Image: John Hershey
In Brief
- Most scientists agree that sleep has significant benefits for learning and memory.
- Conventional wisdom holds that recently formed memories are replayed during sleep and in the process become more sharply etched in the brain.
- Emerging evidence suggests that sleep also serves as a reset button, loosening neural connections throughout the brain to put this organ back in a state in which learning can take place.
Compared with the hustle and bustle of waking life, sleep looks dull and unworkmanlike. Except for in its dreams, a sleeping brain doesn’t misbehave or find a job. It also doesn’t love, scheme, aspire or really do much we would be proud to take credit for. Yet during those quiet hours when our mind is on hold, our brain does the essential labor at the heart of all creative acts. It edits itself. And it may throw out a lot.
In a provocative new theory about the purpose of sleep, neuroscientist Giulio Tononi of the University of Wisconsin–Madison has proposed that slumber, to cement what we have learned, must also spur the brain’s undoing. As the conscious mind settles into sleep, the neural connections that create a scaffold for our knowledge must partially unravel, his theory suggests. Although this nightly dismantling might seem like a curious act of cerebral self-sabotage, it may in fact be a mechanism for enhancing the brain’s capacity to encode and store new information.
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16 Comments
Add CommentI think I could have told you this a decade ago. It was also written down in a Gemara over 2000 years ago.
Reply | Report Abuse | Link to thisAh, so they shouldn't continue researching what happens to the brain during sleep? Even our best guesses or seemingly accurate knowledge about something are pale comparisons to the rigor of scientific experimentation.
Reply | Report Abuse | Link to thisLook! This round thing rolls! Have we discovered something?
Reply | Report Abuse | Link to thisALSO, if you knew what a reset button does, you wouldn't want one in your brain!
Reply | Report Abuse | Link to thisSo, then why didn't you tell us this a decade ago?...
Reply | Report Abuse | Link to this... that "promytius" doesn't know how to spell?
Reply | Report Abuse | Link to this...unless that reset button were under the sole-control of John Malkovich!
Reply | Report Abuse | Link to thisIs it possible, then, that people who take multiple naps throughout the day are more intelligent than those who don't?
Reply | Report Abuse | Link to thisVery exciting article!
It is very interesting article... It is challenging to believe that sleeping more can improve learning and cognitive skills.. Certainly when we are rest, we perform better..
Reply | Report Abuse | Link to thisIs it like disc de-fragmentation in computes?
Reply | Report Abuse | Link to thisIf i recall correctly, it has been shown that naps during the day help improve memory.
Reply | Report Abuse | Link to thisIt has been suggested that Shakespeare hung out with some very smart people. Some of what he learnt leaked into his works.
Even Aristotle's wild guesses were right sometimes.
FYI - here's the comment I posted to:
Reply | Report Abuse | Link to thishttp://blogs.scientificamerican.com/a-blog-around-the-clock/2012/05/19/non-adaptive-function-of-sleep/
http://blogs.discovermagazine.com/crux/2012/05/14/is-the-purpose-of-sleep-to-let-our-brains-defragment-like-a-hard-drive/#more-1548
Defragmentation of disk space is a pretty crude analogy, when more general computer operating system memory management strategies and database management systems have a much richer background to draw from.
A common strategy used to achieve optimal recording of new information is directly analogous to short term and long term memory partitioning. For example, new information might initially be captured by serially recording event data in a short term memory 'buffer'. This would allow optimal 'peripheral (sensory) device' recording performance, with little concern for read access performance or storage space usage.
Retrieval could later be optimized to provide quick access to select data through the use of multiple indexes. The indexes might allow direct retrieval of all memories of a specific person, for example. Creating those indices would require sophisticated analyses of the simple short term memories. This could be accomplished along with migration from short term memory to long term memory during memory database 'down time', thus freeing up the high capture rate short term memory for reuse. Moreover, long term memories could be stored using shared links to redundant data, significantly saving total storage space required. This process would require the recall of stored memory elements, or snippets, to potentially generalize their content and update necessary cross-links.
Internet search engines are also employ sophisticated retrieval optimization methods using offline indexing, etc.
This is just a few of the many processes often employed in memory and database management systems. If similar processes are used to manage our own internal memories, they could help explain why sleep is necessary for to maintain memory performance, why dreaming can involve seemingly meaningless recall of memory 'snippets' and why memory details can change over time, for starters...
It's tempting to see a parallel between (1) the brain needing sleep so that it is fresher and more flexible
Reply | Report Abuse | Link to thisthe next morning, and (2) the often noted phenomenon
where creative persons work intensely for long periods
on some challenging problem. Eventually some external
need or event forces them to take time out, down time,
where the intense, perhaps constricting pressures to
perform are powerfully eased up and relaxed, even gone.
Then in these odd unstructured moments (a sickbed; a
long walk; a trip etc.) these people will often find
a startling and clear path to a solution, seeming to
pop into consciousness out of the blue. Newton forced
away from his intense studies in London to avoid the
plague, Poincare, away from frustrating work to under-
stand one mathematical field, simply raising his foot
casually up to the first step onto a tram on a boulevard
in Paris... and he realized that he suddenly 'gets it'
that his problem was directly analogous to the Fuschian
Functions. Kekule and his dreams with monkeys chasing
one another's tails... und ach! the benzene ring!
Some larger principle seems to be at work here.
Maybe about that old idea that life (creativity too)
can only exist in that thin realm between absolute
perfect order and perfect disorder. ;-]
I would think it's relatively simple. The brain and body need to recoup what they used during the course of the day. Dreams are random firings of what effected us and what we experienced during the course of that same day.
Reply | Report Abuse | Link to thisWhen they say "reset" do they actually mean "reboot"? If so then I suppose it makes sense. My PC gets sluggish as the day progresses. I install new software and the registry keeps growing bigger. I shutdown my PC at the end of the day and it briefly says "Saving Windows settings" before powering down. When I restart it in the morning, the installed programs are there, and everything done previously is there, only it works faster again. Perhaps the brain is like Windows 7 (Quantum Bit version)?
Reply | Report Abuse | Link to thisAnalogies are analogies. Here is a simple one that may help our thinking about the importance of disassembly. If we want to write a new message on a crowded blackboard it often pays to erase what is already there. This should be selective which remains a challenge. Sometimes it might pay to make certain previous messages more bold, to see through the maze of noise, so to speak. Sure its just a crude analogy, but sometimes these departures help us think more clearly. And clearly, an important topic. Wonderful to see more critical direct research as well as theorizing joining hands in the quest.
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