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

Chapter 2 tells the story of Barbara Arrowsmith Young, founder of the Arrowsmith School for children with learning disabilities. It explores how Barbara overcame her learning disabilities, and how this process allowed her to help similar children at a time when schools paid little attention to accessibility. It also demonstrates the extent of neuroplasticity and how the right exercises can help create new neural pathways. Barbara was born in Toronto, Canada, in 1951, and from an early age demonstrated fluctuating skills: For example, she easily processed hundreds of facts but due to an issue in the Broca area of her brain—dedicated to speech and pronunciation—she often had trouble enunciating. She also struggled with spatial reasoning, which prevented her from judging objects in space, including the left side of her body. As a result, Barbara would often lose track of objects or walk into furniture. She also had difficulty understanding the relationship between symbols: For example, she could not tell the difference between “the father’s brother” and “the brother’s father.” This extended to her relationships: She was unable to grasp inflection and tone, and therefore had trouble gauging intention. When Barbara was younger, she would unknowingly cause trouble because she had trouble understanding cause and effect.

Barbara’s learning disabilities caused her grief in school because she was unable to meet teachers’ standards and socialize with peers. At the time, students like her were simply labeled as having “mental blocks,” but no infrastructure existed to help these students succeed. She graduated by memorizing facts and became interested in child development. During her studies at the University of Guelph, Barbara discovered two texts that would encourage her to overcome her high school obstacles. The first text was neuropsychologist Aleksandr Luria’s The Man with a Shattered World, and the second was a paper on neuroplasticity by Dr. Mark Rosenzweig from the University of California. The Man with the Shattered World describes the real case of a Soviet soldier who lost his ability to understand the relationship between symbols after sustaining a bullet wound on the left hemisphere of his brain—between the temporal, occipital, and parietal lobe—which respectively process sound and language, visual images, and spatial relationships. This soldier faced the same obstacles as Barbara, but died before finding treatment. Barbara then learned of Rosenzweig’s research on neuroplasticity, which comprised rats living in stimulating environments and developing heavier brains with more neurotransmitters and better blood supply than their peers.

Barbara first attempted to learn to read clocks. She made hundreds of flashcards of clocks and asked peers to write the correct times on the backs. She shuffled the cards and tried to make sense of the link between the needles’ movement and flow of time. Barbara’s hard work paid off in unexpected ways: After several weeks, not only could she read time faster than the average person, but other weaknesses began to improve. She could make better sense of relationships between symbols, understood inflection and intention better, and improved her grammar. This change convinced Barbara of the plasticity of the brain and became the impetus for her establishing the Arrowsmith School for children with learning disabilities in 1980. The school spends 40 hours assessing each student’s disability and then creating a curriculum designed to help them improve their weakest areas. This curriculum includes practicing tasks that most schools dropped in the 1960s for being “boring” or rigid, such as the memorization of texts, practicing elucidation and pronunciation, learning through visual and auditory cues, and tracing letters to train motor and recognition skills. The school makes use of computers and encourages incremental progress using positive reinforcement. Typically, students who improve in one area also see improvement in others, the same way learning to read clocks helped Barbara better understand nonverbal social cues. The school’s success shows that for some children, “boring” or rigid abilities are necessary for sustained brain development. Overall, Doidge asserts stimulating environments can increase brain mass by creating more branches between neurons. Neuroplasticity, paired with well-designed exercises, allows people to redesign their brains.

Chapter 3 asserts understanding neuroplasticity can help scientists design specific exercises to sharpen the mind. It focuses on the work of Michael Merzenich, who designed innovative training programs to enhance a targeted area in the brain. This chapter seeks to prove all three of Merzenich’s famous claims about neuroplasticity are correct: that exercise can be as useful as drugs in treating certain learning disabilities, that the brain remains plastic until death, and that even the elderly are capable of improving their cognitive functioning. The chapter opens with a brief history of localizationism, the belief that specific mental operations can only be processed in specific areas of the brain. This belief became widespread in the 1930s when researchers attempted to map the brain. It was discovered that the five senses are processed in the temporal, parietal, and occipital lobes behind the frontal lobe. Research by neurosurgeon Wilder Penfield at the Montreal Neurological Institute proved specific areas of the brain controlled specific parts of the body, and that the motor system was governed by the frontal lobes. A part of the brain became active when a patient’s hand was touched, with active stimulation of the brain also producing the feeling of touch. Penfield’s research proved both sensory and motor brain maps are topographical (interpreting the structure and function of the brain by dividing it into areas), with body parts being directed by the same relative positions in the brain. Although Penfield himself never claimed these brain maps are fixed or immutable, localizationism did: If one part of the brain map became damaged, it was assumed the person would never recover the respective function. This bias is partly the result of the imprecise technology of the time, and partly because there were few cases where people who sustained brain damage recovered.

Merzenich’s research refuted localizationism by proving brain maps are not the same between individuals, as their borders and size vary and change depending on personal experiences and age. Using micromapping, a new technology that allows scientists to measure electric signals by a single neuron, Merzenich mapped the hand of an adolescent monkey. He found digits adjacent to each other were represented accordingly in adjacent areas of the brain. Scientists of the time believed neurological signals only traveled from point to point—therefore, when Merzenich surgically shuffled the neurons in the monkey’s thumb and pointer finger, he expected the brain map for the pointer finger to activate when he stroked the thumb. However, the opposite happened: The brain managed to decode the change and rearranged itself accordingly, proving brain maps are not static but plastic.

Merzenich then cut the median nerve in a monkey’s hand, which conveys sensation from the middle of the hand, to see how its brain would respond to a complete loss of signal: The median nerve brain map did not respond when the middle of the monkey’s hand was stroked. However, it became active when Merzenich touched the outside of the monkey’s hand. In other words, the area of the brain that usually processed sensation from the middle of the hand was now handling information from other areas of the hand. Merzenich concluded there was a general law of competition for the brain’s allocation of space. Because the brain’s resources are limited, it prioritizes signals that are the strongest and most frequent in what Doidge calls a “use it or lose it” principle (59). Over the next hundred days, Merzenich continuously monitored the monkey’s brain map and found that despite losing all sensation in the middle part of the hand, the corresponding area of the map grew to process equally detailed information from adjacent areas on the hand.

This rule is called competitive plasticity, and it explains why infants and younger children have an easier time learning. Their brain maps, which have yet to specialize, absorb all sensory information and remain flexible. However, once certain processes become solidified, it becomes harder to modify them to process different information. This is the case with language learning: Adults find it harder to learn new languages because their native tongue dominates the linguistic map space in the brain. Similarly, habits are hard to break because it requires the brain to reallocate space from a practiced function to a new one. This is why there are critical learning periods for young learners; missing these periods results in allocation to other functions, making it difficult to recuperate this loss.

The underlying reasoning of brain specialization can be understood by looking at how neurons communicate information. When people learn new skills, their senses communicate information to the brain through firing neurons; furthermore, when the brain sends information to the body, it fires specific neurons and inhibits others. When two neurons fire in tandem repeatedly, or when one neuron firing always causes another to fire after, they form a connection over time. As the connection between specific groups of neurons solidifies, they function more efficiently; this is why learned skills become easier to perform over time. Neuroscientist Carla Shatz simplifies this dynamic as “neurons that fire together wire together” (63).

In another experiment, Merzenich sewed together two fingers on a monkey and found that the brain map, which used to process the signals of each finger separately, merged. Since the neurons in each finger fired simultaneously instead of separately when they moved, the brain learned to consider them in unison. This also explains why the brain map is arranged topographically: Neurons in the hand (such as the fingers) tend to fire according to proximity (for example, when compared to neurons in the leg), and over time, the brain learns the most efficient way of processing these signals by assigning them to adjacent areas. Behavioral psychologist Bill Jenkins argues there are two steps to learning a new skill: Information in the form of signals takes up more space in the brain, and then the brain learns to process it more efficiently. Efficiency means signals sent to the brain become clearer, and the brain map becomes faster and more precise at decoding signals. In Jenkins and Merzenich’s combined experiments, they found the more animals concentrated on learning a skill, the longer these changes would last and the more they would affect the shape of their brain maps.

Thus, Merzenich concludes that as the brain processes information, it not only stores knowledge but learns how to learn. In 1996, he and his peers established a company called Scientific Learning, dedicated to using neuroplastic research to help people learn better. This company developed Fast ForWord, a computer training program for children with learning disabilities, including language-impaired children. Since understanding speech requires the auditory senses to detect various sound maps, the Fast ForWord program uses fun games to help children distinguish and match different sounds patterns (such as short and long vowels). The program was successful, with many students also improving their reading, handwriting, and attention span. Merzenich hypothesizes that hearing more clearly trains the brain’s temporal processing, and thus improves not only language recognition but time-keeping skills.

Merzenich created another company called Posit Science, which helps the elderly preserve their neuroplasticity. Scientists who believed in a hardwired, unchanging brain assumed it decayed with age, a process that can only be slowed with stimulating drugs. By contrast, Merzenich argues that while general decay is inevitable, the main contributor is a lack of stimulation. As people grow older, they tend to establish fixed routines, and their brain’s plasticity wastes away due to neglect. Merzenich advocates for people in their 60s and older to learn a new language or physical task such as dancing. Thus, Posit Science created a computer learning program like Fast ForWord to help the elderly maintain a sharp memory. After practicing an hour a day for eight to 10 weeks, test subjects ages 60 to 87 performed as well as people in the 40-to-60 range on memory tests. This success paved the way for Posit Science to design more exercises training visual processing, executive functions in the frontal lobe, fine motor control, and gross motor control. Overall, Merzenich’s experiments demonstrate the brain’s capacity to change and learn from birth to old age.

Chapter 4 explores the effects of neuroplasticity on human love and sexuality, leaning heavily on the works of psychoanalyst Sigmund Freud. It opens with the story of Mr. A, a patient of Doidge’s whose mother exhibited alcoholism and sexually abused him when he was young. As a result, his adult self developed a preference for similarly violent women. He finds his love life unsatisfying, and logically knows nonviolent women are better for him, but is simply not attracted to them. Humans exhibit sexual plasticity on a level incomparable to other animals. Most people find their sexual tastes change over time, as proven by changing beauty standards across time and culture. This shows humans’ sexual instinct has become divorced from its original purpose of reproduction. This makes biological sense: The hypothalamus and amygdala, which respectively process behaviors and emotions, are plastic like the rest of the brain. Merzenich’s research proves connected brain systems change as the brain itself changes.

Freud was one of the first people to probe the topic of critical periods for sexual plasticity. He argues that from infancy, children learn from their parents how to love and care, which can pave the way for future tastes and habits. This disputes the popular idea that the first critical period for developing intimacy is puberty. This is why children who are sexually abused during this stage of development often find it difficult to forge healthy relationships as adults. It also explains why baby and dirty talk among adults often reprise maternal language. Freud’s theory is contrary to the popular argument that biology is the primary factor in determining people’s sexual tastes. Doidge sides with Freud, pointing out that though movie stars are generally considered attractive, trends change over time. He distinguishes between acquired tastes and innate tastes: Sexual tastes are acquired, and once learned, they become second nature because the neuroplastic brain reconfigures itself to reflect this new status.

Over the course of his career, Doidge helped several patients addicted to internet pornography to the point of becoming impotent in the bedroom due to the lack of excitement. This is because over time, pornography has become more hardcore, and people have become used to consuming content as one would substance addiction. Doidge argues the neuroplastic brain is at the center of pornographic and other types of addiction. When people feel satisfaction, their body releases dopamine, a substance that causes elation or excitement and encourages repetition. The neuroplastic brain adapts to these changes and can reconfigure certain genes through the production of a protein called ∆FosB (Delta Fos B). Over time, this protein can turn on or off certain genes and lead to increased want of an addictive product; this feeling persists even when aware of potential harm.

Doidge believes intense love can become a powerful catalyst for neuroplastic change. Research has shown that the septal region of the brain fired equally strongly during orgasm and discussion of romantic feelings. Falling in love thus makes it easier for pleasure centers (such as the mesolimbic dopamine system) to fire, rendering people more optimistic about the future. They cycle between positive cycles of anticipatory and fulfilled pleasure, and have a harder time feeling pain or sadness. People in love are more likely to develop new tastes, such as finding faults in partners endearing—which Doidge calls “globalization.” He highlights neuroplasticity is not simply about learning, but forgetting. Falling in love involves both the process of learning new habits and unlearning old ones to accommodate a crush. However, different chemistries are involved in these two processes. When neurons fire and wire together, this chemical process is called “long-term potentiation” (LTP), and allows the brain to learn a new skill. When neurons desync, it is called “long-term depression” (LTD), and frees brain space to form new neuronal networks.

According to neuroscientist Walter J. Freeman at the University of California, the hormone oxytocin is associated with neurological unlearning. He argues humans undergo two main stages of unlearning when they fall in love and when they begin parenting. Oxytocin compels bonding in mammals, releasing during orgasm and when parents nurture their children. It helps melt existing neuronal connections to free space for new attachments. When people become parents, they might find themselves more willing to give up certain habits for their children’s well-being. While such change might be the result of psychological maturity, chemical and hormonal changes also facilitate unlearning. Chapter 4 concludes by circling back to Mr. A’s story within the framework of learning and unlearning. Doidge identified that Mr. A grew up in an environment where sex and violence were intricately linked, with his brain maps reflecting this connection. Over the course of several sessions in which Doidge helped rewire his brain to separate sex and violence, Mr. A found himself increasingly able to fall in love with nonviolent women.