Which of the following is NOT associated with REM sleep

A)  irregular breathing 
B)  sleep spindles 
C)  heightened muscle tension 
D)  dreaming

REM Sleep

A phase of sleep characterized by rapid eye movements, more dreaming, and bodily movement, and faster pulse and breathing.

Sleep Spindles

Bursts of oscillatory brain activity visible on an EEG that occur during stage 2 of NREM sleep, thought to play a role in learning and memory consolidation.

Irregular Breathing

Abnormal patterns of respiration, including variations in rhythm or depth, which may indicate underlying health issues.