KYLE METCALF

On Memory and Aging

I once asked a psychologist how many of his middle-aged clients were worried about their memories. About 100 per cent he replied.

By Fred Stenson

I am 61 years old. My mind functions well enough to write this article and the books that are my living. Nonetheless, what happens to minds as they age is happening to mine. Memory flaws are a frequent topic in my age group. Where did that fact go? What was Richler’s second novel? What Joni Mitchell album followed Blue?-and so on. We pull out our smartphones, our auxiliary brains, and find the answer.

When I can’t find something in my mind that I know is there, I often get an anguished “tip-of-the-tongue” feeling. I say pathetic things like, “Wait, wait. I’ll have it in a second.” I once asked a psychologist how many of his middle-aged clients were worried about their memories. “About 100 per cent,” he replied.

It turns out “tip-of-the-tongue” is a concept in psychology with its own acronym (TOT) and its own French phrase: presque vu. There is an argument over whether it is caused by knowing the answer but not having the power to recollect it, or having some knowledge of the answer and groping in search of it. But why the associated anguish? Experiments have shown that the emotional side of TOT is enhanced if the question has emotional content: that is, what was the song you and your sweetie used to dance to in 1971, as opposed to what is the capital of New Brunswick.

About memory, Aristotle said: “In those who are very young or very old, or too quick or too slow, or strongly moved by passion, an impression is less readily formed because the condition of their receiving organs is not optimal.” Next time your failure to recollect is noted, remember to say, “The condition of my receiving organs was not optimal.”

Memory begins when our minds grasp from the air a name, face or place, and begin the process of putting it into storage in our brains. The first grasp is called “short-term memory” and its contents rapidly erode. The duration may be as brief as 30 seconds, based on experiments with brain-impaired people who have no long-term memory. The number of things that can be held in short-term memory at once is a measly four or five—not much when you consider that a seven-year-old chimp named Ayuma can remember a 19-digit number flash and, what’s more, can reproduce it.

The thing that converts memory’s brief holdings into long-term memory has been called “rehearsal.” If you keep thinking the idea or perception, it is more likely to transform into a stable memory. The complete model goes something like: stimulus; rehearsal; track laid down; memory. Our memories are brain cell circuits. When a memory is cued, its neuron chain “fires,” including the secretion of fluid across the synaptic gap.

Scientists in the crowd will be thinking: That model is outmoded. It is, and I wish it weren’t, because it was so easy to picture. It also explained things such as the indelibility of shocking and pleasurable memories. Because we thought these things over and over, their patterns burned into our brains.

Boomers are attacking the mind problem exactly as they battle with muscle and bone loss…they want to exercise the brain.

Aristotle noted that memory and recollection were two different functions. Having remembered does not always mean you can retrieve (hence: TOT). Also, the fact that you remember doesn’t guarantee the thing happened. One clever experiment took a group and showed them a video of a car accident. Afterwards, the researchers interviewed some of the individuals and asked them how fast the cars were going “when they smashed.” The remainder of the group was asked how fast the cars were going “when they hit.” The “smashed” group remembered the cars as going much faster than the “hit” group. This and other experiments suggest that memory is constructed, not recorded.

Some of the concepts in the “tracks laid down” model are still intact, but studies of brain physiology and function have added scores of refinements. Many newer findings have to do with synapses, the gaps between the axon of one neuron and the dendrite of another (their heads and tails), and the equipment on the sending and receiving ends. Nerve cells can have many synaptic attachments on a single neuron. These can be in many states: active, silent, recently silent, potentiated or depressed. Chemicals involved in the transmission from one neuron to another play a role in changing the states, so neurons “wire together” or not.

The biggest single evolution in thought about the adult brain is that we’ve gone from conceiving of it as static (incapable of growth or development) to plastic (capable of change). One of the first depressing things I ever learned was that my brain had millions of cells but they were steadily dying. Once I was an adult, I could create no more of them. Meanwhile most anything could kill a brain cell. A study of the brain-killing power of LSD in the 1970s proved that LSD did kill brain cells but only at the rate that coffee did. “Hold the phone! Coffee kills brain cells!” said I, who drank half a dozen cups a day.

To figure out if the brain was changing, we had to know it in some detail. A major event along that path was when Dr. Wilder Penfield did his experiments on epilepsy patients at McGill in the 1930s. His goal was to find out if brain cells associated with epileptic seizures could be identified and destroyed, and if this would cure the seizures. He removed a section of skull, exposed the brain and searched for causal brain cells by stimulating the exposed cortex with electricity, while the subject was awake. To his surprise the electric stimulation caused limbs to react and specific memories to be sparked. “I smell burnt toast,” says the patient in Penfield’s Heritage Minute.

The studies that followed “mapped the brain,” showing which parts corresponded to which limbs and functions. These findings were revolutionary, but, combined with the static-brain concept, they produced a cortical map that was also static.

Michael Merzenich and other scientists did experiments on animals from the 1970s to the present in which they were able to prove that the brain is not static. It physically changes when challenged by injury or overstimulation. Study of animals before and after the loss of a digit showed that their brains rewired to adjust to the loss. Training animals to do tasks with repetitive stimulations caused increased activity and connectivity in the brain areas governing the task.

Even adult human brains can change. This is what enables people to recover capacities lost after they’ve had a stroke; their brains reorganize and create new circuitries that compensate for damage. The current belief is that the brain has five systems for memory, not just one as was previously thought.

But the Alamo of brain plasticity was whether or not adult brains could make new cells. Even after “neurogenesis” had been proven in rodent brains, there was no proof of it in human brains. A 1998 study involving injection of a substance that was taken up into the DNA suggested that new cells were being made in the brain’s hippocampus. A more recent study at a Swedish institute was able to replicate the results even more convincingly. Using Carbon 14 in the brains of people affected by US nuclear tests in the 1950s, Spalding et al. were able to age the cells in human hippocampi and found that their ages differed. It proved that the hippocampi were indeed making brain cells, at a rate of about 700 a day.

The hippocampus may be memory’s holy grail. Tucked deep into the brain and not very large, it looks like a sea horse, which accounts for the name (in Greek, hippos means horse and kampos means coiled). Accumulation of research data involving people with amnesia yielded belief that the making of new memories occurs in the brain’s two hippocampi. The fact that their cells regenerate is excellent news.

Now back to the question of how the state of knowledge about the brain and memory is affecting the baby boomer generation’s adjustment to memory loss. What we want to know most is if the effects of our aging on memory are inevitable and irreversible. Or is there something we can do to slow the decline, stop it or even turn it around? To say our search for answers is feverish is to understate.

Baby boomers may legiti-mately differ from other generations when it comes to aging. First, we are aging in a world of unprecedented scientific knowledge and technological know-how. Second, we have been told we will live longer than previous generations. A widespread response has been to try and be the healthiest, fittest generation of aging people ever. We pursue fitness in myriad ways: biking, hiking, gym workouts; perhaps a personal trainer. We play many sports (not only golf) rather than going straight to the bridge table and crib-bage board.

Our attention to diet is legendary and the stuff of jokes. Check out the sales of the book Wheat Belly. As science makes and remakes up its mind about the effects of coffee, gluten, eggs, milk, we stay fit running from one side of the grocery store to the other. Then there are the vitamins, herbs and pharmaceuticals. Most everything promoted as good for the brain has been proven insignificant or even detrimental, but most of us still have our little battery of substances we believe in.

Only the most boosterish believe they can out-hike the grim reaper, but the rest of us have some sense of improving our odds for a long life. But the body part we feel most helpless about is definitely our brains. Chances are, everyone knows someone who has been struck down by Alzheimer’s. Now that science has demonstrated the genetic basis of the disease, occurrences in our family history produce an aura of doom.

As a group, we are frantic to find some mental crutch that will give us the kind of confidence in our minds that sport and moderation give our neck-down bodies. That confidence is hard won when we are so frequently told that “age-related memory impairment” is a fact of life or that we have “age-appropriate brain size.”

So, let’s get to what everyone really wants to know: Can the performance of the aging brain be improved? If our brains know how to rewire in response to injury, could they not learn to rewire to compensate for dying memory storage cells? The neurogenesis of the hippocampus makes us wonder if other brain cells could not also be taught to do the trick. Maybe, like the salamander does with legs, we could grow a whole new brain before the old one packs it in.

The boomer generation is attacking the mind problem exactly the same way they battle with muscle and bone loss. In particular they want to exercise the brain, and this has spawned a great many Internet products that offer to improve your mind—supported by peer-reviewed proof of incredible gains. Whereas our parents did crossword puzzles and endeavoured to keep their brains active and involved, we are entering our brains in marathons.

It might surprise some of you how long the world has been attempting this. The ancient Greeks were at work on a regime of principles and methods to push the brain beyond average performance before the birth of Christ. Art of Memory it was called, and its genesis story featured Greek poet Simonides of Ceos attending a wedding banquet. He left the hall for a moment and the building fell, crushing all the celebrants to death. Simonides was able to create a mental image of where every single person had been sitting, so the bodies could be identified.

This stimulated the idea that geometric and lushly visual images might allow humans to remember far more than they normally would. The images often contained cat’s-cradle interplay of points and lines, numbered and lettered; and the greater goal was the ability to contain all human knowledge in one’s mind.

This concept stuck around for 1,500 years and only died out because it was subsumed into the 17th century pursuit of logic and scientific method.

The test-based mind improvement regimes that are now for sale on the Internet are reminiscent of Art of Memory. The US ones tend to be cartoon- and game-based. The British ones are more print-based and sedate. They have in common advertising, cost and promises. Not surprisingly, they have been the target of much questioning and testing from the academic community. Do they work or are they simply duping aging rubes?

I enrolled in one of these programs and it was thrilling. In just four days, I became 25 per cent smarter. I slowed down after that but was 50 per cent smarter come the end of my introductory month.

Okay, it’s a laughable notion, and lately, major magazines have been lining up to satirize the brain-game fad. Many studies agree on one damning fact: The brain training improves the subject’s ability to play the games but causes no lasting improvement in brain functions such as memory.

This news may not even slow down sales given how badly we want something in which to invest our hope. A good day of training gives you a boost. The games are also highly addictive. Which reminds me: It’s time to give up Word Barrel.

People who seek to improve their brains by exercising them might be better off exercising their bodies, neck down, instead.

But before you throw out brain games, they can tell you a few things about your brain. In the first days of “training,” you find out what you’re good at and lousy at. It comes as a shock to be told you’re in the 23rd percentile of your age group for mind speed. My point is that I don’t think these tests lie, and they may tell us what skills we’ve become reliant on, and which ones we’ve ditched. One of the oddities of education is that it stops for most of us at a young age. Some never read a book again. Many more never use algebra to solve a problem. What the games showed me was which mental abilities I’d given up using and which ones I relied on for everything. An important discovery. If we narrow down to the same couple of skills for all problems, we’re greasing the wheels of our decline.

Now for the good news. Scientific research has found something that really does work for the aging brain. In the 1990s, researchers at California’s Salk Institute found that mice given an exercise wheel produced more brain cells in a memory-related part of the brain than did a control group with no exercise wheel.

Very recently, at the University of British Columbia’s Brain Research Centre, a team tested older women’s memories before and after a period of weight-training and found that after the exercise the women scored better at associative memory—names of people and where you met them, for example. For their next study, they selected women between 70 and 80 years old, all of whom had mild memory impairment. The group was divided into three. One group did regular brisk walking; one did weight training; and the third group did only stretching. After six months, the women were tested again for verbal and spatial memory. Verbal memory includes remembering words. Spatial memory includes knowing where you put things. The two exercising groups improved their memories. The stretching group became more impaired. There was also an interesting difference between the exercising groups. Improvement on the spatial memory tests was about the same between them, but the brisk walkers had more improvement on the verbal test than the weight-trainers.

This experiment has striking similarities to tests on animal memory. Different kinds of exercise affected different kinds of memory in rats. The moral: Don’t stick to one machine when you work out. The powerful irony is that the people who sought to improve their brains by exercising them might have been better off exercising their bodies, neck down, instead.

Often, when thinking about this business of the aging mind, I have thanked goodness that I was born when I was. Older people have probably been groping for lost words and names since the dawn of time, but I was born into the generation with the “auxiliary mind”: the computer. What did it matter if my mind was shrinking as long as RAM and hard drives were growing? But there is apparently a downside.

Some time ago, the Japanese began testing their avid computer-using young and found they were alarmingly poor at memorization. Tests of this kind have continued, and there does appear to be a problem with young people’s memories, problems that may be related to computer and smartphone use. The most obvious “explanation” lies in the use-it-or-lose-it realm—that if you rely on your computer’s hard drive, you are neglecting to train your own. But another testing direction shows that people choose not to remember if they know the material can be found. This is not new. If someone in a family is a hockey trivia buff, the other members tend not to try to remember anything. They ask the trivia person instead. So it goes with the computer. If test subjects are told to remember a group of things that will be erased as soon as they’ve read it, they remember better than if they believe the material is still there to be looked up. If told it is stored in a certain file, they are more likely to remember the file than the stored material. Of course, the problem about relying on computer-stored information is that your childhoods and family stories aren’t there. If you have forgotten how to remember, that sort of information will be lost.

There may also be a problem with “surfing.” I’m speculating here, but if processing of short-term memory must begin in under a minute, then continual switching seems designed to prevent conversion of sense-information into long-term memory. Interference prevents memory formation. A factor in memory decline for older people is that they have so much in their brains with which to interfere. We throw everything we know at each new fact, and this can prevent us from absorbing anything. For the young, listening to music through earbuds while messaging and surfing TV may be creating a storm of interference that prevents recall.

But since the middle-aged to the elderly are computer-using like mad to keep up with the times, we also could be sabotaging our future capacity to remember.

Lastly, let’s consider the importance of memory. It has been said by many that people in undeveloped countries often have amazing memories. Aboriginal Australians can paint the landscape of their childhood and never miss a watering hole. Aboriginal song lines, brought to international attention by Bruce Chatwin’s book of that name, are an auditory Art of Memory for essential facts of landscape, food and water, kinship and religion. In the early 1800s, John Tanner wrote of his life with the Ojibwa after being captured at age 10. Years after the fact, he could remember how many buffalo they killed and where. It is as if he forgot nothing.

The simplest conclusion is that we remember better when our lives depend on it. A water seep in the Australian outback as opposed to the name of the Wookie in Star Wars. Our memories may suck simply because we can stay alive without them. #

Fred Stenson writes historical fiction and non-fiction relating to the Canadian West and is a long-time columnist for Alberta Views.

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