Embedded Figures Performance in the Broader Autism Phenotype

Background: Individuals with autism demonstrate superior capabilities on the Block Design subscale of the Wechsler Intelligence Scales and on the Embedded Figures Test (EFT). Recent research has demonstrated that these abilities extend to individuals in the general population who self-report autistic-like traits using the Autism Spectrum Quotient (AQ). Objectives: The current research examined visual processing in such individuals with the broader autism phenotype in an attempt to determine whether reduced global processing in the ventral stream can explain enhanced performance on visuospatial cognitive tasks such as the EFT. Methods: In conjunction with the EFT, psychophysical tests of local and global visual functioning in the ventral stream were administered. A pulsed-pedestal task was used to investigate parvocellular functioning at the V1 level, and a Glass pattern task was used to assess global processing ability in V4. Results: We found that people who scored high on the AQ  were faster at identifying simple shapes within a complex figure, poorer at global form processing, but no different from those who scored low on the AQ on the pulsed-pedestal task assessing lower-level input to the ventral stream. In addition, higher Glass pattern thresholds were correlated with faster EFT responses. Conclusions: The results indicated that individuals with the broader autism phenotype experience difficulties with global integration of visual information in the visual form pathway. Results are discussed with reference to the notion of an ‘autism spectrum’ and the Weak Central Coherence theory of autism.