Train Your Mind, Change Your Brain: How a New Science Reveals Our Extraordinary Potential to Transform Ourselves, by Sharon Begley

The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science, by Norman Doidge

You cut your finger, and after a few days the cut heals. You break a leg, and the bone can be set so that it mends. You work out, and the muscles you exercise become bigger. In many ways, you can see how your body responds to your activities, and even to injury, and somehow reshapes and regenerates itself. When it comes to the brain, however, the idea for a long time was that it was much more fixed in its capabilities than the rest of the body. But we’re discovering that in fact the brain is much more flexible, more plastic, than anyone had known.

Neuroplasticity is the brain’s ability to rewire its connections and reorganize itself, an ability that was once thought to be minimal in adulthood. For one thing, it was long accepted as a truism that if you lost neurons during adulthood, you were out of luck because you were not going to get any more. Adult neurogenesis is a relatively recent and very exciting discovery; your brain goes on producing new neurons well into old age. (One of the more poignant stories of neuroplasticity is the first observation of the growth of new brain cells in adults. Terminal cancer patients were undergoing a treatment that left a biomarker indicating new cell growth. These patients gave permission for their brains to be examined after they died, and the biomarker clearly illuminated the presence of new brain cells.)

The other old idea unseated by discoveries made in the past couple of decades is the idea that different areas of the brain were able to do only a single task and could not be pressed into service for other purposes. It turns out that this is not the case at all. For example, in a blind person the visual cortex is used not only for touch but for processing language (using the sensory input from the fingers that comes through reading braille). Deaf people use their audio cortex for enhanced peripheral vision. People who have had strokes are able, with the right kind of therapy, to regain functions that had been damaged and initially thought lost.

Two new books deal with some of the discoveries and ramifications of neuroplasticity. Doidge centers each chapter of his book on a person or several people who have experienced sometimes dramatic occurrences of a particular type of neuroplasticity, which gives him a readable framework for presenting the neuroscience behind the stories. Begley’s book presents a well-organized progression from discoveries of brain reorganization in animals, through a discussion of brain plasticity in youth, and on to recent research into neuroplasticity in adult brains, including the reshaping of the emotional brainscape that is possible through psychiatric therapy or mental training such as meditation. The books complement each other fairly well (although if I had time to read only one, I’d pick Begley’s, for reasons that I explain below). Of necessity, both cover some of the same stories of discovery, but often from slightly different angles.

The stories of physical problems that can be remedied to one degree or another through engaging the plasticity of the brain are remarkable and often touching. Doidge’s case histories made for easy reading, and it was heartening to read about people who recovered significant functionality after a stroke or other injury, or about children who were able to overcome dyslexia. The sections of both books that dealt with the more straightforward aspects of brain reorganization in response to outside stimuli were among the strongest, in my opinion.

And it’s not just that the brain can reorganize itself to work around damaged areas and regain some functionality. The idea of enhancing brain function in normal people or delaying the consequences of aging is very exciting. I really enjoyed learning about the ways that the brain reacts as a muscle would to repeated demands–not through the same mechanisms, obviously, but frequently used areas of the cortex do grow disproportionately large. E.g., a study of London cab drivers’ brains showed that they tended to have a larger hippocampus–important for navigation–and a study of violinsts’ brains showed that the four fingering digits of the left hand get a disproportionate amount of neural real estate. I am taking to heart Doidge’s advice about learning a new language in old age, as part of a program to keep my brain challenged, active, and I hope functioning well (although it will be a good many years before I need to start thinking about which language it will be).

Neuroplasticity is active not just in the somatosensory cortex (which controls physical sensation and movement) or physical functioning, but also in our emotional states and mental functioning. I tend to think of the new neuroplasticity discoveries in terms of the two areas I described above: adult neurogenesis and brain rearrangement in response to outside events. Scientists used to think these things didn’t happen, and now we know they do and are finding out the degree to which they do. Doidge seems to use the term in a broader sense, talking about learning emotional or behavioral patterns, although obviously the news here is not that it happens but rather that we’re starting to understand better how it happens. He’s a psychiatrist and psychoanalyst, and this is evident in his interest in mental and emotional problems and their treatment. (Most of his stories are enjoyable to read, but if you are at all prone to squeamishness or are apt to be revisited by distressing mental images, spare yourself the section about masochist Bob Flanagan in chapter 4.)

Doidge tries to explain Freudian psychoanalysis in terms of rewiring brain circuits, but I’m not convinced that this really adds anything explanatory, and the case history he chose to illustrate this section was a life of such heartbreaking early losses that it’s hard to apply any of the things he talks about to more everyday emotional problems. His treatment of obsessive-compulsive disorder (OCD) seemed a bit skimpy, which was disappointing. (One of the most striking observations of mental activity changing the brain is Jeffrey Schwartz’s finding that therapy for OCD affected his patients’ brain chemistry; Begley mentioned this in her book, and in fact co-wrote an earlier book with Schwartz that covered the OCD treatments and other aspects of neuroplasticity. I was hoping for a more extensive case history from Doidge on the subject.)

Begley sets her book in the context of the Mind and Life Conference of 2004, a gathering of neuroscientists, philosophers, and Buddhist monks to discuss neuroplasticity. (The Mind and Life series of meetings between the Dalai Lama and western scientists is organized by the Mind & Life Institute.) I felt like her book provided a much broader neuroscience background and also a lot more detail about some of the scientific work, which I really appreciated. (That’s why if I had time to read only one book about neuroplasticity, it would definitely be Begley’s.) And it’s always impressive to see the Dalai Lama’s openness to the findings of science.

The only place in Begley’s book that really bothered me was a chapter that discussed the difficulty of understanding how the mind can change the brain. The Buddhists at the meeting believe that mind is nonphysical and separate from the brain. This is hard to square with Western science, which has found that as far as we can tell, everything we call “mental” is the result of something physical happening in the brain. Western science is still unclear on some of the mechanisms by which conscious mental processes or states change the brain, but it’s a matter of figuring out how one part of a complex system interacts with another. My impression is that what the scientists are grappling with (figuring out how it works) is a far different question from the old Cartesian mind-body interaction, which is what seemed to be exercising the Buddhists, and yet the chapter seemed to me to be implying more common ground than there in fact was.

The bottom line is that I thought both books were informative and worth reading. It’s good to be around to watch brain science teaching us so much about how our brains work and what previously unsuspected capacities they harbor. I hope to hear more in the future about how to make neuroplasticity work for us when it comes to enhancing mental performance and learning new things (that new language I’m going to save for my old age, for example).

Under a Green Sky: Global Warming, the Mass Extinctions of the Past, and What They Can Tell Us About Our Future, by Peter Ward. Collins, 2007.

Under a Green Sky tells three stories: A story of Earth’s past climate, a story of how scientists have figured out what we know about Earth’s history, and a story of what our future climate might be like. It’s a scary book, but also a call to action.

Peter Ward, a paleontologist, opens with a recent bit of the scientific-discovery story: how we found out that the mass extinction that happened 65 million years ago, the dinosaur-killing one at the end of the Cretaceous, was caused by an asteroid impact. He starts there because, despite the initial controversy over this discovery, cosmic impact became for awhile the dominant model for how most if not all mass extinctions happen. Ward then goes on to describe, with plenty of interesting details about geological field trips and the back-and-forth of scientific discovery, the way this dominant model was nudged aside by the gradual realization that most of the mass extinctions we know about were actually caused by climate change.

After sharing this insider’s view of how science is done, Ward describes how climate change has caused past mass extinctions. Greenhouse gases get into the atmosphere one way or another (e.g., from volcanic eruptions, or more recently of course from human activity), and if the world gets warm enough, the oceans begin to die. Right now, differences in temperature and salinity drive a conveyer system of currents that keep the present-day oceans oxygenated and alive. (The Gulf Stream, which you’ve probably heard mentioned in connection with global warming, is part of this system. Ward describes the movie The Day After Tomorrow, by the way, as a fable that trivializes the ominous possibility of rapid climate change. It sounds like a fast freeze is not the most likely, or even the most scary, possible outcome of the Gulf Stream’s disruption.)

Greenhouse warming disrupts the conveyor system, rendering the ocean depths warmer and less oxygenated and killing the creatures that live there. One of the few things to thrive in these oceans is a type of bacterium that produces toxic (to everything else) hydrogen sulfide. In some cases, carbon dioxide and methane can arise in bubbles from the ocean and enter the atmosphere, along with deadly hydrogen sulfide gas, which is not only noxious–it also breaks down the ozone layer, increasing the amount of ultraviolet radiation reaching the planet’s surface. All these factors contribute to mass extinction. It’s a sobering scenario to contemplate in an era of global warming.

When Ward focuses on the story of Earth’s climate, you get an idea of how unusual the time we’re living in really is. We think of Earth as being like the middle bear’s porridge, just right for life, and we wonder how many other planets are out there that might also be just right. But in fact the Earth has been intermittently all wrong, deeply frozen or stifingly hot with toxic oceans, and it might be so again. A few years ago Ward co-wrote a book with Donald Brownlee about the eventual fate of the Earth; toward the end of it they talked about their belief that interstellar travel is not likely to deliver us from future events on Earth, and this world is likely all we’ll have to depend on. They note:

“We live in a glorious summer of beauty, diversity, and resources. It will not always be so.”

And:

“…this moment on this Earth truly is a precious gift, to be savored and appreciated. If we heedlessly destroy this world, it is unlikely we will find another to replace it. Or be able to get to any refuge, even if we could find it.

Another obvious lesson is that we tinker with our atmosphere and oceans at grave risk.”

Under a Green Sky gives me more context about past conditions on Earth and how unusual the long interglacial period in which humans have had the chance to flourish really is.

This of course is important for the third story Ward tells, that of present-day climate change and where it might lead. Based on what has happened in past conditions of high CO2 levels, he describes possible futures for Earth. It’s in some sense a write-your-own-ending book. Ward closes by outlining three possible future worlds, each with a different atmospheric concentration of carbon dioxide.

Even the best-case scenario is far from ideal, and it would require us to keep the level of CO2 below 450 parts per million (ppm). (It’s currently at 380 ppm and rising.) An intermediate view shows the world at 700 ppm by the year 2100, a discouraging sight, and the worst-case scenario looks at what would happen if the levels hit 1,100 ppm by 2100–the beginning of a return to the hellish conditions of the ultrawarm Eocene epoch, dead oceans and all. He says that we can keep CO2 levels down in the range where we wouldn’t have to face anything worse than the first scenario, but we must act immediately. (It’s outside the scope of the book to go into any detail about how, but check out the action items at stopglobalwarming.org for some ideas about what you can do.)

Coincidentally I recently saw the last two episodes of Carl Sagan’s Cosmos series, in which he talks about SETI and about the perilous choices facing humankind, both topics that have links to what I’ve just been reading in the Ward book.

The Drake equation, which multiplies together factors affecting the odds of contacting intelligent life elsewhere in the cosmos, includes a factor sometimes called L, the average lifetime of an advanced civilization. Of course any number you plug in for L is just a guess. Somewhere years ago I saw a little jingle that went:

Of all the sad stories that SETI could tell,
The saddest would be a small value for L.

I wonder whether the odds of our own survival look subjectively better or worse than they did when Cosmos was made. Nuclear war doesn’t seem as pressing a threat, but climate change certainly seems more urgent. (It was just as urgent then, but, sadly, many of us were not paying enough attention.)

In the final episode of the show, Sagan talks about the dangers of nuclear war and other hazards we face, including climate change. He adapted a quote from Deuteronomy to the effect that we have the choice of life and death before us, and we must “therefore choose life”. I hope we have the collective intelligence and will to do so.

The Three-Pound Enigma: The Human Brain and the Quest to Unlock Its Mysteries, by Shannon Moffett. Algonquin Books of Chapel Hill, 2006.

This overview of the current state of brain science is both entertaining and informative. Each chapter covers a particular facet of the sprawling field: neurosurgery, cognitive neuroscience, neuroethics (itself a multi-faceted field), sleep and dream studies, etc. Moffett, a medical student at Stanford, hung out with some of the top researchers and thinkers in neuroscience, which gives the book the feeling of a series of good conversations with curious minds (e.g., Christof Koch and Francis Crick on the search for the neural correlates of consciousness, John Gabrieli on memory, Daniel Dennett on the nature of consciousness). The book is also filled with interesting tidbits of information, like why you shouldn’t go into an fMRI machine if you’ve ever worked in a machine shop, how the video game Tetris was used to study dreaming and memory, and the story of how Francis Crick and his wife Odile met. I really enjoyed the feeling that I was getting to know some of the personalities behind the research I read about. And while some of the information was not new to me, I learned a surprising amount about how the brain works and how research on the brain proceeds.

The chapters are interspersed with a series of “interludes”, brief descriptions of the brain at various stages of life, starting at three weeks after conception and ending with death. These were probably the most educational for me, because my knowledge of brain anatomy, and in particular brain development, is far from complete. The one that stands out most in my mind described the chemistry of how synapses fire; it’s one of the longer interludes and took a little effort to follow. The payoff came at the end:

The significance of the foregoing, and the reason to have waded through it at all, is that—as Francis Crick pointed out—as far as we can tell, every thought (wondering what you’ll have for lunch or what you’ll wear tomorrow), every desire (for glory, for that hottie you see at the gym, for a peanut-butter sandwich), and every experience (of reading this book, for instance—of your hand on the page, the quality of the light you are reading by, the feeilng of your breathing) that you have or have ever had is nothing but the opening and closing of those ion channels and the release and uptake of those neurotransmitter molecules. One of the great philosophic questions forced upon us today is how that knowledge could or should change our concept of what it means to be human.

I have long believed that we have no immaterial souls, no consciousness beyond what arises out of the activity between our ears, so this is not exactly news to me, but somehow reading the detailed description of how it works at the level of the calcium and potassium channels really brought home to me how wonderful a thing it is that from such small chemical events such a rich variety of experiences can arise.

The interludes were integrated well into the rest of the content; the last one in particular, about brain death and the difficulties that sometimes arise in determining when it has occurred, fits in very neatly after a chapter on neuroethics. And overall I thought there was a good balance between the parts about brain anatomy and physiology, the discussions of what consciousness is and how we can learn about it, and the explorations of human behavior and experience. If you are squeamish and if, as I do, you read while you eat, be aware that the book opens with a description of an autopsy and the first chapter is about brain surgery. The brain surgery chapter in particular, interesting as it was, gave me a mild case of the heebie-jeebies; I really don’t like to think about how vulnerable the brain is and how many things can go wrong with it. Other than that minor caveat, I can say that reading this book was both pleasant and educational.

I began reading The Echo Maker, the latest novel by Richard Powers, with high hopes, but overall it was a disappointment. Powers is an intelligent writer of ambitious novels that link science and the humanities; I enjoyed Galatea 2.2, a moving story of artificial intelligence. The Gold Bug Variations is probably his best-known work, and although that has been recommended highly by friends I could never get further than a couple of chapters into it.

The subject matter of The Echo Makers is full of relevance for thinking-meat types: it tells the story of a young man who suffers from Capgras syndrome after a brain injury. Capgras sufferers believe that a relative or close friend has been replaced with a physically identical imposter. (It might happen as the result of some kind of disconnect between the amygdala and other brain circuits; the brain recognizes the physical appearance of the person, but the emotional resonance that gives the person his or her identity as a spouse or sibling or child is missing, and so the Capgras patient concludes that he or she must be a stand-in for the real thing.) In the case of the man in the book, Mark Schluter, it is his sister and his dog that he can’t recognize.

To explain his situation to himself, Mark devises a story about how his hometown and the people close to him have been either replaced with doubles or co-opted in the service of some shadowy government plot. Mark and his sister are the children of a dysfunctional pair of parents (both dead), and Karin in particular struggles to escape the past but winds up getting sucked back into old familiar destructive patterns of behavior. Partway through the novel she calls on a neuroscientist, Gerald Weber, who writes popular books (à  la Oliver Sacks) to see if he can help her brother. The book is set in Nebraska, and the stories of the humans are intertwined with those of the cranes who visit the area every year as part of their migration.

The theme of identity is well developed throughout the book, in particular the idea that it’s much more fragile than we usually imagine. I think it was in Timothy Ferris’s The Mind’s Sky: Human Intelligence in a Cosmic Context that I first ran across the idea that our brains process information and come to decisions to some degree outside of conscious awareness, and our sense of who we are is basically a story developed by the conscious mind to explain our perceptions of reality and the results of our subconscious processing of it. Basically the “I” is a figurehead, moved around by powers behind the throne but usually not aware of this fact.

Powers plays with this idea and other facets of identity, illustrating through his characters how we integrate our sense of our own identity and that of others over time, how we struggle sometimes to overcome or improve upon our sense of who we are, and how we cobble together our stories of ourselves as best we can. (As I read, I was reminded of a couple of lines from Galatea 2.2: “You make what you think might be a vase for the blooms you are carrying. You tell the stories you need to tell to keep the story tellable.”) Elements of the story also deal with how we incorporate unexpected disclosures about others into our mental image of who they are.

So the book covers themes that I love to explore, and Powers’s style is often beautiful. However, it’s also sometimes maddeningly elliptical, and sometimes ponderous and heavy-handed. He complicates his story with a mystery about what happened on the night of the accident that resulted in Mark’s brain injury, and I found the mystery to be more of an irritant or a distraction than an enhancement. The book seemed to me to drag in the middle, with some of the inner musing of the characters slowing down the story rather than being incorporated into it, and the revelations at the end don’t carry as much of a punch as they could.

In fact the whole thing was surprisingly unengaging emotionally, although I can’t quite put my finger on why. Partly it’s that I didn’t like or couldn’t empathize with some of the main characters. It was frustrating to watch Karin sabotage herself despite her good intentions, and Weber’s midlife crisis felt hollow and unreal to me. I think Powers did a decent job of depicting Weber’s marriage, itself a living thing with an identity made up to some degree of memory, habit, and jokes and phrases shared only by him and his wife. The trouble was that I didn’t like either of them all that well. I did feel a great deal of sympathy for Mark Schluter as he tried to make sense of the new world he found himself in after the accident, but other than that I found myself wanting to shake most of the other characters at one time or another.

I’m glad I read the book, out of curiosity if nothing else, but I can’t say I recommend it. However, I’ll follow this author’s work in the future, and I can highly recommend his earlier Galatea 2.2.