by verbal or nonverbal ability.
Conclusions:
Some, but not all children with ASD have difficulties recognizing faces. Two factors emerged as being related to skill level: a) initial allocation of attention to people, b) movement of eye-gaze between the features of a face. More generally, this research demonstrates the importance of investigating associations between abilities, and of being mindful of variability in symptom profile and skill level within individuals on the autistic spectrum.
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