Tufts University, Department of Psychology, USA.
Pharmacol Biochem Behav. 2011 Jul;99(1):59-65. doi: 10.1016/j.pbb.2011.03.024. Epub 2011 Apr 1.
The effects of caffeine-induced arousal on global versus local object focus were investigated in non-habitual consumers using a double-blind, within-subjects, repeated-measures design. Following an overnight fast, low caffeine consumers (N=36; M=42.5mg/day caffeine) completed 5 counterbalanced test sessions (normal consumption, 0mg, 100mg, 200mg, and 400mg) separated by at least 3 days. During each session, volunteers either consumed their normal amount of caffeine or were administered 1 of 4 treatment pills. One hour later they completed two tasks assessing visual attention, in counterbalanced order. Measures of mood, salivary caffeine and cortisol were taken at multiple time points. Dose-dependent elevation of caffeine in the saliva demonstrated the experimental manipulation was effective. Furthermore, analyses of the mood and arousal measures detected consistent changes on arousal subscales and caffeine administration elevated saliva cortisol. Analyses of the visual attention tasks revealed that caffeine-induced physiological arousal produced global processing biases, after as little as 100mg caffeine. These data suggest caffeine consumption may influence how individuals attend to and process information in their environment and could influence daily tasks such as face recognition, learning new environments and navigation, especially for those who normally consume little caffeine.
采用双盲、自身对照、重复测量设计，研究了咖啡因引起的觉醒对整体与局部对象焦点的影响，对象为非习惯性消费者。在禁食一夜后，低咖啡因消费者（N=36；M=42.5mg/天咖啡因）完成了 5 个平衡测试阶段（正常摄入、0mg、100mg、200mg 和 400mg），每个阶段至少间隔 3 天。在每个阶段中，志愿者要么摄入他们正常的咖啡因量，要么服用 4 种治疗药丸中的 1 种。1 小时后，他们以平衡的顺序完成了两项评估视觉注意力的任务。在多个时间点测量了情绪、唾液咖啡因和皮质醇的水平。唾液中咖啡因的剂量依赖性升高表明实验操作是有效的。此外，对情绪和觉醒测量的分析检测到在觉醒子量表上的一致变化，咖啡因的摄入增加了唾液皮质醇。对视觉注意力任务的分析表明，咖啡因引起的生理觉醒会导致整体加工偏差，即使摄入低至 100mg 的咖啡因也会产生这种影响。这些数据表明，咖啡因的摄入可能会影响个体如何关注和处理环境中的信息，并且可能会影响日常任务，例如人脸识别、学习新环境和导航，特别是对于那些通常摄入少量咖啡因的人。
