Which of the following is not a characteristic of REM sleep?

REM (Rapid Eye Movement) sleep is characterized by several distinct features in both EEG activity and physiological responses. One of the hallmark characteristics of REM sleep is low voltage mixed frequency EEG activity, which indicates a state of heightened brain activity similar to wakefulness. Additionally, during REM sleep, there is a notable reduction in EMG (electromyography) activity due to muscle atonia, which prevents individuals from acting out their dreams.

Saw tooth waves are another specific EEG feature associated with REM sleep, providing a visual representation of the unique brain wave patterns that occur during this stage.

K-complexes, however, are typically associated with NREM sleep, particularly stage 2. They appear as large, slow waves and are often linked to the brain’s response to external stimuli or internal processes during lighter stages of sleep. This is why K-complexes do not occur during REM sleep and are not characteristic of it. Hence, identifying K-complexes as a distinguishing feature prevents confusion between NREM and REM sleep stages. Understanding these patterns and characteristics is essential for interpreting sleep studies and effectively recognizing different sleep stages.