Centre for Occupational and Health Psychology, School of Psychology, Cardiff University,UK.
J Psychopharmacol. 2013 Jan;27(1):77-83. doi: 10.1177/0269881112460112. Epub 2012 Sep 19.
Despite the large number of studies on caffeine and attention, interpretation is often difficult because of methodological weaknesses. In the present study, use of a small battery of tests with four key outcome measures, combined with an appropriate sample size, addresses many of these problems. This methodology was used to examine whether effects of caffeine (a dose of 2 mg/kg) could be explained in terms of reversal of the effects of caffeine withdrawal. This was achieved by examining effects in non-consumers (N = 35), who could not be withdrawn, and also in a group of consumers (N = 35) who had undergone withdrawal for a week and no longer reported symptoms of withdrawal. The results showed no effect of short-term withdrawal on the performance measures, even though subjective reports showed an increase in symptoms after withdrawal. In contrast, the caffeine challenge carried out on Day 8 showed that ingestion of caffeine was associated with faster simple reaction time, fewer long responses, greater detection of targets in the cognitive vigilance task, and faster encoding of new information. These results suggest that it is important to continue to investigate mechanisms underlying these effects of caffeine and to further evaluate the practical implications of such effects.
尽管有大量关于咖啡因和注意力的研究，但由于方法学上的弱点，解释往往很困难。在本研究中，使用了一套由四个关键结果测量指标组成的小测试电池，并结合了适当的样本量，解决了许多这些问题。这种方法用于研究咖啡因（剂量为 2 毫克/千克）的作用是否可以用咖啡因戒断的作用的逆转来解释。这是通过检查非消费者（N=35）的效果来实现的，他们不能被戒断，也通过检查已经戒断一周且不再报告戒断症状的消费者组（N=35）的效果来实现。结果表明，短期戒断对表现测量没有影响，尽管主观报告显示戒断后症状增加。相比之下，在第 8 天进行的咖啡因挑战表明，摄入咖啡因与更快的简单反应时间、更少的长反应、认知警戒任务中目标的更高检测以及新信息的更快编码有关。这些结果表明，继续研究咖啡因这些作用的机制以及进一步评估这些作用的实际意义非常重要。
