How sleep deprivation makes you dumb

Adults, with rare exception, need 7 to 9 hours of sleep per day. That rare exception is less than 1% of the population. I am sure we all know individuals who say they get by with 4 to 6 hours sleep. That is just what they are doing, getting by. They are not performing at their cognitive best. One of the simplest things to do in psychology is to test the cognitive decline that occurs with sleep deprivation. Some of the best studies I have seen have come from the military. They show that if you take a group of military personnel, of mixed ages, give them a cognitive test, then deprive them of sleep so they get six or fewer hours sleep, for five consecutive nights, then retest them. They will have a drop of 60% in those test scores.

The Navy SEALs recognized a long time ago that when deprived of sleep, Seals have impaired judgment. When you or I make a mistake, it may cost us some money, be embarrassing or cause significant relationship problems etc. When a Seal makes a mistake, it may cost him his life or that of his comrades.

Perhaps someone has been pressing you to make a decision on something and you’re not quite sure. We often respond; “let me sleep on it, I will give you an answer in the morning.”

With all the new imaging devices, PRT scans, PEP scans, FMRIs we now realize the brain is far more active while you’re sleeping then it is while you are awake. Neuroscience now believes that while we are sleeping the brain goes over all the information that we took in while we were awake. It sorts that information, compartmentalizes it and stores it for future recall. 


The single best thing you can do to remember new information that you have just taken in is to immediately go to sleep. How many of us did just the opposite during our scholastic years? Panicking before an exam, we would stay up all night and cram. Our short-term memory would function well enough to scrape by and get a pass mark. The problem was, two days later we could not remember a thing we studied. This is because the information was not transferred to our long-term memory. This happens during sleep. 

In the next blog, I will explain how to achieve a quality 7 to 9 hours sleep every night.