The Brain That Changes Itself

Norman Doidge’s best-selling book The Brain That Changes Itself (2007) provides a detailed account of the latest discoveries in neuroscience and brain plasticity. The Canadian-born and Toronto-based psychiatrist, psychoanalyst, and author describes the “behind the scenes” processes in our neurological networks, and the ways in which our brains constantly rewire themselves when we undergo various positive and negative experiences, growth, learning, damage, behavioural changes, relationships, addictions, fetishes, dysfunctions, traumas, or therapy. Here are some of his most interesting observations:

  

On Learning and Exercising:

“[Our brain] doesn’t simply learn; it is always “learning how to learn.””(Norman Doidge, The Brain That Changes Itself, p.47)

“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 brain map and prevents the use of that space for “good” habits. That is why “unlearning” is often a lot harder than learning, and why early childhood education is so important – it’s best to get it right early, before the “bad habit” gets a competitive advantage.” (p.60)

“A major reason memory loss occurs as we age is that we have trouble registering new events in our nervous system, because processing speed slows down, so that the accuracy, strength, and sharpness with which we perceive declines. If you can’t register something clearly, you won’t be able to remember it well. […] That’s why learning a new language in old age is so good for improving and maintaining the memory generally. Because it requires intense focus, studying a new language turns on the control system for plasticity and keeps it in good shape for laying down sharp memories of all kinds. […] To keep the mind alive requires learning something truly new with intense focus. That is what will allow you to both lay down new memories and have a system that can easily access and preserve the older ones.” (pp.86-88)

“This theory, that novel environments may trigger neurogenesis, is consistent with Merzenich’s discovery that in order to keep the brain fit, we must learn something new, rather than simply replaying already-mastered skills.” (p.252)

“Elizabeth Gould also found that learning, even in a nonenriched environment, enhances survival of stem cells. Thus physical exercise and learning work in complimentary ways: the first to make new stem cells, the second to prolong their survival. […] Many studies suggest that people with more education seem better protected from mental decline. The most popular theory is that years of education create a “cognitive reserve” – many more networks devoted to mental activity – that we can call upon as our brains decline.” (p.253)

“Physical activity is helpful not only because it creates new neurons but because the mind is based in the brain, and the brain needs oxygen. Walking, cycling, or cardiovascular exercise strengthens the heart and the blood vessels that supply the brain and helps people who engage in these activities feel mentally sharper – as pointed out by the Roman philosopher Seneca two thousand years ago. Recent research shows that exercise stimulates the production and release of the neuronal growth factor BDNF, which as we saw in chapter 3 plays a crucial role in effecting plastic change. In fact, whatever keeps the heart and blood vessels fir invigorates the brain, including a healthy diet. A brutal workout is not necessary – consistent natural movement of the limbs will do. Simply walking, at a good pace, stimulates the growth of new neurons.” (p.255)

“Nothing speeds brain atrophy more than being immobilized in the same environment; the monotony undermines our dopamine and attentional systems crucial to maintaining brain plasticity. […] Tai chi, though it hasn’t been studied, requires intense concentration on motor movements and stimulates the brain’s balance system. It also has a meditative aspect, which has been proven very effective in lowering stress and so is likely to preserve memory and the hippocampal neurons.” (p.256)

“At ninety, the architect Frank Lloyd Wright designed the Guggenheim Museum. At seventy-eight, Benjamin Franklin invented bifocal spectacles. In studies of creativity, H.C. Lehman and Dean Keith Simonton found that while the ages thirty-five to fifty-five are the peak of creativity in most fields, people in their sixties and seventies, thought they work at slower speed, are as productive as they were in their twenties.”(p.257)

“Human beings change throughout their life because of their “perfectibility.” […] Because our brains were so sensitive to experience, they were also more vulnerable to being shaped by it. Educational schools such as the Montessori School, with its emphasis on the education of the senses, grew out of Rousseau’s observations.” (p.314)

On Sex, Love, and other Addictions:

“In order to determine how addictive a street drug is, researchers at the National Institute for Health (NIH) in Maryland train a rat to press a bar until it gets a shot of the drug. The harder the animal is willing to work to press the bar, the more addictive the drug. Cocaine, almost all other illegal drugs, and even nondrug addictions such as running make the pleasure-giving neurotransmitter dopamine more active in the brain. Dopamine is called the reward transmitter, because when we accomplish something – run a race and win – our brain triggers its release. Though exhausted, we get a surge of energy, exciting pleasure, and confidence and even raise our hands and run a victory lap. The losers, on the other hand, who get no such dopamine surge, immediately run out of energy, collapse at the finish line, and feel awful about themselves. By hijacking our dopamine system, addictive substances give us pleasure without our having to work for it. […] An important link with porn is that dopamine is also released in sexual excitement, increasing the sex drive in both sexes, facilitating orgasm, and activating the brain’s pleasure centers. Hence the addictive power of pornography.”(p.106-107)

“A single dose of many addictive drugs will produce a protein, called ΔFos B (pronounced “Delta Fos B”), that accumulates in the neurons. Each time the drug is used, more ΔFos B accumulates, until it throws a genetic switch, affecting which genes are turned on or off.  Flipping this switch causes changes that persist long after the drug is stopped, leading to irreversible damage to the brain’s dopamine system and rendering the animal more prone to addiction. Nondrug addictions, such as running and sucrose drinking, also lead to the accumulation of ΔFos B and the same permanent changes in the dopamine system.” (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 the “appetite” 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 the 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)

“In 1950 “pleasure centers” were discovered in the limbic system, a part of the brain heavily involved in processing emotions. […] When the pleasure centers are turned on, everything we experience gives us pleasure. A drug like cocaine acts on us by lowering the threshold at which our pleasure centers will fire, making it easier for them to turn on. It is not simply the cocaine that gives us pleasure. It is the fact that our pleasure centers now fire so easily that makes whatever we experience feel great. It is not just cocaine that can lower the threshold at which our pleasure centers fire. When people with bipolar disorder (formerly called manic depression) begin to move toward their manic high, their pleasure centers begin firing more easily. And falling in love also lowers the threshold at which the pleasure centers will fire.” (p.113)

“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 centers are firing so freely, the enamored person fall 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. […] 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. […] Globalization also creates an opportunity for is to develop new tastes in what we find attractive. Neurons that fire together wire together.” (p.114)

“Recent fMRI (functional magnetic resonance imaging) scans of lovers looking at photos of their sweethearts show that a part of the brain with great concentrations of dopamine is activated; their brains looked like those of people on cocaine. […] But the pains of love also have a chemistry. When separated for too long, lovers crash and experience withdrawal, crave their beloved, get anxious, doubt themselves, lose their energy, and feel run-down if not depressed. Like a little fix, a letter, an email, or a telephone message from the beloved provides an instant shot of energy. These “addictive symptoms” – the highs, crashes, cravings, withdrawal, and fixes – are subjective signs of plastic changes occurring in the structure of our brains, as they adapt to the presence or absence of the beloved.” (p.115-116)

“We must be learning of we are to feel fully alive, and when life, or love, becomes too predictable and it seems like there is little left to learn, we become restless – a protest, perhaps, of the plastic brain when it can no longer perform its essential task. […] Love creates a generous state of mind. Because love allows us to experience as pleasurable situations or physical features that we otherwise might not, it also allows us to unlearn negative associations, another plastic phenomenon. […] The science of unlearning is a very new one. Because plasticity is competitive, when a person develops a neural network, it becomes efficient and self-sustaining and, like a habit, hard to unlearn.” (p.116)

“Falling in love for the first time also means entering a new developmental stage and demands a massive amount of unlearning. When people commit to each other, they must radically alter their existing and often selfish intentions and modify all other attachments, in order to integrate the new person in their lives. Life now involves ongoing cooperation that requires a plastic reorganization of the brain centers that deal with emotions, sexuality, and the self. Millions of neural networks have to be obliterated and replaced with new ones – one reason that falling in love feels, for so many people, like a loss of identity. Falling in love may also mean falling out of love with a past love; this too requires unlearning at a neural level.” (p.117)

“Often people cannot move on because they cannot yet grieve; the thought of living without the one they love is too painful to bear. In neuroplastic terms, if the [person] is to begin a new relationship without baggage, each must first rewire billions of connections in their brains. The work of mourning is piecemeal, Freud noted; though reality tells us our loved one is gone, “its orders cannot be obeyed at once.” We grieve by calling up one memory at a time, reliving it, and then letting go. At a brain level we are turning on each of the neural networks that were wired together to form our perception of the person, experiencing the memory with exceptional vividness, then saying good-bye one network at a time. 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.” (p.118)

“Massive neurological reorganization occurs at two life stages: when we fall in love and when we begin parenting. Freeman argues that massive plastic brain reorganization – far more massive than in normal learning or unlearning – becomes possible because of a brain neuromodulator.” (p.118)

“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. […] Many young people who doubt they will be able to handle the responsibilities of parenting are not aware of the extent to which oxytocin may change their brains, allowing them to rise to the occasion. […] A recent study shows that oxytocin also triggers trust.” (p.119)

“Unlearning in love allows us to change our image of ourselves – for the better, of we have an adoring partner. But it also helps account for our vulnerability when we fall in love and explains why so many self-possessed young men and women, who fall in love with a manipulative, undermining, or devaluing person, often lose all sense of self and become plagued with self-doubt, from which it may take years to recover.” (p.121)

On Psychoanalysis:

“Most people assume that our genes shape us – our behavior and our brain anatomy. Kandal’s work shows that when we learn our minds also affect which genes in our neurons are transcribed. Thus we can shape our genes, which in turn shape our brain’s microscopic anatomy.” (p.220)

“Kandal 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 alternations in neuronal networks.” (p.221)

“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. Twenty-six-month-olds are complex, “right-brained” emotional creatures but cannot talk about their experiences, a left-brain function.” (p.226)

“A mother who is with her baby during the critical period for emotional development and attachment is constantly teaching her child what emotions are by using musical speech and nonverbal gestures. […] For children to know and regulate their emotions, and be socially connected, they need to experience this kind of interaction many hundred times in the critical period and then to have it reinforced later in life.” (p.227)

“Procedural memories are generally unconscious. Riding a bike depends on procedural memory, and most people who ride easily would have trouble consciously explaining precisely how they do it. […] Explicit memory consciously recollects specific facts, events, and episodes. It is the memory we use when we describe and make explicit what we did on the weekend, and with whom, and for how long. It helps us to organize our memories by time and place. Explicit memory is supported by language and becomes more important once children can talk.” (p.228-229)

“The newest brain scans show that when we dream, that part of the brain that processes emotion, and our sexual, survival, and aggressive instincts, is quite active. As the same time the prefrontal cortex system, which is responsible for inhibiting our emotions and instincts, show lower activity. With instincts turned up and inhibitions turned down, the dreaming brain can reveal impulses that are normally blocked from awareness. […] Scores of studies show that sleep affects plastic change by allowing us to consolidate learning and memory. When we learn a skill during the day, we will be better at it the next day if we have a good night’s sleep. “Sleeping on a problem” often does make sense.” (p.239)

“Early stresses predispose motherless animals to stress-related illness for the rest of their lives. When they undergo long separations, the gene to initiate production of glucocorticoids gets turned on and stays on for extended periods. Trauma in infancy appears to lead to a supersentization – a plastic alternation – of the brain neurons that regulate glucocorticoids. […] Depression, high stress, and childhood trauma all release glucocorticoids and kill cells in the hippocampus, leading to memory loss. The longer people are depressed, the smaller their hippocampus gets. If the stress is brief, this decrease in size is temporary. If it is too prolonged, the damage is permanent. As people recover from depression, their memories return, and research suggests their hippocampi can grow back.” (p.240-241)

“Antidepressant medications increase the number of stem cells that become new neurons in the hippocampus. Rats given Prozac for three weeks had a 70% increase in the number of cells in their hippocampi. It usually takes three to six weeks for antidepressants to work in humans – perhaps coincidentally, the same amount of time it takes for newly born neurons in the hippocampus to mature, extend their projections, and connect with other neurons. So we may, without knowing it, have been helping people get out of depression by using medications that foster brain plasticity.” (p.241)

“Anything that involves unvaried repetition – our careers, cultural activities skills, and neuroses – can lead to rigidity. Indeed, it is because we have a neuroplastic brain that we can develop these rigid behaviors in the first place. As Pascual-Leone’s metaphor illustrates, neuroplasticity is like pliable snow on a hill. When we go down the hill on a sled, we can be flexible because we have the option of taking different paths through the soft snow each time. But should we choose the same path a second or third time, tracks will start to develop, and soon we will tend to get stuck in a rut – our route will now be quite rigid, as neural circuits, once established, tend to become self-sustaining.” (p.242)

“Because our neuroplasticity can give rise to both mental flexibility and mental rigidity, we tend to underestimate our own potential for flexibility, which most of us experience only in flashes. […] Freud was right when he said that the absence of plasticity seemed related to force of habit. Neuroses are prone to being entrenched by force of habit because they involve repeating patterns of which we are not conscious, making them almost impossible to interrupt and redirect without special techniques.” (p.243)

“The plastic paradox teaches that neuroplasticity can also be responsible for many rigid behaviors, and even some pathologies, along with all the potential flexibility that is within us.” (p.317)

On Culture:

“The Oxford English Dictionary gives one important definition of “culture”: “the cultivating or development of the mind, faculties, manners, etc.; improvement or refinement by education and training; the training, development and refinement of the mind, tastes and manners.” […] So a neuroplastically informed view of culture and the brain implies a two-way street: the brain and genetics produce culture, but culture also shapes the brain.” (p.287-288)

“Even leisure activities change our brain; meditators and meditation teachers have a thicker insula, a part of the cortex activated by paying close attention. […] Signature activities require training and cultural experience and lead to the development of a new, specially wired brain. (p.290-291)

“According to Merzenich, “Our brains are different from those of all humans before us… Our brain is modified on a substantial scale, physically and functionally, each time we learn a new skill or develop a new ability. Massive changes are associated with our modern cultural specializations.” And though not everyone uses the same brain areas to read, because the brain is plastic, there are typical circuits for reading – physical evidence that cultural activity leads to modified brain structures.” (p.293)

“Sublimation” [is] the process by which brutish animal instincts are “civilized.” Clearly, much of parenting involves “civilizing” children by teaching them to restrain or channel these instincts into acceptable expressions, such as in contact sports, board and computer games, theatre, literature, and art.” (p.296)

“Civilization is a series of techniques in which the hunter-gatherer brain teaches itself to rewire itself. […] Because the plastic brain can always allow brain functions that it has brought together to separate, a regression to barbarism is always possible, and civilization will always be a tenuous affair that must be taught in each generation and is always, at most, one generation deep.” (p.298)

“Immigration is hard on the plastic brain. The process of learning a culture – acculturation – is an “additive” experience, of learning new things and making new neuronal connections as we “acquire” culture. Additive plasticity occurs when brain change involves growth. But plasticity is also “subtractive” and can involve “taking things away,” as occurs when the adolescent brain prunes away neurons, and when neuronal connections not being used are lost. Each time the plastic brain acquires culture and uses it repeatedly, there is an opportunity cost: the brain loses some neural structure in the process, because plasticity is competitive.[…] Immigration is usually an unending, brutal workout for the adult brain, requiring a massive rewiring of vast amounts of our cortical real estate. It is a far more difficult matter than simply learning new things, because the new culture is in plastic competition with neural networks that had their critical period of development in the native land. Successful assimilation, with few exceptions, requires at least a generation. Only immigrant children who pass through their critical periods in the new culture can hope to find immigration less disorienting and traumatizing. For most, culture shock is brain shock.” (p.298-299)

“Bruce Wexler, in his book Brain and Culture, argues that the relative decline in neuroplasticity as we age explains many social phenomena. […] As we age, plasticity declines, it becomes increasingly difficult for us to change in response to the world, even if we want to. We find familiar types of stimulation pleasurable; we seek out like-minded individuals to associate with, and research shows we tend to ignore or forget, or attempt to discredit, information that does not match our beliefs, or perception of the world, because it is very distressing and difficult to think and perceive in unfamiliar ways. […] The aging individual begins to micromanage his environment, to control it and make it familiar. But this process, writ large, leads whole cultural groups to try to impose their view of the world on other cultures, and they often become violent, especially in the modern world, where globalization had brought different cultures closer together, exacerbating the problem. Wexler’s point, then, is that much of the cross-cultural conflict we see is a product of the relative decrease in plasticity.” (p.304)

“Television watching, one of the signature activities of our culture, correlates with brain problems. A recent study of more than twenty-six hundred toddlers shows that early exposure to television between the ages of one and three correlates with problems paying attention and controlling impulses later in childhood. For every hour of TV the toddlers watched each day, their chances of developing serious attentional difficulties at age seven increased by 10 percent.” (p.307)

“Most people think that the dangers created by the media are a result of content. But Marshall McLuhan, the Canadian who founded media studies in the 1950s and predicted the Internet twenty years before it was invented, was the first to intuit that the media change our brains irrespective of content, and he famously said,” The medium is the message.” McLuhan was arguing that each medium reorganizes our mind and brain in its own unique way and that the consequences of these reorganizations are far more significant than the effects of the content or “message.” […] Much of the harm from television and other electronic media, such as music videos and computer games, comes from their effect on attention. (p.308-309)

“Video games, like Internet port, meet all the conditions for plastic brain map changes. A team at the Hammersmith Hospital in London designed a typical video game in which a tank commander shoots the enemy and dodges enemy fire. The experiment showed that dopamine – the reward neurotransmitter, also triggered by addictive drugs – is released in the brain during these games. People who are addicted to computer games show all the signs of other addictions: cravings when they stop, neglect of other activities, euphoria when on the computer, and a tendency to deny or minimize their actual involvement.[…] It is the form of the television medium – cuts, edits, zooms, pans, and sudden noises – that alters the brain, by activating what Pavlov called the “orienting responses” which occurs whenever we sense a sudden change in the world around us, especially a sudden movement. We instinctively interrupt whatever we are doing to turn, pay attention, and get our bearings. […] Because typical music videos, action sequences, and commercials trigger orienting responses at a rate of one per second, watching them puts us into continuous orientating response with no recovery. No wonder people report feeling drained from watching TV. Yet we acquire a taste for it and find slower changes boring. The cost is that such activities as reading, complex conversation, and listening to lectures become more difficult. […] All electronic devices rewire the brain.” (p.209-311)