Background and objective: Once a memory is reactivated, it enters a labile state and, thus, is vulnerable to memory decay and/or distortion. Recent research demonstrates that acute, high-intensity exercise is associated with enhanced episodic memory function. Very limited research, however, has evaluated whether acute exercise can attenuate memory distortion from memory reactivation, which was the purpose of this study.
Methods: A between-subject randomized controlled intervention was employed. Participants (N = 80) were randomly assigned to one of four groups, including (1) reminder with exercise, (2) reminder, (3) no reminder, and (4) interference control. For the groups, participants completed three visits (Visit 1, 2, and 3), which all occurred 48 hours apart. An exception to this was the interference control group, which did not complete Visit 2. On Visit 2, the reminder with exercise group engaged in a 15 min bout of high-intensity exercise (80% of heart rate reserve) immediately after memory reactivation. On Visit 3, participants engaged in a free recall (4 trials) of the memory task encoded on Visit 1.
Results: In a 4 (groups) × 4 (learning trials) mixed-measures ANOVA, with the group as the between-subjects variable and the learning trials (1-4) as the within-subject variable, there was a significant main effect group, F(3, 76) = 4.18, p = 0.008, η2p = 0.14, and a significant main effect for the learning trials, F(2.40, 182.59) = 49.25, p < 0.001, η2p = 0.39, but there was no group by learning trials interaction, F(7.20, 182.59) = 1.07, p = 0.38, η2p = 0.04.
Conclusion: Our findings suggest that exercise may, potentially, attenuate memory distortion from memory reactivation. However, future work is needed to confirm these findings before any strong conclusions can be reached.
Keywords: episodic memory; intrusions; memory distortion.