Impaired Cognitive Flexibility & Stimulus Overselectivity in Autism

Introduction Various contemporary theories seeking to explain behavior in autism hypothesize that people with autism possess deficits in integrating contextual information in an appropriate manner. Problems integrating information is argued to result in a processing style which highlights the specific pieces of the environment at the cost of more general high-level information. This “piecemeal” style is capable of explaining an impressive variety of both the advantageous and detrimental behavior demonstrated by people with autism. One possible mechanism that could give rise to information integration difficulties would be a tendency to restrict attention to a small number of features, with difficulty in shifting attention to other features. In this work, we explore this possibility using a simple computational model of the role of prefrontal cortex in attention. Stimulus overselectivity, where a restricted set of components within a compound stimulus tend to dominate behavior, was first documented in the early 1970s in people with autism (Lovaas, Schreibman, Koegel, & Rehm, 1971). This effect has since been demonstrated both within and across different modalities as well as by varying the number of features composing the compound stimulus. The paradigmatic task involves conditioning responses to a stimulus made of multiple, simultaneously presented, components. After the initial association of the compound stimulus with reward/response, each individual component is tested separately, assessing the degree each has aquired control over the subjects behavior. Normally developing individuals respond equally to all components. People with autism, to the contrary, are more likely to respond to a single component, thus demonstrating overselectivity.