The Benefit of an Acute Bout of Exercise for Procedural Consolidation Is Not Related to Avoiding a Temporary Reduction in Motor Cortical Excitability

Abstract

Individuals in two separate experiments implicitly acquired a procedural skill which was tested after a 6-hr, wake-filled interval. In both experiments individuals that were exposed to a vowel counting activity immediately following procedural training exhibited successful procedural consolidation manifest as significant offline gain. This gain was eliminated by replacing the vowel counting task with a declarative learning task. The disruption in procedural consolidation demonstrated in both experiments confirms reports that declarative and procedural systems can interact during wakefulness. A novel finding revealed in Experiment 1, and replicated in Experiment 2, was that exposure to a brief bout of moderate intensity cardiovascular exercise immediately after procedural learning protected the newly acquired motor memory from interference introduced by declarative learning. These data suggest that the interplay between declarative and procedural systems can be modified by exercise. Experiment 2 examined the possibility that the exercise bout in Experiment 1 served to elevate cortical excitability at M1, eliminating the transient reduction that is displayed shortly after training in cases where procedural consolidation does not occur. Findings from Experiment 2 indicated that exercise does instigate an increase in M1 excitability during the immediate time period after practice. However, the increase in M1 excitability induced via exercise was not significantly greater than the increase that occurred for other learning conditions in the absence of exercise. Thus, the benefit of incorporating an acute bout of exercise for procedural learning is not dependent on the upregulation of excitability of a key neural site for procedural skill consolidation, M1.