How Sleep Enhances Learning & Memory
As caffeine-addled college students the world over will tell you, the ability to remember things efficiently is important. Whether you need to memorize facts for an upcoming exam, skills for a new job, or where you put your keys, having a reliable memory can make virtually every facet of your life run smoother. If you’re among the majority of Australians who have experienced sleep deprivation, you already know that a night of poor sleep can cloud your thinking, but do you know the full extent to which a lack of sleep can affect your memory?
First, let’s break up memory the way scientists do. One of the greatest advances in memory research was the discovery that it can be parcelled out into a few different categories, and that different parts of your brain—as well as different stages of sleep—are likely responsible for managing each type.
Memory is roughly divided into two categories, both of which undergo a few stages we’ll discuss later. These are declarative and procedural memory. Declarative memory is factual, like a name, your address, or where you went to primary school. Procedural memory is how to do something, like play an instrument or kick a football.
Both types of memory can be split into three stages: acquisition, consolidation, and recall. In the first stage, you pick up new information. In the second, the information becomes stable and accessible, and in the third, you access the information after it’s been stored. Acquisition and recall occur when you’re awake, but consolidation seems to occur primarily during sleep. When you’re resting, your brain strengthens the neural connections that form your memories. If your brain was a filing cabinet, acquisition would resemble dumping in a bunch of disorganized files, while sorting and labelling for easy retrieval is essentially what would happen during sleep.
The take-away of memory research is this: while there’s still much to learn about the role of sleep in memory, it’s widely understood that a lack of sleep seriously affects your ability to form memories as well as you would if you were well-rested. Also, different phases of sleep seem to be important for different types of memory. For example, tasks that require motor memory, like learning to play a sport, depend crucially on rapid-eye-movement or REM sleep, while slow-wave sleep is particularly important for declarative memory.
Here’s a cool tip I picked up from looking at memory studies: studying information right before you go to sleep makes it easier to recall than learning in the morning and going about a full day. Maybe falling asleep in class isn’t such a bad idea after all!