A third of our life is spent sleeping.  Given this proportion, sleep must be important. Just how important is something that researchers are beginning to figure out.  Although chronic sleep deprivation affects people differently, it is clear that a good night’s rest has a strong impact on learning and memory, and adequate sleep each day is very important. Loss of sleep hurts attention, executive function, working memory, mood, quantitative skills, logical reasoning, and even motor dexterity.

Studies suggest that the quantity and quality of sleep have a strong impact on learning and memory in two distinct ways. First, without enough sleep we cannot focus our attention optimally and, therefore, cannot learn efficiently. When we are sleep deprived, our focus and attention drift, making it more difficult to receive information. Without adequate sleep and rest, over-worked neurons can no longer function to coordinate information properly, and we lose our ability to access previously learned information. In addition, our interpretation of events may be affected. We lose our ability to make sound decisions, because we can no longer accurately assess the situation, plan accordingly, and choose the optimal behaviour. Judgment becomes impaired. Low-quality sleep and sleep deprivation also negatively impact mood, which has consequences for learning. Alterations in mood affect our ability to acquire new information and subsequently to remember that information.

Second, sleep itself has a role in the consolidation of memory, which is essential for learning new information. Learning and memory are often described in terms of three functions. Acquisition refers to the introduction of new information into the brain. Consolidation represents the processes by which a memory becomes stable. Recall refers to the ability to access the information after it has been stored. Each of these steps are necessary for proper memory function. Acquisition and recall occur only during wakefulness, but research suggests that memory consolidation takes place during sleep through the strengthening of the neural connections that form our memories. When we are asleep, the brain is not resting. It is incredibly active. It seems that one of the reasons we need to sleep is so that we can learn. We replay the information we have learned during the day in our brains thousands of times while we sleep that night.  We seem to consolidate the day’s learning while we sleep in order to remember it. Without enough sleep our performance is drastically impaired.

The overall evidence suggests that adequate sleep each day is very important for learning and memory. Sleep is as important in our routines as scheduling time for classes, readings and studying.  When the pressure is on and the work begins to pile up, the temptation is to try to find more time in our day by taking it out of our sleep. Instead of improving the situation, we often make it worse.  What is clear is that if we want to learn well, we must sleep well.

References:
Ellenbogen JM, Payne JD, Stickgold R. The role of sleep in declarative memory consolidation: passive, permissive, active or none? Curr Opin Neurobiol. 2006 Dec;16(6):716-22.
Epub 2006 Nov 7.