Surveying the Brain for Origins of the Senior Moment

[question everything]

DECEMBER 2, 2008

Surveying the Brain for Origins of the Senior Moment
Aging Brings Mental Changes -- Including a Slowdown of Mere Milliseconds -- That Drive Us to Distraction
By ROBERT LEE HOTZ
WSJ

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By recording the electrical activity of her mind at work, neurologist Adam Gazzaley at the University of California at San Francisco was using her healthy brain as a road map of mental changes that age brings to us all. In particular, Dr. Gazzaley and his colleagues were trying to understand why aging drives us all to distraction. At the slightest interruption -- an irritating ring tone, an insistent email alert or the hushed conversation in the adjacent office cubicle -- our thoughts can plunge into the mental underbrush like hounds snuffling after the wrong scent. As scientists document the normal brain changes at fault, they are highlighting a growing conflict between the push-me-pull-you demands of modern multitasking and our waning powers of concentration. By one estimate, the average office worker is interrupted every three minutes. Indeed, our inability to ignore irrelevant intrusions as we grow older may arise from a basic breakdown of internal brain communications involving memory, attention span and mental focus starting in middle age, researchers have discovered.

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America's 78 million baby boomers are turning 60 at the rate of about 8,000 a day. By 2050, the world's population of those over 60 years old is expected to exceed the number of young people for the first time in history, according to the United Nations population division, with more than 2 billion people potentially prone to absent-minded moments of memory lapse and befuddlement... No matter what we do, though, our brains normally shrink as we age -- a man's faster than a woman's -- affecting regions associated with learning and memory. Many genes linked to brain function in the prefrontal cortex also become less active, affecting how deftly we can orchestrate thoughts and actions. By combining different measures of brain activity -- positron emission tomography, functional magnetic resonance imaging and electro-encephalography -- scientists for the first time can see how aging brain regions, designed to work in unison like the interlocking innards of an expensive watch, fail to mesh swiftly and smoothly. Normal aging, for example, disrupts the electrical crosstalk between major brain regions, researchers at Harvard University reported last December in the journal Neuron.


Among the brain circuits that focus attention and memory, his research suggests, aging is a matter of milliseconds. In experiments testing how well people of different ages could recall faces and landscapes, Dr. Gazzaley and scientists at UC Berkeley found that among older people, the brain was slightly slower -- 200 milliseconds or so -- to ignore irrelevant test information. That instant of interference was enough to disrupt a memory in the making, they found. "This is the distractibility," he says. In fact, it significantly affected how well older people did on memory tests compared to younger adults. "In that first fraction of a second, younger adults are much better at blocking things out," Dr. Gazzaley said. During that momentary lapse, we can forget a new name, misplace our keys or lose our train of thought.

(snip)

Moreover, our brains start changing long before we can see the pattern in such shortcomings. Last month, researchers at UCLA reported that, beginning in middle age, we start to lose the myelin insulation that sheathes the nerve fibers running through our frontal lobes. In essence, the electrical wires of our neural circuits begin to fray and that could imperceptibly hamper our thought process. In 2006, scientists at the University of Toronto and the Rotman Research Institute in Canada reported that, among people in their 40s, they already could detect the neural mismatches that make many of us more vulnerable to distractions. By the time we reach age 65 or more, one fourth of us may be wrestling with a failing memory and other mild cognitive problems, researchers at the Indiana School of Medicine reported in the journal Neurology. An 88-year-old widow described the feeling. "My brain argues with itself,"' she says. "Spontaneous thoughts can be a struggle because they keep dancing off. They don't all march along at the same speed. It's very annoying."

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Something seems to be working. Earlier this year, researchers at the University of Michigan reported that, in a study of 11,000 retired people, memory loss and other cognitive problems were becoming less common among older Americans. That could be due to better care of high blood pressure, cholesterol and other medical risk factors. No one is sure. An active social life also appears to slow the rate at which memory fails, researchers at the Harvard School of Public Health reported this past July in the American Journal of Public Health.

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http://online.wsj.com/article/SB122772907868760541.html (subscription)

[emilyg]

1. Thanks.

[BrklynLiberal]

2. Thanks for posting.

[Waiting For Everyman]

3. My theory is accumulated overload of both stress and trash information.

Especially the kind that makes little sense (such as the way product directions are written these days, or Palinesque political spin, or the nonsensical rule-environment at most jobs). After absorbing years of that, a clog of brainscum burnout builds up. That's how it feels, anyway.

A person can only take so much trivial irrationality and infinite picayune stresses which needn't exist... and the two go together.

At some point the brain says, "excuse me, but you're mistaking me for someone who gives a shit".

[question everything]

4. I like that

We are bombarded with information coming from all directions and we think that we miss something if we actually read every single email that we get (and every DU thread...)