Pieter was lying on the couch and had fallen asleep when all of a sudden his body jerked, and he woke up because he felt like he was falling. Pieter was most likely in which stage of sleep?

• A. N1
• B. N2
• C. N3
• D. REM

Answer: (A)

Verified step by step guidance

1. Understand the context: Pieter experienced a sudden body jerk and a sensation of falling while asleep. This is a common occurrence during a specific stage of sleep.
2. Identify the phenomenon: The sensation of falling and the body jerk are known as 'hypnic jerks' or 'sleep starts.' These typically occur during the transition from wakefulness to sleep.
3. Review sleep stages: Sleep is divided into several stages, including N1 (light sleep), N2 (moderate sleep), N3 (deep sleep), and REM (rapid eye movement sleep).
4. Focus on N1 stage: Hypnic jerks are most commonly associated with the N1 stage of sleep, which is the lightest stage and occurs right after falling asleep.
5. Conclude the analysis: Given the description of Pieter's experience, it is most likely that he was in the N1 stage of sleep when he experienced the sensation of falling and the body jerk.