Thursday, May 7, 2009
Northwest Hall (Chicago Hilton)1:30 PM
Background: Recent research suggests that face-coding mechanisms are generally flexible or “adaptive”. For example, repeated exposure (adaptation) to a series of female faces makes an androgynous face more likely to be judged as male. A recent study, however, has reported that children with autism show reduced adaptation (i.e., shift in perception) to changes in facial identity compared to age- and ability-matched typical peers. This finding suggests that adaptive face-coding mechanisms may be disrupted in individuals with the condition. In addition to these possible difficulties with adaptation, there is also evidence to suggest that the processing of social information in faces, including gender, may be atypical in children with autism. Objectives: In this study, we investigated the possible relationships between adaptive difficulties and abnormalities in processing social cues from faces within children with autism. Specifically, we sought to determine whether children with autism would experience less adaptation to gender categories than typically developing children. Methods: Ten cognitively-able children with autism (M age = 11 years 10 months; 2 girls) and 10 typically developing children (M age = 11 years 8 months; 2 girls) of similar age and nonverbal ability were assessed on a gender adaptation task. Faces used in the task were morphed faces, which ranged from “female” (80% female / 20% male) through to “ambiguous” (50% female / 50% male) through to “male” (20% female / 80% male). Each face was presented one at a time and children were asked to decide whether each face was a “girl” or a “boy”. During adaptation, children were exposed to either a 100% male or a 100% female face for 30 seconds. After adaptation, the set of morphed faces was again rated for whether each face looked more like a girl or a boy with regular 5 second top-up adaptation. Results: Although both groups of children showed a significant adaptation effect in the expected direction, children with autism showed considerably reduced adaptation than their typical peers (i.e., aftereffects were significantly smaller for children with autism). This finding suggests that neural mechanisms coding social information such as gender in faces might be less flexible in children with autism. Baseline gender discrimination did not differ between the groups. Conclusions: This study provides converging evidence that adaptive face-coding mechanisms of both identity and gender information may be atypical in autism. Since adaptive mechanisms are ubiquitous in perceptual systems, these findings raise the intriguing possibility that weakened adaptive processes could extend beyond faces and be a general property of autism.