REM (Rapid Eye Movement) sleepis best known as the stage in whichmost vivid dreaming occurs, making optionCthe true description. During REM, brain activity becomes more active and can resemble wakefulness in some ways, which helps explain why dreams can feel intense, emotional, and story-like. REM plays an important role in mental recovery, learning, and emotional processing, which is why adequate sleep time supports mood and cognitive performance.
REM does not usually occur in longer periods during the first half of the night. Instead, sleep cycles repeat roughly every 90 minutes, andREM periods typically become longer later in the night, especially in the second half. That is why cutting sleep short often reduces REM time disproportionately.
OptionBis also incorrect because REM is not defined by a steady slowing of breathing and heart rate. While the body’s muscles are largely relaxed and temporarily “inhibited” to prevent acting out dreams,breathing and heart rate can be more variablein REM compared with deeper non-REM sleep.
OptionDdescribesStage 1 (N1)rather than REM. Stage 1 is the drifting transition where a person can easily wake up, whereas REM is a distinct phase within the sleep cycle.
From a health and wellness perspective, understanding REM can help explain why consistent sleep duration matters. People often feel mentally foggy or emotionally reactive when they miss sleep because REM and other key stages are shortened. Supporting REM sleep involves steady sleep-wake times, limiting alcohol close to bedtime, managing stress, and creating a dark, cool, quiet sleep environment.
