Defence Science and Technology Group, Edinburgh, 5111, Australia.
School of Psychology, University of Sydney, Sydney, Australia.
Sci Rep. 2021 Feb 17;11(1):4027. doi: 10.1038/s41598-021-83504-6.
Caffeine is widely used to promote alertness and cognitive performance under challenging conditions, such as sleep loss. Non-digestive modes of delivery typically reduce variability of its effect. In a placebo-controlled, 50-h total sleep deprivation (TSD) protocol we administered four 200 mg doses of caffeine-infused chewing-gum during night-time circadian trough and monitored participants' drowsiness during task performance with infra-red oculography. In addition to the expected reduction of sleepiness, caffeine was found to disrupt its degrading impact on performance errors in tasks ranging from standard cognitive tests to simulated driving. Real-time drowsiness data showed that caffeine produced only a modest reduction in sleepiness (compared to our placebo group) but substantial performance gains in vigilance and procedural decisions, that were largely independent of the actual alertness dynamics achieved. The magnitude of this disrupting effect was greater for more complex cognitive tasks.
咖啡因被广泛用于在睡眠不足等挑战条件下提高警觉性和认知表现。非消化输送方式通常可减少其效果的可变性。在一项安慰剂对照的 50 小时完全睡眠剥夺（TSD）方案中，我们在夜间生物钟低谷时给参与者服用了四片 200 毫克的含咖啡因咀嚼口香糖，并通过红外线眼动跟踪监测参与者在任务执行过程中的困倦程度。除了预期的困倦减轻外，研究还发现，咖啡因破坏了其对从标准认知测试到模拟驾驶等任务中表现错误的恶化影响。实时困倦数据显示，与我们的安慰剂组相比，咖啡因仅适度减轻了困倦，但在警觉和程序决策方面有了实质性的提高，这些提高在很大程度上与实际达到的警觉动态无关。这种干扰效应的幅度对于更复杂的认知任务更大。
