Consciousness, Sleep, and Psychoactive Drugs

Consciousness: An individual's awareness of internal and external events, including thoughts, sensations, and feelings at any given moment.
Waking Consciousness: A state where thoughts, feelings, and sensations are clear, organized, and the person feels alert.
Altered States of Consciousness: Occur when there is a shift in the quality or pattern of mental activity, such as during sleep, hypnotic states, or drug use.
Thought Processes: Differentiated into controlled processes (focused attention) and automatic processes (less conscious effort).

Circadian Rhythm: A cycle of bodily rhythm occurring over a $24\text{-hour}$ period.
Hypothalamus and SCN: The Suprachiasmatic Nucleus (SCN) serves as an internal clock; it responds to light by signaling the pineal gland to secrete melatonin (increasing sleepiness) or stop its production (increasing alertness).
Sleep Needs: Most adults require $7-8\,\text{hours}$ per night; sleep deprivation causes serious health and mental functioning issues.
Brain Waves (EEG):
- Beta Waves: Small, fast waves indicating mental activity.
- Alpha Waves: Indicate relaxation or light sleep.
- Theta Waves: Indicate early stages of sleep.
- Delta Waves: Long, slow waves indicating the deepest sleep stage.
Sleep Stages:
- N1 (Light Sleep): Characterized by theta waves; may involve hypnagogic images and hypnic jerks.
- N2 (Sleep Spindles): Predominantly theta activity; features brief bursts of activity called sleep spindles.
- N3 (Deep Sleep): Delta activity ranges from $20\%$ to more than $50\%$ ; lowest level of body functioning; time of physiological growth.
- R (REM): Rapid eye movement and dreaming; brain waves resemble beta waves (paradoxical sleep); associated with sleep paralysis (voluntary muscles are inhibited).

Nightmares and Night Terrors: Nightmares occur during REM; night terrors involve extreme fear and agitation during deep sleep (N3).
Somnambulism (Sleepwalking): Occurs during deep sleep (N3); more common in children.
REM Sleep Behavior Disorder (RBD): Failure of the sleep paralysis mechanism, causing individuals to act out nightmares.
Insomnia: Difficulty falling asleep, staying asleep, or getting quality sleep.
Sleep Apnea: The person stops breathing for nearly half a minute or more; often treated with a CPAP device.
Narcolepsy: Falling immediately into REM sleep during waking hours; may involve cataplexy (sudden loss of muscle tone).

Freud’s Theory: Dreams as unconscious wish fulfillment.
- Manifest Content: The actual dream storyline.
- Latent Content: The hidden, symbolic meaning of the dream.
Activation-Synthesis Hypothesis: Dreams are the brain's attempt to make sense of random signals from lower brain areas.
Activation-Information-Mode (AIM) Model: A revision suggesting that waking life experiences influence the synthesis of dreams.
Gender Differences in Dreams: Women often dream of known people and family; men often dream of unfamiliar settings, weapons, tools, or cars.

Hypnosis: A state of consciousness involving high susceptibility to suggestion.
- Elements: Focus, relaxation, "letting go," and imagination.
- Theories: Dissociation (hypnosis works in immediate consciousness while a "hidden observer" is aware) and Social-cognitive theory (hypnosis is a social role-play).
Meditation: Mental exercises to refocus attention; helps reduce chronic pain, anxiety, depression, and stress-related health risks.

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Physical Dependence: The body needs the drug to function; characterized by drug tolerance (needing high doses for the same effect) and withdrawal symptoms (nausea, tremors).
Psychological Dependence: The belief that a drug is necessary for emotional or psychological well-being.
Stimulants: Increase nervous system function (e.g., Amphetamines, Cocaine, Nicotine, Caffeine).
Depressants: Decrease nervous system function.
- Barbiturates and Benzodiazepines: Sedative effects; examples include Valium, Xanax, Halcion, Ativan, and Librium.
- Alcohol: The most commonly abused depressant; slows reaction time and motor control ( $0.10\%$ BAC significantly impairs driving; $0.40\%$ can be lethal).
- Opiates and Opioids: Suppress pain by stimulating endorphin receptors (e.g., Opium, Morphine, Heroin, Methadone, Fentanyl).
Hallucinogens: Alter perception of reality.
- Manufactured: LSD, PCP, MDMA (Ecstasy).
- Nonmanufactured: Marijuana (hemp-derived; produces mild sensory distortions).

Research indicates that most individuals are less effective at multitasking than they perceive.
Multitasking creates significant hazards in everyday environments and reduces overall performance.