Question

What happens exactly when we dream?​

Answer 1

Answer:

The whole brain is active during dreams, from the brain stem to the cortex. Most dreams occur during REM (rapid eye movement) sleep. This is part of the sleep-wake cycle and is controlled by the reticular activating system whose circuits run from the brain stem through the thalamus to the cortex.

Answer 2

Answer:

During REM periods, brain activity shoots back up to levels similar to when you're awake – which explains why REM is associated with the most intense dreams. While breathing and heart rate increase during REM sleep, most muscles are paralyzed, which keeps us from acting out those vivid dreams.