Aserinsky E
Science. 1965 Nov 5;150(3697):763-6. doi: 10.1126/science.150.3697.763-a.
With each flurry of rapid eye movements during the sleep of human subjects there is a decreased amplitude of respiration and a slight increase in rate. Occasionally the rhythmic breathing pattern may even resemble Cheyne-Stokes respiration. The consistency of this breathing pattern suggests that respiration in this stage of sleep is not a direct function of dream content.