Dreaming State:

At various periods during sleep, we enter the dream state, the illusory, unpredictable world where familiar laws of nature release their hold and anything can happen—improbable shifts in time and place, unfamiliar combinations of people and events.

Most dreaming takes place in REM sleep, comprising about 25 percent of our sleep time. Brainwave activity during REM sleep resembles that of the waking state except that the brain inhibits signals to the muscles so we cannot act out our dreams.

Sleeping and dreaming are critical for our physical and emotional health. Each stage of sleep furnishes important benefits, whether regenerating neurons, generating new synaptic connections in the cerebral cortex, processing memories, or integrating what we learned during the day. The brain’s activity during sleep may also support creativity and assist problem-solving.