Direct Evidence for Configural Face Processing in ASD: Use of a Gaze-Contingent Stimulus Presentation

Background:   Children with an Autism Spectrum Disorder (ASD) have impairments in social reciprocity, which may be related to face processing, as indicated by early signals, such as absence or delay of gaze, delayed gaze following, diminished attention to faces, and an absence of social smile (Volkmar, Chawarska, & Klin, 2005). Face identity recognition research, however, has provided mixed evidence for an atypical face processing strategy in children with ASD, using a variety of stimuli and paradigms. Whereas some researchers find strong indications for a disturbed configural face processing and a local processing style, other studies did not support that. However, most of this evidence is rather indirect.

Objectives: Using gaze-contingent stimulus presentation, we wanted to provide more direct evidence for local and global face processing strategies in children with ASD. This technique allows to manipulate the kind of information available at or around fixation, experimentally inducing a more local or global processing strategy.

Methods:   Two groups of 10-to-14-year old boys without intellectual disabilities (IQ >= 70), group-wise matched for age, VIQ, PIQ and TIQ, were tested. The ASD group consisted of 16 boys with a diagnosis based upon a multidisciplinary assessment according to DSM-IV-TR PDD-criteria. The typically developing (TD) group comprised 14 boys with a Social Responsiveness Scale (SRS) score below cut-off for autism.

A same-different task was used with two static neutral faces presented side by side on a computer screen. Whereas the target face was always presented in full view, the amount of information available in the match face was manipulated, using a gaze-contingent stimulus presentation technique. In the window view, a gaze-contingent foveal window restricted the participants’ view to the information of the fixated feature, allowing local processing, but preventing configural face processing. In the mask view, a gaze- contingent foveal mask covered the high-resolution information at the fixated location, necessary for a local processing of the fixated features. Thus, the foveal mask prevented local processing, but configural face processing based on the rest of the information around the mask is still possible.

Results:   Both groups performed better in the foveal mask condition, in comparison to the foveal window condition, suggesting that both groups employed a global (configural) processing strategy. In the foveal window condition, the ASD group did not perform better than the TD group, suggesting that they were not better at using a local strategy. In the foveal mask condition, the ASD group did not perform worse than the TD group, suggesting that they were not worse at using a global (configural) strategy.

Conclusions:   Using a gaze-contingent stimulus presentation, we provided direct evidence for an intact configural face processing style in 10-to-14-year old boys with ASD. Further analyses will focus on the spontaneously fixated regions (e.g., first fixations) and the scanning behavior (e.g., saccade length). We will also present data from an on-going study with younger children (6-to-10-year-olds), using the same paradigm.