During which phase of sleep does dreaming predominantly occur?

Dreaming predominantly occurs during REM sleep, which is characterized by rapid eye movement, increased brain activity, and a state of rest that is similar to wakefulness. This phase of sleep is crucial for cognitive functions such as memory consolidation and emotional regulation. During REM sleep, the brain generates vivid dreams, which can often feel very lifelike or intense.

The distinct features of REM sleep, such as irregular breathing, increased heart rate, and muscle atonia (temporary paralysis of most voluntary muscles), contribute to the conditions that favor dream activity. While dreaming can occasionally occur in other stages of sleep, the dreams experienced during REM sleep are generally more memorable and complex. Thus, this phase is recognized as the primary period for dreaming.