Striatal activation during acquisition of a cognitive skill

The striatum is thought to play an essential role in the acquisition of a w ide range of motor, perceptual, and cognitive skills, but neuroimaging has not yet demonstrated striatal activation during nonmotor skill learning. Fu nctional magnetic resonance imaging was performed while participants learne d probabilistic classification, a cognitive task known to rely on procedura l memory early in learning and declarative memory later in learning. Multip le brain regions were active during probabilistic classification compared w ith a perceptual-motor control task, including bilateral frontal cortices, occipital cortex, and the right caudate nucleus in the striatum. The left h ippocampus was less active bilaterally during probabilistic classification than during the control task, and the time course of this hippocampal deact ivation paralleled the expected involvement of medial temporal structures b ased on behavioral studies of amnesic patients. Findings provide initial ev idence for the role of frontostriatal systems in normal cognitive skill lea rning.