Sleep Stages, Dreams, and Brain Activity

Flashcards covering the stages of sleep, brain wave activity, key sleep phenomena, and theories of dreaming based on the provided lecture notes.

Sleep

A state composed of several different stages, differentiated by patterns of brain wave activity.

Beta waves

Brain wave activity characteristic of being awake, having the highest frequency (13–30 Hz) and lowest amplitude, and showing more variability.

Frequency (brain wave)

The number of brain waves that occur in a second, measured in Hertz (Hz).

Amplitude (brain wave)

The height of the brain wave pattern.

REM sleep

Rapid eye movement sleep, characterized by darting eye movements under closed eyelids, brain waves similar to wakefulness, and where dreaming occurs.

Non-REM (NREM) sleep

Sleep subdivided into three stages, distinguished by characteristic patterns of brain waves and the absence of rapid eye movements.

Stage 1 sleep

A transitional phase between wakefulness and sleep, involving slowdowns in respiration, heartbeat, muscle tension, and core body temperature, associated with alpha and theta waves.

Alpha waves

Patterns of electrical activity resembling a very relaxed, yet awake state, with less variability, lower frequency (8–12 Hz), and higher amplitude than beta waves, occurring in early stage 1 sleep.

Theta waves

Brain waves with a lower frequency (4–7 Hz) and higher amplitude than alpha waves, increasing as an individual continues through stage 1 sleep and dominating stage 2.

Stage 2 sleep

A state of deep relaxation during which theta waves dominate, interrupted by brief bursts of activity known as sleep spindles and the appearance of K-complexes.

Sleep spindles

Rapid bursts of higher frequency brain waves that interrupt theta waves during stage 2 sleep, potentially important for learning and memory.

K-complexes

A very high amplitude pattern of brain activity often associated with stage 2 sleep, sometimes occurring in response to environmental stimuli.

NREM stage 3 sleep

Also called deep sleep or slow-wave sleep, characterized by low frequency (less than 3 Hz), high amplitude delta waves, and a dramatic slowing of heart rate and respiration.

Delta waves

Low frequency (less than 3 Hz) and high amplitude brain waves that characterize NREM stage 3 sleep, representing the lowest frequency and highest amplitude among sleeping brain wave patterns.

Paradoxical sleep

Another term for REM sleep, due to the combination of high brain activity (similar to wakefulness) and the paralysis of voluntary muscles.

REM rebound

The phenomenon where individuals deprived of REM sleep later spend more time in REM sleep to recoup lost time, suggesting its homeostatic regulation and role in emotional processing.

Manifest content

According to Sigmund Freud, the actual content or storyline of a dream.

Latent content

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

Collective unconscious

As described by Carl Jung, a theoretical repository of information believed to be shared by everyone, accessed through dreams.

Activation-synthesis theory of dreaming

A theory developed by Alan Hobson, proposing that dreams are the result of the brain attempting to make sense of (synthesize) the neural activity (activation) occurring during REM sleep.

Protoconsciousness

Hobson's suggestion that dreaming may represent a state of constructing a virtual reality in our heads that helps us during wakefulness.

Lucid dreams

Dreams in which certain aspects of wakefulness are maintained, allowing the person to be aware they are dreaming and potentially control the dream's content.