Our Brains Decipher REM's Mystical Nightly Show: The Dream Dance

Rapid eye movement (REM) sleep is a mysterious stage of sleep associated with dreaming. We may be less vulnerable because this phase, 

A "periscope" into consciousness may be suggested by REM brain activity. While scientists have figured out how dreams work on a physical level,

REM sleep, during which vivid dreams occur, occurs in cycles every 90 to 120 minutes and may function to keep us from falling into a profound sleep state.

REM sleep brain activity is similar to briefly opening our eyes and taking in our environment before returning to deep sleep.

While we have a good handle on how dreams are triggered physiologically, the psychological and spiritual meanings of dreams remain mostly unknown.

You probably got seven or eight hours of sleep last night. For at least a couple of those hours, especially if you're young or energetic, 

Rapid eye movement (REM) sleep accounts for the remaining period. We also dream during other phases of sleep, 

but this is the period of time when our brain activity is most likely to be recalled and reported when we are awake.