EEG patterns in relation to respiratory rate and body movement in Macaca mulatta

Abstract

Daytime EEG, EMG and EOG patterns in twelve juvenile rhesus monkeys were studied in relation to concomitant behavioral aspects, respiratory rate and to body motility. Behavioral observations and EEG analysis showed that in monkeys aged two years and above, there was predominant vigilance associated with fast activity and sporadic episodes of movement, amounting to approximately 72% of a 7-hr recording session. Drowsiness and sleep, constituting the NREM state, were associated with slower frequencies in the EEG amounting to 27.8%, whereas REM episodes occurred at random and amounted to 0.2%. The relative amounts of different stages of arousal and sleep remained constant over a twelve month period. Monkeys below two years of age had a significantly greater amount of slow wave sleep, 1-3 c/sec, than older animals. The rate of respiration was 40-50 breaths/min during wakefulness but ranged from 28-38 breaths/min during drowsiness and sleep. Motility accompanied wakefulness but was reduced during drowsiness and was infrequent during sleep and REM.