Learning new information is rarely done in isolation outside the laboratory. What one does between study sessions is important for later retrieval of the studied material. Previous research has shown that interleaved semantic retrieval leads to enhanced memory for later-learned items but to reduced memory for earlier-learned items (Divis & Benjamin, 2014). Retrieval-induced distinction provides one account for the opposite effects of retrieval on memory for early versus later material. By that view, retrieval serves to "spread out" the memory representations, making them (1) more distinct and less likely to interfere with each other and (2) rendering earlier events mentally more distant and harder to access at the time of test. Here, I expand on prior work examining the influence of intervening tasks on memory. Experiment 1 examines the effect of interleaved periods of task switching on memory for materials learned prior to or following the task switching intervention. Switching tasks (50% retrieval and 50% control) between periods of learning leads to similar benefits as those provided by a retrieval intervention. Experiments 2A and 2B examine the effects of intervening task on interlist intrusions. List distinction is enhanced when lists are separated by retrieval tasks, as seen by a reduction in interlist intrusions. Experiment 3 integrates and extends many of the components of prior studies by examining the influence of intervening retrieval on memory for complex, narrative text materials that share repeated, conflicting, and unique information. It highlights important boundaries to the influence of retrieval-induced distinction and provides a launching point for future studies examining the application of these intervening tasks in more ecologically relevant settings
