FUNCTIONAL MRI EVIDENCE FOR SUBCORTICAL PARTICIPATION IN CONCEPTUAL REASONING SKILLS

LESIONS involving the dorsolateral prefrontal lobes may produce defici ts on conceptual reasoning (CR) tasks in humans. Such deficits can als o occur with subcortical lesions involving the basal ganglia, thalamus , or cerebellum, suggesting a common, yet widespread, neural network s upporting this executive function. Here we report the results of a who le brain functional magnetic resonance imaging (fMRI) experiment in he althy volunteers while performing a CR task. Compared to a sensorimoto r control condition, the CR task resulted in discrete subcortical acti vation sites primarily involving the right basal ganglia, right thalam us and left lateral cerebellum. Cortical activation was present in mul tiple systems, including the dorsolateral prefrontal and inferior fron tal/insular areas; posterior parietal, superior extrastriate, and prem otor areas; inferior extrastriate and middle temporal regions; and mid line pre-supplementary motor and anterior cingulate regions. Our findi ngs provide strong evidence that CR is mediated by interacting neural systems involving the cerebral cortex, basal ganglia, thalamus, and ce rebellum.