In a bulletin a few months back, I emphasized the importance of rest and discussed different techniques to try for optimal relaxation.
Today, I want to take that talk a step further and get into the science behind the different stages of sleep. You may not know this, but it’s really good for us to dream. Not just to daydream (though that has perks as well), but fall deep enough into our body’s sleep cycle to reap the benefits of a solid dream state. A “solid” dream state sounds like an oxymoron, but it’s a thing. Let me explain …
An all white bed lying on a field of flowers overlooking the water
Sleep Stages 1 – 3: NREM
Before Rapid Eye Movement (REM) sleep happens, Non-Rapid Eye Movement (NREM) occurs. This happens in three stages that are characterized by brain waves measured in frequencies from fastest to slowest (gamma, beta, alpha, theta, delta) and in cycles per second using electroencephalograms (EEGs). Different wave speeds are present at different times of day/arousal levels and show our level of activity. Delta are around .5 – 4 hz; Theta are around 4 – 8 hz; Alpha 8 – 12 hz; Gamma can go up to 100 hz. Sleep spindles measure in around 11 – 16 and appear in bursts, every three to six seconds.
Here’s more detail on what happens at each sleep stage:
1) In the first five to ten minutes of slumber, during our alpha brain waves phase, our eyes remain closed, and our muscles and eye movement begin to slow down. Hypnic jerks (where you feel as if you may be falling off of something and your body contracts, forcing you very briefly back to consciousness) happen at this stage. This is all completely normal.
2) In the next phase of theta brain waves and sleep spindles, our heart rate and brain waves become slower, our body temperature decreases, our muscles slightly contract and our eye movement stops. Basically, our body is preparing itself for deep sleep.
3) In this final stage of NREM, you fall into a deep sleep that is difficult to be woken from. No eye movement or muscle activity takes place and your brain produces very slow delta waves.
In those three cycles, your body is busy working! Building bone and muscle, and strengthens the immune system. There is also time for repairs and regeneration of tissues. Young people get the most sleep in this cycle.
Sleep Stage 4: REM
REM sleep, while a later stage in the sleep cycle (about 90 minutes in, to be exact), is not as deep as NREM sleep though delta brain waves continue. In fact, your brain ‘wakes up’ enough to become active as if you were completely conscious. Hence many people experience and remember vivid dreams.
The interesting detail here: while our brains are back in business, our bodies most definitely are not. In fact, our arms and legs basically function in a state of paralysis. Our heart rate, blood pressure and breathing will increase. Rapid eye movement begins and men may experience erections.
While all this is going on, we may also endure our most intense dreams. Sleepwalking may occur as the stages of REM get longer and longer as the sleep stage continues. Many children (and even some adults) also wet the bed during REM because the brain has more difficulty tuning into the night time signals of the bladder.
But this stage is good for us—physically and mentally—partly because of what happens when we dream.
Dissecting Dreams
Have you ever had a crazy dream and ran right over to the bookcase to grab a Dream Dictionary to look up what your subconscious may have tried to tell you? If so, you’re not alone. For centuries, humans have had an inherent curiosity about the meaning of dreams. From prophecies to repression, different cultures and people had different theories, but modern neurobiologists have studied the science behind them and formulated new ideas on the subject.
The most recent conclusions suggest that “the neurophysiological mechanisms that we employ while dreaming (and recalling dreams) are the same as when we construct and retrieve memories while we are awake.”
The same researchers discovered that the dreams people most often remember (which are likely the most intense or weird) have links to parts of our hippocampus, which is involved with key memory functions, and also the amygdala, which helps us process memories and emotional reactions.There is also evidence that dreaming happens in the visual cortex of our brain in the right inferior lingual gyrus.
A different study implies that those who experience less dreams (or are sleep deprived of the REM stage) may have more trouble understanding complex emotions in daily life. In a sense, dreams appear to assist us in working through our emotional battles by “encoding and constructing memories of them.”
So … do you often dream and remember what you dream about? Do you feel better after you dream? I’d love to hear your stories in the comments section.
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