Representational similarity analysis reveals atypical age-related changes in brain regions supporting face and car recognition in autism.

BACKGROUND

Autism Spectrum Disorder (ASD) is associated with atypical activation in the ventral stream during face processing. The current study further characterizes the development of face processing in ASD using a multivoxel pattern analysis, which assesses the similarity in the representation of exemplars from the same category.

METHODS

Ninety-two children, adolescents and adults - with and without ASD - performed the Cambridge Face Memory Test, the Australian Face Memory Test, and a matched car memory test. Regions of interest during these tasks included Fusiform Face Area (FFA), based on the literature, and additional, structurally-defined regions in the ventral stream. Group differences in the patterns of activity within these ROIs when memorizing exemplars were examined using a representational similarity analysis (RSA).

RESULTS

The RSA revealed significant interactions between age group and diagnostic group in R FFA, with increasing similarity within a category (faces, cars) into adulthood typically but not in those with ASD. This pattern was also evident in structurally defined ventral stream regions, namely L inferior frontal gyrus (IFG), bilateral temporoparietal junction (TPJ), L inferior temporal lobule, and the R fusiform gyrus.

CONCLUSIONS

The specialization of face and object processing from adolescence to adulthood evident in typical development may be impaired in ASD, undermining the ability to reach adult-level visual processing in those with ASD.