Unit 1 Part 3 (States of Consciousness)

Consciousness

The state of being aware of and able to perceive one's thoughts, feelings, sensations, and surroundings. It involves various levels, from alert wakefulness to altered states such as sleep or meditation.

Circadian Rhythm

The natural, internal process that regulates the sleep-wake cycle and repeats roughly every 24 hours. It influences patterns of alertness, hormone release, body temperature, and other physiological processes.

Jet Lag

A temporary disruption of the body's circadian rhythm due to rapid travel across multiple time zones. It can result in fatigue, sleep disturbances, and difficulty concentrating as the body adjusts to the new time zone.

NREM Stage 1

The first stage of non-rapid eye movement sleep characterized by drifting in and out of sleep, lasting only a few minutes. Brain waves slow down, muscles relax, and individuals may experience sudden muscle contractions known as hypnic jerks.

NREM Stage 2

The second stage of non-rapid eye movement sleep characterized by light sleep, lasting about 20 minutes. Brain waves further slow down, and sleep spindles (short bursts of brain activity) and K-complexes (sudden, sharp waveforms) appear.

NREM Stage 3

The deepest stage of non-rapid eye movement sleep characterized by the presence of predominantly delta waves.

Restoration of Resources

The process during sleep where the body and brain replenish energy, repair tissues, and remove waste products, promoting physical and mental well-being.

REM (Rapid Eye Movement) Sleep

A stage of sleep characterized by rapid eye movements, vivid dreams, and muscle paralysis. It is associated with increased brain activity, including dreaming, and plays a role in memory consolidation and emotional processing.

REM Rebound

The phenomenon where the body increases the time spent in REM sleep after a period of REM deprivation. It occurs as a compensatory response to the lack of REM sleep, often resulting in more intense and frequent REM sleep episodes.

Activation-Synthesis (Dreams)

A theory proposing that dreams are the result of random neural activity in the brainstem during REM sleep, which is then interpreted and synthesized by the cerebral cortex into a narrative or story.

Consolidation Theory (Dreams)

A theory suggesting that dreams play a role in the memory consolidation and processing of memories. During sleep, the brain organizes and integrates information acquired throughout the day, contributing to memory storage and learning.

Insomnia

A sleep disorder characterized by difficulty falling asleep, staying asleep, or experiencing restorative sleep, leading to daytime impairment such as fatigue, mood disturbances, and decreased cognitive function.

Narcolepsy

A sleep disorder characterized by excessive daytime sleepiness, sudden episodes of muscle weakness (cataplexy), sleep paralysis, and hallucinations during sleep onset or awakening.

Sleep Apnea

A sleep disorder characterized by pauses in breathing or shallow breathing during sleep, leading to disrupted sleep patterns, daytime fatigue, and other health problems.

REM Sleep Behavior Disorder

A sleep disorder where individuals physically act out their dreams during REM sleep, potentially causing injury to themselves or others due to loss of muscle paralysis.

Somnambulism

A sleep disorder commonly known as sleepwalking, characterized by walking or performing other activities while still asleep. It typically occurs during non-REM sleep stages and can result in injuries or accidents.

Psychoactive Drugs

Substances that alter brain function, leading to changes in perception, mood, consciousness, cognition, or behavior. They act on the central nervous system and can be categorized into stimulants, depressants, hallucinogens, and opioids.

Agonists

Substances that bind to neurotransmitter receptors and mimic their effects, enhancing neural activity.

Reuptake Inhibitors

Medications that block the reabsorption of neurotransmitters by the sending neuron, thereby increasing the concentration of neurotransmitters in the synaptic cleft and enhancing neurotransmission.

Stimulants

Drugs that increase neural activity and arousal, leading to heightened alertness, attention, and energy levels.

Caffeine

A natural stimulant found in coffee, tea, and some sodas. It acts on the central nervous system, increasing alertness and reducing fatigue by blocking the neurotransmitter adenosine.

Cocaine

A powerful stimulant derived from the coca plant. It increases neural activity, leading to euphoria, increased energy, and alertness. Cocaine works by blocking the reuptake of dopamine, serotonin, and norepinephrine.

Depressants

Drugs that slow down neural activity and bodily functions. They induce relaxation, sedation, and can lower inhibitions.

Alcohol

A depressant drug that slows down neural activity in the central nervous system. It can impair judgment, coordination, and cognitive functions, leading to relaxation, euphoria, and in higher doses, intoxication.

Hallucinogens

Drugs that alter perception, mood, and cognitive processes, often causing hallucinations or profound changes in consciousness.

Marijuana

A psychoactive drug derived from the cannabis plant. It contains THC, which alters mood, perception, and cognition. Effects include relaxation, altered perception of time, and heightened sensory experiences.

Opioids

Psychoactive drugs that act on opioid receptors in the brain and body, producing pain relief, euphoria, and sedation.

Heroin

A highly addictive opioid drug derived from morphine. It produces intense euphoria, pain relief, and sedation by binding to opioid receptors in the brain.

Tolerance

A condition where increasing amounts of a psychoactive substance are needed to achieve the same effects. It occurs due to the brain's adaptation to the drug, leading to reduced sensitivity to its effects over time.

Withdrawal

The onset of symptoms when a person stops using a psychoactive substance after prolonged use. Symptoms can include physical discomfort, psychological distress, and cravings for the drug.

Addiction

A chronic brain disorder characterized by compulsive drug seeking and use, despite harmful consequences. It involves changes in brain structure and function, leading to a loss of control over drug consumption.

Perception

The process by which our brain organizes and interprets sensory information, transforming it into meaningful objects and events. It's a crucial step in cognition, allowing us to understand and interact with the world around us.