Chapter 7: Attention, Sleep, and Dreaming

Vocabulary flashcards covering sleep stages, biological rhythms, brain activity, sleep disorders, and dream theories from the Chapter 7 lecture.

ADHD (Attention Deficit Hyperactivity Disorder)

A psychological disorder marked by difficulties in sustaining attention for extended periods of time and hyperactivity, affecting about $3\%$ to $7\%$ of all children and diagnosed about $3$ times more commonly in boys.

Biological Rhythms

Recurrent natural cycles that repeat based on an internal biological time scale.

Circadian Rhythms

Biological cycles that follow an internal time scale of approximately $24\text{ hours}$, such as the human sleep-wake cycle.

Ultradian Rhythms

Biological cycles that recur in a period of less than $24\text{ hours}$, such as the human hunger system.

Infradian Rhythms

Biological cycles that last longer than $24\text{ hours}$ but less than a year, such as the monthly human menstrual cycle.

Circannual Rhythms

Biological rhythms that follow an annual or one-year cycle, such as bird reproduction, nesting, and seasonal flowering.

Biological Clocks

Endogenous neural structures within the brain that track time internally to govern biological rhythms.

Suprachiasmatic Nucleus

The biological clock located within the hypothalamus that regulates the circadian sleep-wake cycle.

Zeitgeber

A German term meaning 'time giver'; refers to an external environmental cue, such as light, that synchronizes an organism's internal biological clock with the natural day-night cycle.

Free-Running Rhythm

A self-sustaining biological rhythm observed when an organism is deprived of all external environmental cues, operating solely on endogenous timing (such as the rodent endogenous cycle of about $24.8\text{ hours}$).

Electroencephalography (EEG)

A neuroimaging method that uses electrodes placed on the scalp to measure cortical electrical activity and action potential firing across populations of neurons.

Synchronous Firing

A pattern of neural activity characterized by large populations of neurons firing simultaneously in unified pulses, producing high-amplitude waves on an EEG.

Desynchronized Firing

A pattern of neural activity where individual neurons fire at varying, independent intervals (analogous to popcorn popping), characteristic of wakefulness and complex mental processing.

Beta Waves

Highly desynchronized brain waves emitted during wakefulness when an individual is alert, actively thinking, and attentive.

Alpha Waves

Regular, partially synchronized brain waves characteristic of a relaxed, resting, or drowsy state during wakefulness, most prominent when the eyes are closed.

Stage 1 Sleep

The initial, brief transitional stage between wakefulness and sleep lasting an average of about $10\text{ minutes}$, characterized by theta waves and hypnic jerks.

Hypnic Jerk

A benign myotonic jerk or involuntary muscle twitch that occurs during Stage 1 sleep, frequently accompanied by a falling sensation.

Stage 2 Sleep

A sleep stage lasting about $15\text{ minutes}$ per cycle, characterized by theta wave activity punctuated by sleep spindles and K complexes.

Sleep Spindles

Short bursts of brain wave activity occurring $2$ to $5$ times per minute during Stage 2 sleep that are associated with memory consolidation.

K Complex

A distinctive, sharp EEG waveform seen during Stage 2 sleep that is triggered in response to sudden, external environmental auditory stimuli.

Stage 3 Sleep

The deepest non-REM stage of sleep (combining what was historically Stage 3 and Stage 4), dominated by delta waves and high synchrony; front-loaded in the first half of the night.

Delta Waves

Slow, highly synchronized brain waves that occur during Stage 3 deep sleep.

REM Sleep

Rapid Eye Movement sleep; a desynchronized sleep stage resembling wakefulness on an EEG, featuring rapid eye movements, elevated physiological rates, spinal intercostal paralysis, and vivid dreaming.

Fatal Familial Insomnia (FFI)

A rare, genetically inherited neurological disorder that causes progressive, chronic insomnia, eventually leading to death around age $45$ to $50$.

Memory Consolidation

The cognitive process occurring during sleep where newly learned short-term information is stabilized and converted into permanent long-term storage.

REM Rebound

The physiological phenomenon in which an individual deprived of REM sleep spends a significantly higher proportion of time in REM sleep on subsequent undisturbed nights.

Wish Fulfillment Theory

Sigmund Freud's psychoanalytic perspective proposing that dreams function as a means to express and satisfy repressed, unconscious desires and forbidden wishes.

Manifest Content

The actual storyline, narrative events, and literal symbols remembered and reported by the dreamer.

Latent Content

The disguised, underlying psychological meaning and hidden unconscious desires symbolized by a dream's events.

Lucid Dreaming

The state of consciousness where an individual becomes consciously aware that they are dreaming while remaining asleep, reported by approximately $73\%$ of adults.

Activation-Synthesis Theory

A neuroscientific theory proposing that dreams are the forebrain's attempt to weave a narrative and make sense of random neural impulses generated in the brainstem during REM sleep.

Threat Simulation Theory

An evolutionary theory suggesting that dreaming serves an adaptive function by simulating environmental dangers, allowing humans to mentally practice and refine defensive survival responses.