Knox S S
Biol Psychol. 1980 Aug;11(1):1-6. doi: 10.1016/0301-0511(80)90021-6.
The object of this study was to explore the relevance of an amplitude threshold for defining alpha in biofeedback studies. One of the lowest thresholds used in earlier studies (1.5 microV) was selected and the EEG base level of 94 subjects measured. Due to the importance of reinforcement rate in biofeedback, results were divided into three categories: under 25%, between 26-74%, and over 75% alpha. The results showed a positively skewed distribution with 68% of the subjects displaying under 25% alpha. The subjects' means on the control variables: anxiety, impulsivity, and monotony avoidance were within the range of normal and did not correlate with the amplitude categories. The conclusion drawn was that skewness is not the result of an abnormal sample but of an arbitrarily set amplitude criterion. On the basis of this data, an integrated alpha amplitude measure is advocated.
本研究的目的是探讨在生物反馈研究中定义α波时振幅阈值的相关性。选取了早期研究中使用的最低阈值之一（1.5微伏），并测量了94名受试者的脑电图基线水平。由于强化率在生物反馈中的重要性，结果分为三类：α波低于25%、介于26%-74%之间以及高于75%。结果显示分布呈正偏态，68%的受试者α波低于25%。受试者在控制变量（焦虑、冲动性和避免单调）上的均值处于正常范围内，且与振幅类别无关。得出的结论是，偏态并非异常样本的结果，而是任意设定的振幅标准所致。基于这些数据，提倡采用综合α波振幅测量方法。
