Changes in wakefulness during exposure to whole body vibration

Thirty subjects were exposed to low frequency sinusoidal and random whole body vibration in the vertical direction, 0.3 m/sec2 (rms). Changes in wakefulness during 15 min vibration were compared to changes occurring during corresponding pauses without exposure. Measurements were made on EEG and ECG. Exposure to whole body vibration was found to be correlated with reduction in wakefulness. This effect, verified by an increase of theta and decrease of alpha activity, was greater during sinusoidal than random vibration.