School of Psychology, University of Wales College of Cardiff, Cardiff CF1 3YG.
J Psychopharmacol. 1991 Jan;5(2):120-8. doi: 10.1177/026988119100500205.
Two experiments were carried out to examine the effects of caffeine on performance, mood and cardiovascular function. The results showed that the effects of caffeine depended on the dose, time of administration, the function being examined and the impulsivity of the subject. Changes in blood pressure were only observed when a high dose (3 mg/kg) was used. The effects of this dose on performance depended on the impulsivity of the subject, with high impulsives performing worse in the de-caffeinated condition but getting a greater benefit from the caffeine. The high dose of caffeine also removed the post-lunch dip in sustained attention. The second experiment, which used a lower dose of caffeine (~60 mg), failed to demonstrate any caffeine x impulsivity or caffeine x time of day effects on performance. However, caffeine improved performance on a logical reasoning task and caffeine x time of day x impulsivity effects were found in analyses of visual search tasks. The mood data also support the view that the effects of caffeine depend on a combination of factors similar to those outlined for performance.
进行了两项实验来考察咖啡因对表现、情绪和心血管功能的影响。结果表明，咖啡因的效果取决于剂量、给药时间、被检测的功能以及测试对象的冲动性。只有当使用高剂量（3 毫克/千克）时才会观察到血压的变化。该剂量对表现的影响取决于测试对象的冲动性，高冲动性者在去咖啡因条件下表现更差，但从咖啡因中获益更大。高剂量的咖啡因还消除了午餐后的持续注意力下降。第二项实验使用了较低剂量的咖啡因（约 60 毫克），未能证明咖啡因对表现有任何冲动性或咖啡因对时间的影响。然而，咖啡因改善了逻辑推理任务的表现，并且在视觉搜索任务的分析中发现了咖啡因对时间的影响。情绪数据也支持这样一种观点，即咖啡因的效果取决于类似表现的综合因素。
