Psychology MCAT Practice Exam

Which stage of sleep is characterized by sleepwalking?

1. Stage 1 sleep

2. Stage 2 sleep

3. Stage 3 sleep

4. REM sleep

The correct answer is: Stage 3 sleep

Sleepwalking primarily occurs during the deeper stages of non-REM sleep, particularly in slow-wave sleep, which corresponds to Stage 3 sleep. This stage is characterized by the presence of slow brain waves known as delta waves, and it is during this phase that the body is in a state of deep rest, making it difficult for most external stimuli to awaken the person. During Stage 3 sleep, the body performs restorative functions, including tissue growth and repair, immune system strengthening, and energy replenishment. Sleepwalking, or somnambulism, emerges from this state because the individual is not fully in control of their motor functions. They may appear awake and even carry out complex behaviors, but their cognitive functions remain asleep, resulting in a lack of awareness of their actions. In contrast, lighter stages of sleep, such as Stage 1 and Stage 2 sleep, are associated with transitional periods and light rest, where the likelihood of performing behaviors like sleepwalking is significantly lower. REM (Rapid Eye Movement) sleep is the stage where the majority of dreaming occurs, and the body experiences temporary paralysis, preventing the acting out of dreams. Thus, sleepwalking does not happen during REM sleep either. Overall, Stage 3 sleep is where sleepwalking is most