Brain ImagingThalamic deactivation during early implicit sequence learning: a functional MRI studyRauch, Scott L.1,2,3,5; Whalen, Paul J.1,2,3; Curran, Tim4; McInerney, Sean1; Heckers, Stephan1,3; Savage, Cary R.1,2,3Author Information 1Psychiatric Neuroscience Program, Massachusetts General Hospita, 9th Floor, Bldg 149, Thirteenth Street, Charlestown, MA 02129 2NMR Center East, Massachusetts General Hospital, 9th Floor, Bldg 149, Thirteenth Street, Charlestown, MA 02129 3Department of Psychiatry, Havard Medical School, Boston, MA 4Department of Psychology, Case Western Reserve University, Cleveland, OH, USA 1,5Corresponding Author and Address: Scott L. Rauch ACKNOWLEDGEMENTS: Support was provided by the Tourette Syndrome Association, Inc., NIMH (grants MH01215 & MH01230). and the David Judah Research Fund. P.W. was supported as a Fellow in the Clinical Research Training Program of Harvard Medical School. We acknowledge Halle Brown, Terry Campbell, Mary Foley, Michael Jenike, Linda Leahy, Michael Lee, Bruce Rosen and Mike Vevea for their assistance. Received 3 December 1997; accepted 18 January 1998 NeuroReport: March 30th, 1998 - Volume 9 - Issue 5 - p 865-870 Buy Abstract PREVIOUS research has implicated the striatum in implicit sequence learning. However, imaging findings have been inconsistent with regard to activity within the thalamus during performance of such tasks. Contemporary models of cortico-striato-thalamic circuitry suggest opposing influences on thalamic activity; suppression of thalamic activity is mediated by the indirect pathway and enhancement is mediated by the direct pathway. Using functional magnetic resonance imaging, we studied activity within human thalamus during early and late phases of an implicit sequence learning task known to reliably recruit the striatum. Significant deactivation (decreased signal relative to a baseline condition) was observed within the thalamus during early implicit learning. This finding is consistent with models of cortico-striato-thalamic function and specifically supports a profile of early ‘thalamic gating’ via the indirect pathway. © Lippincott-Raven Publishers.