Do Others' Faces Hold Attention in Children with ASD When They Fixate to the Eyes?

Background: Others’ faces hold attention longer than non-facial objects in typically developed individuals (Bindemann et al., 2005). In our previous study, we demonstrated that faces hold attention longer than non-facial objects in typically developing children. In contrast, children with ASD did not show such specifically longer attentional dwelling towards others’ faces (IMFAR 2008). It is reported that individuals with ASD look at eyes less than typically developed individuals (Klin et al., 2002; Pelphrey et al., 2002). Moreover, individuals with ASD reportedly show comparable level of activation in fusiform gyrus as typically developed individuals when they were instructed to fixate to the eyes of the facial stimuli (Hadjikhani et al., 2004, 2007) and the amount of fixation to the eyes of the facial stimuli correlated with the activation of the fusiform gyrus in individuals with ASD (Dalton et al., 2005).

Objectives: Using the gap and overlap paradigm, we investigated the attentional disengagement from faces and non-facial objects in children with and without ASD when they were instructed to fixate to the eyes.

Methods: Participants consisted of 11 children with ASD (mean 13.2 years; range 10-16 years) and 11 typically developing children (mean 12.3 years; range 10-14 years) matched on IQ. Children were required to saccade towards a peripheral target that followed the central fixation, and children’s eye movements were recorded using electrooculography (EOG). In the gap condition, a central fixation face or object disappeared 200 ms before onset of the peripheral target. In the overlap condition, the central fixation face or object remained until the children’s response. In order to assure that the participants fixate to the eyes, a fixation cross was presented in the middle of the eyes, and participants were instructed to fixate to the cross and detect the gaze shifts, which occurred occasionally between the test trials. In the object condition, a fixation cross and a bar were also presented and participants were instructed to detect when the bar changed to an arrow, which also occurred occasionally between the test trials. The experimental design consisted of one between-participants factor of Group (children with ASD or typically developing children) and two within-participants factors of Synchronization (gap or overlap) and Stimulus (face or object).

Results: Only the interaction between Synchronization and Stimulus was significant. In the gap condition, SRT was not different between the face and object condition. In the overlap condition, SRT for faces was longer than that for objects. No other interactions, including any effects of Group, were significant.

Conclusions: When participants were instructed to fixate to the eyes, faces hold attention longer than objects, and no group difference was found on this effect.