The role of the striatum in implicit learning: a functional magnetic resonance imaging study

Previous research has posited striatal involvement in implicit learning. However, imaging studies have not directly compared learners with non-learners. Using functional magnetic resonance imaging with 15 study participants, we used an implicit learning task previously associated with striatal recruitment. Dorsal and ventral striatum activation was observed in the eight participants who demonstrated implicit learning.Ventral striatum activations occurred to a greater extent in implicit learning versus non-implicit learning participants, and were correlated with the degree of reaction time advantage in implicit learning participants, even after controlling for general decreases in reaction time over time. These ¢ndings strengthen the speci¢city of the striatum in implicit learning and are suggestive of a dissociation of striatal regions relative to elements of implicit learning performance. NeuroReport 16:1291^1295 � c 2005 Lippincott Williams & Wilkins.