Posted on 12/06/2007 8:53:34 PM PST by neverdem
Even seniors fortunate enough to avoid the horrors of Alzheimer's disease typically experience some declines in memory and other cognitive abilities. Little is known about why this happens, but a new study suggests that cognitive declines in healthy older adults may result when brain regions that normally work together become out of sync, perhaps because the connections between them break down.
A team led by Harvard neuroscientists Jessica Andrews-Hanna and Randy Buckner used functional magnetic resonance imaging (fMRI) to monitor brain activity in 38 young adults, mostly 20-somethings, and 55 older adults, age 60 or above. The researchers focused on a "default" network of brain regions that are active when the brain is just idling, not working on any particular task (ScienceNOW, 18 January). The fMRI scans revealed coordinated activity in the default network in younger subjects: For example, two particular brain regions in the network tended to be active at the same time even though one is at the front of the brain and the other is near the back. In the older subjects, however, activity in these areas was poorly coordinated. In nine older adults, the researchers also performed a positron emission tomography (PET) scan that can detect amyloid protein in the brain--a hallmark of Alzheimer's disease. The PET scans were negative, suggesting that an out-of-sync default network is a part of normal aging, not a sign of disease, Buckner says.
Additional experiments using a method called diffusion tensor imaging revealed evidence of deteriorated white matter--the cables of axons connecting one brain region to another--in older adults whose default network activity was poorly coordinated. Although the role of the default network in cognition is poorly understood, coordinated activity made a difference in how people performed on tests of memory and other mental skills. Those with the least coordinated default network activity tended to get the lowest scores, the researchers report in the 6 December issue of Neuron.
"I think it's a great contribution to the field of cognitive aging," says neuroscientist Adam Gazzaley of the University of California, San Francisco. The findings, he notes, add to previous hints that the cognitive declines that happen with age result from changes in the way brain regions interact. Deteriorating white matter may turn out to be the root problem, breaking down communication links between brain regions and impairing their ability to work in a coordinated manner, says Gazzaley.
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My credo for the past 15 years.
Or the more you clutter up the screen with icons or have 20 windows open at once, things move slower.
Our brains are very like a computer - and we do file things away in 'favorites' and 'shortcuts' for fast retrieval = but it's not the entirety of the subject information we store - only the link that will than pull it back out of Zero Point Field faster than doing the search over...
Every thing that ever was or will be is flitting around in the very air we breathe - call it Super Strings or Zero Point Field or Akashic Records or...
It's there for us to pull in when we learn the url...
Because a younger brain is younger than an older one?
I tried to understand your explanation, but now my brain hurts.
“Old Timer’s Disease”?
I have been saying that for years. Nobody listens.
You are missing my point.
Because the article does not give the explicit age range of the younger 38 people, just ‘20 somethings’, for all we know they could all be in the lower 20s, and thus, ALL still having not fully developed, adult brains. And you would expect ALL of these not yet fully developed adult brains to function the same as the results indicate.
You assume that the sampling of the 38 young adults spans the ages of 20-29. But it is quite possible that that is not the case, and that some or all of the people still have developing brains.
It’s quite simple, really. Recall what the aging wires in TWA 800 triggered. Well, the aging wires in your brain cause the same thing.
Someone’s going to hit me in the butt with a missile?
Hey, SAM, it doesn’t matter they all functioned the same. The fMRI scans revealed coordinated activity in the default network in younger subjects. They then compaired this to the functioning of the older brain.
You are parsing the word “is”.
Perhaps you would like to site your source for the mature brain being 25.
But, it really doesn’t matter and it wouldn’t if it did.
Put that in your secret decoder.
http://weblogs.newsday.com/news/opinion/walthandelsman/blog/2007/11/animation_baby_boomers.html
Born to be mild ...
Only if you’re wearing your tinfoil hat. Keep it off and your mis-firing brain wires won’t cause any problems.
It's too bad that you didn't tell me. I only thought PET scans just measured relative metabolism. That's why I looked at PubMed to substantiate the article's claim.
I was going say something to you, but I forgot what it was.
Comes under the heading “left hand doesn’t know what the right hand is doing”
I feel better now .:)
My center tank may be bulging, but at least it hasn't exploded yet.
Hey Sac;
The lesson is clear. One needs to remain engaged in productive activities. That is not to say,"work"...should be "play."
A generative, active lifestyle will often delay if not completely forestall mental and physical deterioration. IOW, metaphorically speaking, stay out of the lounge chair in front of the TV and find something you like to do, or always wanted to do, and do it!
We tend to forget how difficult some of our learning environments were. I found myself being very uncomfortable having to submerge my ego in order to learn something new. But it can and should be done, regardless of age.
Be well, be happy and above all, stay engaged with your life. /patronizing
I’d like for scientists to discover why when I throw 12 socks into the washing machine I only get 11 back. At this point in my life, sock loss is more important than memory loss.
Your last line really struck home with me. I am struggling, really struggling to deal with my dad’s failing mental and physical health, and greiving for the person he used to be. He promised himself that when he retired, he was going to take it easy after working so hard for so many years. Problem is, he quit everything, and all the joys of living. It breaks my heart to see him sitting there, unable to get up because he hasn’t tried to get up in so long, unable to experience laughter or joy or accept love because he is so completely focused on his own pains, both real and imagined.
And I pray, every day, most of the time in private tears, for a measure of kindness, understanding, and patience, when he says something hurtful. I pray NOT to be judgmental about the choices he made that I feel render him so weak and vulnerable, and I try to keep my suspicions to myself about the fact that part of the problem is doctors’ knee-jerk response to an elderly, complaining patient: to significantly overmedicate them. My dad would not thank me for interfering with his pill regimen even if I could prove I was right.
Sometimes the changes that are allowed to happen become irreversible with time; and that’s a lesson we all need to remember.
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