The Brain That Changes Itself

The Brain That Changes Itself

Stories of Personal Triumph from the Frontiers of Brain Science

Norman Doidge

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.

The idea that the brain is like a muscle that grows with exercise is not just a metaphor.

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 each time we repeat it, it claims more control of that 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.

When the brain unlearns associations and disconnects neurons, another chemical process occurs, called “long-term depression,” or LTD. Unlearning and weakening connections between neurons is just as plastic a process, and just as important, as learning and strengthening them. If we only strengthened connections, our neuronal networks would get saturated. Evidence suggests that unlearning existing memories

Buddhists view suffering in meditation: they observe its effects on them and so slightly separate themselves from it.

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.

The idea Freud inherited from his teachers was that events we experience can leave permanent memory traces in our minds. But when he started working with patients, he observed that memories are not written down once, or “engraved,” to remain unchanged forever but can be altered by subsequent events and retranscribed. Freud observed that events could take on an altered meaning for patients years after they occurred, and that patients then altered their memories of those events.

To be changed, Freud argued, memories had to be conscious and become the focus of our conscious attention.

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.

It is not just “highly cultured” activities that rewire the brain. Brain scans of London taxi drivers show that the more years a cabbie spends navigating London streets, the larger the volume of his hippocampus, that part of the brain that stores spatial representations.

Even leisure activities change our brain; meditators and meditation teachers have a thicker insula, a part of the cortex activated by paying close attention.

Sometimes individual identities can be changed in adulthood, even against a person’s will. Human beings can be broken down and then develop, or at least “add on,” neurocognitive structures, if their daily lives can be totally controlled, and they can be conditioned by reward and severe punishment and subjected to massed practice, where they are forced to repeat or mentally rehearse various ideological statements.

In some cases, this process can actually lead them to “unlearn” their pre-existing mental structures, as Walter Freeman has observed. These unpleasant outcomes would not be possible if the adult brain were not plastic.

Almost all neuroscientists, as Merlin Donald writes, had a view of the brain as an isolated organ, almost as though it were contained in a box, and they believed that “the mind exists and develops entirely in the head, and that its basic structure is a biological given.” The behaviorists and many biologists championed this view.

Among those who rejected it were developmental psychologists, because they have generally been sensitive to how outside influences might harm brain development.

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.

About twenty years after the spread of TV, teachers of young children began to notice that their students had become more restless and had increasing difficulty paying attention. The educator Jane Healy documented these changes in her book Endangered Minds, speculating they were the product of plastic changes in the children’s brains. When those children entered college, professors complained of having to “dumb down” their courses each new year, for students who were increasingly interested in “sound bites” and intimidated by reading of any length.

Meanwhile, the problem was buried by “grade inflation” and accelerated by pushes for “computers in every classroom,” which aimed to increase the RAM and gigabytes in the class computers rather than the attention spans and memories of the students. The Harvard psychiatrist Edward Hallowell, an expert on attention deficit disorder (ADD), which is genetic, has linked the electronic media to the rise of attention deficit traits, which are not genetic, in much of the population. Ian H. Robertson and Redmond O’Connell have had promising results using brain exercises to treat attention deficit disorder, and if that can be done, we have reason to hope that mere traits can be treated as well.

Most people think that the dangers created by the media are a result of content. But Marshall McLuhan, 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.”

Erica Michael and Marcel Just of Carnegie Mellon University did a brain scan study to test whether the medium is indeed the message. They showed that different brain areas are involved in hearing speech and reading it, and different comprehension centers in hearing words and reading them. As Just put it, “The brain constructs the message… differently for reading and listening. The pragmatic implication is that the medium is part of the message. Listening to an audio book leaves a different set of memories than reading does. A newscast heard on the radio is processed differently from the same words read in a newspaper.”

Michael and Just’s experiment shows that each medium creates a different sensory and semantic experience— and, we might add, develops different circuits in the brain.

Each medium leads to a change in the balance of our individual senses, increasing some at the expense of others. According to McLuhan, preliterate man lived with a “natural” balance of hearing, seeing, feeling, smelling, and tasting. The written word moved preliterate man from a world of sound to a visual world, by switching from speech to reading; type and the printing press hastened that process.

Now the electronic media are bringing sound back and, in some ways, restoring the original balance. Each new medium creates a unique form of awareness, in which some senses are “stepped up” and others “stepped down.” McLuhan said, “The ratio among our senses is altered.”

We know from Pascual-Leone’s work with blindfolded people (stepping down sight) how quickly sensory reorganizations can take place.

To say that a cultural medium, such as television, radio, or the Internet, alters the balance of senses does not prove it is harmful. Much of the harm from television and other electronic media, such as music videos and computer games, comes from their effect on attention. Children and teenagers who sit in front of fighting games are engaged in massed practice and are incrementally rewarded. Video games, like Internet porn, 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.

Television, music videos, and video games, all of which use television techniques, unfold at a much faster pace than real life, and they are getting faster, which causes people to develop an increased appetite for high-speed transitions in those media. 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 response,” 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.

The orientation response evolved, no doubt, because our forebears were both predators and prey and needed to react to situations that could be dangerous or could provide sudden opportunities for such things as food or sex, or simply to novel situations. The response is physiological: the heart rate decreases for four to six seconds.

Television triggers this response at a far more rapid rate than we experience it in life, which is why we can’t keep our eyes off the TV screen, even in the middle of an intimate conversation, and why people watch TV a lot longer than they intend. Because typical music videos, action sequences, and commercials trigger orienting responses at a rate of one per second, watching them puts us into continuous orienting 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. People who write on a computer are often at a loss when they have to write by hand or dictate, because their brains are not wired to translate thoughts into cursive writing or speech at high speed. As we use an electronic medium, our nervous system extends outward, and the medium extends inward.

Electronic media are so effective at altering the nervous system because they both work in similar ways and are basically compatible and thus easily linked. Both involve the instantaneous transmission of electric signals to make linkages. Because our nervous system is plastic, it can take advantage of this compatibility and merge with the electronic media, making a single, larger system. Indeed, it is the nature of such systems to merge whether they are biological or man-made.

The nervous system is an internal medium, communicating messages from one area of the body to another, and it evolved to do, for multicelled organisms such as ourselves, what the electronic media do for humanity— connect disparate parts.

“Today, after more than a century of electric technology, we have extended our central nervous system itself in a global embrace, abolishing both space and time as far as our planet is concerned.” Space and time are abolished because electronic media link faraway places instantaneously, giving rise to what he called the “global village.” This extension is possible because our plastic nervous system can integrate itself with an electronic system.

We must be careful clinically too, as we speak of brain plasticity, not to fall into blaming those who, despite this new science, cannot benefit or change. Clearly neuroplasticity teaches that the brain is more malleable than some have thought, but to move from calling it malleable to calling it perfectible raises expectations to a dangerous level.

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.