The Brain that Changes Itself - Norman Doidge

Read 06.22.2020

Read on Kindle* page # may be slightly off.

“Plasticity has been, after all, a property inherent in the brain since prehistoric times. The brain is a far more open system than we ever imagined, and nature has gone very far to help us perceive and take in the world around us. It has given us a brain that survives in a changing world by changing itself.” (26)

How fortunate are we to possess a brain that is plastic? A brain that we ourselves have the power to change by exploiting the interdependence between the mind and body. It makes me wonder the extent to which we are able to better ourselves, and the science seems to suggest endless possibilities.

The Brain that Changes Itself emphasizes the innate plastic capabilities of the brain in an awe-inspiring way, exploring the avenues through which neural change can be stimulated and how various experiments have successfully captured the phenomenon. Perhaps the most enlightening of the ideas presented, is named the “plastic paradox”, which describe the two-pronged nature of plasticity:

“The plastic paradox is that the same neuroplastic properties that allow us to change our brains and produce more flexible behaviors can also allow us to produce more rigid ones.” (241)

The plastic paradox presents us with both hope and alarm, reminding us that the capability to change not only gives us an opportunity to escape but also reinforces our thoughts, habits, and existing neural patterns. By learning of the plastic paradox, I am urged to become more introspective in order to take advantage of plasticity instead of being taken advantage by it.

While the rest of the book highlights the benefits plasticity offers in treating developmental and mental disorders, the implications at the individual level should not go unnoticed. Effectively, the plasticity of the brain dismisses certain impossibilities. No longer should we be afraid to learn a new language, a musical instrument, advanced-math, or to break bad habits. The principle of plasticity teaches us that although difficult, no mental task is definitively impossible. What better encouragement could there be? Plasticity shifts the responsibility of failure from what we used to believe was the unchanging brain, to the consciousness that occupies it. It may be a heavy burden to bear, but it is somewhat freeing as well. Understanding plasticity invalidates the excuses we tell ourselves over and over, that refrain us from making the positive changes we project onto our ideal selves. Alternatively, plasticity also suggests that the failure to act for change now further heightens the difficulty of change later. This realization is a game-changer for me, who justifies the delay of action by viewing self-improvement as a departure from the plateaued self, when in fact every day I fail to act takes me further away from who I wish to become. Rejoice! For there is no incentive to idle any longer!

 As usual, here are my favorite snippets:

“The brain Merzenich describes is not an inanimate vessel that we fill; rather it is more like a living creature with an appetite, one that can grow and change itself with proper nourishment and exercise.” (47)

“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 changes in your brain maps.” (68)

“The difference between critical-period plasticity and adult plasticity is that in the critical period the brain maps can be changed just by being exposed to the world because “the leaning machinery is continuously on.”” (78)

“Recent brain scans studies now confirm that autistic children no 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. Merzenich thinks this same problem, in milder form, may contribute to more common attention disorders.” (81)

“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.” (86)

“A tolerance, akin to tolerance for a drug, can develop in happy lovers as they get used to each other. Dopamine likes novelty. When monogamous mates develop a tolerance for each other and lose the romantic high they once had, the change may be a sign, not that either of them is inadequate or boring, but that their plastic brains have so well adapted to each other that it’s harder for them to get the same buzz they once got from each other. Fortunately, lovers, can stimulate their dopamine, keeping the high alive, by injecting novelty into their relationship. When a couple go on a romantic vacation or try new activities together, or wear new kinds of clothing, or surprise each other, they are using novelty to turn on the pleasure centers, so that everything they experience, including each other, excites and pleases them. Once the pleasure centers are turned on and globalization begins, the new image of the beloved again becomes associated with unexpected pleasures and is plastically wired into the brain, which has evolved to respond to novelty. We must be learning if 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 tasks.” (115-116)

“Freeman proposes that oxytocin melts down existing neuronal connections that underlie existing attachments, so new attachments can be formed. Oxytocin, in this theory, does not teach parents to parent. Nor does it make lovers cooperative and kind; rather, it makes it possible for them to learn new patterns.” (120)

“Stroke is a sudden, calamitous blow. The brain is punched out from within. A blood clot or bleed in the brain’s arteries cuts off oxygen to the brain’s tissues, killing them. The most stricken of its victims end up mere shadows of who they once were, often ware-housed in impersonal institutions, trapped in their bodies, fed like babies, unable to care for themselves, move, or speak.” (135)

“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.” (155)

“The gate theory also made Western scientists less skeptical of acupuncture, which reduces pain by stimulating points of the body often farm 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.” (191)

“In India, Ramachandran grew up in a world where many things that seem fantastic to Westerners were commonplace. He knew about yogis who relieved suffering with meditation and walked barefoot across hot coals or lay down on nails. He saw religious people in trances putting needles through their chins. The idea that living things change their forms was widely accepted; the power of the mind to influence the body was taken for granted, and illusion was seen as so fundamental a force that it was represented in the deity Maya, the goddess of illusion. He has transposed a sense of wonder from the streets of India to Western neurology, and his work inspires questions that mingles the two. What is a trance but a closing down of the gates of pain within us? Why should we think phantom pain any less real than ordinary pain? And he has reminded us that great science can still be done with elegant simplicity.” (194-195)

“But now we can see that our “immaterial” thoughts too have a physical signature, and we cannot be so sure that thought won’t someday be explained in physical terms. 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.” (213)

“It has recently been discovered that early childhood trauma causes massive plastic change in the hippocampus, shrinking it so that new, long-term explicit memories cannot form. Animals removed from their mothers let out desperate cries, then enter a turned-off state—as Spitz’s infants did—and release a stress hormone called “glucocorticoid.” Glucocorticoids kill cells in the hippocampus so that it cannot make the synaptic connections in neural networks that make learning and explicit long-term memory possible. These early stresses predispose these 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 supersensitization—a plastic alteration—of the brain neurons that regulate glucocorticoids. Recent research in humans shows that adult survivors of childhood abuse also show signs of glucocorticoid supersensitivity lasting into adulthood.” (239-240)

“[Gage’s] 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. But as we’ve said, there is a second way to increase the number of neurons in the hippocampus: by extending the life of neurons already there. Studying the mice, the team found that learning how to use the other toys, balls, and tubes didn’t make new neurons, but it did cause the new neurons in the area to live longer. Elizabeth Gould also found that learning, even in a nonenriched environment, enhances survival of stem cells. Thus physical exercise and learning work in complementary ways: the first to make new stem cells, the second to prolong their survival.” (251-252)

“Wexler’s point then, is that much of the cross-cultural conflict we see is a product of the relative decrease in plasticity.” (304)

“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. As the idea of plasticity becomes the focus of human attention in our time, we would be wise to remember that it is a phenomenon that produces effects we think of as both bad and good—rigidity and flexibility, vulnerability, and an unexpected resourcefulness… Thus, while it is true that the history of Western political thought turns in large part upon the attitudes that various ages and thinkers have held toward the question of human plasticity broadly understood, the elucidation of human neuroplasticity in our time, if carefully thought through, shows that plasticity is far too subtle a phenomenon to unambiguously support a more constrained or unconstrained view of human nature, because in fact it contributes to both human rigidity and flexibility, depending upon how it is cultivated.” (316-317)