Smith B D, Rafferty J, Lindgren K, Smith D A, Nespor A
Department of Psychology, University of Maryland, College Park 20742.
Physiol Behav. 1992 Jan;51(1):131-7. doi: 10.1016/0031-9384(92)90214-m.
A recently proposed model of the biobehavioral effects of caffeine suggests that acute ingestion impacts physiology and behavior differentially depending on the level of habitual usage of the drug. Acute ingestion and habitual usage are particularly expected to affect arousal and attentional processes. Subjects in the present study were preselected for high and low habitual caffeine use, given caffeine or a placebo, exposed to white noise or no white noise, and asked to perform on several tasks. Included were an arousal/habituation task (pure tones), reaction time, paired associates, anagrams, and vigilance. Electrodermal activity and performance were recorded. As predicted, virtually all effects were on the arousal/habituation and attentional (vigilance) tasks. Both acute ingestion and habitual use increased tonic EDA, and chronic use also reduced phasic responding, especially in the presence of a strong habituating stimulus. Both acute and habitual use also liberalized the vigilance response criterion, in that subjects risked more false alarms in order to attain more hits. In addition, habitual use increased sensitivity and reduced accuracy, and acute ingestion increased vigilance response time in the presence of white noise. Overall, the model was partially supported by these early results, though considerable further research is needed.
最近提出的一个关于咖啡因生物行为效应的模型表明，根据药物的习惯性使用水平，急性摄入对生理和行为的影响存在差异。急性摄入和习惯性使用尤其预计会影响唤醒和注意力过程。本研究中的受试者预先被挑选为习惯性高咖啡因使用者和低咖啡因使用者，给予他们咖啡因或安慰剂，使其暴露于白噪声或无白噪声环境中，并要求他们完成几项任务。这些任务包括一个唤醒/习惯化任务（纯音）、反应时间、配对联想、字谜游戏和警觉性任务。记录了皮肤电活动和表现。正如预测的那样，几乎所有的效应都体现在唤醒/习惯化和注意力（警觉性）任务上。急性摄入和习惯性使用都会增加静息皮肤电活动，并且长期使用还会减少相位反应，尤其是在存在强烈习惯化刺激的情况下。急性和习惯性使用还放宽了警觉性反应标准，即受试者为了获得更多命中而冒更多误报的风险。此外，习惯性使用会提高敏感性并降低准确性，而急性摄入会增加在白噪声存在时的警觉性反应时间。总体而言，这些早期结果部分支持了该模型，不过还需要进行大量进一步的研究。
