Effect of feedback type on enhancing subsequent memory: Interaction with initial correctness and confidence level.

Feedback is an important factor to enhance subsequent memory, showing that memory performance increases after the feedback than after the no feedback condition during retrieval practice. However, most studies have provided answers as feedback and only examined memory accuracy. It is unclear whether memory is enhanced over time when other types of feedback (e.g., correct/incorrect) is given. In addition, during retrieval practice, participants' responses differ in correctness and confidence level. To what extent these initial memory features interact with feedback type to influence subsequent memory accuracy and confidence level remains unclear. In this study, to address these questions, participants learned a series of sentences, then during the retrieval practice phase, different types of feedback-feedback with correct/incorrect and answer (CA-feedback), feedback with answer (A-feedback), feedback with correct/incorrect (C-feedback), and no feedback-were given after they performed a cued-recall test and rated the confidence. After retention intervals of 5 min, 1 day, and 7 days, they took final tests, followed by the confidence rating. The results showed that different types of feedback influenced subsequent memory and forgetting by different mechanisms. The CA-feedback and A-feedback enhanced memory performance by correcting initial errors and increasing the confidence of correct trials, but the corrected memory was more easily forgotten from 5 min to 7 days. Compared to A-feedback, the CA-feedback maintained the corrected memory after 1 day. The C-feedback did not correct initial errors but slowed the forgetting rate and reduced the confidence of incorrect trials. This study highlighted the interaction between feedback type and initial memory features (correctness, confidence) to influence subsequent memory performance, including memory accuracy and confidence level.