Intentional Control and Behavioural Rigidity in Individuals with Autism

Background: Different clinical studies have provided empirical evidence for impairments in cognitive control in individuals with autism spectrum disorders (ASD). These cognitive control impairments become evident as rigid and repetitive patterns of behaviour. The challenge arises, however, when trying to specify the neurocognitive mechanisms behind the reported observations of deviant patterns of goal-directed behaviour in ASD. In fact, studies trying to test specific assumptions by applying designs that are based on a more controlled experimental conditions often fail in providing strong evidence for an impairment in specific cognitive functions.

Objectives: The main objective of this study is to test the idea recently put forward in the literature that the preference for repetitive behaviour in ASD reflects intentional deficits rather than problems at the level of the implementation of intentions. We tested the idea of problems with intentional control— a specific subset of cognitive control processes that biases the choice of our behavioural goals—in the broader autism phenotype.

Methods: Participants were healthy individuals with either a low or a high number of autistic traits as measured by a self-report questionnaire that quantifies the extent of autistic traits in healthy population—the Autism-spectrum Quotient (AQ). Participants chose between two tasks differing in their relative strength by indicating first their voluntary task choice and then responding to the subsequently presented stimulus. The tasks included responding to the location or responding to the shape of the presented stimuli. This voluntary task-switching paradigm allowed us to disentangle the intentional task choice from its implementation at the level of task execution (i.e., responding to the presented stimulus).

Results: The findings demonstrate a significantly stronger tendency to repeat tasks more often for the participants with high level of autistic traits. Crucially, while the patterns of task choice showed a stronger bias toward repeating the harder task in participants with more autistic traits, no differences in behavior during actual task execution were found between high and low AQ participants.

Conclusions: The present study indicates that the tendency of individuals with autism to engage in repetitive behavior arises at the level of the formation of task intentions when tasks are chosen voluntarily. Our results reveal that the way in which global task intentions are formed—as measured by behavioral patterns in task choice—depends on the quantification of where an individual lies along the dimension of autistic traits. On the contrary, the way that tasks are being executed—as measured by behavioral patterns in RTs and errors—seems not to be related to the amount of autistic traits in healthy individuals.