Learning while you sleep is such a tantalizing idea that much research has gone into it. Unfortunately, all we know is that it doesn’t work. If only life were so easy.
But the problem may have been that researchers were investigating REM sleep learning, when the brain is at its most active and we’re dreaming. Humans are subject to dream amnesia, though, and any learning that may have taken place could be forgotten as quickly as a dream.
Deep sleep exhibits different brain wave patterns, and when researchers tested subjects’ ability to retain associations in this stage of sleep, their study met with success.
Scientists at the Weizmann Institute of Science, Israel, found that subjects who had been exposed to smells and associated sounds during deep sleep, reacted to the tones even when the smell was not present, showing that their brains had retained the association.
It’s a long way from learning a foreign language in your sleep, but we can live in hope.