Value restructures the organization of free recall

A large body of research illustrates the prioritization of goal-relevant information in memory; however, it is unclear how reward-related memories are organized. Using a rewarded free recall paradigm, we investigated how reward motivation structures the organization of memory around temporal and higher-order contexts. To better understand these processes, we simulated our findings using a reward-modulated variant of the Context Maintenance and Retrieval Model (CMR; Polyn et al., 2009). In the first study, we found that reward did not influence temporal clustering, but instead shifted the organization of memory based on reward category. Further, we showed that a reward-modulated learning rate and source features of CMR most accurately depict reward's enhancement on memory and clustering by value. In a second study, we showed that reward-memory effects can exist in both extended periods of sustained motivation and frequent changes in motivation, by showing equivalent reward effects using mixed- and pure-list motivation manipulations. However, we showed that a reward-modulated learning rate in isolation can support reward's enhancement of memory in pure-list contexts. Overall, we conclude that reward-related memories are adaptively organized by higher-order value information, and contextual binding to value contexts may only be necessary when rewards are intermittent versus sustained.