REM sleep is characterized by all of the following except:

• A. Muscle paralysis
• B. Increased brain activity similar to wakefulness
• C. Rapid eye movements
• D. Deep, slow brain waves

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the characteristics of REM (Rapid Eye Movement) sleep. REM sleep is a unique phase of the sleep cycle marked by rapid eye movements, muscle paralysis (to prevent acting out dreams), and brain activity that closely resembles wakefulness.
2. Step 2: Review each option given in the problem and compare it to the known features of REM sleep:
3. - Muscle paralysis: This occurs during REM sleep to inhibit movement.
4. - Increased brain activity similar to wakefulness: REM sleep shows brain waves similar to an awake state.
5. - Rapid eye movements: This is a defining feature of REM sleep.
6. - Deep, slow brain waves: These are typical of deep non-REM sleep stages, not REM sleep.
7. Step 3: Identify which characteristic does not belong to REM sleep by recognizing that deep, slow brain waves are associated with deep non-REM sleep (such as stages 3 and 4), not REM sleep.
8. Step 4: Conclude that the exception in the list is 'Deep, slow brain waves' because it does not characterize REM sleep.
9. Step 5: Summarize that REM sleep is characterized by muscle paralysis, rapid eye movements, and brain activity similar to wakefulness, but not by deep, slow brain waves.