Although circumscribed interests are a hallmark characteristic of autism spectrum disorders, providing a means for quantifying their functional impairment has proven difficult. We developed a passive viewing task to measure aspects of visual attention in children with autism spectrum disorders and typically developing controls. Task stimuli included picture arrays that were matched for social and nonsocial content. Nonsocial content was balanced to include items related to circumscribed interests (e.g., trains) as well as more commonplace items (e.g., furniture). Discrete aspects of gaze behavior were quantified using eye-tracking technology. Results indicate that visual attention in the autism group was more circumscribed (as indicated by the exploration of fewer images), more perseverative (as indicated by longer fixation times per image explored), and more detail oriented (as indicated by a greater number of discrete fixations on explored images). This pattern of results was similar for both social and object arrays. Within the autism group, overall severity of repetitive behavior symptoms correlated positively with exploration of object pictures and negatively with perseveration on social pictures. Results suggest that children with autism have a domain-general pattern of atypical visual attention that may represent an exaggeration of a typical attentional process and is related to a tendency to perseverate on images of interest and explore them in a more detail-oriented manner. Discrete measures of visual attention may therefore provide a reasonable means of quantifying aspects of the repetitive behavior phenotype in autism.

Circumscribed interests (CI) are important and understudied symptoms that affect individuals with autism spectrum disorders (ASD). The present study sought to develop quantitative measures of the content, intensity and functional impairment of CI in 50 children with high-functioning ASD compared to an age-, IQ-, and gender-matched sample of 50 typically developing (TD) peers. The Interests Scale, a parent-rating questionnaire, and the Interview for Repetitive Behaviors, a semi-structured interview, were used to assess CI. Groups did not differ on the number of interests children held, but they did differ on types of interests and impairment associated with them. The interests of ASD participants were more likely to be nonsocial in nature (e.g. mechanical systems) than TD participants. Parents of children with ASD endorsed higher degrees of functional impairment on metrics including frequency, interference, resistance when interrupted, flexibility, and accommodation required, as well as less involvement of other people, than parents of children with TD. These findings suggest that interests of individuals with ASD differ qualitatively and in intensity from individuals with TD. The present study offers further support for the notion that CI reflect a clinically significant feature of ASD that warrants intervention in some children.

This study examined the relationship between repetitive behaviors and sensory processing issues in school-aged children with high functioning autism (HFA). Children with HFA (N = 61) were compared to healthy, typical controls (N = 64) to determine the relationship between these behavioral classes and to examine whether executive dysfunction explained any relationship between the variables. Particular types of repetitive behavior (i.e., stereotypy and compulsions) were related to sensory features in autism; however, executive deficits were only correlated with repetitive behavior. This finding suggests that executive dysfunction is not the shared neurocognitive mechanism that accounts for the relationship between restricted, repetitive behaviors and aberrant sensory features in HFA. Group status, younger chronological age, presence of sensory processing issues, and difficulties with behavior regulation predicted the presence of repetitive behaviors in the HFA group. KeywordsAutism Spectrum Disorder; Repetitive Behaviors; Sensory Features; Executive Function Repetitive behaviors comprise one faction of the triad of clinical symptoms that characterize autism spectrum disorder (ASD), presenting concomitantly with social and communication deficits. Restricted, repetitive behaviors (RRBs) in autism refer to an assemblage of behaviors defined by their topographical similarity across contexts, inappropriateness, and repetition. These behaviors have been conceptualized as part of a continuum that ranges from lower order (stereotypy, self-injury) to higher order (compulsions, rituals /sameness, restricted interests) (Carcani-Rathwell, Rabe-Hasketh, & Santosh, 2006; Cucarro et al., 2003;Hus, Pickles, Cook, Risi, & Lord, 2006;Turner, 1999). Higher order behaviors, specifically the presence of restricted/narrow interests, odd object attachments or unusual object preoccupations (e.g., fascination with ceiling fans), are thought to be more unique to autism in comparison to other types of repetitive behaviors (e.g., self-injury) (Lam, Bodfish, & Piven, 2008 Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access Author ManuscriptRes Autism Spectr Disord. Author manuscript; available in PMC 2011 April 5. The clinical presentation of repetitive behaviors in autism has been linked to deficits in executive functioning (Turner, 1999). Executive function is an umbrella term for a set of subfunctions that are integrated throughout cortical and subcortical areas of the brain and used to carry out higher order cognitive tasks (O'Hearn, Asato, Ordaz, & Luna, 2008;Zelazo, Carter...

Restricted and repetitive behaviors in autism spectrum disorders have been conceptualized to reflect impaired executive functions. In the present study, we investigated the performance of 6–17-year-old children with and without an autism spectrum disorder on a dimension-change card sort task that explicitly indicated sorting rules on every trial. Diagnostic groups did not differ in speed of responses after the first rule switch or in speed or accuracy on blocks with mixed versus single sort rules. However, performance of the ASD group was significantly slower and less accurate overall than the typically-developing group. Furthermore, within the ASD group, poorer DCCS task performance did not predict more severe autism symptoms. Implications for the executive dysfunction theory of autism are discussed.