Betel nut chewing effects on sustained attention and inhibitory control after sleep deprivation

Abstract

Objective

Betel nut is a common stimulant and addictive substance in Asian countries. We wondered whether chewing betel nut affects sustained attention and inhibitory control after sleep deprivation.

Method

After one night of deprived or normal sleep, habitual chewers and non‐chewers were asked to complete the sustained attention to response task and the stop‐signal task. Before each task, participants chewed one gum or betel nut. The gum was to control for the effect of mere chewing. In the sustained attention to response task, participants responded to a sequence of numbers on a screen, but to withhold their response whenever they saw the number 3. In the stop‐signal task, they responded to a square or a circle, but withheld their response when a stop signal appeared.

Results

In the sustained attention to response task, the habitual chewers had lower false alarm rate and longer RT prior to false alarm (particularly when they had normal sleep) than the non‐chewers. In the stop‐signal task, deprived‐sleep participants had longer stop signal reaction time than normal‐sleep participants.

Conclusion

We reported that the habitual chewers have better sustained attention than the non‐chewers. Also, sleep deprivation weakens inhibitory control. Betel nut chewing does not have an acute effect on either sustained attention or inhibitory control.

Key words:

• betel nut
• inhibitory control
• sleep deprivation
• sustained attention

Conflict of interest: None.

Conflict of interest: None.

Acknowledgements

This study was supported by NSC‐98‐2410‐H‐040‐005‐MY3 from the National Science Council. We thank Wei‐Jyun Sie, Kun‐Bang Lin, Jun‐Yu Chen, Ya‐Ling Shih, Kai‐Hui Hsu, and Je‐Fu Deng for their assistance with the current study.

Notes

Conflict of interest: None.

1. This and other marginal significances in the current study require about 153 participants (p = .05, power = .7) to achieve significance (Cohen, 1988). Since the effect sizes are rather small and these two marginal significances did not change our main conclusions, we will not discuss them further in the General Discussion.

2. In Ho and Wang (2011), the arecoline was extracted from 60 betel nuts and weighed 80.2-mg. Therefore, it was estimated that each betel nut may contain about 1.3-mg arecoline. The test dose is similar to the chewing behaviour in daily life in which the chewers usually chew one betel nut at a time.

3. We thank one anonymous reviewer for this possibility.

Additional information

Funding

National Science Council