Understanding the elements of sleep architecture

Sleep cycles through the night

A hypnogram/sleep architecture chart that is color coded, showed the continuous sleep cycles. Each cycle lasts about 90 minutes.

Starting at the wakeful state, a person then goes into progressively deeper sleep known as Delta, then back up toward lighter sleep, closing the 90 minute cycle with REM (rapid eye movement, also called dream sleep).

The color coding shows that the duration of each stage varies as the cycles proceed during the night’s sleep, such that upon falling asleep, a person spends more of the 90 minute cycle in deep sleep, and by morning, much a greater proportion of time is spent in REM.

Dr. Solet mentioned that up until 1929, when the Electroenchephalogram (EEG) was invented, researchers thought when a person went to sleep, there was no brain activity and considered it a dead zone period.  With the results of the EEG, which measured the electrical activity of the brain, researchers discovered that the brain is very active during sleep and that challenged the thinking of the day. Scientists and researchers had to rethink what they thought they knew about sleep. 

What defines the sleep stages  

During sleep studies, the person’s brain is hooked up to an EEG and the brain-wave activity is measured. Each stage produces certain brain-wave activities that define the stage. Therefore, researchers can tell which stage of sleep the person is in by looking at the frequency and amplitude of the waves.

Need for sleep changes during development. A sufficient night of sleep for children should be around 10-12 hours. For adults, somewhere between 7.5 and 9.5 hours is good. Very few people are natural short sleepers. Many adults run on 5-6 hours of sleep and think this is not a problem. Most are really sleep-deficient and not operating at their best, especially if limited sleep has been a lasting behavior.

Muscle paralysis during dreams

Researchers are always studying sleep and there have been many discoveries. Most people, while dreaming, have muscle paralysis, which is normal and prevents people from acting on their dreams.

There are a few conditions that Dr. Solet did not elaborate on where people get up during the dream state. By depriving research subjects of sleep, researchers have learned about the important contributions of sleep and that different sleep stages may serve different restorative requirements.

Positive sleep effects

Sleep produces positive effects on memory, problem-solving and creativity, enhancing integration and extraction. There are many reported cases of a person wrestling with a problem and falling asleep and by morning, waking with a solution.

Research has shown that well-slept people are more likely to produce a creative answer to a problem than those who are not well-slept. Sleep has a consolidating effect and enhances learning.

Dr. Solet stated “It is most efficient to give some of your time to sleep.” Babies are sleeping 18 hours a day, half of which is spent in dream stage. As people get older, sleep changes and the quality of the sleep changes, with the proportion of deep sleep decreasing.