Operant control of alpha EEG and the effects of illumination and eye closure

The effects of eyelid position (open or closed) and three levels of room illumination on operant control of alpha EEG were investigated utilizing a factorial design. After base-line levels were determined, subjects were given alpha-contingent feedback and instructed to increase and decrease alpha production during six successive 4-min intervals. In addition, a comparison was made between percent time and average amplitude as dependent measures. The percent time data indicated that eyes-open training facilitated alpha enhancement and suppression. However, this was not supported by the average amplitude data. Ambient illumination, regardless of the measure utilized, facilitated alpha training, particularly when the eyes were open. These results are related to previous research and theoretical issues.