PT  - JOURNAL ARTICLE
AU  - Jarrod A. Lewis-Peacock
AU  - Jonathan D. Cohen
AU  - Kenneth A. Norman
TI  - Decoding the Contents of Working Memory Tracks Strategy and Performance in Prospective Remembering
AID  - 10.1101/055004
DP  - 2016 Jan 01
TA  - bioRxiv
PG  - 055004
4099  - http://biorxiv.org/content/early/2016/05/24/055004.short
4100  - http://biorxiv.org/content/early/2016/05/24/055004.full
AB  - Theories of prospective memory (PM) posit that it can be subserved either by working memory (WM) or episodic memory (EM). Testing and refining these multiprocess theories of PM requires a way of tracking participants’ reliance on WM versus EM. Here we use multi-voxel pattern analysis (MVPA) to derive a trial-by-trial measure of WM use in prospective memory. We manipulated strategy demands by varying the degree of proactive interference (which hurts EM) and the memory load required to perform the secondary task (which hurts WM). Our MVPA measures showed 1) greater WM use and 2) a trial-by-trial correlation between WM use and PM behavior for the condition in which participants were pushed to rely more on WM. Finally, we also showed that MVPA measures of WM use are not redundant with other behavioral measures: in the condition in which participants were pushed more to rely on WM, using neural and behavioral measures together led to better prediction of PM accuracy than either type of measure on its own.Significance Statement To accomplish our goals, we must remember them, and this can be challenging when our cognitive resources are in demand. Multiple strategies can support prospective remembering — people can use working memory to actively maintain the goal, or they can store the goal in episodic memory and retrieve it later when needed. Here we measured participants’ use of working memory on a trial-by-trial basis using functional MRI. Our neural measure of working memory varied according to task conditions that were designed to manipulate strategy use, and it led to better prediction of trial-by-trial prospective memory accuracy than could be achieved based purely on behavioral measures. These data provide the strongest connection to date between neural data and prospective memory behavior.