Unit 2: States of Consciousness - Sleep Terms and Stages

Vocabulary flashcards covering the key terms, sleep stages, and physiological characteristics of consciousness and sleep from Unit 2.

Consciousness

Our awareness of ourselves and our environment.

Circadian rhythm

Our biological clock consisting of body rhythms that occur on a $24\text{-hr}$ cycle, such as sleep and wakefulness.

Stage 1 (N1)

The lightest stage of NREM sleep, characterized on an EEG by high frequency and low amplitude waves, a slowed heart rate, and irregular slowed breathing.

Stage 2 (N2)

An NREM sleep stage characterized by sleep spindles, K-complexes, and sleep talking.

Stage 3 (N3)

A deep NREM sleep stage characterized by low frequency, high amplitude EEG waves, the release of growth hormone, and confusion upon waking.

REM

The dream stage of sleep where $90\%$ of dreams occur, characterized by rapid eye movement and being paralyzed with no muscle movement.

REM Rebound

A phenomenon where REM sleep increases and dream sleep is reached rapidly after experiencing sleep deprivation.

Hypnagogic sensations

Sensations occurring in Stage 1 sleep characterized by drifting to sleep and then jerking to alertness.

Sleep Spindle

A distinctive burst of brain activity observed during Stage 2 (N2) NREM sleep.

K-Complex

A characteristic brain wave pattern observed on an EEG during Stage 2 (N2) NREM sleep.