It's Mad Cow!
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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Is it an imaging problem? Is it a wish function like in an awakened state of dreaming?
Basically, it says that the insulation (white matter) of the brain’s wiring breaks down with age and that that is a normal process which results in less than optimal cognitive (thinking) function.
Our brain must be similar to a computer...filing everything and then searching. The more records you put into your computer...the longer the search process....if you’ve been away from your computer.
That's because you have alka-seltzer's disease or whatever it is.
This is also a popular look with academics.
I resent that just because I am 60 I can not remember things and am slowing down. I mean yesterday, I think it was yesterday but it could have been last week or I might be planning it for tomorrow and just think I remember, ok what was the post about.
I see this as one more step towards euthanasia of the elderly. The tests were done on twenty-somethings and on people 60 and above. I want to know the actual ages. Twenty-somethings is a 10-year range. But 60 and above could be a 40-year range!!!!!!! The 60's, the 70's, the 80's, and the 90's. What a shady test! Do you suppose they have an agenda???
It's Mad Cow!
I empathize with your concern but don’t think it is necessary here.
That’s fascinating. If we’re not gifted with genetic memory like most animals are we must be getting ahead through the creative centers that they don’t possess.
But I may have just lost what you were trying to illuminate - we tend to overthink when we shouldn’t and often miss what should be obvious. Darn this mortal coil and it’s insistence on linear thought!
Merry Christmas, Secret Agent Man. My brain tells me to go to bed.
I’m 66 plus. Can I get some money to study my brain please.
Well, at least he’s not wearing dress shoes like some snowbirds I’ve seen.
Say what?
It's far to late in the evening - ?early in the morning - to spring that on us...
That's a great and totally accurate summation.
Grant money, Smant money. You should get the Pulitzer...
“It’s not the older people that I was concerned about. I was saying if they want to compare a young adult brain to an older adult brain, they should make sure that ALL the younger people measured should be over 25, because that’s the age when the brain is fully developed and the brain’s structure is done going thru major changes.”
Well, SAM the article clearly states the young adult brain 20-30 functioned the same. IOW’s in the twenty something group the two particular brain regions tended to be active at the same time.
http://www.prairiefarmscactusclub.com/view/?pageID=274960
I’m impressed with the snowbirds we get in South Texas. ;o)
Maybe we've learned not to sweat the small stuff - so aren't cluttering up the brain with stuff not needed at the time - don't need as many connections firing all at once...we learn how to sort out and how to pace...we've learned the sky probably won't fall today, so enjoy the sun
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