title: Functional contributions and interactions between the human hippocampus and subregions of the striatum during arbitrary associative learning and memory.
abstract: The hippocampus and striatum are thought to have different functional roles in learning and memory. It is unknown under what experimental conditions their contributions are dissimilar or converge, and the extent to which they interact over the course of learning. In order to evaluate both the functional contributions of as well as the interactions between the human hippocampus and striatum, the present study used high-resolution functional magnetic resonance imaging (fMRI) and variations of a conditional visuomotor associative learning task that either taxed arbitrary associative learning (Experiment 1) or stimulus-response learning (Experiment 2). In the first experiment, we observed changes in activity in the hippocampus and anterior caudate that reflect differences between the two regions consistent with distinct computational principles. In the second experiment, we observed activity in the putamen that reflected content specific representations during the learning of arbitrary conditional visuomotor associations. In both experiments, the hippocampus and ventral striatum demonstrated dynamic functional coupling during the learning of new arbitrary associations, but not during retrieval of well-learned arbitrary associations using control variants of the tasks that did not preferentially tax one system versus the other. These findings suggest that both the hippocampus and subregions of the dorsal striatum contribute uniquely to the learning of arbitrary associations while the hippocampus and ventral striatum interact over the course of learning.
authors.affiliation: Department of Psychology, Florida International University, 11200 S.W. 8th Street, AHC-4 Room 462, Miami, Florida.
authors.forename: Aaron T
authors.initials: AT
authors.lastname: Mattfeld
authors.affiliation: Department of Neurobiology and Behavior, University of California, Irvine, 213 Qureshey Research Lab, Irvine, California.|Center for the Neurobiology of Learning and Memory, University of California, Irvine, 320 Qureshey Research Lab, Irvine, California.
authors.forename: Craig E L
authors.initials: CE
authors.lastname: Stark
mesh_terms: D000293:Adolescent; D000328:Adult; D001245:Association Learning / Q000502:physiology*; D001931:Brain Mapping; D003342:Corpus Striatum / Q000098:blood supply / Q000502:physiology*; D025461:Feedback, Physiological; D005260:Female; D006624:Hippocampus / Q000098:blood supply / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D009434:Neural Pathways / Q000098:blood supply / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D011601:Psychophysics; D012044:Regression Analysis; D013269:Stochastic Processes; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: MTL; basal ganglia; fMRI; functional connectivity; memory systems