Semantic memory structure in children and adolescents with Autism Spectrum Disorder

Little research has examined the structure of semantic memory (i.e., how knowledge and facts about the world are stored) in people with autism spectrum disorder (ASD). In typical individuals, semantic memory is organized such that related information is grouped and linked to form meaningful categories. This is a natural part of how we process and later remember newly learned information. Some previous studies have demonstrated differences in the way that people with ASD categorize. Thus, we hypothesize that the structure of semantic memory is atypical in people with ASD. We will examine semantic memory and object categorization in 25 youths (8-18 years of age) with ASD, compared to 25 age-, IQ-, and gender-matched typically developing comparison participants. Results from the following tasks will provide information about the structure of semantic memory: 1) Match-mismatch task: participants indicate whether a simultaneously presented picture and word match, and 2) Triadic comparison task: participants indicate which two of three stimuli are the most similar. On the match-mismatch task, we expect youths with ASD will be fastest at identifying objects at the most specific (i.e., subordinate or specific name of object, such as blue jay) level of categorization, whereas typical controls who will be fastest at the basic level (e.g., general category, such as bird). On the triadic comparison task we expect less efficient category structure in youths with ASD, relative to controls. In addition, we expect that ASD participants will organize objects based on visually concrete, rather than abstract features, whereas the opposite will be true for controls. Results of this research will provide information about how youths with ASD learn, which will be important for guiding intervention research and practice.