Chapter 4 – Consciousness, Sleep, and Drugs (Psychology 2e, OpenStax)

Vocabulary flashcards covering key terms from Chapter 4 on consciousness, biological rhythms, sleep stages, sleep disorders, psychoactive drugs, and altered states such as hypnosis and meditation.

Consciousness

Awareness of internal states (e.g., hunger, pain) and external stimuli (e.g., light).

Wakefulness

State of high sensory awareness, thought, and behavior while awake.

Biological Rhythm

Internal cycle of biological activity such as temperature fluctuation or menstrual cycle.

Circadian Rhythm

24-hour biological cycle regulating sleep–wake and other functions.

Suprachiasmatic Nucleus (SCN)

Hypothalamic “brain clock” that synchronizes circadian rhythms with light.

Hypothalamus

Brain region that maintains homeostasis and helps regulate sleep.

Melatonin

Pineal hormone released in darkness that promotes sleepiness.

Sleep Regulation

Brain control of switching between sleep and wake and syncing with environment.

Chronotype

Individual’s characteristic circadian activity pattern (early bird vs. night owl).

Jet Lag

Fatigue and irritability from mismatch between internal clock and new time zone.

Rotating Shift Work

Variable work hours that disrupt circadian rhythm, causing exhaustion and mood issues.

Sleep Debt

Cumulative effect of chronic insufficient sleep.

Sleep Rebound

Quicker onset of sleep after deprivation.

Sleep (definition)

Low physical activity state with reduced awareness, governed by various brain areas.

Polysomnograph (PSG)

Multi-variable recording (EEG, EMG, etc.) used to study sleep.

Slow-Wave Sleep (SWS)

Deep non-REM stages 3 & 4 characterized by delta waves.

Adaptive Sleep Hypothesis

Idea that sleep saves energy and avoids predators (evolutionary).

Cognitive Sleep Hypothesis

Proposal that sleep supports cognition and memory formation.

Alpha Waves

Synchronized, high-amplitude, low-frequency EEG waves of relaxed wakefulness.

Theta Waves

Low-amplitude, low-frequency EEG waves of light sleep (Stage 2).

Delta Waves

High-amplitude, very low-frequency EEG waves of deep sleep (Stages 3-4).

Sleep Spindle

Brief burst of high-frequency brain activity in Stage 2 sleep.

K-Complex

Single high-amplitude EEG pattern during Stage 2 signifying environmental monitoring.

Rapid Eye Movement (REM) Sleep

Sleep stage with eye movements, dreaming, muscle paralysis, wake-like EEG.

Hypnogram

Graph depicting progression through sleep stages over a night.

Manifest Content

Freud’s term for the literal storyline of a dream.

Latent Content

Freud’s hidden, symbolic meaning of a dream.

Collective Unconscious

Jung’s shared reservoir of archetypal symbols accessible in dreams.

Lucid Dream

Dream in which the sleeper gains awareness of dreaming and can sometimes control it.

Insomnia

Difficulty falling or staying asleep ≥3 nights/week for ≥1 month.

Parasomnia

Group of unwanted motor or experiential events during sleep.

Sleepwalking (Somnambulism)

Motor activity during slow-wave sleep without conscious awareness.

REM Sleep Behavior Disorder (RBD)

Lack of REM muscle paralysis leading to acting out dreams; treated with clonazepam.

Restless Leg Syndrome

Uncomfortable leg sensations relieved by movement when trying to sleep.

Night Terror

Panic episode during NREM sleep with screams or escape attempts.

Sleep Apnea

Breathing stoppages during sleep causing fatigue.

Obstructive Sleep Apnea

Blocked airway prevents airflow to lungs during sleep.

Central Sleep Apnea

Brain fails to initiate breathing during sleep.

Continuous Positive Airway Pressure (CPAP)

Device delivering pressurized air to keep airway open in sleep apnea.

Sudden Infant Death Syndrome (SIDS)

Unexplained infant death during sleep, linked to risk factors like smoking.

Narcolepsy

Irresistible daytime sleep attacks often with REM features.

Cataplexy

Sudden loss of muscle tone while awake, seen in narcolepsy.

Hypnagogic Hallucination

Vivid dream-like perception at sleep onset, common in narcolepsy.

Substance Use Disorder

Compulsive drug use despite harm, involving dependence and craving.

Physiological Dependence

Body adaptation to drug with withdrawal on cessation.

Psychological Dependence

Emotional or mental need for a drug.

Tolerance

Need for increasing doses to achieve previous effect.

Withdrawal

Negative symptoms when drug use stops.

Depressants

GABA-agonist drugs that suppress CNS activity (e.g., alcohol, barbiturates, benzodiazepines).

GABA

Major inhibitory neurotransmitter; activation quiets neurons via Cl- influx.

Stimulants

Drugs increasing neural activity, often by blocking dopamine reuptake (e.g., cocaine, amphetamine).

Dopamine Agonist

Substance that enhances dopamine signaling, producing reward and addiction risk.

Caffeine

Stimulant that blocks adenosine receptors, raising alertness.

Nicotine

Highly addictive stimulant acting on acetylcholine receptors; boosts arousal and reward.

Opioids

Analgesic drugs (heroin, morphine) acting on endogenous opioid system; highly addictive.

Analgesic

Substance that reduces pain perception.

Hallucinogens

Drugs causing sensory/perceptual distortions (e.g., LSD, mescaline, PCP).

Mescaline

Serotonin-agonist hallucinogen derived from peyote cactus.

LSD

Potent synthetic hallucinogen acting primarily on serotonin receptors.

Hypnosis

State of focused attention and suggestibility used clinically for behavior change.

Meditation

Practice of focused awareness on a target (breath, mantra) to enhance mindfulness and reduce stress.