The Wisdom Paradox Read online

  The simple message I am trying to convey is this: Just as the slightest movement of your body depends on the work of a particular muscle group, so, too, even the most minute, seemingly elusive mental activity calls upon the resources of your brain. And even the simplest of mental activities may be disrupted by brain disease. So as we embark with humility but also with fortitude on our exploration of the seasons of the mind at different life stages, and of the nature of wisdom, we must regard it as a matter of the brain. To borrow from our political folklore, “It’s the brain, stupid” is the main theme of this book. Please don’t take it personally.

  Is the aging of our brains all gloom and no triumphs? I don’t think so. In fact, I will use all the mental vigor left in my own aging brain to promote the thesis that the aging of the mind has its own triumphs that only age can bring. That is the central message of this book.

  It is time to stop thinking about the aging of our minds and our brains solely in terms of mental losses, and losses alone. The aging of the mind is equally about gains. As we age, we may lose the power of our memory and sustained concentration. But as we grow older, we may gain wisdom, or at least expertise and competence, which is nothing to sneer at either. Both the losses and the gains of aging minds are gradual rather than precipitous. Both are rooted in what happens in our brains. There have been enough books written about the losses of aging minds. This book is devoted to the gains, and the balance between the losses and the gains.

  Our culture demands a happy ending to every story. As a product of a harsher environment in my youth, I find this amusing to this day, despite the fact that I have lived this side of the Atlantic for three decades. I recall a television interview I watched after a particularly cataclysmic event of recent years. After a talking-head expert painted a dramatically stark and unfortunately accurate picture of the issue at hand, the interviewer, a famous TV personality, said with a tinge of impatience and even entitlement: “But what can you say to reassure the American public?” At which point I said to myself, What an interesting cultural idiom! Give me a happy ending or else!

  Reassurance is not always a good thing. There are circumstances when grabbing the public by the scruff of its collective neck, so to speak, and shaking it up with alarm will do more good in the long run. But on the issue of aging the public has already received its therapeutic shake-up dose. We hear constantly about the scourges of dementia and Alzheimer’s disease, and about the symptoms of neuroerosion,1 the encroachment of forgetfulness and increasing mental fatigue. Unfortunately, these scourges are real. But it is time to look for good news, providing that the good news is also real and not a phony “reassurance” ploy.

  Explaining Wisdom

  Wisdom is the good news. Wisdom has been associated with advanced age in the popular lore of all societies and through history. Wisdom is the precious gift of aging. But can wisdom withstand the assault of neuroerosion, and for how long?

  This raises a question about the nature of wisdom. In our culture we use the word frequently and reverently. But has wisdom ever been sufficiently defined? Its neural basis understood? Can the phenomenon of wisdom be understood in principle in biological and neurological terms, or is it too elusive and multifaceted to be tackled with any degree of scientific precision?

  Without claiming any particular wisdom of my own, I believe I can contribute to this understanding by enlarging on my earlier introspections, which help elucidate the nature of wisdom, or at least one important aspect thereof. The train of thought and the argument developed in this book will flow from this introspection and this insight.

  With age, the number of real-life cognitive tasks requiring a painfully effortful, deliberate creation of new mental constructs seems to be diminishing. Instead, problem-solving (in the broadest sense) takes increasingly the form of pattern recognition. This means that with age we accumulate an increasing number of cognitive templates. Consequently, a growing number of future cognitive challenges is increasingly likely to be relatively readily covered by a preexisting template, or will require only a slight modification of a previously formed mental template. Increasingly, decision-making takes the form of pattern recognition rather than of problem-solving. As the work by Herbert Simon and others has shown, pattern recognition is the most powerful mechanism of successful cognition.

  Evolution has resulted in a multilayered brain design, consisting of old subcortical structures and a relatively young cortex with a particularly young subdivision appropriately called the neocortex. The cortex of the brain is in turn divided into two hemispheres: right and left. The passage from problem-solving to pattern recognition changes the way these different parts of the brain contribute to the process. Firstly, cognition becomes more exclusively neocortical in nature and increasingly independent of subcortical machinery and of the machinery contained in the old cortex. Secondly, the balance of our use of the two hemispheres of the brain shifts. As I will show, in neural terms this probably means a decreasing reliance on the right hemisphere of the brain and an increasing reliance on the left cerebral hemisphere.

  In neuroscientific literature, the cognitive templates that enable us to engage in pattern recognition are often called attractors . An attractor is a concise constellation of neurons (nerve cells critical for processing information in the brain) with strong connections among them. A unique property of an attractor is that a very broad range of inputs will activate the same neural constellation, the attractor, automatically and easily. In a nutshell, this is the mechanism of pattern recognition.

  FIGURE 1. Human Brain. Cerebral hemispheres (1 and 2) and subcortical structures (3). The frontal portion of the left hemisphere is removed, exposing the brain stem and the diencephalon.

  I believe that those of us who have been able to form a large number of such cognitive templates, each capturing the essence of a large number of pertinent experiences, have acquired “wisdom,” or at least a certain crucial ingredient thereof. (As I write this, I hear the indignant howling of critics from various corners of science, humanities, and social activism, accusing me of scandalously gross oversimplification, so I am hedging my bets).

  By the very nature of the neural processes involved, “wisdom” (at least in my admittedly narrow definition of it) pays dividends in old age by allowing relatively effortless decision-making requiring only modest neural resources. That is, modest as long as the templates have been preserved as neural entities. Up to a point, wisdom and its kin qualities, competence and expertise, may be impermeable to neuroerosion. These will be the main themes of the book.

  But before we delve into the brain mechanisms of the cognitive gains in aging, we need to dispense with several preliminaries. We need to examine the nature of wisdom as a psychological and social phenomenon. We need to establish to our satisfaction, whether it is truly the case that a powerful mind may persevere and, to a point, prevail and triumph, even in the face of neuroerosion. This will be the book’s humanistic foundation and its point of departure, followed by a journey into the mysteries of the neural machinery of wisdom, competence, and expertise, and of the cognitive gains in aging.

  A Morning in the Life of Your Brain

  Before we delve into these intriguing issues, let’s have an introduction to our own brain. How does this magnificent piece of biological hardware work, and how do you use it in your everyday activities? Let’s start from the beginning, so to speak, and consider a morning in the life of the brain.

  The alarm has just rung, rudely assaulting your brain stem, your thalamus, and your auditory cortex. The sound awakened you out of deep sleep, which means that the auditory signal somehow activated a particular part of the brain stem, the reticular formation in charge of general arousal. Had it been a different sound—a dog barking, a fire-engine siren blaring, raindrops falling—you would have sighed with annoyance and gone back to sleep. But reluctantly, you open your eyes. Your auditory cortex, with the help of certain thalamic nuclei, has recognized the sound for its source: it
is an alarm clock. And your frontal lobes, the superego of the brain, tell you that this is important and you must get up.

  You get out of bed and look out the window. You are barely awake, but your visual cortex is already working away allowing you to appreciate the beautiful morning outside. Don’t take it for granted. When the visual cortex is damaged, cortical blindness develops even though the eyes continue to work just fine. A patient afflicted with cortical blindness (due to stroke or mechanical injury to the brain) will be able to see gradations of brightness, will even be able to tell that something is moving in the environment, but will not be able to identify objects. In certain cases, when damage to the visual cortex is particularly extensive, the patient will even lose the ability to realize that his vision has been lost. This condition is known as Anton’s syndrome.

  FIGURE 2. Different Brain Regions:What They Do. Waking up (1); recognizing alarm clock (2); spotting the toothbrush (3); using it (4); checking time (5); planning the day ahead (6).

  FIGURE 3. Different Brain Regions: What Happens When They Are Damaged. Anton’s syndrome—cortical blindness (1); visual object agnosia—inability to recognize common objects (2); ideational apraxia—loss of skilled movements (3);Wernicke’s aphasia—affects mostly object words (4); Broca’s aphasia—affects mostly action words (5); executive deficit—impaired planning (6).

  It is sunny outside your window and you feel good. “Feeling good” means that your left frontal lobe is active, since it is in charge of positive affect. It probably also means that in a particular biochemical system in the brain, the neurotransmitter dopamine is kicking in.

  As you walk into the bathroom, you survey the familiar objects: your toothbrush, your toothpaste, your mouthwash, your razor. Familiar? Of course, you know exactly what these objects are. But recognizing things as meaningful objects would not be possible without a brain region in the left hemisphere, roughly between the occipital and temporal lobes, called the visual association cortex. This part of your brain is hard at work, despite the fact that you go about your bathroom business effortlessly and casually, maybe not even fully awake. If this part of the brain is damaged, you would continue to see things, but fail to recognize them as familiar, meaningful objects.

  This is precisely what happened to a patient of mine, a middle-aged woman who walked into the bathroom one morning, looked around, and did not recognize any of the objects lying about. Alarmed, she had herself driven to the local hospital, where a CT scan was immediately performed. It turned out that she had had a stroke the night before, which affected her visual (occipital) cortex, causing a condition called visual object agnosia. It can also be caused by head injury or dementia. To help restore the function of her brain, a comprehensive program of cognitive rehabilitation was indicated, which is how she became my patient.

  Luckily, your visual association cortex is doing just fine. You are reaching for the brush with your hand. The odds are about nine to one that it will be your right hand because approximately 90 percent of the population is right-handed. The motor cortex in your left hemisphere (the pathways between the brain and the body are mostly crossed) rushes into action, and so do your cerebellum and your basal ganglia. Without these brain structures, even the simplest, most automatic and effortless movement would be impossible.

  You grasp the toothbrush in your hand—it seems like a simple activity, despite all this neural commotion—and lo and behold, you did it right: you took the toothbrush by its handle and not by the brush itself. But to accomplish this ridiculously simple feat, complex neural machinery had to kick in. It is not enough to know what the object is, one must also know how to use it. The knowledge of the motor program corresponding to the use of common objects is stored in the parietal lobe, mostly in the left hemisphere. Damage to this part of the brain due to stroke or Alzheimer’s disease often leads to ideational apraxia. The patient loses the ability to use common objects according to their function and instead begins to manipulate them randomly, like a newcomer from a different culture, where the object does not exist and therefore cannot be meaningfully recognized. Sometimes this deficit takes the peculiar form of dressing apraxia, when the patient loses the ability to put on his or her clothes correctly. This, too, is commonly seen in dementias.

  But your neural machinery is in top shape, and after finishing in the bathroom you have your business suit on in no time at all. Outside the city is coming to life and loud music begins to blare from a nearby construction site and in through the kitchen window. “What trash,” grumbles your right temporal lobe, in charge of processing music, causing you to wince. Strictly speaking, the right temporal lobe generates the aesthetic judgment, but it is your left hemisphere that parlays it into words.

  Time for a hasty cup of coffee and the morning newspaper. As you scan the front page, your left hemisphere is abuzz. The left temporal lobe is processing and understanding nouns, the left frontal lobe is processing and understanding verbs, and the left parietal lobe is processing grammar. Damage to these parts of the brain causes various forms of aphasia. Meanwhile, the prefrontal cortex is figuring out frenetically what the news of an impending recession means for your own job. The NASDAQ is down the third day in a row and so is the Dow Jones Industrial Average. You can remember what the newspapers said a few days ago when the markets were still up, which means that, unlike your stock portfolio, your hippocampi are still OK. The hippocampi, of course, are critical for learning new information.

  Despite the sunny spring morning, the stock exchange set you temporarily in a foul, seething sort of mood, and your amygdala, in charge of emotions, briefly lights up. For reasons to be explained later, it is likely to be your right amygdala.

  As you are rushing out the door, you are figuring out feverishly how to juggle five meetings and three conference calls, all scheduled for today. Your prefrontal cortex, responsible for organizing things in time, is hard at work, trying to do the near-impossible: to sequence eight activities with clockwork precision and no room for slack.

  In the elevator you notice an unfamiliar face. A new tenant in the building? It was your right hemisphere that analyzed the face in the elevator and concluded that it was a new one.

  You catch a cab and look at your watch. Your parietal lobe quickly takes in the dial display. You are going to make it to your office on time, more or less. But as you are about to sigh with relief, you notice that the cab driver has just taken a wrong turn. No wonder, you think, he is probably just off the boat and does not know the city. You quickly take control of the situation and attempt to guide the driver back on the right track. That takes a coordinated action of the frontal lobe (sequencing) and the parietal lobe (spatial information). But the good man does not understand what you are saying, since he does not speak English! You improvise by using universal sign language to direct him (your frontal, parietal, and temporal lobes are working furiously in concert).

  You are finally there. You quickly pay the driver and count your change (left parieto-temporal part of the brain, which if damaged produces a deficit called acalculia, loss of computational skills). You made it. Your brain can relax for a few precious moments while you are waiting for the elevator.

  So what is going on here? Your working day has not even started yet, and your brain has already been hard at work. The few trivial, effortless, routine morning activities required the involvement of virtually every part of the brain. And I will be the first to admit that my account of the morning in the life of the brain was a gross oversimplification, highlighting just a few main actors on the stage of the brain theater, just a few main players in the cerebral orchestra. In reality, every stage of my account involved a myriad of supporting actors in addition to the lead ones, all blending into complex and intricate cerebral ensembles, different at every moment of our lives, and fluidly communicating with one another in time.

  In scientific terms, these ensembles are called functional systems , a term introduced by the great Jewish-Russian neuropsychologist Aleksandr
Romanovich Luria (more about him later). Even though neuroscientists had inferred the existence of such intricate, dynamic processes long ago, it has become possible to actually observe them only recently, with the advent of powerful new technologies of functional neuroimaging, which literally offer us a window into the inner workings of the living, acting, thinking brain.

  Just Watching TV

  To flesh out the notion of a functional system, many aspects of the mind and thus many parts of the brain working together in concert, let us consider the following, so-familiar situation: just watching TV.

  It is the end of a late Saturday afternoon, and you are sitting in your living room basically not doing much at all. Your dog is snoozing at your feet. You are nursing your cup of coffee, or whatever your favorite late-Saturday-afternoon drink may be. You are doing nothing, really, just watching CNN.

  In the midst of this blissful nothingness, your brain is hard at work, engaged in a complex and fluid ensemble of activities, while you are ostensibly lazing around. Your visual and auditory cortex are abuzz, processing the images on the screen and the voice of Christiane Amanpour delivering the breaking news of the day. For simple signal detection, older subcortical structures in the brain stem and the thalamus may suffice, without particularly engaging the neocortex. But this is highly meaningful information and the neocortex is involved.

  FIGURE 4. Brain Regions Involved in Watching TV. How functional systems work. Examining visual images (1); understanding what the commentator says (2); putting it all together (3).

  Indeed, digesting the news about a tense confrontation half the world away takes up the resources of much of the brain. The verbal content of Amanpour’s narrative engages much of your left hemisphere. (This assumes you are right-handed, and if you are left-handed, the odds are still approximately six to four that your left hemisphere is mostly in charge of language). First engaging the part of the temporal lobe called the superior temporal gyrus in charge of speech sound perception, it then engages much of the rest of the left hemisphere.