New research uncovers details about how sleep affects learning and memory, according to Psychology Today.

All day long, while we’re awake, our brains are busy. They take in the world, learn from our experiences, and form memories of what we have seen, done, heard and learned. Sleep plays an essential role in consolidating learning and memory. How exactly that works, however, is still mostly a mystery. This week, at the Society for Neuroscience’s annual meeting, researchers presented a few new clues as to what might be happening in the brain while we are asleep.

Scientists have previously been able to watch the neural patterns—the sequence in which brain cells fire—that reactivate waking experiences as animals sleep. In other words, they’ve pinpointed memories in animals’ brains. Memories aren’t stored in a particular place in the brain. Instead, a memory represents a particular sequence of brain activity.