This study evaluated whether the timing of acute exercise can attenuate a memory interference effect. Across two experiments, participants completed an AB/AC memory task. Participants studied eight word pairs; four denoted AB (e.g., Hero - Apple) and four control (DE) pairs. Following this List 1, participants studied eight additional word pairs (List 2); four denoted AC, re-using words from the AB pairs (e.g., Hero - Project) and four control (FG) pairs. Following their study of both lists, participants completed a cued recall assessment. In Experiment 1 (N = 100), an acute exercise bout occurred before the AB/AC memory interference task, and the participants' three lab visits (successive conditions) were control, moderate-intensity (50% HRR; heart rate reserve) exercise, and vigorous-intensity (80% HRR) exercise. In Experiment 2 (N = 68), the acute exercise occurred between List 1 and List 2, and the participants' two lab visits (successive conditions) were a (80% HRR) vigorous-intensity exercise visit and a control visit. Across both experiments, we observed evidence of both proactive and retroactive interference (p < .05), but acute exercise, regardless of intensity, did not attenuate this interference (p > .05). Acute moderate-intensity exercise was better than control or vigorous-intensity exercise in enhancing associative memory (p < .05), independent of interference. In Experiment 2, vigorous intensity exercise was associated with more pronounced interference (p < .05). Our results suggest that acute exercise can enhance associative memory performance, with no attenuation of interference by exercise.
Keywords: acute exercise; associative interference; memory discrimination; memory similarity; mnemonic discrimination.