Do Individual Differences Moderate the Cognitive Benefits of Chewing Gum?

Richard Stephens,Nicola M J Edelstyn

doi:10.4236/psych.2011.28127

Abstract

Recent experiments investigating whether chewing gum enhances cognitive performance have shown mixed results and a recent replication failed to reproduce earlier findings. The present experiment aimed to investigate whether participant individual differences underlie the discrepant findings. Therefore, in addition to examining differences in Digit Span and Spatial Span performance across gum and control groups, chronotype, extraversion, habitual tiredness, current stress, current arousal and current thirst were assessed using questionnaires. Task difficulty was also manipulated. While there were no chewing gum effects under standard testing conditions, chewing gum enhanced Digit Span performance in the more difficult dual task condition. Furthermore, Spatial Span performance was improved by chewing gum in introverts but not extraverts and chewing gum was shown to eliminate the negative relationship between thirst and Digit Span performance. In explaining these data it is proposed that chewing gum may act both to reduce stress and to alleviate thirst.

Highlights

Around 90 years ago, when chewing gum sales began to take-off in North America, there were a variety of views pertaining to whether gum was an altogether suitable mass-consumer product
The absence of enhanced cognitive performance brought about by chewing gum is consistent with other research (Tucha et al, 2004, experiment 1; Miles & Johnson, 2007; Johnson & Miles, 2007; Allen, Norman, & Katz, 2008; Johnson & Miles, 2008; Smith, 2009a; Smith, 2009b)
Chewing gum was shown to be beneficial to performance compared with not chewing on the Digit Span test when a secondary task of counting sounded tones was concurrently performed

Summary

Introduction

Around 90 years ago, when chewing gum sales began to take-off in North America, there were a variety of views pertaining to whether gum was an altogether suitable mass-consumer product. Three variables pertinent to tiredness were assessed―chronotype (whether a person is most productive in the morning or the evening hours) was assessed using the Morningness-Eveningness Scale (Horne & Ostberg, 1976); habitual tiredness (as opposed to current level of tiredness) was assessed using the Epworth Sleepiness Scale (Johns, 1991); and current arousal level was assessed using the Stress and Arousal Checklist (Cox & Mackay, 1985) This was on the basis that chewing gum-mediated cognitive enhancement would be more likely to be present in participants who were tired or fatigued relative to those that were not so affected. Cognitive enhancement with chewing gum was hypothesised regardless of task difficulty for individuals reporting any of: higher levels of evening typeness, higher levels of tiredness, lower levels of arousal, higher levels of extraversion, higher levels of stress and/or higher levels of thirst

Participants

Design

Procedure

Results

Discussion