Reward enhancement of item-location associative memory spreads to similar items within a category

ABSTRACT

The experience of a reward appears to enhance memory for recent prior events, adaptively making that information more available to guide future decision-making. Here, we tested whether reward enhances memory for associative item-location information and also whether the effect of reward spreads to other categorically-related but unrewarded items. Participants earned either points (Experiment 1) or money (Experiment 2) through a time-estimation reward task, during which stimuli-location pairings around a 2D-ring were shown followed by either high-value or low-value rewards. All stimuli were then tested for location memory or recognition (yes/no), immediately and after a 24-hour delay. Across both experiments (combined analysis), there was a robust improvement in location memory following high-value rewards, even though evidence supporting this effect was reliable in Experiment 2 but not in Experiment 1. The memory-enhancing effect of reward was observed on both the immediate and delayed location-memory tests. Reward-enhanced memory for both directly rewarded stimuli and categorically related stimuli that were not directly rewarded. No reliable effect of reward value on yes/no recognition-memory performance was observed in either experiment. We hypothesise that reward enhances the consolidation of recent experience and conceptually related memories to make these more available for future decisions.

KEYWORDS:

• Reward
• memory
• item-location
• retroactive reward influence
• categorically related

Acknowledgements

The authors thank Y. Catherine Han for her feedback on the statistical analyses and for creating the avatar images used in Experiment 1, and Caelie P. McRobert and Thomas C. Dixon for their support with data collection for both experiments.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data and materials for all experiments are available at the Open Science Framework, https://osf.io/zv4ah/. None of the experiments were pre-registered in advance, although the two experiments are largely replications of each other.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This research was supported by the T32 Training Program in Neuroscience of Human Cognition [EG, MSC; T32 NS047987-04]. Support was also provided by the Office of Naval Research [PJR; N00014-18-1-2316, N00014-22-1-2162].