states of conciousness

NREM-1

Slow breathing, irregular brain waves, lack of awareness; hallucinations may occur.

NREM-2

The longest period of sleep characterized by slow delta waves.

Sleep

Natural loss of consciousness.

Hallucinations

Sensory experiences that occur without external stimuli, often described as hypnagogic.

Hypnagogic sensation

Bizarre experiences such as feeling weightless, occurring while transitioning to NREM-1.

Alpha waves

Slow brain waves that occur in a state of relaxation while awake.

LSD

A powerful hallucinogenic drug also known as acid.

Near-death experience

An altered state of consciousness often described as an out-of-body experience.

THC

The active compound found in marijuana.

Theta waves

Brain waves characteristic of light sleep.

Delta waves

Long, slow brain waves associated with deep sleep.

Beta waves

Brain activity indicative of being awake and alert.

Sleep spindles

Bursts of brain activity that occur in NREM-2.

NREM sleep

Non-rapid eye movement sleep, encompassing all stages of sleep except REM.

Insomnia

A condition characterized by difficulty falling or staying asleep.

Narcolepsy

A sleep disorder involving uncontrollable sleep attacks leading to REM sleep.

Sleep apnea

A sleep disorder often found in overweight individuals, characterized by temporary stopping of breathing.

Night terrors

Episodes that typically occur in children during NREM 3, marked by awakening without memory of the event.

Paradoxical sleep

Another term for REM sleep, where the body is relaxed but the brain is active.

Dream

A sequence of images, emotions, and thoughts occurring in a sleeping person's mind during REM sleep.

Manifest content

The storyline of a dream, according to Freud.

Latent content

The underlying meaning of a dream.

Methamphetamine

A drug that stimulates the central nervous system and speeds up body functions.

Ecstasy (MDMA)

A synthetic stimulant and mild hallucinogen that produces euphoria by releasing dopamine and serotonin.

Alcohol

A depressant that slows neural and bodily functions.

Cocaine

A stimulant that increases energy and alertness.

Caffeine

A common stimulant found in coffee and soft drinks.

Consciousness

Our awareness of ourselves and our environment.

Preconscious

Information not currently in consciousness but can be recalled when prompted.

Unconscious

Thoughts and processes occurring without awareness.

Circadian rhythm

The body's biological 24-hour cycle.

Infradian rhythm

Biological rhythms occurring once a month or seasonally, such as the menstrual cycle.

Ultradian rhythm

Biological rhythms that occur more than once a day, such as sleep stages.

Suprachiasmatic Nucleus

A cluster of neurons in the hypothalamus that controls circadian rhythms and melatonin production.

Melatonin

A hormone involved in regulating the sleep/wake cycle.

Sleep Theories

Theories proposing reasons why we sleep: energy conservation, brain repair, memory consolidation, growth, and creative thinking.

REM sleep

Rapid eye movement sleep where dreams occur; it is referred to as paradoxical sleep.

Hallucinations

Sensory experiences without an external stimulus.

Hypnagogic

Bizarre experiences, often like falling weightlessly, that occur while falling asleep.

Activation synthesis

A theory that dreams are the brain's attempt to synthesize random neural activity.

Consolidation theory

The theory that dreams help strengthen and integrate new memories.

REM rebound

The increase in REM sleep following deprivation of REM sleep.

Psychoactive drugs

Chemicals that alter perception and mood.

Depressants

Drugs that slow body and neural functions, such as alcohol and heroin.

Stimulants

Drugs that excite neural activity and increase body functions, e.g., caffeine, nicotine.

Hallucinogens

Drugs that distort perceptions and evoke sensory images in absence of input.

Barbiturates

Drugs that depress CNS activity, reducing anxiety but impairing memory.

Opiates

Drugs that depress neural activity and alleviate pain, like morphine and heroin.

Amphetamines

Stimulants that speed up neural activity and increase mood.