Given the limited capacity of working memory (WM), its resources should be allocated strategically. One strategy is filtering, whereby access to WM is granted preferentially to items with the greatest utility. However, reallocation of WM resources might be required if the utility of maintained information subsequently declines. Here, we present behavioral, computational, and neuroimaging evidence that human participants track changes in the predicted utility of information in WM. First, participants demonstrated behavioral costs when the utility of items already maintained in WM declined and resources should be reallocated. An adapted Q-learning model indicated that these costs scaled with the historical utility of individual items. Finally, model-based neuroimaging demonstrated that frontal cortex tracked the utility of items to be maintained in WM, whereas ventral striatum tracked changes in the utility of items maintained in WM to the degree that these items are no longer useful. Our findings suggest that frontostriatal mechanisms track the utility of information in WM, and that these dynamics may predict delays in the removal of information from WM.
Keywords: working memory, predicted utility, Q-learning, gating, filtering
Citation: Chatham CH and Badre D (2013) Working memory management and predicted utility. Front. Behav. Neurosci. 7:83. doi: 10.3389/fnbeh.2013.00083
Received: 13 May 2013; Accepted: 23 June 2013;
Published online: 17 July 2013.
Edited by:Rutsuko Ito, University of Toronto, Canada
Reviewed by:Tobias Egner, Duke University, USA
Copyright © 2013 Chatham and Badre. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: Christopher H. Chatham, Metcalf Research Laboratory, CLPS, Brown University, 190 Thayer St., Providence, RI 02912, USA e-mail: firstname.lastname@example.org