Brilliant Old BrainsPrint
By Priscilla Long
March 7, 2012
Does age limit learning? Are good learners young learners? Do brains decline with age, as a normal thing? As an inevitable thing? I myself am growing older—at the rate of one day per day. One day, it may be, I will wake up old. Therefore I have a strong interest in the outcome of this experiment. Objectivity be damned.
The experiment to see how much new knowledge a person can capture, assimilate, digest, integrate, broadly associate, mentally masticate, replicate, and reshape during the four decades between the ages of 60 and 100, should life last so long.
Our brain contains a hundred billion neurons, more or less, each of which can make connections (by emitting electrical pulses or “firing”) with maybe 10,000 other neurons. This gives us a million billion connections. Our brain is exceedingly plastic in two ways. One: these synaptic connections are constantly forming and reforming as we experience, remember, learn, question, think, create, and imagine. Two: the hippocampus—a brain structure essential for learning—can generate stem cells, that is, new neurons.
But plasticity—as Richard Restak reminds us in his excellent book Think Smart (2009)—works both ways. The less we learn, the duller we become. Connections disconnect. “Senior moments,” God forbid, may occur. Brain-imaged by the Northwestern University Super Aging Project, octogenarians with average (for whatever reason) cognition showed a significant loss of gray matter. A thinning of the cortex. But the sharp-witted old are different. They retain the gray matter of the middle-aged. They have a noticeably thicker left anterior cingulate cortex (good for memory and learning). Autopsy reveals these brilliant old brains to have fewer tau tangles. Tau is a protein found in moderate amounts in “normally aged brains” and in large amounts in Alzheimer’s-afflicted brains. Tau tangles kill cells.
In Stahl’s Essential Psychopharmacology, psychiatrist Stephen Stahl notes that “… so far, the only intervention that has been consistently replicated as a disease-modifying treatment to diminish the risk of MCI [mild cognitive impairment] or Alzheimer’s disease and that can slow the progression of these conditions is cognitive activity.”
Cognitive activity. As I see it, certain times of life are synonymous with intense learning. Infancy, obviously. Adolescence, in which intense social learning occurs whether or not our teenager is a good student. Entry into college or into any new job brings intense learning. Big life changes of any kind involve, I suspect, intense learning.
But then there’s that long drone of a busy middle age. And we are busy. How much new learning do competent middle-aged professionals or tradespersons actually do? I mean learning beyond what one is already so very good at. Looking around, I would say, not much. Might not those years of mental coasting end in compromised cognition?
I keep in mind certain figures who went out in a blaze of intellectual vigor and creativity. Francis Crick was one. Sharer of the 1962 Nobel for unraveling the structure of DNA, he turned to neuroscience in 1976 at the age of 60, remaining in hot pursuit of the neuronal correlates of consciousness until his death at 88. Crick used his brain, undertaking huge binges of study to educate himself as he crisscrossed disciplines and helped to create the new field of molecular biology. Other notable creators who declined to decline: Beethoven, Picasso, Jean Genet, Johnny Cash, Martha Graham. The renowned artist Anna Mary Robertson Moses did not even start painting until she was 70.
I want an older age full of intense learning and creative productivity. But I would never leave it to chance. The brain requires blood (exercise). The brain requires nourishment (walnuts and blueberries and leafy greens). The brain requires sleep. It needs to dream. It needs protection from chronic stress, chronic depression, and blows to the head. It needs to learn.
Play video games, Restak says. Learn Spanish or Italian or ancient Greek. Learn to play the cello. Learn math (if you were terrible at math). Enter some new area of inquiry and blast your way through its veil of vocabulary.
It may be that brilliance in old age has more to do with genetics than with a person’s consumption of fish oil and pedometer miles. But why not try to prove otherwise? We’ve got nothing to lose but our gray matter.
Read “My Brain on My Mind,” an essay from our Winter 2010 issue
Priscilla Long is the author, most recently, of Crossing Over: Poems and The Writer’s Portable Mentor. Her essay “Genome Tome,” which appeared in our Summer 2005 issue, won the National Magazine Award for Feature Writing.