The many faces of control: brain-behavior interactions in development

Abstract

Young children often find it difficult to control their impulses and respond almost immediately to all stimuli they perceive. This behavior is considered normal in toddlers and preschoolers, but older children are expected to be able to suppress immediate responses. This skill falls under the broader concept of cognitive control. Cognitive control is an umbrella term that is essential for mental processes involved in controlling impulsive behavior. As with many other skills, two main factors contribute to the development of cognitive control, namely: brain maturation and life experience. In most of children and teenagers, the development of cognitive control will follow a normal course. However, under the influence of biological and/or environmental factors, some children develop more slowly in this area than the majority of their peers, for example children with a behavioral disorder such as Autism Spectrum Disorder (ASD) or Obsessive-Compulsive Disorder (OCD). The central question of this dissertation is therefore: how does the development of cognitive control and associated brain activity occur in typical and atypical populations (such as ASD and OCD), specifically children, and which individual and environmental factors determine how well children can control independently? We operationalized cognitive control as the ability to stop an ongoing response in the context of a stop-signal task during fMRI. In th stop-signal task (SST), the participant is challenged to withhold a motor response after it has been initiated. Measures derived from this task include the stop-signal reaction time (SSRT), which reflects the speed of the stopping process. In conclusion, the findings do not support differences in cognitive control or associated neural circuitry in children with ASD and OCD compared to typically developing (TD) individuals. Similarly, we found no notable developmental differences in cognitive control or brain activity in children with ASD or OCD compared to TD children. Instead, our results suggest that changes in cognitive control may be more specifically related to elevated levels of hyperactive/inattentive symptoms. Paradigm variation and heterogeneity of samples are factors that likely contribute to inconsistency in the psychiatric literature. Traditional statistical approaches are not suitable to address these issues, as relationships between different modalities (brain, behavior, environment) are complex in nature. We therefore advocate the use of multivariate, unsupervised approaches that provide a means for addressing these issues and uncovering meaningful brain-behavior relationships, by exploiting the full potential of large, longitudinal datasets, such as the YOUth cohort.