Which one of the following statements is incorrect?

• A. People commonly sleepwalk during the first half of their night’s sleep.
• B. Growth and repair processes take place during stage 3 NREM sleep
• C. Vivid dreaming occurs during the REM phase of sleep.
• D. In response to the lack of daylight, SCN stimulates the pineal gland to release melatonin.
• E. During REM sleep all muscle movements are ceased.

Answer: (E)

Verified step by step guidance

1. Understand the context of the question: It is asking which statement is incorrect about sleep stages and related physiological processes. Each statement needs to be evaluated based on scientific knowledge about sleep.
2. Review the first statement: 'People commonly sleepwalk during the first half of their night’s sleep.' Sleepwalking typically occurs during deep sleep, which is part of stage 3 NREM sleep, and this stage is more prevalent in the first half of the night. This statement is correct.
3. Review the second statement: 'Growth and repair processes take place during stage 3 NREM sleep.' Stage 3 NREM sleep is also known as deep sleep, during which the body focuses on physical restoration, including growth and repair. This statement is correct.
4. Review the third statement: 'Vivid dreaming occurs during the REM phase of sleep.' REM sleep is characterized by rapid eye movement and vivid dreaming. This statement is correct.
5. Review the fourth and fifth statements: 'In response to the lack of daylight, SCN stimulates the pineal gland to release melatonin.' This is correct as the suprachiasmatic nucleus (SCN) regulates melatonin production in response to light exposure. However, the statement 'During REM sleep all muscle movements are ceased' is incorrect because while most voluntary muscles are paralyzed during REM sleep (a phenomenon called REM atonia), some involuntary movements, such as breathing and eye movements, still occur.