The aging brain: a dense forest of wisdom
Wed, 01/25/2006
I’m standing in the greeting card section at the drugstore, searching for a funny birthday card for a friend who is about my age. Turns out the greeting card industry’s idea of birthday humor is to ridicule the aging process. Card after card about wrinkles, memory lapses and bodily mis-functions.
The folks who write greeting cards need to read the Jan. 16 issue of Newsweek. Dr. Gene Cohen, a gerontologist, dismisses current ideas about aging with one word: “Rubbish.”
Especially when it comes to the brain, says the doctor, the older the better. Recent discoveries in neuroscience show that “the aging brain is more flexible and adaptable than we previously thought.”
For years, scientists have been jumping to the wrong conclusions about aging, writes Cohen in a lengthy article entitled “The Myth of the Midlife Crisis.”
At the age of 51, Freud dismissed old people as “no longer educable,” then produced some of his most notable work after the age of 65.
COHEN notes that we who possess older brains have one distinct advantage that is often overlooked: “older brains have learned more than young ones.” He follows that with a poetic description that warrants being posted on the refrigerator.
“Throughout life, our brains encode thoughts and memories by forming new connections among neurons. The neurons themselves may lose some processing speed with age, but they become ever more richly intertwined. Magnified tremendously, the brain of a mentally active 50-year-old looks like a dense forest of interlocking branches, and this density reflects both deeper knowledge and better judgment.”
Not only do older people have a beautifully dense brain, they seem to know how to use it more efficiently.
PET scans and magnetic resonance imaging show that the older we get, the more skilled we are at using both hemispheres of the brain. Younger brains are stuck with functioning from either one side or the other.
Neuroscientist Robert Cabeza at Duke University calls the two-sided approach “HAROLD” -- Hemispheric Asymmetry Reduction in Older Adults.
It just keeps getting better. Older brains “also tend toward greater equanimity,” continues Cohen. Our strongest negative emotions originate in the amygdalae, which screen sensory data for signs of trouble.
“At the first hint of a threat, the amygdalae fire off impulses that can change our behavior before our conscious, thinking brains have a chance to weigh in,” writes Cohen.
But like good wine, the amygdalae appear to “mellow with age.”
“In brain-imaging studies, older adults show less evidence of fear, anger and hatred than young adults.”
OF COURSE there’s a catch. If we want to keep our brains supple and resilient, we have to take care of them.
Cohen recommends both physical and mental exercise, challenging activities, and establishing strong social networks.
There are other impacts on the brain. For years, neuroscientists have been working with the Dalai Lama to study the effects of meditative discipline.
“Virtuous qualities are skills of the mind which can be developed through certain practices because of the plasticity of the brain,” says Harvard neuroscientist Richard Davidson in the February issue of Sojourners magazine.
We can think, pray or meditate - whatever you want to call it - our way to self-improvement.
Caring for a stroke survivor, I’ve learned how tiny, errant blood vessels in the brain can devastate a body, a personality and a life. More important, I’ve learned the power of that brain to heal, in its own time. It’s thrilling to think that we are now recognizing that power and on the threshold of harnessing it.
Mary Koch is caregiver for her husband, John E. Andrist, a stroke survivor. They welcome your comments at P.O. Box 3346, Omak WA 98841 or e-mail marykoch@marykoch.com. Recent columns are on the Internet at www.marykoch.com.