REM Sleep: The Stage of Vivid Dreaming

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REM sleep gets its name from the rapid eye movements that first brought it to the attention of scientists in the 1950′s. This is the stage of sleep where we have the most vivid, intense, and strange dreams.

As we fall asleep, our muscle activity and eye movement slows… until we reach REM (also called “paradoxical”) sleep, when our muscles become paralyzed, but our eyes jerk rapidly and our breathing and heart rate increase. Brain scans show that the parts of the brain which process sensory information are less active than when we’re awake – but the centres which deal with our emotions, vision, memory and thought are firing on all cylinders.

Jeffrey Sutton, an assistant professor of psychiatry who uses brain scans to learn more about what our brain does while we dream, says “The amygdala, an almond-shaped gland responsible for emotion, goes ballistic during dreams”.

How Often Do We Dream?

4 to 6 times a night.

As adults, we usually sink into the REM state about an hour and a half after we’ve fallen asleep, for around 10 minutes. Later in the night our periods of dream sleep get longer, with the final one lasting for an average of 60 minutes. However, as infants and children we spend much more time in the dreaming state, and there’s evidence that people with clinical depression fall into REM sleep faster, and stay in it for longer, than non-depressed adults.

REM Sleep: The Stage of Vivid Dreaming

Do We Dream in non-REM sleep?

Although it’s the rapid eye movement stage that’s most associated with dreams, research shows that people do report dreamlike images when they’re woken from non-REM sleep. Some people who don’t experience REM sleep due to brain damage still have dreams. In the 1990′s, studies at the University of Chicago found that these non-REM dreams tend to be short and dull, unlike the primarily emotional and imaginative REM dreams.

Brain damage in two particular areas can cause lack of dreams- but neither of them regions known to affect REM sleep. These are:

  • Damage to the white matter of the frontal lobe, above the eye sockets. This area is related to the brain chemical dopamine, one of the “pleasure chemicals” connected with motivation. Medication which reduces dopamine levels can reduce dreaming; medication which enhances dopamine (such as drugs for Parkinson’s disease) can cause more intense dreams.
  • Damage to the occipitotemporoparietal cortex – behind and above ears. This region is connected with thought & perceptions.

So, many of the secrets of the dreaming brain are still to be unlocked!

Our brains work on chemicals that transmit signals from nerve cell to nerve cell.