Subconscious

Circadian Rhythm

REM
Rapid-Eye-Movement sleep

NREM
Non-Rapid-Eye-Movement sleep

Alpha waves

Sleep spindles

Theories of sleep:

Insomnia

Narcolepsy

Sleep apnea

Night terrors

REM rebound

Hypnosis

Ernest Hilgard & "the Hidden Observer"

Psychoactive drugs

Agonistic drugs

Antagonistic drugs

Withdrawal

Tolerance

Depressants

Stimulants

Opiates

Hallucinogens