Assessing the effects of caffeine and theanine on the maintenance of vigilance during a sustained attention task

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• 作者：John J. Foxe^a ; ^b ; ^c ; ^{john.foxe@einstein.yu.edu} ; Kristen P. Morie^a ; ^b ; ^c ; Peter J. Laud^d ; Matthew J. Rowson^e ; Eveline A. de Bruin^f ; Simon P. Kelly^c
• 关键词：Attention ; Vigilance ; Alpha-band ; Oscillations ; EEG ; Human ; Tea ; Theanine ; Caffeine
• 刊名：Neuropharmacology
• 出版年：2012
• 期刊代码：33_00283908
• 类别：pha
• 出版时间：June, 2012
• 卷：62
• 期：7
• 页码：2320-2327
• 文件大小：810 K

摘要

Caffeine and l-theanine, both naturally occurring in tea, affect the ability to make rapid phasic deployments of attention to locations in space as reflected in behavioural performance and alpha-band oscillatory brain activity (8-14聽Hz). However, surprisingly little is known about how these compounds affect an aspect of attention that has been more popularly associated with tea, namely vigilant attention: the ability to maintain focus on monotonous tasks over protracted time-periods. Twenty-seven participants performed the Sustained Attention to Response Task (SART) over a two-hour session on each of four days, on which they were administered caffeine (50聽mg), theanine (100聽mg), the combination, or placebo in a double-blind, randomized, cross-over fashion. Concurrently, we recorded oscillatory brain activity through high-density electroencephalography (EEG). We asked whether either compound alone, or both in combination, would affect performance of the task in terms of reduced error rates over time, and whether changes in alpha-band activity would show a relationship to such changes in performance. When treated with placebo, participants showed a rise in error rates, a pattern that is commonly observed with increasing time-on-task, whereas after caffeine and theanine ingestion, error rates were significantly reduced. The combined treatment did not confer any additional benefits over either compound alone, suggesting that the individual compounds may confer maximal benefits at the dosages employed. Alpha-band oscillatory activity was significantly reduced on ingestion of caffeine, particularly in the first hour. This effect was not changed by addition of theanine in the combined treatment. Theanine alone did not affect alpha-band activity.