AP PSYCHOLOGY

Detailed explanation-1: -[1] The NREM sleep phase again subdivides into stage N1, stage N2, and stage N3. The K-Complex is a waveform identified on electroencephalography (EEG), which primarily occurs during Stage 2 (N2) of NREM sleep, along with sleep spindles, which make up the two distinct features seen in this stage.

Detailed explanation-2: -Along with another wave pattern called K-complexes, sleep spindles are considered a hallmark of stage 2 NREM sleep.

Detailed explanation-3: -Stage 2 NREM: Usually referred to as light sleep, you can still be easily awoken in this stage. However, stage 2 sleep is not shallow. Light sleep takes up more than half of the night.

Detailed explanation-4: -Sleep spindles and K-complexes are features specific to non-REM sleep that may be related to sleep homeostasis and memory consolidation.

Detailed explanation-5: -As we move into stage 2 sleep, the body goes into a state of deep relaxation. Theta waves still dominate the activity of the brain, but they are interrupted by brief bursts of activity known as sleep spindles (Figure SC. 9).