Investigating how reward retroactively improves memory for associations and items

Given we cannot remember all our experiences, it seems intuitive that we should prioritize events of consequence, like those that lead to a reward. However, rewards have had inconsistent effects on people’s memory for preceding neutral experiences in experiments, raising questions as to whether our minds are equipped to remember adaptively. Here, we will use online testing in a registered report to investigate whether rewards tend to retroactively enhance certain types of memories. Consistent with prior research and theories involving how dopamine modulates the hippocampus, we hypothesize that reward retroactively enhances memory in a delay-dependent manner, emerging only after a period of consolidation. Crucially, we further predict that this long-delay modulation of memory will be stronger for associative memory than for item recognition—a factor not previously considered despite its clear theoretical grounding. This work will answer important open questions about the mechanisms by which reward retroactively enhances memory, elucidating the conditions under which this key aspect of adaptive memory emerges.