Typically, there are shifts in perceptions, emotions, memory, time sense, thinking, feelings of self-control, and suggestibility. It is an innate biological rhythm essential to survival. We will spend some 25 years of life in a strange state of semi-consciousness called sleep 1. Eyes close, breathing becomes slow and regular, pulse rate slows, and body temperature drops. Loss of consciousness, enter light sleep, heart rate slows.
Breathing becomes more irregular, body muscles relax.
Small irregular brain waves with some alpha. If awakened, may or may not say they were asleep. Delta waves begin to appear. Pure delta waves. Reached about 1 hour after sleep begins.