Scientific American Community has a fun short article about memory and Sleep. The author summarizes a number of known results about the need for sleep in translating memory into deeper understanding. (Apparently, sleep is valuable for “digesting” learning. For instance, if you’ve been drilling over and over on a technique, sleeping on it may help you find a shortcut that you haven’t seen while awake.)
However, the focus of the present article is on how going without sleep affects learning. There has been a debate within the sleep community about whether sleep deprivation primarily hurts attention, or whether it hurts the ability to form memories also. A number of studies have shown that attention suffers more severely from lack of sleep than other cognitive functions. By contrast, rat studies show that the memory apparatus itself is less responsive in sleep-deprived animals — even after that apparatus is removed from the animal!
The study discussed in this article took a bunch of college students and used fMRI to study what regions of the brain were active. Intriguingly, the sleep-deprived students who did best on the learning tasks had more activation of their attention network — though their memory network was still struggling. Perhaps sleep deprivation most directly affects memory, and the affect on attention is less crucial.
In any case, the lesson for this time of year is easy: get enough sleep before studying for exams!