The Association between Childhood Aerobic Fitness and Source Memory Function

Abstract

Recent literature suggests that greater childhood aerobic fitness is associated with superior memory performance. Event-related brain potentials (ERPs) that have a high temporal resolution combined with behavioral task performance might further increase our understanding of the association between fitness and memory function. PURPOSE: This study was design to provide new insights into the association between childhood aerobic fitness and memory processing using ERPs during a source memory task. METHODS: Lower-fit and higher-fit children (mean = 12.0 years, SD = 1.1) performed a source memory task consisting of two test phases: an item recognition test and a source recognition test. In the former test, participants were asked to make an old/new judgement, whereas in the latter test they were asked to discriminate whether a presented line drawing was seen in a particular color (target-old) or a different color (non-target-old) from the study phase, or new. We assessed early and late ERP episodic memory (EM) effects that reflected the retrieval of item content and source information, respectively. RESULTS: Contrary to our expectation, memory accuracy was significantly lower in the higher-fit group, relative to the lower-fit group, and this difference was disproportionately greater for source recognition trials. ERP data during the source test indicated that the higher-fit group had smaller amplitude in the early EM effect, relative to the lower-fit group, whereas during the item test, the higher-fit group had a smaller amplitude in the late EM effect relative to the lower-fit group. These ERP data could reflect more flexible, but less effective retrieval processing in higher-fit children. CONCLUSIONS: It has been suggested that familiarity contributes to associative memory. Therefore, flexible retrieval processing by higher-fit children might have resulted in unexpectedly lower memory accuracy. In conclusion, it is likely that the association between childhood fitness and memory performance could be either positive, or negative, depending on the nature of the cognitive task. Supported by a NIFS (National Institute of Fitness and Sports) project (1201200005).