Visual Search Cancellation and Autism Symptoms: What Young Children Search for and Co-Occurring ADHD Matter

Background: Enhanced visual search is one of the most replicated findings in the autism spectrum disorder (ASD) literature and has been documented as young as in infancy and toddlerhood. Visual search in this context often refers to locating one target amongst distracters—less research has investigated search strategies when there are multiple targets amongst distracters, and no studies to our knowledge have manipulated targets and distracters to investigate varying search strategies based on task requirements. It is possible that in ASD performance will be poorer in a multiple target cancellation task, in particular when targets represent a conceptual category as opposed to an exemplar and thus require conceptual knowledge. Alternatively, poor search organization might be associated with attention deficit/hyperactivity disorder (ADHD) symptoms. In contrast, it is possible that performance will be enhanced when exemplar targets are perceptually similar to distracters, thus requiring perceptual abilities known to be enhanced in ASD.

Objectives: This study sought to investigate cancellation performance in 36-month-olds at high and low familial risk for autism, as well as associations with ASD and ADHD symptoms.

Methods: One-hundred and thirty-one 36-month-olds at high (n = 106) and low (n = 25) familial risk for ASD participated in the visual search cancellation task on a touchscreen monitor as a part of a battery of cognitive tasks. In this task, children were asked to search for and touch a) cats among inanimate objects (baseline, “exemplar search”), b) animals amongst inanimate objects (to test categorization, such that higher autistic symptoms were hypothesized to relate to worse performance, “conceptual search”), and c) dogs amongst furniture (to test for the ability to discriminate between perceptually similar objects, such that higher autistic symptoms were hypothesized to relate to better performance, “perceptual search”). The Autism Diagnostic Observation Scale (ADOS) was used to assess severity of autism symptoms and the Child Behavior Checklist (CBCL) was used to assess ADHD symptoms.

Results: While controlling for motor and language abilities, we found that ASD symptom severity did not associate with general enhanced performance in search, but did associate with poorer categorical search in particular, consistent with literature describing impairments in categorical knowledge in ASD. Furthermore, ASD and ADHD symptoms were both independently associated with more disorganized search paths across all conditions

Conclusions: ASD traits therefore do not always convey an advantage in visual search—this depends upon the nature of the stimuli (e.g., exemplar vs. categorical) and the presence of co-occurring ADHD symptoms.