Etevenon P, Peron-Magnan P, Guillou S, Toussaint M, Gueguen B, Boulenger J P, Deniker P, Loo H
Centre Esquirol, CHU Côte-de-Nacre, Caen, France.
Neurophysiol Clin. 1988 Aug;18(4):355-67. doi: 10.1016/s0987-7053(88)80092-3.
A group of 10 subjects, normal volunteers (6 men, 4 women), mean age 27.2 years, right-handers, has been selected for a double-blind study of caffeine effects (400 mg per os) versus placebo. One week delay separated the two EEG sessions quantified by spectral analysis. During each session (16 EEG channels, common reference), each subject was recorded four times: 2.5 min, in eyes-closed condition, under diffuse attention, followed by 2.5 min, during a visuo-spatial task ("eyes open" condition: presentation of a picture). These two EEG recordings were obtained before the oral administration and repeated 1 hr after the administration of caffeine or placebo. Individual and group results presented globally: 1) an increase in mean frequencies of alpha activity in "eyes closed" condition, and of delta activity in "eyes open" condition; 2) a decrease of alpha activity amplitudes (both RMS and % values) in both conditions; 3) a decrease of total RMS amplitudes in "eyes closed" condition; 4) an increase of relative % amplitudes for beta 2% fast activity in the "eyes open condition". These results characterize the psycho-stimulant effects of caffeine, especially over the left temporal area which was confirming an initial statistical hypothesis of specific cerebral local activation. The non-parametric permutation tests of Fisher, were not always reaching statistical significance for the same EEG channel quantified by one of the 17 analyzed spectral parameters, except on the left temporal area. During the visuo-spatial task, the decrease in alpha amplitudes (RMS and %) was also statistically significant, but over larger areas: over left and right temporal, central and parietal regions. In both conditions, eyes closed and eyes open, the alpha RMS amplitude was also decreased over the right anterior frontal area.
一组10名正常志愿者（6名男性，4名女性）被选入一项关于咖啡因（口服400毫克）与安慰剂效果对比的双盲研究，平均年龄27.2岁，均为右利手。两次通过频谱分析量化的脑电图（EEG）测试之间间隔一周。在每次测试期间（16个EEG通道，共同参考电极），每个受试者被记录4次：闭眼状态下，在漫不经心状态持续2.5分钟，随后在视觉空间任务（“睁眼”状态：呈现一幅图片）期间持续2.5分钟。这两次EEG记录在口服咖啡因或安慰剂之前进行，并在给药1小时后重复。个体和组的结果整体呈现如下：1）闭眼状态下α活动平均频率增加，睁眼状态下δ活动增加；2）两种状态下α活动幅度（均方根值和百分比值）均降低；3）闭眼状态下总均方根幅度降低；4）睁眼状态下β2%快速活动的相对百分比幅度增加。这些结果表明了咖啡因的精神兴奋作用，特别是在左侧颞叶区域，这证实了最初关于特定脑区局部激活的统计假设。除左侧颞叶区域外，对于通过17个分析频谱参数之一量化的同一EEG通道，Fisher非参数置换检验并不总是达到统计学显著性。在视觉空间任务期间，α幅度（均方根值和百分比）的降低在统计学上也具有显著性，但涉及的区域更大：左侧和右侧颞叶、中央和顶叶区域。在闭眼和睁眼两种状态下，右侧前额叶前部区域的α均方根幅度也降低。
