Zuperku, E.J., Hosek, R.S., Larson, Sanford J., Reigel, D.H., Sances Jr, Anthony and Henschel, Ernest O. Studies during electrotherapeutic sleep. In Reynolds, David V. and Anita Sjoberg (Eds.) Neuroelectric Research. Charles Thomas, Springfield, Pp. 235-241, 1971.
CES currents from 2.5 to 80 Hz, with amplitudes from 20 A to 1.5 mA were applied to stump-tail macaque and squirrel monkeys and various physiological recordings made. It was found that visual and somatosensory evoked potentials were not significantly altered during and after CES. A reduction in EMG amplitude occurred during CES, and the EEG showed a greater tendency toward slower, high-voltage activity. Respiration and EKG were stable.