Juan is in the midst of REM sleep. What is most likely happening?

• A. His heart rate and breathing are unusually slow and regular.
• B. He is experiencing deep, slow-wave sleep.
• C. His brain activity is similar to that of being awake.
• D. His muscles are highly active and he is likely to move around.

Answer: (C)

Verified step by step guidance

1. Understand that REM (Rapid Eye Movement) sleep is a unique stage of the sleep cycle characterized by specific physiological and neurological features.
2. Recall that during REM sleep, brain activity resembles that of an awake state, meaning the brain waves are fast and desynchronized, similar to when a person is awake.
3. Recognize that despite this high brain activity, the body experiences muscle atonia, which means the muscles are essentially paralyzed to prevent acting out dreams, so movement is minimal or absent.
4. Note that heart rate and breathing during REM sleep tend to be irregular and variable, not unusually slow and regular as seen in deep, slow-wave sleep (non-REM stages).
5. Conclude that the most accurate description of what is happening during REM sleep is that the brain activity is similar to being awake, while the body remains largely immobile.