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Posts Tagged ‘memory’

This is your brain with not enough sleep

How does your brain work with too little sleep? As police officers, firefighters, nurses, grad students…and most parents…all know, sleep deprivation can cause your mind to react in odd ways. New research by Washington State University scientists has found that the sleep-deprived mind works differently than previously thought.

Hans Van Dongen (right) with Gregory Belenky

Gregory Belenky, M.D. and Hans Van Dongen of the Sleep and Performance Research Center at WSU Spokane use handheld devices to check the sleep habits and reaction times of their sleep study volunteers. Photo by Robert Hubner

Hans Van Dongen and his colleagues at WSU Spokane’s Sleep and Performance Research Center have found that some executive functions of the mind, such as working memory, are essentially unaffected by as much as 51 hours of sleep deprivation. Other functions are highly affected, including information intake, where information becomes distorted before it’s processed in the mind.

Van Dongen’s work appears in the January 2010 journal SLEEP. You can read more about the sleep deprivation research at WSU Today.

To read about WSU’s sleep research, visit Washington State Magazine‘s Spring 2006 feature, “The Secrets of Sweet Oblivion.” 

In the Winter 2009 feature “How We Eat is Who We Are,” you can read about WSU researcher Jim Krueger’s analysis of weight gain and sleep deprivation. (See the sidebar of the article.)


Impact of sleep deprivation different than once thought (WSU Today, Feb. 10, 2010)

WSU Sleep and Performance Research Center 

Remember that memory story…

If you enjoyed reading my WSM story on memory, check out this article from Monday’s New York Times. It gets into one of the deepest questions about memory, which is, how and when does the brain select which memories to keep and which to discard? We take in far more information every day than we can remember, and since our brains are of finite size, they can’t retain a record of everything.

New York Times article on memoryThe memories with the greatest staying power, says WSU psychologist Jay Wright, are those that are important to us personally, especially those with a strong emotional element. Such memories seem to be engraved so deeply in our minds that we can vividly recall a moment that occurred decades ago, even if we haven’t thought about it for years.

But scientists don’t know how that happens. The brain records many things in short-term memory but only a few make it into long-term storage. The hypothesis is that the brain has a mechanism to strengthen the synapses, or active connections between nerve cells, that encode memories that the brain deems to be worth keeping longer.

The work described in the NYT article is a big step in understanding that process. Researchers at the SUNY Downstate Medical Center in Brooklyn, working with rats, have identified a protein that accumulates in heavily-used nerve endings, those that receive a lot of input from other neurons. The protein probably has something to do with stabilizing those synapses and creating long-term memories, because the scientists have also found that a drug that interferes with the protein destroys the memory of something the rats had learned weeks or months ago.


Testing 1 2 3

While working on my WSM story about memory research, I came across online versions of tests that are similar to those that Maureen Schmitter-Edgecombe used in her study of different aspects of memory. Maureen couldn’t give her tests to me directly, because she pays for their use and they are copyright-protected. But I wanted to see what they were like, so I Googled some of the tests mentioned in her most recent journal article and spent a happy hour trying them. Here are a couple of my favorites.

The trail-making test (PDF) resembles a connect-the-dots game. It looks like this:

Trail-making test

Trail-making test

Part A has numbers only, 1 through 25, which you connect in numerical order. The time it takes you to do that provides a baseline for the more challenging Part B, which has numbers 1 through 12 and letters A through L. Your task there is to connect the numbers in order and the letters in order, while alternating between numbers and letters; the line you draw will go 1-A-2-B-3-C and so on. This tests your ability to switch tasks while still doing each one correctly. It was an interesting sensation, feeling the switching going on in my brain as I did this.

To really feel the gears mashing, try the interactive tests at this site from the University of Washington (shout-out to the Huskies!). Each test presents your brain with contradictory information you sort out as quickly as you can. In the color/word interference test, you first read a list of color names. Each name appears in the color it describes; the word “red” is red, the word “blue” is blue, and so on. The site tells you how long that took. Then it gives you another screen, on which the names appear in other colors; the word “red” may be blue or green or yellow, for instance. In this case, your job is to say what color each word appears in, not what color it names. It’s surprisingly hard. Once again, you’re timed. There’s no penalty for stumbles, other than the time it takes you to correct yourself.

Another test starts with pictures of animals with the name of the animal superimposed on it. A penguin has the word “penguin” written across it, for instance. The next part of the test scrambles the pictures and names, so the penguin may have the word “tiger” written on it. Your job is to name the animal pictured, regardless what label it bears.

The site has more tests in the same interactive format. Don’t go there unless you have a few minutes to tarry!