Considered to be NREM, (or quiet sleep), a transitional stage from wake to sleep wherein a person is close to being awake, but whose eyes exhibit slow, rolling movements, while the recorded brain waves are about 8 to 13 cycles per second.
See Behavioral state, Behavioral state concept, EEG stage 2 sleep, EEG stage 3 sleep, EEG stage 4 sleep, Electroencephalogram (EEG), NREM sleep, Sleep architecture