The Brain That Changes Itself

Quotations from Norman Doidge’s, The Brain that Changes Itself:

Cheryl’s problem is that her vestibular aparatus, the sensory organ for the balance system, isn’t working.
p. 2.

The accelerometer, or sensor, in the hat detects movement in two planes. As I nod my head, the movement is translated onto a map on the computer screen that permits the team to monitor it. The same map is projected onto a small array of 144 electrodes implanted in the plastic strip on my tongue. As I tilt forward, electric shocks that feel like champagne bubbles go off on the front of my tongue, telling me that I am bending forward.
p. 6

The first time [Cheryl] put on the hat, the sense of perpetual falling left her-for the first time in five years.
p. 6.

Now comes the second neuroplastic marvel. Cheryl removes the tongue device and takes off the hat. She gives a big grin, stands free with her eyes closed, and doesn’t fall.
p. 7.

Zazetsky’s bulet had lodged in the left hemisphere, at the junction of three major perceptual areas where the temporal lobe (which normally processes sound and language), the occipital lobe (which normally processes visual images), and the parietal lobe (which normally processes spatial relationships and integrates information from different senses) meet. At this junction perceptual input from those three areas is brought together and associated. While Zazetsky could percieve properly, Luria realized he could not relate his different perceptions, or parts of things to wholes. Most important, he had great difficulty relating a number of symbols to one another, as we normally do when we think with words.
p. 34.

The ability to recognize shapes depends on a brain function quite different from those functions required for drawing or seeing colour; it is the same skill that allows some people to excell at games like Where’s Waldo? Women are often better at it than men, which is why men seem to have more difficulty finding things in the refridgerator.
p, 40.

The irony of this discovery [that weak links in brain function can be improved with exercise] 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 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…The 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 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.
pp.41-42

Over the years his labs [which experiment on rats] and others have shown that stimulating the brain makes it grow in almost every conceivable way. Animals raised in enriched environments — surrounded by other animals, objects to explore, toys to roll, ladders to climb, and running wheels — learn better than genetically identical animals that have been reared in impoverished environments. Acetylcholine, a brain chemical essential for learning, is higher in rats trained on difficult spatial problems than in rats trained on simpler problems. Mental training or life in enriched environments increases brain weight by 5 percent in the cerebral cortex of animals and up to 9 percent in areas that the training directly stimulates. Trained or stimulated neurons develop 25 percent more branches and increase their size, the number of connections per neuron, and their blood supply.
p.43

In the crucial experiment, Hubel and Wiesel sewed shut one eyelid of a kitten during its critical [brain development] period, so the eye got no visual stimulation. When they opened this shut eye, they found that the visual areas in the brain map that normally processed input from the shut eye had failed to develop, leaving the kitten blind for life….
When Hubel and Wiesel examined the brain map for that blind eye, they made one more unexpected discovery about plasticity. The part of the kitten’s brain that had been deprived of input from the shut eye did not remain idle. It had begun to process visual input from the open eye, as though the brain didn’t want to waste any “cortical real estate” and had found a way to rewire itself–another indication that the brain is plastic in the critical period.
pp.51-52

They micromapped the hand maps in the brains of several adolescent monkeys, cut a peripheral nerve to the hand, and immediately sewed the two severed ends close together but not quite touching, hoping the many axonal wires in the nerve would get crossed as the nerve regenerated itself. After seven months they remapped the brain. Merzenich assumed they would see a very disturbed, cahotic brain map. Thus, if the nerves for the thumb and the index finger had been crossed, he expected that touching the index finger would generate activity in the map area for the thumb. But he saw nothing of the kind. The map was almost normal.
“What we saw,” says Merzenich, “was absolutely astounding. I couldn’t understand it.” It was *topographically* arranged as though the brain had unshuffled the signals from the crossed nerves.
pp.54-55

Competitive plasticity also explains why our bad habits are so difficult to break or “unlearn.” Most of us think of the brain as a container and learning as putting something in it. When we try to break a bad habit, we think the solution is to put something new into the container. But when we learn a bad habit, it takes over a brain map and prevents the use of that space for “good” habits. That is why “unlearning” is often harder than learning, and why early childhood education is so important–it’s best to get it right early, before the “bad habits” gets the competitive advantage.
p.60

When we perform an activity that requires specific neurons to fire together, they release BDNF (brain-derived neurotrophic factor). This growth factor consolidates the connections between those neurons and helps to wire them together so they fire reliably in the future. BDNF also promotes the growth of the thin fatty coat around every neuron that speeds up the transmission of electrical signals.
During the critical period BDNF turns on the nucleus basalis, the part of our brain that allows us to focus our attention–*and keeps it on, throughout the entire critical period*…It allows map differentiation and change to take place effortlessly.
p.80

“Infants are reared in continuously noisy environments. There is always a din.” White noise is everywhere now, coming from fans in our electronics, air conditioners, heaters, and car engines. How would such noise affect the developing brain?…
To test this hypothesis, [Merzenich’s] group exposed rat pups to pulses of white noise throughout their critical period and found that the pups’ cortices were devastated.
“Every time you have a pulse,” Merzenich says, “you are exciting everything in the auditory cortext–every neuron.” So many neurons firing results in a massive BDNF release. And as his model predicted, this exposure brings the critical period to premature close. The animals are left with undifferentiated brain maps and utterly indiscriminate neurons get turned on by any frequency.
Merzenich found that these rat pups, like autistic children, were predisposed to epilepsy, and exposing them to normal speech caused them to have epileptic fits…
Recent brain scan studies now confirm that autistic children do indeed process sound in an abnormal way. Merzenich thinks that the undifferentiated cortex helps to explain why they have trouble learning, because a child with an undifferentiated cortex has a very difficult time paying attention. When asked to focus on one thing, these children experience booming, buzzing confusion–one reason autistic children often withdraw from the world and develop a shell.
p. 82

Finally, they are working on “gross motor control,” a function that declines as we age, leading to a loss of balance, the tendency to fall, and difficulties with mobiliy. Aside from the failure of vestibular processing, this decline is caused by the decrease in sensory feedback from our feet. According to Merzenich, shoes, worn for decades, limit the sensory feedback from our feet to our brain. If we went barefoot, our brains would receive many different kinds of input as we went over uneven surfaces.
p. 90

Sexual plasticity may seem to have reached its height in those who have many different partners, learning to adapt to each new lover; but think of the plasticity required of the aging married couple with a good sex life. They looked very different in their twenties, when they met, than they do in their sixties, yet libidos adjust, so they remain attracted.
But sexual plasticity goes further still. Fetishists desire inanimate objects. The male fetishist can be more excited by a high-heeled shoe with a fur trim, or by a woman’s lingerie, than by a real woman. Since ancient times some human beings in rural areas have had intercourse with animals. Some people seem to be attracted not so much to people as to complex sexual scripts …
pp.95-96

In Elizabethan times lovers were so enamored of each other’s body odors that it was common for a woman to keep a peeled apple in her armpit until it had absorbed her sweat and smell. She would give this “love apple” to her lover to sniff at in her absence.
p. 101

Pornogrpahy’s growth has been extraordinary; it accounts for 25 percent of video rentals and is the forth most common reason people give for going online. An MSNBC.com survey of viewers in 2001 found 80 percent felt thet were spending so much time on pornographic sites that they were putting their relationships or jobs at risk. Softcore pornogrpahy’s influence is now most profound because, now that it is no longer hidden, it influences young people with little sexual experience and especially plastic minds, in the process of forming their sexual tastes and desires. Yet the plastic influence of pornogrpahy on adults can also be profound, and those who use it have no sense of the extent to which their brains are reshaped by it.
p. 103

The addictiveness of internet pornography is not a metaphor. Not all addictions are to drugs or alcohol. People can be seriously addicted to gambling, even to running. All addicts show a loss of control of the activity, compulsively seek it out despite negative consequences, develop tolerance so that they need higher and higher levels of stimulation for satisfaction, and experience withdrawal if they can’t consumate the addictive act.
All addiction involves long-term, sometimes lifelong neuroplastic change in the brain. For addicts, moderation is impossible, and they must avoid the substance or activity completely if they are to avoide addictive behaviours. Alcoholics Anonymous insists that there are no “former alcoholics” and makes people who haven’t had a drink for decades introduce themselves at a meeting by saying, “My name is John, and I am an alcoholic.” In terms of plasticity, they are often correct.
p. 106

Dopamine, as we saw in Merzenich’s work, is also involved in plastic change. The same sure of dopamine that thrills us also consolidates the neuronal connections responsible for the behaviours that led us to accomplish our goal.
p. 107

Pornography is more exciting than satisfying because we have two separate pleasure systems in our brains, one that has to do with exciting pleasure and one with satisfying pleasure. The exciting system relates to “appetitive” pleasure that we get imagining something we desire, such as sex or a good meal. Its neurochemistry is largely dopamine-related, and it raises our tension level.
The second pleasure system has to do with satisfaction, or consummatory pleasure, that attends actually having sex or having that meal, a calming, fulfilling pleasure. Its neurochemistry is based on the release of endorphins, which are related to opiates and give a peaceful, euphoric bliss.
p. 108

Globalization is intense when falling in love and is, I believe, one of the main reasons that romantic love is such a powerful catalyst for plastic change. Because the pleasure centres are firing so freely, the enamoured person falls in love not only with the beloved but with the world and romanticizes his view of it. Because our brains are experiencing a surge of dopamine, which consolidates plastic change, any pleasurable experiences and associations we have in the initial state of love are thus wired into our brains.
p. 114

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 thier children. In women oxytocin is released during labour and breast-feeding. An fMRI study shows that when mothers look at photos of their children, brain regions rich in oxytocin are activated.
p.119.

[Robert Stoller MD] interviewed people who practiced hardcore sadomasochism, which inflicts real pain on the flesh, discovered that masochistic participants had all had serious physical illnesses as children and had undergone regular, terrifying painful medical treatment.
p. 125

Phantom limbs are troubling because they give rise to chronic “phantom pain” in 95 percent of amputees that often persists for a lifetime. But how do you remove a pain in an organ that isn’t there?
p. 180

Several leg amputees reported…that when they had sex, they often experienced their orgasms in their phantom legs and feet. One man confessed that because his leg and foot were so much larger than his genitals, the orgasm was “much bigger” than it used to be…The Penfield brain map shows the genitals next to the feet, and since the feet no longer recieve input, the genital maps likely invade the foot map, so when the genitals experience pleasure, so do the phantom feet.
p. 184

[Ramachandran said]: “Pain is an opinion on the organism’s state of health rather than a mere reflexive response to injury.” The brain gathers evidence from many sources before triggering pain. He has also said that “pain is an illusion” and that “our mind is a virtual reality machine,” which experiences the world indirectly and processes it at one remove, constructing a model in our head.
p. 192

[about Rüdiger Gamm, math genius]: Investigators who examined him with a positron emission tomography (PET) brain scan while he was calculating found he was able to recruit five more brain areas for calculating than “normal” people.
p. 203

In an experiment that is as hard to believe as it is simple, Drs. Guang Yee 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 ont hat 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.
p. 204

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 thought “press the bar,” the computer would recognize the neuronal firing pattern and send a signal to the water to dispense the drop.
After a few hours, the rat realized it did not have to touch the bar to get water. All it had to do was to imagine its paw pressing the bar, and water would come!
p. 205

As van Praag and Gage discovered, simply walking, at a good pace, stimulates the growth of new neurons.
p. 255

Grafman’s theory provides an explanation of how Michelle’s brain evolved. Michelle’s loss of brain tissue occurred before there could have been any significant commitment of her right hemisphere. Since plasticity is at its height in the earliest years, what probably saved Michelle from certain death was that her damage occurred so early. When her brain was still forming, her right hemisphere had time to adjust in the womb, and Carol was there to care for her.
p.277

Grafman’s theory is that over the course of evolution the prefrontal cortex developed the ability to capture and retain information over longer and longer periods of time, allowing human beings to develop both foresight and memory. The left-frontal lobe became specialized in storing memories of *individual events* and the right in *extracting a theme* or the main point from a series of events or from a story.
p, 279.

Since there are many thousands of brain activities going on at once, we need forces to inhibit, control, and regulate our brains in order to keep us sane, organized and in control of ourselves so we don’t “ride off in all directions at once.” It would seem that the most frightening thing about brain disease is that it might erase certain mental functions. But just as devastating is a brain disease that leads us to express parts of ourselves we wish didn’t exist. Much of the brain is inhibitory, and when we lose that inhibition, unwanted drives and instincts emerge full force, shaming us and devastating our relationships and families.
p. 281