A study of attention to social and non-social stimuli in preschool children with autism spectrum disorder through eye-tracking

Introduction. Reduced attention to faces and increased attention to non-social stimuli, compared to typically developing children (TD), is an early sign of the atypical development of social cognition in autism spectrum disorder (ASD) (Frazier et al. 2017). While this bias is well documented in regard to circumscribed interest objects (Sasson & Touchstone, 2014), less is known about its robustness when social stimuli are paired with non-circumscribed in-terest objects. Our study aimed to fill this gap in the literature, by investigating visual atten-tion to faces and everyday objects in preschoolers with ASD and TD, through an eye-tracking paradigm. Methods. A group of 19 preschool children with ASD (15 males) and 19 children with TD (14 males) participated. The two groups were matched for gender, age (ASD mean age: 56.63 m., SD: 8.42 m., range: 45-73 months; TD mean age: 60.42 m., SD: 2.26 m., range: 57-64 months), and non-verbal IQ - Leiter-R Vr battery (ASD mean NVIQ: 110, SD: 13.38, range: 90–133; TD mean NVIQ: 109, SD: 10.69, range: 90–126). Our stimuli were 20 images com-posed of a picture of a human face (5 males and 5 females), with a neutral expression, paired with a picture of an object not related to circumscribed interests. We recorded visual atten-tion with an eye tracker. Participants were instructed to watch a series of images. Each stimulus-image lasted 5 seconds. We measured preference (the total looking time) and sus-tained attention (the mean duration of consecutive fixations) to the stimuli. Results. Children with ASD showed a significantly reduced preference for faces and paid significantly more sustained attention to the objects than controls. Moreover, within-group analysis showed that while TD children showed a significant preference and greater sus-tained attention to the face over the object, children with ASD did not differentiate the two images in terms of preference or sustained attention. Discussion. These findings add to the literature by indicating that objects not related to cir-cumscribed interests might not be as attractive for children with ASD in comparison to faces. These results might have important implications for early intervention. Caretakers could in-vest valuable time in exposing children with ASD to faces so to promote attention to such stimuli and make them more relevant compared to everyday objects in daily environments.