Supervised and unsupervised categorization in children with autism spectrum disorder

Supervised categorization concerns learning pre-specified categories, while the unsupervised categorization refers to the spontaneous classification of stimuli where no corrective feedback is given. Children with autism spectrum disorder (ASD) show reduced supervised categorization. Only a few studies investigated unsupervised categorization in individuals with ASD. The main aim of this study is to evaluate supervised and unsupervised categorizations (at two levels of difficulty) in ASD group and to compare their performances with typical development (TD) children. The understanding of categorization abilities of this population allows us to analyze the underlying deficits in the cognitive mechanisms of over-selectivity and exploration. 30 children, gender and mental age matched (mean chronological age ASD = 10.2 (DS=1.07), mean mental age ASD = 8.0 (DS=0.97), n= 15), (mean chronological age TD = 7.6 (DS=1.07), mean mental age TD = 8.5 (DS=0.97), n= 15), participated in the study. The Murphy and Medin paradigm was used to evaluate the unsupervised categorization using two stimulus sets that differed in their difficulty of Categorization. The Klinger and Dawson paradigm was used to evaluate the supervised categorization. Accuracy and time of execution were used as measures in both paradigms. t tests for independent samples were used to compare groups, stating the level of significance at .01. Time but not accuracy showed a statistical significant effect between the two groups. In both cases, with supervised and unsupervised categorizations, children with ASD showed a longer time to complete the tasks but the same accuracy measures. ASD participants displayed a greater tendency to be slower in the categorization process than the TD participants. These results are discussed in terms of the deficits in the cognitive mechanisms of over-selectivity and exploration processes. SUPPRESSION