Repeated extrinsic rewards following retrieval practice facilitate later memory

The anticipation of extrinsic reward facilitates memory formation. However, it is unclear how reward following memory retrieval influences the information that is retrieved and later remembered. Here, we conducted four behavioral experiments (N=42 male/female young adults per experiment) in which we manipulated retrieval practice reward delivery. Across all experiments, participants studied word-image pairs and then completed two rounds of retrieval practice, followed by a final recognition test. Participants made vividness judgments during retrieval practice and in three of four experiments each response had a 50% chance of yielding positive feedback. We find that repeated rewards following retrieval practice facilitate later memory whereas low vivid retrieval practice impairs later memory. Together, these results suggest that the benefit of both retrieval practice and reward may be dependent on the strength of the memory that is retrieved.