Abstract

Although the facilitative effects of chewing gum on free recall have proved contentious (e.g. Wilkinson et al., 2002; Tucha et al., 2004), there are strong physiological grounds e.g. increased cerebral activity and blood-flow following the act of mastication, to suppose facilitation. The present study manipulated resistance to mastication i.e., chewing 4 pellets versus 1 pellet of gum, with the assumption that increased resistance will accentuate cerebral activity and blood-flow. Additionally, chewing rate was recorded for all participants. In a within-participants design, participants performed a series of immediate free recall tasks whilst chewing gum at learning (1 or 4 pellets) and recall (1 or 4 pellets). Increased chewing resistance was not associated with increased memory performance, despite consistent chewing rates for both the 1 pellet and 4 pellet conditions at both learning and recall. However, a pattern of recall consistent with context-dependent memory was observed. Here, participants who chewed the equivalent number of gum pellets at both learning and recall experienced significantly superior word recall compared to those conditions where the number of gum pellets differed.