It’s every student’s dream, isn’t it: just put your textbook under your pillow, and somehow the information will be magically transmitted up into your brain overnight. Or maybe there’s a pre-recorded tape of lectures that you can leave on automatic replay to drone away while the night goes by, as your subconscious absorbs the lesson. But how much of that is a dream, and how much is reality? Scientists continue to research what happens in the brain while we’re sleeping, and they’ve come up with some amazing results.

The importance of sleep in helping you learn is well known. Your brain uses that “down” time to process what you’ve experienced during the day, and when you sleep you improve your memory of the information, facts, and figures that you’ve learned. In fact, if there’s something you particularly want to remember, like the new vocabulary words you learned that day, it’s a good idea to review them right before you go to sleep so that the vocabulary information is fresh in your mind, which will create stronger memories. Don’t forget to review the words as soon as you get up as well, to really cement the details in your long-term memory.

Can you really learn new things in your sleep, though? A study recently published in Nature Neuroscience seems to indicate you can, in at least a limited fashion. Researchers in Israel just completed a series of tests on sleeping subjects to find out exactly how the sleeping brain processes new information. They used pairs of sounds and smells in their test, using one sound with an unpleasant odor and another sound matched with a pleasant perfume. They sprayed the sleeping people with the nasty smell while playing one tone, and watched as the sleepers automatically took a shorter breath to avoid the smell. Later, they played the other sound while spraying the test subjects with the sweet-smelling odor, and saw that they took a deeper breath. After the subjects woke up, the researchers replayed the “bad smell” sound and the “good smell” sound, and realized that the reactions were the same. Even though the participants in the study couldn’t remember hearing or smelling anything while they were asleep, their bodies and brains remembered that one tone was associated with something they didn’t like, and automatically took shorter breaths on hearing it.

Like any other level of learning at this stage (often called “conditioning”) which operates on a subconscious basis, it’s difficult to see a practical aspect right now, but the results of this test do open up possibilities for future research. With the right stimuli, a “sleep while you learn” program might be a part of your vocabulary study in the future!

Cross-posted at the Ultimate Memory blog.