Sleep, Memory, and the Brain

We all know we do better when we’re well-rested than when we’re not. Modern sleep studies have started to uncover exactly why that’s true. Concerning memory, there are at least two important reasons to be sure you’re getting enough sleep.

First, we better remember what we heard the day before. This is because sleep plays a vital role in the conversion of short-term memory to long-term memory. Short-term memory is based heavily on a brain region called the hippocampus (named after the Greek word for seahorse, given its shape), while long-term memory relies on a broad network of cortical association areas. As soon as we learn new information, the hippocampus is very active, and once we sleep, it turns out that the action of our hippocampus predicts how well we will remember what we heard when we wake up. Researchers have even found interesting ways to manipulate and enhance this process. By way of example, in 1 study, experimenters paired the scent of a rose with a spatial memory task. After the study’s participants slept, some of these were again subjected to the same rose scent. Relative to participants in a control condition, they experienced greater activation in the hippocampus during sleep, and performed better on the recall test when they awakened. The same pattern held for auditory stimulation. (I like to listen to something I don’t ordinarily listen to while I’m studying (e.g. a recording of ocean waves or of fireside noises), and then let it play again while I sleep.) While we sleep, the hippocampus actively works with the relevant cortical association areas to move what we heard, so that when we wake up, not only is our memory improved, but our hippocampus can also be freed to encode new memories.

So when you’re working hard to learn something new, ensure to get enough sleep! Obviously you’ll feel better, but perhaps more importantly, you’ll do better. (I encourage you to check out
Which brings us to the second reason sleep is essential to memory: it prepares our brains for studying the next day. We need our hippocampus to encode new memories. After we’re sleep deprived, it does not function correctly.
The full paper. I have highlighted some of the parts I think are most interesting!)