STRENUOUS PHYSICAL EXERCISE CAUSES THE BODIES OF healthy people to get stronger. The exercise can be focused on very specific parts or systems of the body. For example, a weight lifter who does biceps curls but nothing else will de- velop large biceps but little else. Marathon runners focus on developing their cardiovascular system, with the result that they often have extraordinary endurance, powerful hearts and lungs, and the torsos of ninety-eight pound weaklings, with arms and legs like rubber bands. But body building does work, and it works the same way in every case, from weight lifters to distance runners: select that part of your body you want to grow in size and strength and use it. And, most im- portant, use it against increasingly arduous challenges, for it is the steady increase in difficulty, whether through lifting ever heavier weights or running longer or faster, that stimulates the target muscle to grow.
Now, imagine that all this is true of the brain as well as the body. Substituting "brain" for "body," the above paragraph states, in effect, that strenuous intellectual exercise causes the brains of healthy people to get stronger. This brain-building
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GETTING SMART: BRAIN EXPANSION THROUGH STIMULATION exercise can be focused on very specific parts of the brain - simply select that part (or quality) of the brain you want to grow in size and strength and use it, against increasingly diffi- cult challenges.
Imagine further that just as we now have devices to stimu- late the body to healthy growth, and to speed up the slow process of body growth - barbells, Nautilus and Universal machines, treadmills and bicycles, rowing and cross-country skiing machines - so we also have devices to stimulate brain growth and to speed up the process of brain building enor- mously.
"Nice pipe dream," I hear someone scoffing, "but pure fantasy - everyone knows that the anatomy and physiology of the brain simply can't be changed by sensory stimulation or experience."
The scoffer is voicing what was, until recently, an undis- puted scientific truth. Long ago scientists established that ab- solute brain size has little to do with intelligence - when they weighed brains during autopsies, they found that the brains of idiots were sometimes larger than those of great intellects, and genuises at times had comparatively small brains.
And if brain size seemed irrelevant to intelligence, the idea that either brain size or intelligence could be changed by expe- riences seemed absurd. First, it was an accepted fact that in- telligence was genetically determined - people with high intelligence are born that way, and while life experiences may nurture or thwart that inborn genetic potential, experiences can't increase or decrease that innate intelligence; that is, ex- periences can't change the structure of the actual brain. Freud and his followers had demonstrated clearly that experiences we have in early childhood largely mold our characters, but whether someone born with a brain of a specific anatomical structure goes through experiences that mold him into a bold, creative leader or timid follower, that person's brain anatomy and chemistry remain unchanged.
And finally, it was commonly accepted that the growth in the total number of brain cells we have is completed by age two. As techniques of microscopic examination of brain cells
2
GETTING SMART:
BRAIN EXPANSION
THROUGH STIMULATION
FROM PUMPING IRON TO PUMPING IDEAS
STRENUOUS PHYSICAL EXERCISE CAUSES THE BODIES OF healthy people to get stronger. The exercise can be focused on very specific parts or systems of the body. For example, a weight lifter who does biceps curls but nothing else will de- velop large biceps but little else. Marathon runners focus on developing their cardiovascular system, with the result that they often have extraordinary endurance, powerful hearts and lungs, and the torsos of ninety-eight pound weaklings, with arms and legs like rubber bands. But body building does work, and it works the same way in every case, from weight lifters to distance runners: select that part of your body you want to grow in size and strength and use it. And, most im- portant, use it against increasingly arduous challenges, for it is the steady increase in difficulty, whether through lifting ever heavier weights or running longer or faster, that stimulates the target muscle to grow.
Now, imagine that all this is true of the brain as well as the body. Substituting "brain" for "body," the above paragraph states, in effect, that strenuous intellectual exercise causes the brains of healthy people to get stronger. This brain-building
24
GETTING SMART: BRAIN EXPANSION THROUGH STIMULATION exercise can be focused on very specific parts of the brain - simply select that part (or quality) of the brain you want to grow in size and strength and use it, against increasingly diffi- cult challenges.
Imagine further that just as we now have devices to stimu- late the body to healthy growth, and to speed up the slow process of body growth - barbells, Nautilus and Universal machines, treadmills and bicycles, rowing and cross-country skiing machines - so we also have devices to stimulate brain growth and to speed up the process of brain building enor- mously.
"Nice pipe dream," I hear someone scoffing, "but pure fantasy - everyone knows that the anatomy and physiology of the brain simply can't be changed by sensory stimulation or experience."
The scoffer is voicing what was, until recently, an undis- puted scientific truth. Long ago scientists established that ab- solute brain size has little to do with intelligence - when they weighed brains during autopsies, they found that the brains of idiots were sometimes larger than those of great intellects, and genuises at times had comparatively small brains.
And if brain size seemed irrelevant to intelligence, the idea that either brain size or intelligence could be changed by expe- riences seemed absurd. First, it was an accepted fact that in- telligence was genetically determined - people with high intelligence are born that way, and while life experiences may nurture or thwart that inborn genetic potential, experiences can't increase or decrease that innate intelligence; that is, ex- periences can't change the structure of the actual brain. Freud and his followers had demonstrated clearly that experiences we have in early childhood largely mold our characters, but whether someone born with a brain of a specific anatomical structure goes through experiences that mold him into a bold, creative leader or timid follower, that person's brain anatomy and chemistry remain unchanged.
And finally, it was commonly accepted that the growth in the total number of brain cells we have is completed by age two. As techniques of microscopic examination of brain cells
MEGABRAIN
were developed, scientists made the discovery that apparently brain cells, called neurons, do not reproduce themselves. In! other words, the absolute number of one's brain cells is deter- mined from infancy, and no matter what experiences or stimu-; lations the brain receives, the number of brain cells could not increase. In this the neurons are unlike the other cells of the body, which can reproduce many times - if a muscle cell is damaged or destroyed it can be replaced by a new cell; it is i this capability that is exploited by body builders, whose large muscles are the result of the repair and regeneration of muscle cells damaged or destroyed by strenuous exercise. No wonder scientists found it hard to conceive of any way brain structure and function could be changed by sensory input. No wonder our scoffer finds it hard to believe in brain machines that can be used like body-building devices, stimulating the brain and triggering brain growth and increases in mental powers.