Wake up call!
Chapter 7, Rejuvenation, changed my life. Doidge talks about the natural processes that cause and that can accelerate the inevitable cognitive decline that accompanies the inevitable process of aging. To summarize what I've learned in this book and others I read later:
You're always learning something. You never stop learning. But you're either learning how to get better, or you're learning how to get worse.Young people are driven to use up energy, take risks, and learn how to get better. When I walked to kindergarten with my grandson Luke, he didn't walk. He ran, skipped and hopped. He saw some large rocks along the side of the road, and instead of walking, like a "normal person" he jumped onto the first rock and jumped from rock to rock--like a normal kid. That kid-drive kept him learning how to move his changing body better, and improving his balance. Normal young people like Luke create unnecessary challenges, then use the challenges to drive them to improve.
Old people like me are driven to conserve energy, avoid risks, and so we learn how to get worse. When I walked with Luke to school I didn't think of jumping from rock to rock--until I saw him doing it, and realized what he was learning and what I was learning. I was learning that I didn't need to improve the complex machinery of my vestibular system to help me keep my balance; I learned that there were muscles I didn't need to know how to operate, and I didn't need my proprioceptors tuned up. I was teaching myself to be old.
Our brains tell us do that. You could call brains efficient, but if you do you're just sucking up to your brain, and for no good reason. Our brains are not efficient. They are lazy. A brain figures out how to an acceptable result with the least effort. It doesn't do anything it doesn't have to do.
When you've got an immature brain in an immature body, surrounded by adults and older kids who can do more than you can, your brain tells you that in order to survive you have to LEARN! When society puts kids in situations in which they compete with other kids, then in order to survive they have to LEARN! But eventually you find a niche and survival is no longer a problem, and you don't have to keep learning to catch up. You can live well with what you already know.
When a brain figures that out, then you're on your way down hill. Once it finds out that it can get just about the same result with less work, it does less work. When it figures out that it doesn't need a certain neural network because the skill that the network confers is no longer needed, it decommits the neurons. The process goes on throughout our lives. During the growing phase, neural networks are trimmed to find more efficient networks and to leave space for new learning. During the growing old phase, the old networks are trimmed and replaced by not much.
The PBS show based on Doidge's book gives a compelling example of skill-deaquisition and cognitive decline in the aging. It shows us an old person walking the classic old person walk: legs spread apart for a more stable platform; head down, looking at the feet to make sure that there are no missteps; small stiff movements to avoid imbalance and using unnecessary muscles. Old people don't walk that way simply because they have to: they walk that way because they learn to. And the show explains how that comes about.
When babies stumble they don't slow down; they're driven to compete and to do that they need to walk and then run and keep up their speed. They're driven to learn how to go faster. When young kids stumble, they pick themselves up and learn to do it better. Tripping and falling aren't disasters: they're a sign that more practice is needed. Sometimes it's something to laugh about.
Later on, skills are maintained, and no longer improved. So what if you slow down a litle? As long as you're doing not much worse than your peers, you're doing fine. An occasional tumble is no laughing matter, but youthful bodies heal fast enough, so there's nothing to be concerned about. Skills decline, but slowly.
When people grow old enough and stumble they don't laugh. They've hurt themselves; they heal slowly, and they worry. So they teach themselves a different set of lessons; that they need to slow down; that they can avoid stumbles by spreading their feet by looking down rather than up, and by minimizing the time when one is in a state of dynamic imbalance by taking small stiff steps. Arthritis helps. If normal movement leads to pain--even a little pain--you stop moving normally, and start moving like an old person.
Old people teach themselves to be older than they need to be.
After reading Doidge's book at age sixty-something I realized that I was teaching myself to act old. I realized that I had learned to walk down stairs differently than young people. They moved at a brisk pace, kept their heads up, occasionally glancing down to check that where their brains said they were was actually where they were. And they often walked down the center of the staircase. Sometimes they took a couple of steps at a time. I was starting to walk down stairs more slowly, with my eyes down, occasionally looking up to avoid bumping into someone and holding the handrail to keep from falling. The more I did it, the more my brain learned I could get away with it. Unlike younger people, I was in no hurry.
I was teaching myself to act old.
I decided to force myself to reverse the process. It was hard. When I took a step or two without looking at my feet I could feel the adrenaline rushing. I felt anxiety bordering on fear. I had to fight to keep my eyes up. Then after a while, as I retrained my brain it got easier.
This is not just physical decline, I realized. Sure, part of it is physical, but it's cognitive decline as well. When I was in my thirties I used to run through the woods, head up, checking my feet rarely. My brain was good enough to process my visual input, build a model of the trail I was running, compute when the root that I had seen in front of me was about to be underneath my feet, and take a longer or shorter step, avoiding a stumble. Now that's too much computing for me, and the cost of a brittle-boned mistake is too high to risk. I don't run the way I used to because my arthritic
knees won't allow it. But I also don't do it because my brain won't support me.
Doidge's book made me realize the vital importance of attention. Attention is a limited resource; controlling attention is a learned skill. Kids have so much attention that they don't have to control it. They have enough so that new skills are learned effortlessly. Older people have less attention and have to focus the attention that remains to learn and to perform. It gets harder to control it when you don't practice, and the the lazy brains of aging people discover that they can get by without paying much attention. Every time they slide by they learn that they can pay even less attention. And that accelerates their spiral of decline.
I see my waning ability to pay attention in small ways and large. "What did I just say?" my wife might have asked, years ago, when she thought I wasn't paying attention. Well, I wasn't paying enough attention to have listened to and understood what she had said. But I had enough excess attention to have recorded the last thirty seconds of speech. I could access it, recite it back and pretend that I had been listening. Now I can't do that. When she asks "What did I just say?" I have no idea.
Back in the day when I was aware that someone was saying something of interest, I could access a recording of what I had missed, for context. No longer.
I see lots of other signs of cognitive decline, now that I know what's happening, and I'm doing the only thing that I can do: I fight back.
Writing this blog is one way of fighting back. It takes a lot of attention to write 1300 words in a sitting. Forcing my head up when I'm walking down stairs is a way of fighting back. Getting up on the rocks with Luke is a way of fighting back.
The bad thing is that it's a losing battle.
The good thing is that the battle's fun to fight.
Update: 4 years later. Sometimes it's fun to fight. Sometimes it sucks. Note to self: since it's bound to be a losing battle, work harder at making losing fun.
No comments:
Post a Comment