And so this is what I study. I study specifically how it relates to recovery from stroke. So recently stroke dropped from being the third leading cause of the death in the United States to be the fourth leading cause of the death. Great news, right? But actually it turns out that the numbers of people having a stroke has not declined. We are just better at keeping people alive after a severe stroke. It turns out to be very difficult to help the brain recover from stroke. And frankly we have failed to develop effective rehabilitation interventions.
The net result of this is that stroke is the leading cause of long term disability in adults in the world. Individuals with stroke are younger and tending to live longer with that disability. And research from my group actually shows that the health related quality of life of Canadians with stroke has declined.
So clearly we need to be better at helping people recover from stroke. And this is an enormous societal problem, and it’s one that we are not solving. So what can be done? One thing is absolutely clear: the best driver of neuroplastic change in your brain is your behavior. The problem is that the dose of behavior, the dose of practice that’s required to learn new and relearn old motor skills, it’s very large. And how to effectively deliver these large doses of practice is a very difficult problem. It’s also a very expensive problem.
So the approach that my research has taken is to develop therapies that prime or that prepare the brain to learn. And these have included brain simulation, exercise and robotics. But through my research I’ve realized that a major limitation to the development of therapies that speed recovery from stroke is that patterns of neuroplasticity are highly variable from person to person.
Now as a researcher, variability used to drive me crazy. It makes it very difficult to use statistics to test your data and your ideas. And because of this, medical intervention studies are specifically designed to minimize variability. But in my research it’s becoming really clear that the most important, the most informative data that we collect, is showing this variability.
So by studying the brain after a stroke, we’ve learned a lot and I think these lessons are very valuable in other areas. So the first lesson is that the primary driver of change in your brain is your behavior, so there is no neuroplasticity drug you can take. Nothing is more effective than practice at helping you learn and the bottom line is you have to do the work.
And in fact, my research has shown that increased difficulty, increased struggle if you will, during practice actually leads to both more learning and greater structural change in the brain. The problem here is, is that neuroplastcity can work both ways. It can be positive, you learn something new and you refine the motor skill. And it also can be negative though, you forgot something you once knew, you become addicted to drugs, maybe you have chronic pain. So your brain is tremendously plastic and it’s being shaped both structurally and functionally by everything you do, but also by everything that you don’t do.
The second lesson we’ve learned about the brain is that there is no one size fits all approach to learning. So there is no recipe for learning. Consider the popular belief that it takes 10,000 hours of practice to learn and to master a new motor skill. Now I can assure you it’s not quite that simple. For some of us it’s going to take a lot more practice and for others it may take far less. So the shaping of our plastic brains is it’s far too unique for there to be any single intervention that’s going to work for all of us.
And now this realization has forced us to consider something call personalized medicine. So this is the idea that to optimize outcomes each individual requires their own intervention. And the idea actually comes from cancer treatments. And here it turns out that genetics are very important in matching certain types of chemotherapy with specific forms of cancer.
My research is showing that this also applies to recovery from stroke. So there’re certain characteristics of brain structure and function we called biomarkers. And these biomarkers are proving to be very helpful and helping us to match specific therapies with individual patients. And the data for my lab suggests it’s a combination of biomarkers that best predicts neuroplastic change and patterns of recovery after stroke. And that’s not surprising given how complicated the human brain is.
But I also think we can consider this concept much more broadly. Given the unique structure and function of each of our brains what we’ve learned about neuroplasticity after stroke applies to everyone.
Behaviors that you employ in your everyday life are important. Each of them is changing your brain. And I believe we have to consider not just personalized medicine but personalized learning. The uniqueness of your brain will affect you both as a learner and also as a teacher. And now this idea helps us to understand why some children can thrive in tradition education settings and others don’t. Why some of us can learn languages easily and yet others can pick up any sport and excel.
So when you leave this room today, your brain will not be the same as when you entered this morning. And I think that’s pretty amazing. But each of you is going to have changed your brain differently. Understanding these differences, these individual patterns, these variability and change, is going to enable the next great advance in neuroscience. It’s going to allow us to develop new and more effective interventions, and allow for matches between learners and teachers, and patients and interventions. And this does not just apply to recovery from stroke, it applies to each of us as a parent, as a teacher, as a manager, and also because you are at TEDx today, a life long learner.
Study how and what you learn best. Repeat those behaviors that are healthy for your brain and break those behaviors and habits that are not. Practice. Learning is about doing the work that your brain requires. So the best strategies are going to vary between individuals. You know what, they’re even going to vary within individuals. So for you learning music may come very easily, but learning to snowboard, much harder.
I hope that you leave today with a new appreciation of how magnificent your brain is. You and your plastic brain are constantly being shaped by the world around you. Understand that everything you do, everything you encounter, and everything you experience is changing your brain. And that can be for better, but it can also be for worse.
So when you leave today go out and build the brain you want.
Thank you very much.