Gilbert D G, Dibb W D, Plath L C, Hiyane S G
Department of Psychology, Southern Illinois University at Carbondale, 62901-6502, USA.
Psychophysiology. 2000 Sep;37(5):583-95.
Effects of nicotine and caffeine, separately and in combination, were assessed in 12 male habitual smokers in a repeated-measures design. Caffeine (0-mg vs. two 150-mg doses administered in a decaffeinated/sugar-free cola drink post-baseline and 90 min later) was crossed with nicotine (ad libitum own dosing vs. 1.0-mg machine-delivered dose vs. 0.05-mg machine-delivered dose). Participants smoked a total of five cigarettes at 30-min intervals over a 2-hr period. Caffeine and nicotine had large effect sizes on electroencephalogram (EEG) power; however, these effects were modulated by the eyes open versus closed condition, the other drug, and electrode site. EEG effects of open versus closed eyes tended to be of the same size and direction as those of nicotine and caffeine. However, whereas nicotine increased EEG power in some higher frequency bands in some conditions, caffeine decreased EEG power across almost all conditions. Serum cortisol concentration, vigor, and pleasantness were increased by nicotine, but not by caffeine. Level of depressive mood depended on an interaction of caffeine and nicotine. Vigilance performance was enhanced significantly by caffeine and was increased almost significantly by nicotine. The findings were interpreted in terms of common and differential mechanisms of the two drugs.
采用重复测量设计，对12名男性习惯性吸烟者分别及联合使用尼古丁和咖啡因的效果进行了评估。咖啡因（基线后和90分钟后，在不含咖啡因/无糖可乐饮料中分别给予0毫克与两个150毫克剂量）与尼古丁（随意自行给药与1.0毫克机器输送剂量与0.05毫克机器输送剂量）交叉使用。参与者在2小时内每隔30分钟共吸5支香烟。咖啡因和尼古丁对脑电图（EEG）功率有较大效应量；然而，这些效应受睁眼与闭眼状态、另一种药物和电极部位的调节。睁眼与闭眼的EEG效应在大小和方向上往往与尼古丁和咖啡因的效应相同。然而，虽然尼古丁在某些情况下会增加某些高频波段的EEG功率，但咖啡因在几乎所有情况下都会降低EEG功率。尼古丁会增加血清皮质醇浓度、活力和愉悦感，但咖啡因不会。抑郁情绪水平取决于咖啡因和尼古丁的相互作用。咖啡因显著提高了警觉表现，尼古丁几乎显著提高了警觉表现。从两种药物的共同和不同机制方面对研究结果进行了解释。
