SLEEP 2009, the ultimate sleep research event, wrapped up this week with a slew of intriguing studies about the benefits of bedtime. The one that has my eyes perked is about sleep’s role in memory formation.
Researchers, led by Jessica Payne of Harvard Medical School, set out to determine if sleep boosts the creation of emotionally salient memories, and memories relevant to future goals, when it follows soon after learning. At the heart of the study is the notion that the sleeping brain actively and selectively consolidates memory. So, let’s say that what you are trying to learn is a side of beef, and your sleeping brain is the butcher. When you sleep (according to this hypothesis) the butcher takes the side of beef and trims it down to a stack of top sirloin and fillet mignon.
It turns out that’s not too far off the mark, but it’s even better than that. The results show that not only does sleep consolidate the most relevant, adapative and useful information, but the effect can last for up to four months. The trick is that you have to sleep soon after learning. Waiting approximately 24 12 hours after learning negates the effect.
This research adds more substance to the argument that the sleeping brain isn’t dormant in any sense of the word. It’s actively calculating what’s most important about our recent experience, and selecting what can be consolidated for long-term storage.
And while we’re talking about sleep, below is an interesting video in two parts called “The Secrets of Sleep” about the remarkable sleep deprivation stunt of Peter Tripp, which became a classic case study in the field. It’s a really well done piece, about 15 minutes in total.
David DiSalvo is a writer and research wonk whose work appears in Scientific American Mind magazine, True/Slant and a variety of other venues. More info 
3 Comments
June 13, 2009 at 2:27 am
This theory has been arround for many years
June 15, 2009 at 12:35 pm
From the link you provide, it seems like you lose the benefit even if you go to sleep considerably less than 24 hours after learning. Guessing that the morning-study group went to sleep within a few hours of midnight, we’re looking at 12-15 hours. Or did you get the 24 hour number from elsewhere?
June 15, 2009 at 2:51 pm
Martin – good point. I think you’ve got that exactly right. Going back over it, I can see that I misread the 24 hour stat. Thanks for the catch!