Selectivity in Postencoding Connectivity with High-Level Visual Cortex Is Associated with Reward-Motivated Memory

Abstract

Reward motivation has been demonstrated to enhance declarative memory by facilitating systems-level consolidation. Although highreward information is often intermixed with lower reward information during an experience, memory for high value information is prioritized. How is this selectivity achieved? One possibility is that postencoding consolidation processes bias memory strengthening to those representations associated with higher reward. To test this hypothesis, we investigated the influence of differential reward motivation on the selectivity of postencoding markers of systems-level memory consolidation. Human participants encoded intermixed, trial-unique memoranda that were associated with either high or low-value during fMRI acquisition. Encoding was interleaved with periods of rest, allowing us to investigate experience-dependent changes in connectivity as they related to later memory. Behaviorally, we found that reward motivation enhanced 24 h associative memory. Analysis of patterns of postencoding connectivity showed that, even though learning trials were intermixed, there was significantly greater connectivity with regions of high-level, category-selective visual cortex associated with high-reward trials. Specifically, increased connectivity of category-selective visual cortex with both the VTA and the anterior hippocampus predicted associative memory for high-but not low-reward memories. Critically, these results were independent of encoding-related connectivity and univariate activity measures. Thus, these findings support a model by which the selective stabilization of memories for salient events is supported by postencoding interactions with sensory cortex associated with reward.

Transcending time in the brain: How event memories are constructed from experience

“…Relevant to the discussion here, recent work suggests that postencoding hippocampal activity and functional connectivity immediately following an event may enhance associative memory of that just‐experienced information (Murty et al, ; Tambini & Davachi, ; Tambini et al, ). These neural patterns even emerge if measured in the few seconds following an item's presentation (Cohen et al, ; Staresina et al,).…”

“…Such rapid neural replay has been hypothesized to be important for preserving memory for the sequential order of recent information, although more evidence supporting this hypothesis is needed (Ólafsdóttir, Bush, & Barry, ). Identifying similar postencoding replay and/or reactivation patterns in humans is an intense and active area of research (de Voogd, Fernández, & Hermans, ; Gruber, Ritchey, Wang, Doss, & Ranganath, ; Murty, Tompary, Adcock, & Davachi, ; Schlichting & Preston, , ; Tambini, Ketz, & Davachi, ; Tambini, Rimmele, Phelps, & Davachi, ; Tompary, Duncan, & Davachi, ).…”

Reward retroactively enhances memory consolidation for related items

“…Further, emotional learning, albeit in the aversive domain, has been shown to restructure representations of objects in category-selective cortex (i.e., animal versus tool cortex) associated with reinforcement (Dunsmoor et al 2014). Finally, reward motivation, albeit in an intentional encoding paradigm, has been shown to selectively facilitate post-encoding interactions of the ventral tegmental area, the source of dopamine neurons, and the hippocampus with category-selective cortex in service of better memory (Murty et al 2016b). Future work, however, will have to validate this proposed mechanism of retroactive memory enhancements by reward.…”

Cash or Credit? Compensation in Psychology Studies: Motivation Matters

“…One area of research in which the motivation to participate and thus the method of participant compensation might be critical to the results of the study is in experiments examining the effects of motivation on task performance. In the design adopted by many studies examining motivation (e.g., Adcock, Thangavel, Whitfield-Gabrieli, Knutson, & Gabrieli, 2006;Murayama & Kitagami, 2014;Murty, Tompary, Adcock, & Davachi, 2016;Shigemune et al, 2010;Spaniol, Bowen, Wegier, & Grady, 2015;Spaniol, Schain, & Bowen, 2013;Wittmann et al, 2005), in addition to compensation for time, rewards are manipulated within task and used as incentive for participants to earn additional monetary rewards based on their task performance. In these studies, the overall finding is that memory for items associated with a high reward are remembered better than items associated with a low reward.…”

“…In line with the overjustification effect, those who choose to be compensated with for their time with credit, may be more intrinsically motivated to participate thus extra performance based incentives may interfere with their willingness or ability to perform the task well. We chose to examine this within the context of a rewarded memory task where better memory for high versus low reward (e.g., Adcock et al, 2006;Murty, LaBar, Hamilton, & Adcock, 2011;Murty et al, 2016) usually only after a period of consolidation (e.g., Murayama & Kitagami, 2014;Murayama & Kuhbandner, 2011;Spaniol et al, 2013) is a robust finding, but the motivation and compensation for completing the study is rarely reported nor included as a factor in the results.…”