Temporal effects of exercise on retrieval-induced forgetting.

Retrieval-induced forgetting (RIF) refers to the phenomenon whereby selectively retrieving some information impairs later recall of related, non-retrieved information, often interpreted as reflecting inhibitory control processes during memory retrieval. Recent work suggested that acute aerobic exercise performed between repeated memory tests may preserve the RIF effect over time. The present study sought to directly replicate and extend this finding using a larger and more controlled experimental design. Healthy young adults (N = 372) completed a standard category-exemplar RIF task involving selective retrieval practice followed by two final test assessments. Between the two tests, participants were randomly assigned to one of five conditions that manipulated exercise exposure, duration, and order (exercise, standing control, or combined sequences). Exercise was performed on a treadmill at vigorous intensity (80% heart-rate reserve), whereas control conditions involved standing on a stationary treadmill. Replicating the classic RIF effect, recall for Rp- items was significantly lower than for Nrp- items. However, contrary to prior findings, acute exercise did not preserve RIF across the two tests. Instead, the magnitude of RIF decreased from the first to the second test across all groups, driven primarily by improved recall of previously suppressed items. These findings indicate that RIF can attenuate with repeated retrieval but fail to provide evidence that acute exercise acts to stabilize retrieval-induced forgetting.