Visual processing in adolescents with autism spectrum disorder: evidence from embedded figures and configural superiority tests

Color Vision Losses in Autism Spectrum Disorders

Autism spectrum disorders (ASDs) are neurodevelopmental conditions characterized by impairments in social/communication abilities and restricted behaviors. The present study aims to examine color vision discrimination in ASD children and adolescents without intellectual disability. The participants were also subdivided in order to compare color vision thresholds of autistic participants and those who achieved diagnostic criteria for Asperger Syndrome (AS). Nine subjects with autism, 11 participants with AS and 36 typically developing children and adolescents participated in the study. Color vision was assessed by the Cambridge Color Test (CCT). The Trivector protocol was administered to determine color discrimination thresholds along the protan, deutan, and tritan color confusion lines. Data from ASD participants were compared to tolerance limits for 90% of the population with 90% probability obtained from controls thresholds. Of the 20 ASD individuals examined, 6 (30%) showed color vision losses. Elevated color discrimination thresholds were found in 3/9 participants with autism and in 3/11 AS participants. Diffuse and tritan deficits were found. Mechanisms for chromatic losses may be either at the retinal level and/or reflect reduced cortical integration.

Automatic and controlled processing and the Broad Autism Phenotype

Research related to verbal fluency in the Broad Autism Phenotype (BAP) is limited and dated, but generally suggests intact abilities in the context of weaknesses in other areas of executive function (Hughes et al., 1999; Wong et al., 2006; Delorme et al., 2007). Controlled processing, the generation of search strategies after initial, automated responses are exhausted (Spat, 2013), has yet to be investigated in the BAP, and may be evidenced in verbal fluency tasks. One hundred twenty-nine participants completed the Delis-Kaplan Executive Function System Verbal Fluency test (D-KEFS; Delis et al., 2001) and the Broad Autism Phenotype Questionnaire (BAPQ; Hurley et al., 2007). The BAP group (n=53) produced significantly fewer total words during the 2nd 15" interval compared to the Non-BAP (n=76) group. Partial correlations indicated similar relations between verbal fluency variables for each group. Regression analyses predicting 2nd 15" interval scores suggested differentiation between controlled and automatic processing skills in both groups. Results suggest adequate automatic processing, but slowed development of controlled processing strategies in the BAP, and provide evidence for similar underlying cognitive constructs for both groups. Controlled processing was predictive of Block Design score for Non-BAP participants, and was predictive of Pragmatic Language score on the BAPQ for BAP participants. These results are similar to past research related to strengths and weaknesses in the BAP, respectively, and suggest that controlled processing strategy use may be required in instances of weak lower-level skills.