Abstract

Inhibitory mechanisms that begin to develop in childhood are essential for efficient and goal-directed behaviors. These inhibitory mechanisms may go awry in several childhood-onset neuropsychiatric disorders, such as Tourette syndrome, obsessive-compulsive disorder and attention deficit hyperactivity disorder. Negative visuospatial priming is a well-established behavioral probe of inhibition that has been used to demonstrate deficits in children with neuropsychiatric disorders of inhibition, but the brain correlates of negative visuospatial priming have not previously been well delineated. In the present study, we use a visuospatial priming paradigm and event-related functional magnetic resonance imaging (fMRI) to probe inhibitory brain mechanisms in healthy children. When subjects performed the control (i.e. neutral) motor task, a network of cortical and subcortical sensorimotor regions was activated. In contrast, during performance of the negative priming (i.e. inhibitory) task, several regions of the prefrontal cortex were selectively engaged. These results support the notion that the prefrontal cortex is involved in inhibitory processing in healthy children and demonstrate that negative visuospatial priming shares brain correlates with other inhibitory tasks. In conjunction with fMRI, the visuospatial priming task described in the current study may be useful for studying the pathophysiology of childhood-onset neuropsychiatric disorders characterized by deficient inhibitory processing.