FAMILIARITY AND AFFECT IN ADOLESCENTS WITH AUTISM SPECTRUM DISORDER

Abstract

In typically developing (TD) individuals, simple repeated exposure to stimuli results in greater affinity toward them. The main goal of the current project was to test the hypothesis that this mere repeated exposure (MRE) effect would be atypical in individuals with autism spectrum disorder (ASD). An abnormal MRE effect in ASD was suspected for several reasons, including evidence of: 1) stronger preference for familiarity in those with ASD, 2) slowed stimulus habituation in individuals with ASD, and 3) atypicalities in the neural reward circuitry of those with ASD, relative to TD comparison participants. In the current study, we also sought to examine the influence of stimulus type (i.e., social vs. non-social) on the MRE effect, as well as the association between the MRE effect and several individual difference variables (i.e., anxiety, intolerance of uncertaintly, and restricted and repetitive behaviours). In order to answer the research questions described above, we administered several experimental tasks and characterization measures to a group of 28 adolescents with ASD and 28 matched TD comparison participants. We found that, while TD adolescents displayed a typical MRE effect, the liking ratings of participants with ASD did not increase across stimulus presentations, even at the highest exposure frequencies. We interpreted this result as an indication that the MRE is either absent or delayed in ASD. The pattern of liking ratings across exposures frequencies was similar across stimulus categories for both the TD and ASD groups, suggesting that differences in the MRE effect in ASD are domain general. Few relationships between MRE findings and individual difference variables were observed. The current study represents an important contribution to the literature for several reasons. First, it provides a valuable window into one of the processes that may contribute to familiarity preference and novelty aversion in ASD (i.e., a disrupted MRE effect). Second, through identifying a clinical population in which the MRE effect is atypical, the present study has revealed new opportunities for researchers examining theoretical accounts of this phenomenon and hypotheses regarding its neural underpinnings. Third, it has provided us with a better understanding of the MRE effect in TD youth.