Final answer:
REM sleep features eye movements, brain wave patterns similar to wakefulness, dreaming, and muscle atonia. It is associated with learning and memory and when muscle paralysis does not occur, it may result in REM sleep behavior disorder, causing physical activity during sleep.
Step-by-step explanation:
Characteristics of REM Sleep
Rapid eye movement (REM) sleep is a distinct phase of sleep with several observed characteristics. During REM sleep, the eyes make darting movements under closed eyelids. The brain waves during this stage are remarkably similar to those experienced in wakefulness, which can be seen with electroencephalography (EEG).
One major feature of REM sleep is that it is the period where dreaming frequently occurs. Additionally, REM sleep is associated with muscle paralysis, sparing the muscles needed for vital functions like circulation and respiration; this lack of voluntary muscle activity is known as atonia.
This combination of high brain activity and muscle atonia is why REM sleep is sometimes referred to as 'paradoxical sleep.' Another aspect of REM sleep is its role in learning and memory processes.
Occasionally, when the typical muscle paralysis does not occur, a person may experience REM sleep behavior disorder (RBD), which leads to physical activity during their sleep, sometimes correlating with disturbing dreams.
The presence of RBD can result in various actions being carried out, such as kicking or punching, which may disrupt the sleep and potentially cause injury.