| Research demonstrates that individuals with autism process facial information in a different manner than typically developing individuals. Several accounts of the face recognition deficit in individuals with autism have been posited with possible underlying mechanisms as the source of the deficit in face recognition skills. The current study proposed a new account that individuals with autism are less sensitive at perceiving configural manipulations between faces than typically developing individuals leading to their difficulty recognizing faces. A change detection task was used to measure perceptual sensitivity to varying levels of configural manipulations involving the eye and mouth regions. Participants with and without autism, matched on chronological age, verbal IQ, performance IQ, full scale IQ, visual acuity, and gender, studied upright and inverted faces in a delayed same/different face recognition test. An eye tracker recorded eye gaze throughout the experiment. Results revealed a significant group difference with respect to detection accuracy. The control group was more accurate at detecting subtle changes between upright faces than the autism group, particularly with manipulations to the spatial relation of eyes. Furthermore, an analysis of detection accuracy within groups revealed that a greater proportion of participants in the control group were better at detecting differences at subtler levels of spatial manipulations. Eye tracking results revealed a significant group difference in number of fixations to relevant vs. irrelevant areas of interest; however, both groups utilized eye information more than mouth information to detect changes in both upright and inverted faces. Furthermore, there was some indication that eye gaze differed within groups, with a small proportion of individuals in both the autism and control groups demonstrating a bias to look more toward the mouth than eyes. Results are discussed with respect to featural vs. configural processing in autism and the use of eye vs. mouth information in face processing strategies by individuals with autism. |
