Theta oscillations (rhythmic, slow-wave activity) have been extensively studied in the rat hippocampus where they are especially prominent during spatial exploration. Recently, it has become possible to study these oscillations in human cortex as well, using intracranial electrode arrays implanted in epileptic patients awaiting surgery for potentially curative resection surgery. Studies using this technique have found that these oscillations increase with the increasing demands of a spatial navigation task, and are tightly linked to a working memory task. The proposed studies aim to further elucidate the role of these oscillations in human cognition. More specifically this research aims to assess theta's role in encoding, rehearsal, and retrieval processes during working memory. It also seeks to determine the conditions under which task- related cognitive operations produce reset of theta oscillations. These results will inform our understanding of both normal and impaired memory and may ultimately lead to new treatments for debilitating memory disorders.
