AP PSYCHOLOGY

Detailed explanation-1: -The correct answer is c. increased voluntary muscle movement. Instead, the body becomes nearly immobile. The other answers do in fact occur in REM sleep.

Detailed explanation-2: -Rapid eye movement sleep, also known as REM sleep, is the third stage in your sleep cycle. It’s characterized by small, variable-speed brain waves, rapid eye movements, increased heart rate, and muscle paralysis.

Detailed explanation-3: -Therefore, delta waves are an integral part of REM sleep in humans and the two identified subtypes (sawtooth and medial-occipital slow waves) may reflect distinct generation mechanisms and functional roles.

Detailed explanation-4: -Indeed, they distinguished two groups of delta waves occurring during REM sleep: slower (<2 Hz) waves, recorded in medial-occipital regions, present in both NREM and REM sleep, and faster (2.5–3 Hz), REM-sleep-exclusive, fronto-central/occipito-temporal “sawtooth” waves.