It's not news that sleep is tied to learning — even a 90-minute nap can significantly help boost your brain power. If you want to cement new knowledge in your brain, recent sleep research demonstrates that a good night's sleep following your studies has a significant impact on your ability to retain information.
Photo remixed from Muhammad Rehan.
The study in question asked participants to memorise related word pairs (such as circus — clown) and unrelated word pairs (such as cactus — brick). Some participants learned the words at 9am, some at 9pm. The 9pm crowd went to sleep shortly after learning the words. The 9am crowd did not.
The results: Sleep made no difference when participants were asked to recall the related words, but when participants were asked to recall unrelated word pairs, the 9pm group — the group that slept right after learning — did significantly better. So where your brain already has a strong semantic roadmap for learning (as is the case with the related word pairs), sleep doesn't have a major effect. Where it's forming new connections, sleep makes all the difference.
Stick that in your mind pipe next time you need to do some serious cramming.