The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science

by Norman Doidge

Other children, like little pirates, wear eye patches on their left eyes and diligently trace intricate lines, squiggles, and Chinese letters with pens. The eye patch forces visual input into the right eye, then to the side of the brain where they have a problem. These children are not simply learning to write better. Most of them come with three related problems: trouble speaking in a smooth, flowing way, writing neatly, and reading. Barbara, following Luria, believes that all three difficulties are caused by a weakness in the brain function that normally helps us to coordinate and string together a number of movements when we perform these tasks.

Bueno?

At the Arrowsmith School this boy’s brain exercises involved tracing complex lines to stimulate his neurons in the weakened premotor area. Barbara has found that tracing exercises improve children in all three areas—speaking, writing, and reading.

The irony of this new discovery is that for hundreds of years educators did seem to sense that children’s brains had to be built up through exercises of increasing difficulty that strengthened brain functions. Up through the nineteenth and early twentieth centuries a classical education often included rote memorization of long poems in foreign languages, which strengthened the auditory memory (hence thinking in language) and an almost fanatical attention to handwriting, which probably helped strengthen motor capacities and thus not only helped handwriting but added speed and fluency to reading and speaking. Often a great deal of attention was paid to exact elocution and to perfecting the pronunciation of words. Then in the 1960s educators dropped such traditional exercises from the curriculum, because they were too rigid, boring, and “not relevant.” But the loss of these drills has been costly; they may have been the only opportunity that many students had to systematically exercise the brain function that gives us fluency and grace with symbols. For the rest of us, their disappearance may have contributed to the general decline of eloquence, which requires memory and a level of auditory brain-power unfamiliar to us now.

Holy shit

Merzenich and Jenkins also found that as neurons are trained and become more efficient, they can process faster. This means that the speed at which we think is itself plastic.

Finally, Merzenich discovered that paying close attention is essential to long-term plastic change. In numerous experiments he found that lasting changes occurred only when his monkeys paid close attention. When the animals performed tasks automatically, without paying attention, they changed their brain maps, but the changes did not last. We often praise “the ability to multitask.” While you can learn when you divide your attention, divided attention doesn’t lead to abiding change in your brain maps.

In 1996 Merzenich, Paula Tallal, Bill Jenkins, and one of Tallal’s colleagues, psychologist Steve Miller, formed the nucleus of a company, Scientific Learning, that is wholly devoted to using neuroplastic research to help people rewire their brains.

Fast ForWord is the name of the training program they developed for language-impaired and learning-disabled children. The program exercises every basic brain function involved in language from decoding sounds up to comprehension—a kind of cerebral cross-training.

Whenever a goal is achieved, something funny happens: the character in the animation eats the answer, gets indigestion, gets a funny look on its face, or makes some slapstick move that is unexpected enough to keep the child attentive. This “reward” is a crucial feature of the program, because each time the child is rewarded, his brain secretes such neurotransmitters as dopamine and acetylcholine, which help consolidate the map changes he has just made. (Dopamine reinforces the reward, and acetylcholine helps the brain “tune in” and sharpen memories.)

Heath showed that when our pleasure centers fire, it is more difficult for the nearby pain and aversion centers to fire too. Things that normally bother us don’t. We love being in love not only because it makes it easy for us to be happy but also because it makes it harder for us to be unhappy.

In grief, we learn to live without the one we love, but the reason this lesson is so hard is that we first must unlearn the idea that the person exists and can still be relied on.

Walter J. Freeman, a professor of neuroscience at Berkeley, was the first to argue that there is a connection between love and massive unlearning. He has assembled a number of compelling biological facts that point toward the conclusion that massive neuronal reorganization occurs at two life stages: when we fall in love and when we begin parenting.

Freeman believes that when we commit in love, the brain neuromodulator oxytocin is released, allowing existing neuronal connections to melt away so that changes on a large scale can follow.

Oxytocin is sometimes called the commitment neuromodulator because it reinforces bonding in mammals. It is released when lovers connect and make love—in humans oxytocin is released in both sexes during orgasm—and when couples parent and nurture their children. In women oxytocin is released during labor and breast-feeding.

In male mammals a closely related neuromodulator called vasopressin is released when they become fathers.

Whereas dopamine induces excitement, puts us into high gear, and triggers sexual arousal, oxytocin induces a calm, warm mood that increases tender feelings and attachment and may lead us to lower our guard.

The rewiring of our pleasure systems, and the extent to which our sexual tastes can be acquired, is seen most dramatically in such perversions as sexual masochism, which turns physical pain into sexual pleasure. To do this the brain must make pleasant that which is inherently unpleasant, and the impulses that normally trigger our pain system are plastically rewired into our pleasure system.

Based on his work with plasticity, Taub has discovered a number of training principles: training is more effective if the skill closely relates to everyday life; training should be done in increments; and work should be concentrated into a short time, a training technique Taub calls “massed practice,” which he has found far more effective than long-term but less frequent training.

In all of medicine, few conditions are as terrifying as a stroke, when a part of our brain dies. But Taub has shown that even in this state, as long as there is adjacent living tissue, because that tissue is plastic, there may be hope that it might take over.

The agony of the obsessive worrier is that whenever something bad is remotely possible, it feels inevitable.

After a patient has acknowledged that the worry is a symptom of OCD, the next crucial step is to refocus on a positive, wholesome, ideally pleasure-giving activity the moment he becomes aware he is having an OCD attack. The activity could be gardening, helping someone, working on a hobby, playing a musical instrument, listening to music, working out, or shooting baskets. An activity that involves another person helps keep the patient focused. If OCD strikes while the patient is driving a car, he should be ready with an activity like a book on tape or a CD. It is essential to do something, to “shift” the gear manually.

By refocusing, the patient is learning not to get sucked in by the content of an obsession but to work around it.

Each moment they spend thinking of the symptom—believing that germs are threatening them—they deepen the obsessive circuit. By bypassing it, they are on the road to losing it.

In chapter 3, “Redesigning the Brain,” we learned two key laws of plasticity that also underlie this treatment. The first is that Neurons that fire together wire together. By doing something pleasurable in place of the compulsion, patients form a new circuit that is gradually reinforced instead of the compulsion. The second law is that Neurons that fire apart wire apart. By not acting on their compulsions, patients weaken the link between the compulsion and the idea it will ease their anxiety. This delinking is crucial because, as we’ve seen, while acting on a compulsion eases anxiety in the short term, it worsens OCD in the long term.

Normal pain, “acute pain,” alerts us to injury or disease by sending a signal to the brain, saying, “This is where you are hurt—attend to it.” But sometimes an injury can damage both our bodily tissues and the nerves in our pain systems, resulting in “neuropathic pain,” for which there is no external cause. Our pain maps get damaged and fire incessant false alarms, making us believe the problem is in our body when it is in our brain. Long after the body has healed, the pain system is still firing and the acute pain has developed an afterlife.

Wall and Melzack’s theory asserted that the pain system is spread throughout the brain and spinal cord, and far from being a passive recipient of pain, the brain always controls the pain signals we feel. Their “gate control theory of pain” proposed a series of controls, or “gates,” between the site of injury and the brain. When pain messages are sent from damaged tissue through the nervous system, they pass through several “gates,” starting in the spinal cord, before they get to the brain. But these messages travel only if the brain gives them “permission,” after determining they are important enough to be let through. If permission is granted, a gate will open and increase the feeling of pain by allowing certain neurons to turn on and transmit their signals. The brain can also close a gate and block the pain signal by releasing endorphins, the narcotics made by the body to quell pain.

High vs low pain tolerance?

The gate theory led to new treatments for blocking pain. Wall coinvented “transcutaneous electrical nerve stimulation,” or TENS, which uses electric current to stimulate neurons that inhibit pain, helping in effect to close the gate. The gate theory also made Western scientists less skeptical of acupuncture, which reduces pain by stimulating points of the body often far from the site where the pain is felt. It seemed possible that acupuncture turns on neurons that inhibit pain, closing gates and blocking pain perception.

The discovery of pain maps has also led to new approaches to surgery and the use of pain medication. Postoperative phantom pain can be minimized if surgical patients get local nerve blocks or local anesthetics that act on peripheral nerves before the general anesthetic puts them to sleep. Pain-killers, administered before surgery, not just afterward, appear to prevent plastic change in the brain’s pain map that may “lock in” pain.

Ramachandran and Eric Altschuler have shown that the mirror box is effective on other nonphantom problems, such as the paralyzed legs of stroke patients. Mirror therapy differs from Taub’s in that it fools the patient’s brain into thinking he is moving the affected limb, and so it begins to stimulate that limb’s motor programs. Another study showed that mirror therapy was helpful in preparing a severely paralyzed stroke patient, who had no use of one side of the body, for a Taub-like treatment. The patient recovered some use of his arm, the first occasion in which two novel plasticity-based approaches—mirror therapy and CI-like therapy—were used in sequence.

What is a trance but a closing down of the gates of pain within us?

great science can still be done with elegant simplicity.

Pascual-Leone found that both groups learned to play the sequence, and both showed similar brain map changes. Remarkably, mental practice alone produced the same physical changes in the motor system as actually playing the piece.

prisoners in isolation often fall apart mentally because the use-it-or-lose-it brain needs external stimulation to maintain its maps.

One reason we can change our brains simply by imagining is that, from a neuroscientific point of view, imagining an act and doing it are not as different as they sound. When people close their eyes and visualize a simple object, such as the letter a, the primary visual cortex lights up, just as it would if the subjects were actually looking at the letter a. Brain scans show that in action and imagination many of the same parts of the brain are activated. That is why visualizing can improve performance.

In an experiment that is as hard to believe as it is simple, Drs. Guang Yue and Kelly Cole showed that imagining one is using one’s muscles actually strengthens them. The study looked at two groups, one that did physical exercise and one that imagined doing exercise. Both groups exercised a finger muscle, Monday through Friday, for four weeks. The physical group did trials of fifteen maximal contractions, with a twenty-second rest between each. The mental group merely imagined doing fifteen maximal contractions, with a twenty-second rest between each, while also imagining a voice shouting at them, “Harder! Harder! Harder!” At the end of the study the subjects who had done physical exercise increased their muscular strength by 30 percent, as one might expect. Those who only imagined doing the exercise, for the same period, increased their muscle strength by 22 percent. The explanation lies in the motor neurons of the brain that “program” movements. During these imaginary contractions, the neurons responsible for stringing together sequences of instructions for movements are activated and strengthened, resulting in increased strength when the muscles are contracted.

In the mid-1990s, at Duke University, Miguel Nicolelis and John Chapin began a behavioral experiment, with the goal of learning to read an animal’s thoughts. They trained a rat to press a bar, electronically attached to a water-releasing mechanism. Each time the rat pressed the bar, the mechanism released a drop of water for the rat to drink. The rat had a small part of its skull removed, and a small group of microelectrodes were attached to its motor cortex. These electrodes recorded the activity of forty-six neurons in the motor cortex involved in planning and programming movements, neurons that normally send instructions down the spinal cord to the muscles. Since the goal of the experiment was to register thoughts, which are complex, the forty-six neurons had to be measured simultaneously. Each time the rat moved the bar, Nicolelis and Chapin recorded the firing of its forty-six motor-programming neurons, and the signals were sent to a small computer. Soon the computer “recognized” the firing pattern for bar pressing. After the rat became used to pressing the bar, Nicolelis and Chapin disconnected the bar from the water release. Now when the rat pressed the bar, no water came. Frustrated, it pressed the bar a number of times, but to no avail. Next the researchers connected the water release to the computer that was connected to the rat’s neurons. In theory, now, each time the rat had the thought “press the bar,” the computer would recognize the neuronal firing pattern a...

Nicolelis and Chapin hoped their work would help patients with various kinds of paralysis. That happened in July 2006, when a team led by neuroscientist John Donoghue, from Brown University, used a similar technique with a human being. The twenty-five-year-old man, Matthew Nagle, had been stabbed in the neck and paralyzed in all four limbs by the resulting spinal cord injury. A tiny, painless silicone chip with a hundred electrodes was implanted in his brain and attached to a computer. After four days of practice he was able to move a computer cursor on a screen, open e-mail, adjust the channel and volume control on a television, play a computer game, and control a robotic arm using his thoughts.

Pascual-Leone has profound observations about how neuroplasticity, which promotes change, can also lead to rigidity and repetition in the brain, and these insights help solve this paradox: if our brains are so plastic and changeable, why do we so often get stuck in rigid repetition? The answer lies in understanding, first, how remarkably plastic the brain is.

He blindfolded people for five days, then mapped their brains with TMS. He found that when he blocked out all light—the road “block” had to be impermeable—the subjects’ “visual” cortices began to process the sense of touch coming from their hands, like blind patients learning Braille. What was most astounding, however, was that the brain reorganized itself in just a few days. With brain scans Pascual-Leone showed that it could take as few as two days for the “visual” cortex to begin processing tactile and auditory signals. (As well, many of the blindfolded subjects reported that as they moved, or were touched, or heard sounds, they began having visual hallucinations of beautiful, complex scenes of cities, skies, sunsets, Lilliputian figures, cartoon figures.)

What it implies is that people learning a new skill can recruit operators devoted to other activities, vastly increasing their processing power, provided they can create a roadblock between the operator they need and its usual function.

We have seen that imagining an act engages the same motor and sensory programs that are involved in doing it. We have long viewed our imaginative life with a kind of sacred awe: as noble, pure, immaterial, and ethereal, cut off from our material brain. Now we cannot be so sure about where to draw the line between them. Everything your “immaterial” mind imagines leaves material traces.

These experiments are not only delightful and intriguing, they also overturn the centuries of confusion that have grown out of the work of the French philosopher René Descartes,

Fucking Descartes

By depicting a mechanistic brain, Descartes drained the life out of it and slowed the acceptance of brain plasticity more than any other thinker.

While we have yet to understand exactly how thoughts actually change brain structure, it is now clear that they do, and the firm line that Descartes drew between mind and brain is increasingly a dotted line.

He was also first to demonstrate that when we form long-term memories, neurons change their anatomical shape and increase the number of synaptic connections they have to other neurons—work for which he won the Nobel Prize in 2000.

Eric Kandel

Each cell in our body contains all our genes, but not all those genes are turned on, or expressed. When a gene is turned on, it makes a new protein that alters the structure and function of the cell. This is called the transcription function because when the gene is turned on, information about how to make these proteins is “transcribed” or read from the individual gene. This transcription function is influenced by what we do and think.

Kandel argues that when psychotherapy changes people, “it presumably does so through learning, by producing changes in gene expression that alter the strength of synaptic connections, and structural changes that alter the anatomical pattern of interconnections between nerve cells of the brain.” Psychotherapy works by going deep into the brain and its neurons and changing their structure by turning on the right genes. Psychiatrist Dr. Susan Vaughan has argued that the talking cure works by “talking to neurons,” and that an effective psychotherapist or psychoanalyst is a “microsurgeon of the mind” who helps patients make needed alterations in neuronal networks.

The first plastic concept Freud developed is the law that neurons that fire together wire together, usually called Hebb’s law, though Freud proposed it in 1888, sixty years before Hebb.

Freud stated that when two neurons fire simultaneously, this firing facilitates their ongoing association. Freud emphasized that what linked neurons was their firing together in time, and he called this phenomenon the law of association by simultaneity. The law of association explains the importance of Freud’s idea of “free association,” in which psychoanalytic patients lie on the couch and “free-associate,” or say everything that comes into their minds, regardless of how uncomfortable or trivial it seems. The analyst sits behind the patient, out of the patient’s sight, and usually says little. Freud found that if he didn’t interfere, many wardedoff feelings and interesting connections emerged in the patient’s associations—thoughts and feelings the patient normally pushed away. Free association is based on the understanding that all our mental associations, even seemingly “random” ones that appear to make no sense, are expressions of links formed in our memory networks. His law of association by simultaneity implicitly links changes in neuronal networks with changes in our memory networks, so that neurons that fired together years before wired together, and these original connections are often still in place and show up in a patient’s free associations.

Freud’s fourth neuroplastic idea helped explain how it might be possible to make unconscious traumatic memories conscious and retranscribe them. He observed that in the mild sensory deprivation created by his sitting out of the patients’ view, and commenting only when he had insights into their problems, patients began to regard him as they had important people in their past, usually their parents, especially in their critical psychological periods. It was as though the patients were reliving past memories without being aware of it. Freud called this unconscious phenomenon “transference” because patients were transferring scenes and ways of perceiving from the past onto the present. They were “reliving” them instead of “remembering” them. An analyst who is out of view and says little becomes a blank screen on which the patient begins to project his transference. Freud discovered that patients projected these “transferences” not only onto him but onto other people in their lives, without being aware of doing so, and that viewing others in a distorted way often got them into difficulty. Helping patients understand their transferences allowed them to improve their relationships. Most important, Freud discovered that transferences of early traumatic scenes could often be altered if he pointed out to the patient what was happening when the transference was activated and the patient was paying close attention. Thus, the underlying neuronal networks, and the associated memories, ...

The right hemisphere generally processes nonverbal communication; it allows us to recognize faces and read facial expressions, and it connects us to other people. It thus processes the nonverbal visual cues exchanged between a mother and her baby. It also processes the musical component of speech, or tone, by which we convey emotion. During the right hemisphere’s growth spurt, from birth until the second year, these functions undergo critical periods. The left hemisphere generally processes the verbal-linguistic elements of speech, as opposed to the emotional-musical ones, and analyzes problems using conscious processing. Babies have a larger right hemisphere, up to the end of the second year, and because the left hemisphere is only beginning its growth spurt, our right hemisphere dominates the brain for the first three years of our lives.