REM sleep is characterized by which of the following?

REM sleep is characterized by complete muscle paralysis, a condition known as REM atonia. This paralysis occurs to prevent individuals from acting out their dreams, as dreaming is most vivid during this stage of sleep. The brain is highly active during REM sleep, similar to wakefulness, which raises the risk of physical actions during dreams. Therefore, muscle paralysis is crucial for safety during this phase.

While it is true that REM sleep also features irregular breathing and rapid eye movement, the defining trait that captures its essence is the complete muscle paralysis. This unique aspect of REM sleep serves to protect both the individual and the integrity of the dreaming experience.