Most neuroscientists agree that sleep is when we organize memories for long-term storage. People whose sleep is disturbed after studying have far more imperfect recall than people who get a good eight hours of shuteye. But a study published a couple of weeks ago shows that you can use simple memory reinforcement techniques while you're sleeping that will make your recall better than average. ... What our brains do while we sleep has a lot to do with how well we remember what we've done while we're awake.