Controlling the Contents of Working Memory

PROJECT SUMMARY The overarching goal of this proposal is to understand, at a mechanistic level, how visual working memory is controlled. It will achieve this by pursuing two Specific Aims: Specific Aim I: To elucidate the mechanisms underlying the control of priority in working memory Specific Aim II: To elucidate the mechanisms underlying the active removal of information from working memory Working memory is understood to be a necessary elemental contributor to many aspects of high-level cognition – including cognitive control, problem solving, and planning – and its impairment is characteristic of many psychopathologies and psychiatric syndromes – including attention deficit hyperactivity disorder (ADHD), major depressive disorder (MDD), and schizophrenia. The research pursuing Specific Aim I entails modeling working memory behavior with recurrent neural networks, to refine algorithm-level models of the operations that contribute to the control of priority working memory, then testing these models in human brains with functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and transcranial magnetic stimulation (TMS). The research pursuing Specific Aim II entails the study of active-removal from working memory with model-based analysis (using a reinforcement learning-based model of cognitive control) and computational simulations of fMRI data, and with repetitive (r)TMS targeting frontal circuits responsible for active-removal versus for the control of priority.