Rapid eye movement sleep in the brains of sleeping cats. In 1944, Ohlmeyer reported 90-minute ultradian sleep cycles involving male erections lasting for 25 minutes. At University of Chicago in 1952, Eugene Aserinsky, Nathaniel Kleitman, and William C. Dement, discovered phases of rapid eye movement during sleep, and connected these to dreaming. Their article was published September 10, 1953. Aserinsky, then Kleitman, first observed the eye movements and accompanying neuroelectrical activity in their own children. William Dement advanced the study of REM deprivation, with experiments in which subjects were awoken every time their EEG indicated the beginning of REM sleep. He published "The Effect
Rapid eye movement sleep the number of attempts to go into REM stage while asleep. On recovery nights, an individual will usually move to stage 3 and REM sleep more quickly and experience an REM rebound, which refers to an increase in the time spent in REM stage over normal levels. These findings are consistent with the idea that REM sleep is biologically necessary. However, the "rebound" REM sleep usually does not last fully as long as the estimated length of the missed REM periods. After the deprivation is complete, mild psychological disturbances, such as anxiety, irritability, hallucinations, and difficulty concentrating may develop and