Module 9: Sleep and Dreams

Vocabulary flashcards covering biological clocks, sleep architecture, brain-wave stages, disorders, and dream theories from Module 9.

Circadian Rhythms

The natural cycles of physical, mental, and behavioral changes that the body undergoes in a $24\text{-hour}$ cycle, primarily influenced by light and darkness and regulated by a small area in the middle of the brain.

Alpha Waves

The relatively slow brain waves characteristic of a relaxed, awake state.

Delta Waves

Large, slow brain waves associated with deep sleep.

Sleep Spindles

Bursts of rhythmic brain-wave activity occurring during N2 sleep that aid in memory processing.

Hallucinations

False sensory experiences, such as seeing something in the absence of an external visual stimulus.

REM Sleep

Rapid Eye Movement sleep; a recurring sleep stage featuring brain waves that resemble near-waking N1 sleep, during which dreams commonly occur and internal body systems are more aroused than during non-REM sleep.

Paradoxical Sleep

Another term for REM sleep, named because the muscles are relaxed (except for minor twitches) while other body systems remain active.

REM Rebound

The tendency for the amount of REM sleep to increase following periods of REM sleep deprivation.

Suprachiasmatic Nucleus (SCN)

A brain structure activated by light-sensitive retinal proteins that signals the pineal gland to decrease melatonin production in the morning and quiets down at night to allow melatonin release.

Melatonin

A sleep-inducing hormone secreted into the bloodstream by the pineal gland, whose production is suppressed by light via the suprachiasmatic nucleus (SCN).

Social Jet Lag

The disruption of normal biological sleep routines that occurs when sleep schedules shift significantly during weekends.

Sleep Debt

An accumulated shortage of sleep resulting from successive short nights (such as $5\text{-hour}$ nights) that cannot be satisfied by a single long sleep session.

Insomnia

A major sleep disorder characterized by persistent, recurring problems in falling asleep or staying asleep.

Narcolepsy

A sleep disorder characterized by sudden, uncontrollable sleep attacks, with the sleeper sometimes lapsing directly into REM sleep.

Sleep Apnea

A sleep disorder involving repeated temporary cessations of breathing during sleep and momentary awakenings, frequently associated with obesity, especially in men.

REM Sleep Behavior Disorder

A condition characterized by dream-enacting behaviors during REM sleep, often accompanied by dramatic motor movements and loud, profane vocalizations.

Night Terrors

A disorder characterized by high arousal and the appearance of being terrified, occurring primarily during NREM-3 sleep and distinct from typical nightmares.

Sleepwalking

A childhood sleep disorder characterized by walking or wandering that occurs specifically during N3 sleep.

Sleeptalking

A childhood disorder involving vocalizations that can occur during any stage of sleep.

Manifest Content

According to Sigmund Freud, the remembered storyline and surface details of a dream.

Latent Content

According to Sigmund Freud, the underlying, hidden, or symbolic meaning of a dream.

Freud's Wish-Fulfillment Theory

The perspective that dreams act as a psychic safety valve to express otherwise unacceptable feelings, consisting of manifest content and deeper latent content.

Information-Processing Theory

The theory proposing that dreaming functions to help sort out the day's events and consolidate memories.

Physiological Function Theory

The perspective proposing that regular periodic brain stimulation during REM sleep helps develop and preserve neural pathways.

Activation-Synthesis Theory

The theory that REM sleep triggers neural activity evoking random visual memories, which the sleeping brain synthesizes and weaves into stories.

Cognitive Development Theory

The view that dream content reflects the dreamer's level of knowledge and understanding, simulating life experiences including worst-case scenarios.

Sleep Across the Lifespan

The developmental pattern in which infants spend progressively less time in REM sleep during their first few months, and humans overall spend less total time asleep as age advances.