Unit 2: Chapter 4-Consciousness and Altered States

Consciousness

Awareness of internal and external stimuli.

Biological rhythms

Cyclical patterns in physiological functioning.

Circadian rhythm

24-hour biological cycle (sleep, wake, temperature).

Suprachiasmatic nucleus (SCN)

Brain structure regulating circadian rhythms.

Sleep

State of consciousness with distinct stages and functions.

Sleep debt

Deficiency from not getting enough sleep.

Polysomnography

Recording brain waves, eye movement, muscle activity during sleep.

EEG sleep stages

Distinct patterns of brain activity.

NREM sleep

Non-rapid eye movement sleep; stages 1

Stage 1 sleep

Light sleep; theta waves.

Stage 2 sleep

Deeper sleep; sleep spindles, K-complexes.

Stage 3 sleep

Deep sleep; delta waves.

REM sleep

Rapid eye movement; dreaming, brain active, muscle paralysis.

Sleep cycle

Repeats every ~90 minutes.

Insomnia

Difficulty falling or staying asleep.

Sleep apnea

Stopping breathing during sleep.

Narcolepsy

Sudden sleep attacks and cataplexy.

Parasomnias

Abnormal sleep behaviors (sleepwalking, night terrors).

Restless legs syndrome

Unpleasant sensations causing urge to move legs.

Dreams

Sequences of images, emotions, thoughts during sleep.

Freud’s dream theory

Dreams express unconscious wishes.

Activation-synthesis theory

Dreams are brain’s attempt to make sense of neural activity.

Lucid dreams

Awareness of dreaming during the dream.

Hypnosis

State of suggestibility with focused attention.

Meditation

Practices inducing focused awareness and relaxation.

Psychoactive drugs

Chemicals altering perceptions, moods, and behaviors.

Depressants

Slow CNS activity (alcohol, barbiturates).

Stimulants

Increase activity and alertness (caffeine, nicotine, cocaine).

Hallucinogens

Alter perception and cause hallucinations (LSD, marijuana).

Opioids

Relieve pain and cause euphoria (heroin, morphine).

Tolerance

Needing more of a substance for the same effect.

Dependence

Physiological or psychological need for a substance.

Withdrawal

Negative symptoms when stopping a drug.

Addiction

Compulsive drug craving and use despite harm.