Why Michael Jordan Couldn't Hit a Baseball
HIS ANNOUNCEMENT STUNNED SPORTS FANS around the world: Basketball superstar Michael Jordan told us that he was going to retire from professional basketball. Not many other sports figures had turned their backs on sports at the top of their games, and most who had were boxers, world champion heavyweights like Gene Tunney and Rocky Marciano. But that was boxing, and this was basketball. M.J. had been living out the great American dream. How could he give it all up? The roars of the crowds? The adulation? The success?
Chicago fans were devastated. How could this be happening, and why? Michael was the greatest basketball player of his era and possibly of all time, right up there with Bill Russell and Julius Erving. Beyond that, Michael was certainly one of the most popular sports figures ever. He was a recognized superstar around the world. What made his retirement even harder to accept was that he was still in the prime of his career. Although no longer a kid--he was just over thirty--M.J. wasn't an old man, even in basketball terms. He had no lingering or recurringinjuries. He had plenty of great years left in him, years that promised more National Basketball Association championships for the city of Chicago. Why would he retire?
In his retirement announcement, Michael Jordan gave the sports world two reasons for his premature departure. First, he had nothing left to prove--and in basketball terms that may well have been true. Jordan had been larger than life since he had been a college freshman. In his last game as a freshman, he had made a long jump shot in the final seconds to win the NCAA championship for coach Dean Smith and his North Carolina teammates. After leading the United States to a Gold Medal in the 1984 Olympics, he was drafted third by the Chicago Bulls in the 1984 NBA draft. All-star center Hakeem Olajuwon and the oft-injured Sam Bowie were drafted one and two. Jordan was named rookie of the year, playing shooting guard for the Chicago Bulls. Soon he became the perennial scoring champion, a perennial all-star, and one of the best defensive players in the league. For the previous three years before he quit basketball, he had been at the pinnacle of his game and had led the Bulls to a "three-peat," three consecutive NBA championships, a feat no team had accomplished since the almost mythical Boston Celtics, coached by Red Auerbach and led by Bill Russell. During those three seasons before his retirement, Michael had led the league in scoring all three times, giving him seven consecutive scoring titles. He was the league's most valuable player in the play-offs during all three of the Bulls' consecutive championships. Along the way he led the NBA "Dream Team" to the 1992 Olympic championship and thereby added a second Olympic Gold Medal to his collection of mementos.
Michael Jordan's other reason for his retirement echoed one excuse that Chicago sports fans had been asked to accept since 1920. That was the year the Black Sox scandal broke and eight players of the Chicago White Sox were accused of throwing the 1919 World Series to the Cincinnati Reds. One of the organizers of the plot, the star pitcher of the team, Eddie Cicotte, was asked why he had done it. His reply, "I did it for the wife and kids." Michael echoed the same sentiments. He wanted to spend more time with his family. What could anyone say to that? Nothing.
Then a few months later there was another announcement, this one bringing joy to the hearts of Chicago fans. Michael Jordan was coming back to us. He was going to leave wife andfamily behind and come out of retirement, not to return to the Chicago Bulls but to become a professional baseball player. M.J. had signed a contract with the Chicago White Sox. True, it was a minor league contract, but to most fans that was a mere technicality. It would only be a matter of time until Jordan would be patrolling right field for the White Sox and leading another Chicago team on to glory. He could become the first man to be in both the Baseball Hall of Fame in Cooperstown and the Basketball Hall of Fame in Springfield, Massachusetts. That was what the local pundits were predicting. Considering his overall athletic skills and talents, it was only a matter of time and practice. The Chicago fan in me wanted that to be true.
Michael Jordan is a great athlete. There's no question about that. He was, at the time of his initial retirement (in the spring of 1993), the greatest athlete of his era, or darn close to it. But it was hard for me to join the accolades that pronounced him the greatest athlete of the century. He was a basketball player. Period. Others had been great athletes in more than just one game. Jim Thorpe, the great Native American athlete, had won both the decathlon and the pentathlon at the 1912 Olympics, an accomplishment never matched before or since. Then, after he was stripped of his medals for having played a couple of games of semipro baseball, he went on to play both major league baseball and professional football. Despite his unexcelled variety of athletic skills, Thorpe only managed a lifetime batting average of .252 in six seasons as a major leaguer. His best season was his last, 1919. That year he hit .327 in sixty games. But as soon as professional football beckoned him, he gave up baseball. In football he was a star people would and did pay money to see.
Michael Jordan had played basketball and only basketball, and because of that the neurologist in me knew he could never make the grade as a major league baseball player. We would never have the pleasure of watching him star for the White Sox or even for the Birmingham Barons, or whichever team the Sox picked out for him. For wherever he swung the bat, Michael Jordan would not be able to hit a baseball, at least not well enough to play competitively at a major league level.
That was a bet you could take to the bank. Not because Michael Jordan wasn't a great athlete, with both speed and quickness, or because he would get poor batting instruction. And certainly not because of any lack of effort on his part. He could be taught and could learn to play the field and run the bases with the best of them. No one would work harder to develop his own abilities. Unfortunately, hard work and dedication would not be the issues. His inability to hit would be the direct result of a neurological problem. It would not be due to any undiagnosed neurological malady but to the way in which his brain and ours have evolved to do what they do. His lack of hitting skill is part of his legacy as a member of the human race.
No matter how great a superstar he had become, no matter how superhuman the rest of his body seemed, his brain was still a human brain with all its attendant abilities and limitations. Hitting successfully is not a pure muscular skill, like pressing a couple of hundred pounds. Hitting is a visual-motor skill, and like all other skills it has to be learned. The brain has to learn how to recognize the spin and speed and direction of the ball as it leaves the pitcher's hand, and then to swing the bat at just the right speed and in precisely the proper location to hit the ball solidly as it crosses home plate. This is a tall order for anyone's brain. And the sad fact was that at age thirty-one, Michael Jordan's brain was just too old to acquire that skill.
How could that be? Thirty-one is young. People learn at ages far older than that. Hitting is not exactly nuclear science. And that is precisely why it can't be learned at such an ancient age.
To realize why this is so, it is necessary to try to understand the human brain and how it learns and acquires skills. The human brain did not just appear fully developed within our skulls. It evolved to get there. Our evolution, like that of every other species, began as a biological one. It was part of the process of classical Darwinian descent. But the evolution of we humans and how we live and function no longer consists of merely biological evolution but also includes social, cultural, and environmental changes. We have developed the ability to alter our environment to an extent that no other species caneven approach. Hence, by changing and controlling our own environment, we have effected a second form of evolution, which guides and directs the brain's further functions. In other words, our brains have evolved the ability to guide and direct their own development.
While rarely looked at in that way, baseball is a prime example of such an environmental change, a change that can be fed into the developing brain and alter the way in which it develops and functions. Not even Abner Doubleday made that claim. American children grow up being exposed to baseball as a man-made environmental condition and learn how to hit baseballs with baseball bats. We do not all do that equally well, but we do it. We also learn how to dribble basketballs while for reasons unknown to us our French counterparts are raised in an environment deprived of baseballs but replete with soccer balls. These French kids acquire the skill to dribble that ball with their feet.
How does this difference come about? How does baseball as an environmental input act upon the brain? And why could that input not act on M.J.'s brain?
The increase in the size and complexity that characterizes the human brain has been achieved with remarkably little genetic change. There is an embarrassingly close similarity between our genetic makeup and that of the gorilla or the chimpanzee. More than that, the total amount of genetic information coded in the double helixes of DNA has remained fairly constant throughout all of mammalian evolution, from shrews to kangaroos to dolphins to us. It is thought that there are about one million genes. That number is pretty much the same in the mouse and in humans. It is divided up into different numbers of chromosomes in different species, but the total number of genes is relatively stable. In all humans it is, of course, identical, and the actual number of active genes is far less than one million. In fact, the number is closer to one-half that, since forty percent or more of all chromosomal DNA appears to be redundant and plays no active role in development.
The best estimates suggest that about ten thousand genes, which is one percent of the total gene pool (or approximately two percent of the active gene pool), play an active part in the design and construction of the brain and the rest of the nervous system. This is true for humans and chimpanzees and walruses and even pet gerbils.
For humans, this number seems to be woefully inadequate, especially when the size and complexity of the human brain are considered. It seems enough for a simple house cat, or maybe even a chimpanzee--but for us? The human brain is made up of 1010 nerve cells--that is ten billion cells--one cell for each dollar it would cost to build a couple of top-of-the-line nuclear submarines. Looked at in that way, ten thousand genes do not seem quite so inadequate. After all, the defense budget took only three or four hundred members of Congress to set it into place. And we all know how many of them are redundant (or at least seem that way).
There are, in addition, 1014 synapses, or active connections between nerve cells, where messages can be sent or interrupted. That is one hundred trillion, a number that dwarfs any projection of the national debt into insignificance. That is a number worthy of respect.
How can a mere ten thousand genes manage to control so many synapses? How can these relatively few genes do so much more for us than they do for other species? Remember that most of what they do for us is not that different. Any survey of comparative anatomy of the nervous systems of mammals supports that conclusion resoundingly. The major structures are all the same, whether the brain belongs to a sheep or a person; and so are most of the major pathways. The hardwiring is pretty much the same, far more similar than dissimilar.
Consider the optic nerves. They always start as outpouchings of the brain itself, beginning in the retinas of the universally paired sets of eyes. They then travel back toward the rest of the brain and decussate (or cross) partially in order to read the same geniculate bodies of the thalamus. There, pathways known asthe optic radiations carry the visual images back to the occipital lobes. It is pretty much the same in every species.
This arrangement sends information from the right visual field (everything seen with either eye that is to the right of the middle when looking straight ahead) into the left visual cortex, an area known as the calcarine cortex of the occipital lobe. Analogously, images from the left visual field end up in the right calcarine cortex. This system has the same structure and function in all mammals. The same genes have done the same job and produced the same basic wiring diagram. It is this system that lets lions see which gnu is straying too far from the pack and that Chicago fans hoped would allow Michael Jordan to pick up the exact spin on a baseball as it leaves the pitcher's fingers. For it is learning within this pathway that is critical to the batter. Without it, he cannot hit a lick.
The baseball world is divided between right-handed hitters and left-handed hitters. But hitting (with the exception of one-armed Pete Gray, who played outfield for the St. Louis Browns during the last year of World War II) is a two-handed affair. Both hands grasp and swing the bat. Right-handed batters differ primarily from their left-handed counterparts not in the use of a dominant arm for hitting but on which side of the plate they stand. And how they look at the opposing pitchers. And, of course, pitchers do differ as to which hand releases the ball and where that release point is in relation to the vision of the batter.
It is the visual fields that differ with batting stance. The right-handed hitter stares out at the pitcher and must pick up the pitch coming out of his left visual field, if that pitcher is right-handed. But he must see the ball rotating out of the center of his vision and right visual field from a left-handed pitcher. This is undoubtedly why right-handers fare better against left-handed pitchers. They get a better look at the ball. This has a neurophysiological and neuroanatomical basis. There's nothing psychological about it. For the same reason left-handers see the baseballs coming at them from right-handed pitchers better andhit those pitches far better. Yet hitting is never easy, and as Yogi Berra put it, good pitching always beats good hitting. And vice versa.
The best example of our phylogenetic debt to other species in the design of the hardwiring of our brains is probably the entire process of decussation, or crossing, to the other side of the brain. The right brain directs the left arm. Why? It also feels sensation from the left side of the body: pain, touch, temperature, pressure, position sense. It sees to the left. Again, why? This all results from a crossed wiring diagram filled with decus-sations galore. But why? How did it get that way? Put most simply, it came about because the pineal eye of early amphibians had a lens.
On our long trip from amphioxus to human, one stage was the amphibians. Many amphibians developed a single extra eye in the top of the head. Although this eye was above the parietal lobes, and is sometimes called the parietal eye, because it served to transmit signals to the pineal area of the brain, it is more often called the pineal eye.
The pineal eye had a lens, and it is the lens that makes all the difference. If an object, say, some insect the amphibian would love to eat, moves from left to right, the image on the retina of the pineal eye also moves. If there were no lens, the image would move in the same direction. Since there is a lens, however, the image moves in the opposite direction, to the left. The fly is now on the right, but the image is on the left side of the pineal retina and the left half of the brain. And the amphibian still wants to eat that fly.
To eat it, he must catch it; to catch it, he must see it. So as the fly moves farther to the right, he must turn his eye by lowering the right side. A muscle on the right side of the head must pull that right lens down. But the sensation to trigger that movement is in the left brain. So the left brain has to send an impulse out along a nerve to that muscle on the other side of the skull--from left to right. That phenomenon is called decussation, or crossing of nerve fibers, and it all started with the amphibians.
If the hardwiring and the basic structure of the human brain are so similar to those of other species, why do our brains function so differently?
The complexity of our brain is not achieved just by our genetic heritage but also by what that heritage allows the brain to do. Our genetic coding allows the brain to grow and develop while interacting with the environment. It is, in essence, still growing and developing as it is learning. This interaction with the environment shapes and directs the brain's growth and development. No other species can make that statement.
Human infants are underdeveloped and helpless at birth and remain so for a long time. The human brain is far less developed at birth than were the brains of our newborn ancestors. We are born with an immature, almost embryonic brain that continues to grow and evolve in relation to its environment to a degree and for a duration of time that is unprecedented in any other species. How did that happen? And why?
The brains of most other species are fully formed by birth, whereas the brains of the primates continue to grow during a brief, early postnatal period. However, the brains of humans continue to grow at rapid fetal growth rates long after birth. This process extends for many years. The duration is different in different systems of the brain, and in some even continues into what we consider adult life. At birth, the human brain is only about one-quarter of its eventual adult size and weight. In other words, at least seventy-five percent of the brain develops after birth where environmental influences can help shape that development. It is during this prolonged period of dependency, of growth and development of the brain, that the brain is most plastic and thereby most susceptible to environmental influence. It is not just the ten thousand genes that figure out how all those synapses are to interact but the environment that helps write the software. It is during this period that most environmentally dependent skills are acquired by the brain.
This is one reason why it is almost impossible to discuss the inheritance of acquired skills, including such skills as language abilities or intelligence, as purely genetic issues. Naturedetermines the limits of what nurture can accomplish. That is an absolute. But at the same time nurture determines not only what nature can do but the way in which nature develops in order to do it. In so doing, nurture determines what we measure as nature. It is not because it was good politics that the Head Start program was the most successful aspect of Lyndon Johnson's Great Society. It was because it was good science.
The drawn-out period of brain development means the period of infantile and childhood dependency on adults lasts many years. This dependency is both a result of the lack of adult adaptive function by the brain and a sign that the process of acquiring adaptive skills is still proceeding. The ongoing brain-environment interactions build upon the plasticity of the still-developing brain, but this is not a process that goes on equally forever. The human brain is distinguished from the brains of other species by the postnatal capacity for learning and its apparent plasticity, but there are limits. There are critical periods, or windows of opportunity, for different types of learning. If a skill is not acquired during its critical period, then the acquisition of that skill in later life will be harder, if not impossible. Language has usually been our model for such skills, but no skill is more environmentally dependent than hitting a baseball. In other words, an adult who was deprived of exposure to baseball as an adolescent and tries to learn to hit a baseball would be much like an adult who had never been exposed to language trying to learn to speak at the age of twenty. To extend the analogy, hitting a major league change of pace is far more like trying to learn to read. Skills must be learned at the right time, if they are ever to be learned well.
We are not unique in this. Birds learn the specific songs that they will spend their lives singing by imitating the songs of other birds. In order to be able to do this, almost every species of bird must hear these songs quite early in life, in the first couple of months in fact. If the songs are not heard during this critical period, they are never learned. Birds deprived of this input remain songless. The one exception to this rule are canaries. It appears that each season canaries can learn newsongs. It is almost as if they can recapture their youth. This annual rebirth of a critical period for learning is accompanied by an annual crop of new auditory neurons that makes the acquisition possible.
Would Michael Jordan be able to recapture his youth, or was he merely a human whose window of opportunity had come and gone? His superior athletic skills did not mean that he had a unique ability to regenerate new visual-motor neurons on an annual basis. His brain was no different from any other human brain. His unparalleled basketball skills were the results of talents he had acquired and developed long before his thirtieth birthday, at a time when his brain was still developing and was still capable of selecting such neurons and neuronal networks.
Human infants acquire a bewildering number of different skills as their brains mature. They learn to sit up, to stand, to crawl, to walk. None of these physical skills requires any teaching. None is even based on mimicry. A blind infant masters them all. It is as if the acquisition of these skills is hard-wired--built--into the nervous system.
The process is not the same for hitting. A child who is unfortunate enough to be born into an environment without baseball will never learn to swing a bat on his own. The acquisition of a particular athletic skill is analogous to the acquisition of particular songs by songbirds. The ability to acquire songs is there. It has been ingrained genetically into the brain. The specific song depends on the environment. So it is with hitting. It is just like our acquisition of language. The ability to learn language is genetically encoded in our brains. What language we will learn depends on exposure. So Americans learn English and how to swing a bat. The French learn French and how to kick a soccer ball.
Children do acquire language with very little assistance from anyone else. It is primarily self-taught, as long as a child is exposed to language. Our brains appear to be innately equipped with systems that are able to acquire language. But this innate capability is both governed and limited by the maturation of the brain.
As the human brain matures and acquires specific self-taught hard-wired skills, it simultaneously passes through a succession of stages when language may be acquired. By age one, when the child can stand alone, she is capable of duplicating some syllables and understanding some words. Six months later she is creeping backward and downstairs and can walk forward. She now has a repertoire of anywhere from a few to fifty words, but they are used as single words, not phrases. By two years of age, she is running with numerous falls but nonetheless running, and now she uses short phrases; the babbling that had begun at about six months, when she begansitting up, disappears. And so it goes until age four, by which time language is well established. Hitting a baseball remains in the future. The physical skills a person can acquire are entirely constrained by hardwiring. They can only be learned when that wiring is completed and can be activated.
There is an attempt now to apply this type of stepwise approach to learning to hit by starting very young kids off hitting a stationary ball resting on an elongated tee. Whether this is educationally or even neurologically sound is unclear. Most baseball hitters are not exceptionally good at hitting golf balls. And hitting a stationary golf ball does not in any way prepare one to see and hit a baseball. They are far different neurological processes. Golf at its most basic depends primarily on maintaining a posture that allows the golfer to carry out a finely controlled skilled movement. Hitting a baseball is a visual-motor skill that is about recognizing where a baseball is going to be at a particular instant of time and then getting your bat there, posture be damned. They are not the same skill at all. Besides, the window of opportunity for hitting may not begin until later than the age of six or seven. Having a youngster at age five hitting off a tee could be like reading to a six-week-old baby--it could just be too early to matter at all.
The same stepwise learning occurs in the acquisition of language, with one other constraint. Just like the learning of bird songs by birds and learning how to hit a curveball, the acquisition of language requires environmental input. Infants acquire the language they hear. American children learn English, French children French, Arabian children Arabic, and so forth. No matter what the language, the process and the stages are pretty much the same. And no matter what culture the human infant is raised in, no matter what language he is exposed to, acquisition of language can only occur during a critical period of development. A critical period is a specific time interval in which an ability must be acquired if it is ever to be acquired at all. It is the entire window of opportunity. For language, that critical period, or window of opportunity, is estimated to end at about puberty.
But how do we know that there is a window of opportunity for language? The earliest evidence came from those few humans who had not been exposed to language until after this critical period had passed. Their hardware was never given the needed software. One of the first and most celebrated of such instances was that of the Wild Boy of Aveyron. This boy, who was given the name Victor, was found living alone in the woods near Aveyron, France, toward the end of the eighteenth century. He was thought to be about twelve years old when he was captured. At that time he could neither speak nor understand language. In fact, he had no understanding of the concept of using language for communication.
Professor Jean-Marc-Gaspard Itard, a physician who was interested in the study of human behavior, took charge of him. Itard had published the first case of what later became known as Tourette's syndrome. For over five years, Itard tried to teach Victor to speak, to get him to learn even the rudiments of language, but Victor was unable to acquire the skill. After years of effort, he was able to understand a number of words and phrases but had learned only a few utterances, such as milk ("lait") and Oh God ("O Dieu"). These he often said incorrectly. The now tamed Wild Boy never came close to acquiring the use of language. His critical period for doing so had passed.
We do not have all of the details of Victor's case history. It is possible that he may have been mentally retarded or deaf. But neither need be true to explain Victor's failure to learn language. For Victor, no language exposure before puberty translated into no language ever. Does that mean that the failure to see a ball hurtling toward you during childhood will translate into an inability to ever pick up a bat and hit a ball? That's hard to believe. Especially based on one eighteenth-century French kid.
Other far better documented cases of children who were completely deprived of environmental language input make the same point. A girl who has been dubbed "Genie" is one of the most recent examples (1977). She had been isolated in a room and kept away from virtually all human contact from the time she was twenty months old and should already have been ableto say a number of words and understand a great deal more. Her isolation was continued until she was thirteen and had passed puberty. This imprisonment was enforced by her father, who was obviously schizophrenic and who treated her like an animal, to the extent that he barked at her instead of talking to her.
When Genie was finally discovered and rescued from her isolation, she was totally without language. Like Victor, she could neither speak nor understand speech. Whatever she may have learned early in her life had been lost. It was at this point that language exposure and instruction were initiated. Genie did better than Victor. She did learn to comprehend language but her speech lagged far behind her comprehension and she never mastered even the rudiments of grammar. According to her mother, she had learned single words prior to her incarceration. This suggests that she was not retarded, but more significantly that during the critical period early in her life, she had already started to learn language. So perhaps she had an advantage over Victor in that the key element of her postpubertal learning of language was relearning. As a result, Genie was able to reattain at least a fair measure of comprehension. Overall, however, her level of achievement was poor.
If Victor is the right model for the study of critical periods of development, then Genie does more than bring us into the twentieth century. The acquisition process may not be entirely all or none. Genie did learn something. By analogy, she could learn to swing a bat. Perhaps she could play sixteen-inch softball. But she could not really hit successfully, and certainly not at a major league level. And that is what has to be kept in mind when looking at Michael Jordan's career switch. What M.J. wanted to do at age thirty-one was not just to be able to play pickup games of softball in the park on Sunday mornings. He wanted to play major league baseball. He wanted to hit against the best pitchers in the game. He didn't want to learn to say a few phrases; he wanted to learn how to perform Shakespeare in the same company with Olivier and Gielgud. Not a bad fantasy.
What is the neurophysiological basis of learning that underlies both language skills and the hitting of baseballs? How doesthe genetically encoded brain actually learn the specific language to which it becomes exposed, or learn the sport of its environment? There are two opposing theories. One is referred to as instructive or constructive, and the other is called selective. The older, standard view is the instructive view, in which networks of nerve cells are "instructed" by experience to form certain synapses, or pathways, which, once formed and reinforced, are retained. This could easily produce a neural network capable of learning language as a process and then learning new languages with increasing ease. In this view, the critical period would close when the network would no longer be able to reinforce pathways.
A selective process works in just the opposite way. All the pathways are there waiting to be used. If used, they are reinforced. If not, they atrophy and disappear forever. In other words, the brain "learns" by selecting from a preexisting, wide range of possible pathways. The critical period starts when the maturation of the pathways sets out the range of adaptations that can be chosen. Those that are not chosen are eventually eliminated by continued maturation. The end of the critical period represents the time at which unchosen networks are eliminated. You learn to speak one language by such closure and you can add on to that one language of information. If you don't, you can't. End of ball game.
The theory of a selective process is very attractive and seems more consistent with the acquisition of language, which is far more dependent on exposure and selection than on instruction. The child hears sounds and learns to select the same sounds as part of its language. Whichever model is right, and most cognitive scientists are leaning toward selection, that process is bound by a critical period. The parameters of this window of opportunity remain the same, whether the process is selective or constructive. The relative skills of American athletes in world competition have not improved in the last two decades, but today we can field a competitive soccer team. Why? Because kids in the United States now play soccer. We, too, can now dribble with our feet.
Stories like those of Victor and Genie can be argued to be nothing more than aberrations. Such children were deprived of far more than just speech; they were both socially and emotionally deprived. Are they the only evidence we have for a critical period for speech?
Of course not. Victor was merely the starting place. The best support for the concept of a critical period during which speech and language must be acquired comes from clinical neurology and what neurologists have learned by studying patients who have lost the ability to use language. They have what neurologists call aphasia. The term aphasia denotes an abnormality with the use of language, either understanding language, producing meaningful language, or both. These disorders of the symbolic use of language are differentiated from neurological problems of the motor skills required for producing sounds on the one hand and disorders of generalized loss of intellectual function on the other.
Neurologists are a peculiar breed, and we think about the brain in a strange way. We begin by studying the anatomy of the normal brain and then superimposing on this the areas of injury, or "lesions," that we identify in patients with strokes and other neurological diseases. Whatever function was lost by a patient with a stroke must have been the normal function of the injured area.
For example: a patient had a stroke. At autopsy his brain shows an area of destroyed brain tissue called encephalomalacia, a brain softening. In this case the softening was in the right occipital lobe. Clinically, neurological examination before death had revealed loss of vision in the left eye, that is, loss of his left visual field. Hence we infer that vision of the left visual field is the normal province of the right occipital lobe. This has been demonstrated to be a hard-wired process genetically built into the brain. It is a structural-functional reality that we share with other mammalian species. Visual imagery from the left visual field enters both eyes. That from the right eye stays on the same side of the brain and, by way of the right thalamus, gets to thevisual cortex of the right occipital lobe. The images of the left half of the visual field that enter the left eye cross the midline (our old friend, hard-wired decussation), meet up with those mediated by the right eye in the thalamus, and then are relayed together to end up in the right visual cortex.
Once these neuroanatomical and clinical facts are known, the system is infallible. When the next patient comes with a history of visual loss, the knowledge can be used. Examination of this patient shows complete loss of vision in the left visual fields of both eyes. The localization of the lesion is obvious. This patient has a lesion in the right occipital lobe that is interrupting the function of that lobe.
This hard-wired system is also influenced by the environment, and there is a critical period during which this influence can be expressed. These conclusions come from the studies of David H. Hubel and Torsten N. Weisel, who shared the 1981 Nobel Prize for physiology or medicine for this work. The visual cortex of cats and monkeys, and it is assumed of humans, contains neurons that respond selectively to specific features of the environment such as color or orientation. This selectivity can then be manipulated by the environment. For example, if a kitten is reared in an environment made up entirely of vertical stripes, then the neurons that respond to visual-spatial orientation will learn to respond primarily to vertical lines as opposed to horizontal lines. This bias can only be acquired during a critical period of growth and is an example of a selective rather than an instructive process. In other words, the system could initially respond to either vertical or horizontal lines, but the exposure to vertical lines results in vertical bias. Experience serves to define or select neurophysiological function. This is a good model for the role of the environment in ever more complex learning such as acquisition of language and hitting a baseball.
Each time a young batter tries to see a pitch and hit it, certain cells are "selected" to see that pitch and start off that process. If no pitches are seen, then absolutely no selection is made. Players talk about picking up the rotation on the ball as itleaves the pitcher's hand. It is this rotational bias that must be selected. It cannot be selected at age six by hitting off a tee, or later in life when the time for selection is over.
Language, like hitting, must be selected to occur in the correct area of the brain at the correct time during the brain's development. What is known about aphasia can be summarized into a couple of general rules derived from neurological observations:
Rule 1. A lesion of only one hemisphere is needed to cause aphasia. Ergo, one hemisphere is dominant for speech. If a patient is aphasic, he has a lesion of the dominant hemisphere for speech. In right-handers the dominant hemisphere is all but invariably the left. So if a right-hander is aphasic, he has a problem in his left hemisphere. In left-handers the situation is not as clear, because in most left-handers the left hemisphere is dominant for speech.
Rule 2. Not all aphasias are identical. If a patient has more trouble speaking than understanding, the lesion is more toward the front of the dominant hemisphere. If the patient has more trouble understanding than speaking, the lesion is more toward the back of the hemisphere. All of the rest of the theorization is secondary and, in a way, mere commentary.
What does all of this have to do with Michael Jordan and the art of hitting? The study of aphasia proves that critical periods for learning particular skills are part and parcel of normal brain function and development.
While the selection of the left hemisphere as the dominant hemisphere for speech is fairly automatic, injury to the left side of the brain can force the opposite side to be selected. And this is done automatically, at least early in life. How long can this ability last?
Until puberty or thereabouts. Every neurologist knows this from personal experience in treating brain-injured patients. The commonest cause of this form of acquired aphasia is a stroke, and though strokes are relatively rare in childhood, they do occur. In children, they are often related to inflammation of one carotid artery supplying blood to one of the cerebralhemispheres. This results in a significant injury of that hemisphere and a contralateral in hemiplegia or infantile hemiplegia. If the dominant hemisphere for speech is involved, this also produces aphasia. So what happens to children with aphasia from such strokes?
If the infantile hemiplegia and aphasia occur at age three or four, speech becomes severely impaired, but after a short time is almost invariably fully reacquired. The ability to be selected to acquire speech had not yet been lost by the so-called minor hemisphere, which as a result is willing and able to become the dominant hemisphere for speech. This switching of dominance is carried out almost without skipping a beat. In fact, once recovery begins, these brain-injured children pass their language milestones at an accelerated rate until they catch up to their expected age-related capabilities. They then move on as if nothing had ever happened to them. However, the hemiplegia often remains as a serious deficit. Thanks to our evolution, the control of movement in the opposite half of the body is entirely hard-wired. No other area can be selected to take over.
But this plasticity does not go on forever. Most children fully recover speech as long as they were stricken with aphasia before the age of nine and as long as the disease process was a stroke or other lesion that involved only one hemisphere of the brain. Puberty is the turning point. By the age of fifteen or sixteen, the prognosis for recovery from aphasia is the same as that of adults.
Although recovery from aphasia is more difficult in adults, it is not impossible. Most recovery, if it occurs, occurs rapidly and represents neither adaptation nor relearning. Selection of new networks plays no role in this whatsoever. This recovery represents healing and "shrinkage" of the initial lesion. Such rapid recovery suggests that the initial loss was due to loss of function of areas of the brain that were partially injured but not permanently destroyed. The symptoms that are still there after a few weeks tend to be permanent.
Children who become aphasic between the age of nine and their mid-teens fall in between in their recoveries. They rarelyfully reacquire speech but they recover more than adults do. So what does all of this mean? There is a critical period for the acquisition of speech, but this critical period is not an all-or-nothing phenomenon with a sharp cutoff. Up to age nine, the brain has areas on either hemisphere that can be selected to carry out all language functions. By age fifteen or sixteen this kind of recovery is no longer possible; the period for selectivity is over. In between there is a period of transition.
So much for the neurological data. The logic of neurology is not beyond reproach. It depends on the loss of function in an abnormal brain to imply normal function. M.J.'s brain was not abnormal, and certainly not in the area of visual-motor skills. He could hit a running jump shot with the best of them.
Support for the notion of a critical period for language is within the experience of almost every one of us. Just consider the struggles of normal brains to acquire new language skills. All of us are aware of the problems faced in learning a second language. What tourist hasn't returned from France amazed that four-year-old French children have mastered the skill of speaking French, complete with correct accents, a skill that has stumped the tourist most of his life. Second languages are far easier to acquire during childhood than during adolescence or adulthood. This situation is now being played out in classrooms across the United States, as it has been to some degree with each successive generation of immigrants to this country. The results will be no different for this generation, but this time the results have been far better studied. Learning has become a subject of research.
The acquisition of English by Chinese and Korean immigrants to the United States has been carefully tracked. And guess what? These children learned English quickly and correctly, with no accents at all, right up to the age of puberty. After puberty, the acquisition of English became harder. Between puberty and age seventeen it was moderately, but significantly, more difficult, and after that age it got even harder. Between puberty and seventeen, some accent usually remained. Afterseventeen, there was almost always a definite accent, and one that sounded foreign to anyone who learned English before puberty, including the immigrant's own family members. This should have been news to no one. It had been the experience of many American families for the last century or more. But it is always nice when science confirms everyday experience and tells us what we already knew.
Despite all the hurdles, people can and do learn a second language after puberty and even during adult life. Much of the population of Israel has. But it takes considerable effort, far more than it does prior to puberty. Furthermore, a second language learned after puberty is always that, a second language grafted onto the first rather than a natural language fully and easily acquired. It is disturbing that despite our continued educational experience of the inverse relationship between age and the acquisition of a second language--a relationship that must be within the experience of every teacher and school administrator--the teaching of a second language in our schools is almost always begun seriously only in high school, at precisely the time when the critical period has already passed and the learning of a second language has become increasingly difficulty.
Learning to hit may be difficult, but it is not as difficult as learning a language. It is a motor skill, visual-motor in fact, but still a nonverbal motor skill. But nonverbal motor skills also have critical periods. These windows of opportunity are well within the everyday experience of all of us. Since the explosion of Pac-Man on the American scene about two decades ago, such computer games have been proliferating. Computers themselves have become a part of the workplace and home life of many of us, and despite a late start, many of us have learned a variety of computer skills. Some of our contemporaries, beginning as adults, have become surprisingly proficient.
But give an adult computer pro a Nintendo, match her against an eight-year-old kid who can barely read the instructions, and see how well the adult does. Reading the instructionsis scarcely a necessity for kids raised with computers. The games are visual and the rules are all pretty much the same and easily learned by visual-motor experience.
So what happens?
The kid wins--every time, day in, day out, year after year. The adult who first played such games as an adult can never catch up, and each year another crop of kids can and do beat him. Why? The adult computer pro was too old when he got started. In our terms, there is a critical period for acquiring this nonverbal visual-motor skill, and if you first start to learn it after that period you can never really master it.
The same is true of learning to hit a baseball. It is a fact of baseball life. Not one major league baseball player has ever learned to hit a baseball after the age of twenty-six and certainly not after the age of thirty. Michael Jordan was thirty-one when the 1994 baseball season started.
How can I be certain of this, and why was I, as a neurologist, one who knew it was true? I was certain because I was both a neurologist and a baseball buff. But I was not alone in my knowledge. Every major league baseball coach and manager knew it was true. They had just never thought about it in this way.
Every year there are pitchers, major league pitchers, good pitchers, sometimes even star pitchers, whose careers suddenly come to an end. There are a variety of causes. Sometimes it is tendonitis. Other times they develop what are called sore arms or dead arms. The exact process is not relevant; the result is functionally the same. Their fastballs are suddenly no longer as fast as they once were, and they can no longer get them past anyone. What happens to these pitchers? No one ever tries to convert them into hitters.
Why not? Such a conversion seems a natural option. Many still have contracts that must be paid off over the next two, three, or more years, contracts that may call for payments of several million dollars each year. Why not let them hit for a living? In high school, almost all of them did far more than pitch. On the days they didn't pitch, they played first base orshortstop or somewhere in the outfield, depending on their speed and fielding skills, and batted third or fourth in the lineup and starred as both the best pitcher and the best hitter on their teams. Then came decision time. To hit or not to hit. Or more specifically, to hit or to pitch, but never both. A choice had to be made and was made, usually by someone else, a college coach or more traditionally by the major league team that drafted the player out of high school and guided his minor league career.
The decision was made and the future major leaguer became a pitcher. He excelled and progressed. Eventually, he developed a sore arm. He had been a hitting star in high school, a mere eight to ten years ago. Not exactly another lifetime. Why not make him into a hitter once again? It can't be that hard.
It isn't hard, it's impossible. Hitting in high school is analogous to the few words that Genie acquired before she was locked away in that room. It is the right start but that start must be built on before it is too late. The sore-armed pitcher's ability to hit is like Genie's ability to talk; it is rudimentary at best, and rudimentary never makes it in the big leagues.
So each year big-league pitchers get sore arms that end their careers, and no one ever contemplates converting them into hitters because everyone involved in major league baseball knows it can't be done. The pitchers themselves know it. Their coaches know it, and the managers know it. Their general managers, the team owners, and even the fans know it.
And Michael Jordan was not a hitting star in high school. He played basketball in high school. What kind of chance did he have to learn to hit major league pitching? As the sports cliché goes, he had two chances: remote and none. The smart money was on none.
Yet whenever baseball fans have been confronted with this concept, they have been skeptical. Can their heroes all be that human? Is it really true that no one ever has learned to hit after the mid-twenties?
Then they all ask the same questions. What about Babe Ruth? Didn't he switch from being a pitcher to being a hitter when he was already well into his career? The fact is that hedidn't. The Babe was probably the greatest baseball player of all time. He had both pitching and hitting records that stood for over thirty years. Not only did he hit sixty home runs in a single season and seven hundred fourteen in his career, he also had a lifetime batting average of .342. Only Ted Williams has managed to compile that high a lifetime average in the last fifty years, at .344. As a pitcher, the Babe won ninety-four games and lost only forty-six for a career winning percentage of .671. He won over twenty games in both 1916 and 1917. His record of consecutive shutout innings pitched in the 1918 World Series lasted longer than his record of most home runs in a season, before it was broken by Roger Maris's Yankee teammate, Hall of Famer Whitey Ford. Both records were broken the same year--1961. Maris hit his sixty-one home runs during the regular season, and Ford pitched his shutout innings during the World Series. The home-run record had been set in 1927; the pitching record in 1918.
In 1920, when the Babe hit fifty-four home runs, he actually hit more home runs than any team in either the American or the National League. The number two home-run hitter in the American League that year was fellow Hall of Famer George Sisler of the St. Louis Browns, who hit a career high of nineteen round-trippers. Only ten other American League players hit ten or more home runs that year, and two teams had no player who even managed to hit ten homers.
That season (1920), Ruth hit almost fifteen percent of all the home runs in the American League. For Maris to have accomplished a similar feat the year he broke Ruth's one-season home-run record (1961), he would have had to hit over two hundred home runs. Instead, he managed only sixty-one, which represented less than a measly four percent of league totals or, relatively speaking, only about one-fourth of the percentage that the Babe managed in a single season. Ain't statistics great? The Babe still holds several records, including lifetime slugging percentage and lifetime ratio of home runs per times at bat.
No question about it, he was great. But the Babe did not actually switch from pitching to hitting. Ruth's first full season in the major leagues was 1915, when he was twenty years old. He pitched in thirty-two games and had a record of eighteen wins and eight losses. That year he played in forty-two games, including ten in which he did not pitch but in which he did hit. He hit .315 and knocked out four home runs. The league leader in home runs that year was Braggo Roth, who hit only seven while splitting the season between the Chicago White Sox and the Cleveland Indians. In order to smack three more home runs, Roth came to bat over four times more than Ruth did. The next year, Ruth pitched in forty-four games and had a record of twenty-three wins and twelve losses. He hit in sixty-seven games, batting .272. In 1917, his third year in the majors, he was twenty-two years old and hit .325; and by the time he was twenty-three he pitched in only twenty games, compiling a record of thirteen and seven, but played in a total of ninety-five games. That year he hit .300 and led the league in home runs with eleven. He played in fewer than one hundred games and in fact played fewer games than anyone who ever led the league in home runs. The next year (1919), his last as a Boston Red Sox, he again led the league with an unprecedented twenty-nine round-trippers. The rest of his team managed only four that entire year. Alas, Babe Ruth did not start learning to hit at age twenty-three. By then he had been an accomplished major league hitter for three full seasons. He had never had to decide whether to hit or not to hit. He always hit. In 1919, the decision was made to pitch or not to pitch. He chose to hit.
There are two other players that true baseball aficionados suggest as having made a late-life transition from pitching to hitting. The first was Babe Ruth's one-time Boston Red Sox teammate Smokey Joe Wood. Wood came up as a pitcher and only batted in games he pitched. In 1912 he won thirty-four games and lost only five. During the season he won sixteen straight games and then won three games during the World Series. Not a bad season. In 1915, the year the Babe made the team, Smokey Joe won fifteen and lost only five, leading the American League in win-loss percentage and earned run average; but his arm caused him so much pain that season that he could no longer pitch. Three years later he made a comeback as an outfielder for the Cleveland Indians, and in 1921, in sixty-six games, he hit .366. Joe Wood was twenty-six when his arm gave out. Baseball lore traces Wood's bad arm back to the spring of 1913 when he slipped fielding a ground ball on wet grass and fractured the thumb on his right (pitching) hand. Wood always thought that was the root cause of his problem. He was not certain whether he also hurt his shoulder in the fall or whether he injured it by coming back too soon and putting an abnormal strain on the joint. There were no MRIs back then, and no one specialized in sports medicine. In either case, he wound up with shoulder pain whenever he pitched.
So you'd think Wood must have learned to hit a baseball after the window of opportunity was supposed to be closed. Anice try, but in his eight years as a major league pitcher, Wood averaged .241 as a batter. As a full-time hitter he averaged only some forty points higher. He may have further developed his skills as a hitter when he switched from full-time pitcher to full-time hitter, and he may well have perfected them then, but he already had these skills. The year (1912) he had won thirty-four games as a pitcher, he had hit .290.
The other candidate for the legend of learning to hit late is Francis "Lefty" O'Doul. True believers would have it that Lefty started unsuccessfully as a pitcher, returned to the minor leagues and became a position player, struggled to learn to hit, and finally reached the majors at age thirty-one as a bona fide slugger.
Unfortunately, it is not really true. Not in the way the legend would have you believe. O'Doul did make it as a hitter in the majors in 1928 at the age of thirty-one and then played seven full seasons, putting together a lifetime batting average of .349, an average topped only by Ty Cobb (.367), Rogers Hornsby (.358), and Shoeless Joe Jackson (.356). Not bad for an ex-pitcher. In 1929, playing for the Philadelphia Phillies, O'Doul led the National League in batting (.388) and set a National League record for hits in one season (.254) that still stands.
But, alas, he did not begin as a pitcher, per se. He started off his major league career in 1919 and in the first three seasons played in all forty games, but he pitched in only eleven of those games, playing outfield or pinch-hitting in the others. He returned to the minors when he was twenty-six, playing for the San Francisco Seals. His first year there, when he concentrated primarily on hitting, he just missed winning the Pacific Coast League batting title with an average of .392. Over the next three years, with pitching behind him, he averaged two hundred seventy hits a season.
So much for the legend. Lefty O'Doul was always a position player and in his mid-twenties, when he gave up pitching, immediately improved as a hitter. And he was in his mid-twenties, not his thirties. His late appearance in the majors was related to the structure and economics of baseball in the 1920s, not Lefty O'Doul's limitations as a hitter.
The reverse switch is far more common. Players who start out as position players have become successful pitchers even at the age of thirty, long after their careers began even. Hal Jeffcoat played center field for the Chicago Cubs for half a dozen seasons before he first started pitching at age thirty. He then pitched for six seasons in the majors, winning thirty-nine and losing thirty-seven. Jack Harshman hit forty-nine home runs in the minors one year but couldn't hit in the majors. He switched to pitching and made it to the big leagues for good at age twenty-seven, winning sixty-nine games over his nine-year career.
Then there is Bob Lemon. He made the majors in 1941 as an outfielder and third baseman, and became a pitcher in 1946 at the age of twenty-five. Lemon pitched his way into the Hall of Fame.
Baseball is statistics, and the glory of statistics is that they can lead to more statistics. Statistics galore. There is some information that can be gleaned directly from an analysis of baseball statistics that confirms that hitting skill is governed at least in part by a critical period. In 1994 Robert Schulz and a group of coworkers from the Department of Psychiatry and the Center for Urban and Social Research at the University of Pittsburgh studied the relationship between age and performance among baseball players. They analyzed the lifetime performance data of two hundred thirty-five major league hitters who were playing in the major leagues in 1965, to determine the age of peak hitting abilities and age-performance relationships. To no one's surprise, they found that performance in hitting improves rapidly after the age of nineteen and peaks around age twenty-seven. This is as true of Hall of Famers as it is of benchwarmers. In addition, the performance of the best hitters is better than that of less able players (judged by career totals) even at a very early age. This, too, is not surprising.
There were, however, a couple of interesting results. The primary difference between the best players and the others was that the performance of such elite players remained at peaklevel for more years and declined more slowly. One or two good years at the peak does not a Hall of Famer make. The biggest surprise was that hitting ability, as judged by performance and not promise of performance, improved very little after fifteen hundred at bats. And as all fans know from bitter experience, less able players never catch up to the better players, no matter how hard they work and how long they play. In other words, the gains derived from years of experience become marginal over time. And over those years, the brain ages. It takes four to six years for most players to acquire sufficient experience, or until they are somewhere around age twenty-six. There is no coincidence in that.
The case of Jim Thorpe is interesting here. As soon as he was stripped of his Olympic medals, Thorpe turned to baseball. It was virtually the only professional sport around. He started to play baseball seriously in 1913 when he was already twenty-six years old. He never even got his fifteen hundred appearances at bat in his six short seasons in the majors. It is possible that he may still have been learning in his last season, when at age thirty he had his best year and hit .327 in sixty games. We'll never know for sure. It could have been little more than the baseball equivalent of statistical scatter: a few more seeing-eye ground balls that made it into the outfield or a few more leg hits. Take away five of each and he would have hit about fifty points lower. Ten more hits doesn't prove that he learned how to hit. Only time and a few more seasons would have told. But he quit baseball and went back to running with a football.
So why do teams have all these batting coaches? Not to make players who are already in the big leagues better hitters. If that were the reason, the data suggest they should all look for new jobs. The primary role of batting coaches is to try to maintain peak performance and to slow decline, and give some supportive psychotherapy during the bad times.
Do batting instructors help? I know of no statistical theory that suggests that they do. Who was Shoeless Joe Jackson'shitting instructor? Or Babe Ruth's? Ted Williams's? Mostly their own brains during their windows of opportunity. And none of them ever became renowned for teaching his own skills to others.
Right-handed hitters hit left-handed pitchers better than right-handed pitchers, and vice versa, as noted above. Sometimes the differences are so great that players are platooned and only play against pitchers who pitch from the opposite side, so to speak. So why not make them into switch-hitters? That would give the batting coaches something to do. These players have made the big leagues. They already know how to hit. There are batting coaches around who can teach them how to hit. What's the big deal?
Training other neurons to see the ball is the big deal, and another series of experiments conducted by Hubel and Weisel explains why. Hitting is all visual-motor skill with an emphasis on the visual. Left-handed hitters see the ball with different brain cells than do right-handed hitters. They have trained different cells--selected different cells. To become a switch-hitter means that new cells must be self-taught to acquire those skills necessary to hit. Can this be done?
In the early 1980s, Hubel and Weisel studied the early development of cats and showed that most of the nerve cells in a cat's visual cortex can respond to light coming from either eye. These "binocular" cells make up some eighty percent of the cells in the normal visual cortex. The other twenty percent respond to only one eye and are "monocular" cells. However, this can all be changed. If one eye was sutured shut, almost all of the cells became monocular and even remained so later in life after the eye was opened. If the sutured eye was opened later in infancy and the other eye was then closed, the cells remained monocular but now they were monocular to the other eye. This is another example of plasticity in the nervous system, but plasticity with a time frame. The ability of the brain to select cells to perform a function is determined by the timing of the environmental exposure. Recruiting visual cells to respond to particular binocular cues can only be done if those cues are presented tothose cells at the right time during the development of the brain. By the time players are trying to learn to hit in the majors it's too late to select new cells to take over the job.
Switch-hitters like Mickey Mantle are not born that way, but they usually get that way by early adolescence or so--at the latest.
Before you start feeling sorry for ball players and conceding that their limited careers justify their overblown salaries, you should ask yourself if they are unique. A number of researchers over the last seventy or more years have studied the age-related rise and fall of artistic, intellectual, and athletic performance. Age is a factor in all areas and the age-performance relationship is similar in all fields. Productivity in all these fields increases rapidly to a definite peak, after which there is a gradual decline. In artistic and scientific domains, productivity typically begins in the twenties, peaks in the thirties or early forties, and then begins to decline gradually.
But there are also differences among the general fields of endeavor. Productivity in mathematics, physics, and lyric poetry tends to peak some time in the late twenties. Novelists, philosophers, and historians peak in their late forties and early fifties. Those fields in which people peak earlier are typified by steeper declines than those in which they peak later and decline more gradually. This, too, is true of baseball. Pitchers, on the average, peak two years later and have careers that last two years longer than those of hitters.
Despite all of this, Michael Jordan was given his chance and he made the effort. He went to spring training with the White Sox and played in thirteen exhibition games. In twenty appearances at the plate, he managed to hit only three weak singles for an anemic batting average of .150. The White Sox then sent him to play for their Class Double A farm club, the Birmingham Barons. Class Triple A is the highest level in the minor leagues and is where the best minor league players and future prospects play. Double A Birmingham is one step below that. Michael Jordan played the full season for the Barons. His final batting average was a dismal .202. This was better than he hadmanaged during spring training, but it was still the lowest batting average of any regular player in the entire Southern League, and many of Jordan's hits were leg hits based on his quickness and speed.
Outfielder Michael Jordan managed a grand total of only three home runs and struck out 28.4 percent of the time. In baseball terms, his strikeout average (.284) was higher than his batting average (.202). He was still fast. He stole thirty bases, fifth best in the league, but he was caught stealing eighteen times. His record the next winter in the instructional league was not much better. It was time to go back to basketball.
It had made about as much sense for Michael Jordan to try to learn to hit for the first time at age thirty-one as it would have for a sore-armed, thirty-year-old, left-handed pitcher to try to learn to pitch right-handed.
Absurd? Perhaps. But what is handedness other than an acquired nonverbal motor skill? About ninety percent of the population is right-handed. Those who are right-handed not only prefer to use the right hand but are far more skillful in the use of that hand for a wide variety of learned skilled activities, including writing, drawing, and, it goes without saying, throwing. This difference in function is not paralleled by any difference in structure, as the two hands and arms remain perfect mirrors of each other. Thus, handedness has no structural basis but is dependent entirely on brain function. Such right-handed preference is universal; it is characteristic of the entire family of humans.
Given that universal preference, why does some ten to twelve percent of the population come up left-handed, generation after generation? Some left-handers, of course, become so pathologically, or through disease. But was Babe Ruth a pathological left-hander? We should all have such brain damage!
Handedness is inherited, at least in part. The most attractive genetic theory was proposed by British psychologist Marian Annett in 1985. She proposed that genetic variations in handedness could be due to the function of a single gene, which can exist in either of two alternates, or alleles. The dominant alleleproduces a right shift in those who possess it. This would account for the fact that the distribution of handedness in this population is heavily biased toward right-handedness. Some tiny fraction of this population will be left-handed, due to environmental influences, but that factor is not enough to explain the ten percent incidence of left-handedness in the population as a whole.
The recessive allele does not cause left-handedness but results in an absence of any bias toward handedness, so either side can be selected to become dominant. This explains why the children of two left-handed parents are themselves equally divided into left- and right-handers, and also explains why left-handers show a very mixed pattern of asymmetry on other measures, such as eye dominance, footedness, and even fingerprints.
But when is handedness acquired? Quite early in life, it seems, and as expected, here, too, there is a window of opportunity. It is not as obvious as the critical period for speech but it is just as definite. Adults who have a stroke resulting in severe paralysis of their dominant right hand do learn to use their left hand for skills they previously performed with their right hands. They can learn to write, to use a fork, and to perform a wide variety of tasks. However, these tasks are never performed as skillfully as they were with the dominant right hand.
Although the studies haven't been as numerous as those for speech, the rules of recovery from hemiplegia (with switching of dominance for handedness) parallel those rules that apply to speech. The brain, as the basis of genetic inheritance and environmental input, selects a dominant hemisphere for handedness. If this hemisphere is injured early in life, the brain can select the opposite hemisphere and switch dominance. After puberty this becomes difficult and in adults it cannot be done. Abilities can be acquired by the noninjured hand and hemisphere but true skilled handedness cannot.
So a pitcher with a sore dominant arm cannot learn to pitch skillfully with his other arm. He is never even given the opportunity. He also cannot learn to hit and is not given the chance to do that, either.
Michael Jordan could not learn to hit but was given the chance. Why? That may have been a business decision. It certainly was not a neurological one. The Barons set a franchise attendance record in 1994: 467,867 people paid to see them play. The rest of the league also prospered as attendance swelled everywhere Michael and the Barons played.
But reality is reality. A batting average like Jordan's does not a major leaguer make. Michael Jordan summed it up in his second retirement statement: "As a thirty-two-year-old minor leaguer who lacks the benefit of valuable baseball experience during the past fifteen years, I am no longer comfortable that there is meaningful opportunity to continue my improvement at a satisfactory pace." The critical period had passed and even he recognized that fact. All that was left for him was to return to the NBA and be a superstar once again.
Michael's achievements following his return to the NBA demonstrated that he had lost none of his athletic skills. Clearly, whatever problems he had hitting could not be attributed to an overall decrement in his athletic abilities. He played briefly at the end of the 1994-1995 season, but his real comeback was staged during the 1995-1996 season. He once again led the NBA in scoring, and led the Chicago Bulls to the best single-season record in the history of the NBA (seventy-two wins and ten losses) and to the NBA championship. Along the way he picked up all three Most Valuable Player awards (All-Star game, regular season, and final series of the championship playoffs). Not bad for a guy who couldn't hit a baseball. Incidentally, this "triple crown" had been achieved only once before, when New York Knicks center Willis Reed was voted all three awards in 1970.
For those of us who have retained our personal fantasies of someday becoming superstars, the sad truth is that Jordan's window of opportunity may have been gone long before he was thirty. And, by analogy, so may have ours. There are no scientific studies of windows of opportunity in baseball players, but the appropriate studies have been done in violinists. Becoming an accomplished violinist requires motor skills that must bemastered by the brain. Instead of learning to recognize the spin on a speeding baseball and translate that into a muscular response, playing a violin consists of the brain learning to give rapid and complex directions to the fingers of both hands in response to visual or aural clues.
Scientific investigation of the process showed pretty much what professional musicians have always known. In order to become a violin virtuoso, a musician has to start playing before the age of thirteen. Not at fourteen, not at fifteen, but before the age of thirteen. That's a pretty slim window of opportunity.
How was that shown? Edward Taub of the University of Alabama at Birmingham, along with two colleagues from Germany, studied magnetic images of the brain in violinists. This technique shows which neuronal circuits are activated during a specific activity. They found that those fiddlers who started playing early in life (age thirteen or younger) activated larger and more complex circuits in their brains than those who started learning to play their instrument later in life. The magnetic images of those who had started at age three or four looked no different than those who started at eleven or twelve. After that things changed. The abrupt change occurred between the ages of twelve and thirteen. Those who hadn't started by thirteen never caught up. The circuits they activated were smaller, less complex, and more restricted. The time frame during which their brains could be guided to select those circuits had come and gone and left them forever without that ability.
No one wanted Michael Jordan to become a virtuoso violinist. Had he tried and failed, no one would have cared very much. At his age, though, what he had wanted to do was equally impossible. Because he was Michael, we hoped that he could do it. We should have known better. Perhaps, deep down in our hearts, we did.
© 1996 by Harold L. Klawans, M.D.