Sleep studies have uncovered a link between sleep and memory, according to recent research by Michigan State University. Their study found insufficient or disturbed sleep can contribute to weight gain, mood swings, high blood pressure and even an impaired immune system. These sleep disorder side effects have long been known, but the study also found some people's memories are strengthened while they sleep.
"We speculate that we may be investigating a separate form of memory, distinct from traditional memory systems," study researcher Kimberly Fenn, assistant professor of psychology, said in a statement. "There is substantial evidence that during sleep, your brain is processing information without your awareness and this ability may contribute to memory in a waking state."
This form of memory is called working memory capacity, or WMC, and researchers wrote in the study that it could "contribute substantially to individual differences in online processing," that is then a predictor of how well a person can then problem-solve, learn vocabulary, make decisions and comprehend reading passages.
More studies are now being planned, to see if the sort of improved memory witnessed in the study is actually translatable to better learning in school or elsewhere.
"Our memory systems are still active while we're asleep. Memories can be strengthened while we're asleep," study researcher John Rudoy, a doctoral student in neuroscience at Northwestern University, told ABC News.
The researchers also noted that people who dreamt while napping had a greater ability to solve problems once awake.
Dream level or REM (rapid eye movement) sleep is a deep level of sleep. Typically, people who are in the REM level experience 'flaccid paralysis', meaning most of the body's muscles are relaxed. The prevailing theory is that this is so we do not respond physically to the images we dream of, i.e., we don't run from the tiger we see in our dreams.
The deep state of relaxation also means the musculature which controls the upper airway is relaxed. This is why many people snore or experience sleep apnoea (breathing stoppages) while in this state.
If you snore or suspect you might have sleep apnoea, arrange a sleep study to determine the nature and severity of your condition.