Sleep is not only important for memory but also for learning

Physorg.com - Learning while we sleep and dream

For a less interesting overview, see also: Physorg.com - Scientists explore the mysteries of why we sleep

Good memory might be considered accurate recall, but learning is also placing new beliefs into the broader context of what you already know. Previous work has shown that sleep is an important factor in good memory; this study focused on learning as well. Scientists showed 5 pairs of abstract pictures of 'eggs' to groups age 18-30 and asked them to recall not just what they looked like but also a seemingly unrelated label for each. It turns out the labels were part of an underlying pattern that the subjects weren't told about. Tests on whether they recognized this pattern then took place on one group 20 minutes later, another 12 hours, and another after 24 hours. The groups that slept on it did remarkably better at intuiting and recognizing the hidden pattern than those tested 20 minutes later or those who waited 12 hours but hadn't slept during that time. The conclusion was that sleep is not only useful in memory but also in making connections between new data and old, essentially a crucible for learning.