Understanding the Relationship Between Working Memory and Long-Term Memory

How lasting memories are created is a question that has driven much research into human cognition. An area of renewed research interest concerns the relationship between working memory and long-term memory. Recent research has investigated how the processing that occurs while information is held in working memory influences successful long-term memory creation. Both working memory consolidation and maintenance have been identified as critical in long-term retention, but the mechanisms underlying the working memory/long-term memory relationship remain unclear. The present dissertation examined different working memory mechanisms and their impact on long-term memory in a broader context by addressing two questions: 1) What factors influence immediate post-encoding working memory processes such as maintenance and consolidation and their effect on long-term memory?, and 2) How does one’s current state influence the relationship between immediate post-encoding processing and long-term memory? The first set of experiments explored how trait and state creativity influenced the efficacy of working memory consolidation on subsequent long-term memory. The motivating hypothesis for this was that working memory consolidation may facilitate the formation of novel associations between items during learning, leading to improved memory search at delayed retrieval. We found that while trait creativity, but not state creativity, corresponded with general performance on memory tasks, this effect was not related to working memory consolidation. The results of these two experiments suggest that creativity is not related to the mechanism underlying the effect of working memory consolidation on delayed recognition. The second set of experiments investigated the effects of mind-wandering and multitasking during working memory tasks in remote and in-person environments. While overall remote participants reported significantly more mind-wandering and poorer secondary task performance than the in-person participants, this pattern was not reflected in their working memory accuracy and both groups exhibited similar multitasking effects on memory performance. Additional analyses found that for remote participants the level of engagement with the task was a better predictor of working memory performance than either multitasking difficulty or mind-wandering rates. A follow-up experiment extended this finding to delayed recognition to investigate if active working memory maintenance is critical for robust long-term memory. In this experiment, we tested if repeatedly retrieving memory items into the focus of attention improved performance on a delayed recognition test. We found that how much a participant engaged with the secondary task (i.e., the opportunities for repeated retrieval) during the working memory task corresponded with delayed memory performance. Together, these results demonstrate the importance of considering multiple metrics when assessing performance and that repeated retrieval is a key mechanism in the relationship between working memory processing and long-term retention. The final set of experiments explored how working memory consolidation and long-term memory creation are impacted by stress. Previous research has shown that pre-encoding stress modulates long-term memory and working memory performance, but they have not yet been considered together. We found that stress has small, if any, beneficial effects on both working memory and long-term memory and no evidence that stress impaired either type of memory. We also found evidence that the benefits of working memory consolidation on long-term retention may be limited to non-visual memory. Taken together, the results of these experiments provide evidence that the processing that occurs while information is held in working memory influences the subsequent retrieval of that information after a delay, though there are boundaries to this relationship. The experiments in this dissertation also demonstrate the importance of individual variability that underlies performance across cognitive tasks and contexts