Thursday, July 25, 2013

The Brain That Changes Itself

One day I walked into a room at the Dojo and sat down. Someone was already at the table, on the opposite side, a guy who didn't appear totally thrilled at the prospect of sharing his space for the day. There was relief when I didn't need much real estate, and we left each other alone.

Over the next hour it dawned on me that the other three humans in the room might all be coworkers, working on the same project. Still, not leaving. Table space with quiet in a room, not easy to come by at the Dojo. Not easy at all.

Technically it's all public space. Yet lots of projects need to fly under the radar. There's some tension around those two things. And that's how I met Ahksar, who eventually asked what I was working on. Then he told me about this book.

After Mirroring People and the thrill of cutting-edge neuroscience research, I was a bit skeptical. Anecdotes are less powerful, less generalizable, less useful as hard science. Forget about the feel-good, just give me some functional progress! After a few chapters, my patience was rewarded. That's when I realized that anecdotes are the only way to tell this story. We have been engaged in a shockingly basic debate over the brain's ability to heal itself.

From the 1700's to about 25 years ago, the medical establishment viewed the human brain as a fascinating machine. They discovered that damage to specific brain areas caused loss of specific mental functions. This theory became known as "localizationism", tying mental functions to a dedicated physical neighborhood in the brain. It makes me think of the diagram of a steer you see at the meat counter, and the various cuts of beef labeled on parts of the animal. But the theory outran the data, morphing from
a series of intriguing correlations (observations that damage to specific brain areas led to the loss of specific mental functions) to a general theory that declared that every brain function had one hard-wired location-an idea summarized by the phrase "one function, one location," meaning that if a part was damaged, the brain could not reorganize itself or recover that lost function.
Until recently, localizationism was so entrenched in the medical community that research to disprove it was subject to hostility and ridicule. Discussing and researching a contrary position could be hazardous to your career. And of course, it painted a bleak picture for survivors of brain injuries. You start life as an infant with a certain number of neurons and it's a long slope downward from there. You might lose them to injuries or disease during the course of your life and then as you age function declines and then you die.

Yet examples kept surfacing of humans who recovered lost function after strokes, congenital abnormalities, and injury. And research kept happening. A couple of renegade scientists, Paul Bach-y-Rita and Edward Taub kept advancing the theory of neuroplasticity. They and others showed that
the damaged brain can often reorganize itself so that when one part fails, another part can often substitute; that if brain cells die they can often 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 and off, thus shaping our brain anatomy and our behavior
While reading the examples in this book at some point I made the connection that most of the doctors I've interacted with were schooled according to the theory of localization. By virtue of when and how rigorously they were trained, they had to embrace it. When it was discovered to be wrong, that the brain is actually plastic and it changes according to its environment, they were already practicing medicine. When you really, really like the feeling of being an expert, it's tough to give that up. It's easier to tell wrong things to patients to get them to go away.

So, that was definitely a feel-good moment!

More excitement when I read about the implications for rebuilding brain function. Edward Taub, a neuroscientist who worked with monkeys, developed the technique of constraint-induced (CI) therapy. If your left arm is damaged from a stroke and needs to recover function, the right arm is constrained using a cast and a sling. The left arm is then forced to figure out how to execute instructions. It is a long, arduous process but it does work. The brain rebuilds and recruits neurons to recover use of the left arm.

The brain responds to the requirements of situations it finds itself in. To recover function, you have to plunge into uncomfortable situations that you have lost the ability to deal with. Avoidance only tells the brain that it doesn't need to do those things any more.

This, of course, is one premise behind Route 66, a journey. After the accident my comfort zone was surprisingly small, very basic. It's truly frightening and humiliating to step outside that comfort zone. But that's exactly what has to happen. When it comes to brain function, use it or lose it.

It also confirms that torturing myself for a month in language school was completely, exactly the right thing to do after a brain injury. Not to mention slogging around on a bike, relearning what navigation feels like.

There's a story behind how a brilliant maverick like Bach-y-Rita got into the backwater of rehabilitation medicine:

Paul Bach-y-Rita - Neuroplasticity from Dr Bob on Vimeo.

Something was still nagging at me. Why, only six months after the accident, did Dr. H. inform me "the time for physical healing is past. The time for emotional healing has begun"? There has been so much research that shows otherwise! He's a neurologist who specializes in strokes. He's a smart man. It's possible for stroke patients to make incredible recoveries years after their injuries. The ability to recover function does not go away.

I don't know for sure but Dr. H. probably did his residency in neurology 40 years ago. Dr. L., the rehabilitation doctor at Valley Medical, is probably from the same era. Localizationalism was the accepted, unquestioned truth at that time.

Can't help but notice it also fits a lot easier into 15 or 30 minutes, telling a TBI survivor that they're screwed. Rather than working with them for 3 years on a journey to rehab their brain.

According to Marco Iacoboni, there's a saying among neuroscientists to the effect that progress is made one funeral at a time. In other words, for a rapidly-changing field like brain science to progress, the previous generation of neuroscientists has to die, taking their precious long-held outdated beliefs with them.

The author of The Brain That Changes Itself would say this is a downside of brain plasticity. Once we are taught something and we believe it's true our brains adapt, holding tightly onto that belief. Long after it has been disproved. Long after it's outgrown its usefulness.

For now I'll settle for the validation and hope of this book!

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