Why We Need Sleep To Learn

May 11, 2009

By Amanda Dervaitis, B.Ed.

We spend about one third of our lives sleeping. Besides being critical for good health, sleep also plays an important role in the process of learning. For the most effective learning to happen, experts suggest that we get at least eight hours of shut-eye every night. We need sleep so we can be mentally alert the next day allowing us to concentrate and absorb new information, but there is more to it than that. When we sleep our brains are busy processing what we have already learned. To get a better understanding of why students (and you too!) should pass on the all-nighter and go to bed early instead, let’s examine exactly what our brain is doing when we are taking the well-deserved rest at the end of the day.

There are three distinct, yet equally important phases during a sleep cycle, in which our brains are processing and learning the information we have taken in that day. The first, which typically lasts for two hours, is spent in a very deep sleep. During this time, certain brain chemicals are used to move all of the memories of the day from the short term memory centre, the hippocampus, to the cortex which is the outer layer of the brain where long-term memories are stored. Without this transfer of information long-term learning cannot occur.

During the next four to six hours, the information that is now in the cortex needs to be “sorted” and “filed”. Information is sent to various networks where nerve connections are strengthened as memories are preserved. This process requires the formation of new protein and is very slow. If this process is interrupted, new information will not be effectively stored, and therefore you will not remember what was learned or experienced that day. This is like sorting your class notes so they can be organized by subject and added to your existing notes in a binder. According to research, four hours of sleep is the minimum requirement for this phase to be effective.

The last phase of the sleep cycle lasts approximately two hours and is known as “Rapid Eye-Movement” or “REM” sleep. This is when we dream. The brain shuts down the hippocampus and focuses solely on reviewing information it has stored in the previous hours. This process reinforces and strengthens connections between nerve cells that make up the new memory. Just like learning a speech, this our brain’s way of achieving accuracy — practice makes perfect.

So, how can students avoid an “all-nighter” before a test or exam? Study a little bit every night leading up to an exam and get at least eight hours of sleep every school night. That way you’re more alert and will remember test material more effectively getting you better results. Now that’s a good reason to go to bed early!

Thanks to contributing author Amanda Dervaitis. Amanda has been an educator for 9 years and is the director at Oxford Learning in High Park. For information about exam preparation programs call the Oxford Learning Centre at 416-762-4447.

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