The role of mental rehearsal and working memory resource depletion in the spacing effect: influence of element interactivity on learning

This study investigates the spacing effect and its underlying two mechanisms: working memory resource depletion and mental rehearsal, using materials with varying complexity. In Experiment 1, using simpler materials, the spaced group outperformed the massed group, indicating a spacing effect likely attributed to mental rehearsal, without working memory resource depletion. In Experiment 2, involving complex materials, a spacing effect was observed again, but again without working memory resource depletion. These findings suggest that the spacing effect can be primarily explained by mental rehearsal, particularly when the materials are simple, allowing for effective rehearsal during rest periods. Moreover, working memory resource depletion may not occur even with more complex materials if learners have developed schemas that reduce cognitive load of learning materials. This study contributes to our understanding of how instructional design and material complexity influence the spacing effect and highlights the importance of considering element interactivity (complexity) in educational contexts.