Sleep and psychoactive drugs

Consciousness

Our awareness of ourselves and our environment

Selective attention

Focusing conscious awareness on a particular stimulus

Inattentional blindness

Failing to see visible objects when our attention is directed elsewhere

Change blindness

Failing to notice changes in the environment

Hypnosis

A social interaction in which a subject responds to a hypnotist's suggestions

Posthypnotic suggestion

A suggestion made during hypnosis to be carried out afterward

Social influence theory (hypnosis)

Hypnosis reflects normal social processes and role-playing

Divided consciousness theory (hypnosis)

Hypnosis involves a split in awareness

Dissociation

A split in consciousness allowing simultaneous streams of thought

Circadian rhythm

Biological clock; regular bodily rhythms that occur on a 24-hour cycle

Alpha waves

Slow brain waves of a relaxed, awake state

NREM-1

Transition to sleep; slowed breathing, irregular brain waves, hypnagogic sensations

NREM-2

Sleep stage with sleep spindles (bursts of brain-wave activity)

NREM-3

Deep sleep; large, slow delta waves; hard to awaken

REM sleep

Rapid eye movement sleep; vivid dreams; paradoxical sleep

Sleep cycle

N1 → N2 → N3 → N2 → REM (about 90 minutes)

Sleep theory: Sleep protects

Evolutionary survival value of sleep

Sleep theory: Sleep recuperates

Restores and repairs body tissues

Sleep theory: Memory consolidation

Sleep helps restore and rebuild fading memories

Sleep theory: Creative thinking

Sleep feeds problem-solving and insight

Sleep theory: Growth

Sleep supports growth hormone release

Sleep deprivation effects

Fatigue, irritability, poor memory, weakened immunity, weight gain, depression risk

Insomnia

Ongoing difficulty falling or staying asleep

Narcolepsy

Sudden sleep attacks, sometimes directly into REM

Sleep apnea

Temporary cessation of breathing during sleep, repeated awakenings

Night terrors

High arousal, appearance of being terrified, NREM-3 sleep

REM rebound

Tendency for REM to increase after REM deprivation

Freud's dream theory (wish-fulfillment)

Dreams express unacceptable desires (manifest vs latent content)

Information-processing dream theory

Dreams help sort out daily events and consolidate memories

Physiological function theory

Dreams stimulate neural pathways

Activation-synthesis dream theory

Dreams are the brain's attempt to make sense of random activity

Neural development theory

Dreams reflect brain maturation and cognitive development

Psychoactive drugs

Chemical substances that alter perceptions and moods

Tolerance

Needing larger doses for the same effect with repeated use

Withdrawal

Discomfort and distress when stopping drug use

Depressants

Drugs that reduce neural activity and slow body functions (alcohol, opiates, barbiturates)

Barbiturates

Depress CNS activity; reduce anxiety but impair memory/judgment

Opiates

Depressants (heroin, morphine); relieve pain, mimic endorphins, cause withdrawal

Stimulants

Excite neural activity, speed up body functions (caffeine, nicotine, cocaine, meth)

Nicotine

Highly addictive stimulant in tobacco

Cocaine

Stimulant; increases alertness/euphoria; depletes dopamine, serotonin, norepinephrine

Methamphetamine

Triggers dopamine release; enhances mood/energy; reduces baseline dopamine long-term

Hallucinogens

Distort perceptions and evoke sensory images (LSD, THC)

LSD

Potent hallucinogen; vivid sensory hallucinations, 'acid trip'

Marijuana (THC)

Mild hallucinogen; relaxes, impairs memory, amplifies sensory input

Substance use disorder

Continued substance craving and use despite life disruption or risk