Excerpt
from The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science
by Norman Doidge MD
This book is about the
revolutionary discovery that the human brain can change itself, as told
through the stories of the scientists, doctors, and patients who have
together brought about these astonishing transformations. Without
operations or medications, they have made use of the brain's hitherto
unknown ability to change. Some were patients who had what were thought
to be incurable brain problems; others were people without specific
problems who simply wanted to improve the functioning of their brains
or preserve them as they aged. For four hundred years this venture
would have been inconceivable because mainstream medicine and science
believed that brain anatomy was fixed. The common wisdom was that after
childhood the brain changed only when it began the long process of
decline; that when brain cells failed to develop properly, or were
injured, or died, they could not be replaced. Nor could the brain ever
alter its structure and find a new way to function if part of it was
damaged. The theory of the unchanging brain decreed that people who
were born with brain or mental limitations, or who sustained brain
damage, would be limited or damaged for life. Scientists who wondered
if the healthy brain might be improved or preserved through activity or
mental exercise were told not to waste their time. A neurological
nihilism -- a sense that treatment for many brain problems was
ineffective or even unwarranted -- had taken hold, and it spread
through our culture, even stunting our overall view of human nature.
Since the brain could not change, human nature, which emerges from it,
seemed necessarily fixed and unalterable as well.
The belief that the brain could not change had three major sources: the
fact that brain-damaged patients could so rarely make full recoveries;
our inability to observe the living
brain's microscopic activities; and the idea -- dating back to the
beginnings of modern science -- that the brain is like a glorious
machine. And while machines do many extraordinary things, they don't
change and grow.
I became interested in the idea of a changing brain because of my work
as a research psychiatrist and psychoanalyst. When patients did not
progress psychologically as much as hoped, often the conventional
medical wisdom was that their problems were deeply "hardwired" into an
unchangeable brain. "Hardwiring" was another machine metaphor coming
from the idea of the brain as computer hardware, with permanently
connected circuits, each designed to perform a specific, unchangeable
function.
When I first heard news that the human brain might not be hardwired, I
had to investigate and weigh the evidence for myself. These
investigations took me far from my consulting room.
I began a series of travels,
and in the process I met a band of brilliant scientists, at the
frontiers of brain science, who had, in the late 1960s or early 1970s,
made a series of unexpected discoveries. They showed that the brain
changed its very structure with each different activity it performed,
perfecting its circuits so it was better suited to the task at hand. If
certain "parts" failed, then other parts could sometimes take over. The
machine metaphor, of the brain as an organ with specialized parts,
could not fully account for changes the scientists were seeing. They
began to call this fundamental brain property "neuroplasticity."
Neuro is for "neuron," the
nerve cells in our brains and nervous systems. Plastic
is for "changeable, malleable, modifiable." At first many of the
scientists didn't dare use the word "neuroplasticity" in their
publications, and their peers belittled them for promoting a fanciful
notion. Yet they persisted, slowly overturning the doctrine of the
unchanging brain. They showed that children are not always stuck with
the mental abilities they are born with; that the damaged brain can
often reorganize itself so that when one part fails, another can often
substitute; that if brain cells die, they can at times be replaced;
that many "circuits" and even basic reflexes that we think are
hardwired are not. One of these scientists even showed that thinking,
learning, and acting can turn our genes on or off, thus shaping our
brain anatomy and our behavior -- surely one of the most extraordinary
discoveries of the twentieth century.
In the course of my travels I met a scientist who enabled people who
had been blind since birth to begin to see, another who enabled the
deaf to hear; I spoke with people who had had strokes decades before
and had been declared incurable, who were helped to recover with
neuroplastic treatments; I met people whose learning disorders were
cured and whose IQs were raised; I saw evidence that it is possible for
eighty-year-olds to sharpen their memories to function the way they did
when they were fifty-five. I saw people rewire their brains with their
thoughts, to cure previously incurable obsessions and traumas. I spoke
with Nobel laureates who were hotly debating how we must rethink our
model of the brain now that we know it is ever changing.
The idea that the brain can change its own structure and function
through thought and activity is, I believe, the most important
alteration in our view of the brain since we first sketched out its
basic anatomy and the workings of its basic component, the neuron. Like
all revolutions, this one will have profound effects. The neuroplastic
revolution has
implications for, among other things, our understanding of how love,
sex, grief, relationships, learning, addictions, culture, technology,
and psychotherapies change our brains. All of the humanities, social
sciences, and physical sciences, insofar as they deal with human
nature, are affected, as are all forms of training. All of these
disciplines will have to come to terms with the fact of the
self-changing brain and with the realization that the architecture of
the brain differs from one person to the next and that it changes in
the course of our individual lives.
While the human brain has apparently underestimated itself,
neuroplasticity isn't all good news; it renders our brains not only
more resourceful but also more vulnerable to outside influences.
Neuroplasticity has the power to produce more flexible but also more
rigid behaviors -- a phenomenon I call "the plastic paradox."
Ironically, some of our most stubborn habits and disorders are products
of our plasticity. Once a particular plastic change occurs in the brain
and becomes well established, it can prevent other changes from
occurring. It is by understanding both the positive and negative
effects of plasticity that we can truly understand the extent of human
possibilities.
Copyright
© 2008 Norman Doidge, M.D.