The Neuroscience of Movement
Every movement you make—walking, reaching for your keys, or writing your name—is carefully orchestrated by hundreds of millions of neurons in the brain, with barely a conscious thought. But when a brain injury occurs, a person’s ability to move may become impaired. A once effortless movement may now seem impossible.
At the Motion Analysis Laboratory, investigators are studying how the brain learns movement patterns. Ultimately, they hope to find new interventions that can enhance movement after brain damage.
Some of the team’s most fascinating research involves non-invasive brain stimulation—applying mild electric current or magnetic pulses through the scalp to stimulate the brain. This type of brain stimulation—conducted either through electrodes placed on the skull or through a coil placed above the scalp that induces a magnetic field—can help speed up learning.
“If you stimulate part of the brain that is important for a learning process, you can make it a little more excitable and make it learn a little bit better,” explains lab director Amy Bastian.
This effect on learning could potentially apply to a broad range of conditions, from brain injury and stroke to behavioral disorders and psychiatric conditions.
Stimulating the brain's surface (red) can induce changes in activity deep into the brain (blue).
What’s more, the team is discovering that reward circuitry in the brain—the brain’s so-called pleasure center—is important in how well new movements can be learned and retained. That’s the focus of biomedical engineer Vikram Chib’s research. His studies have shown that mild electrical brain stimulation to the scalp can penetrate deep into the brain, to the area responsible for motivation, reward, and movement.
His research has also shown that there is an optimal amount of reward that motivates a person. If you give too big of a reward, people start to reframe the situation. Instead of thinking about how much they stand to gain, they start focusing on how much they could lose. As a result, they underperform, or “choke.”
So how does all of this translate to helping patients? “It turns out that different people value loss or reward in different ways,” explains Dr. Bastian. Some people are more motivated by rewards, while others are motivated by avoiding loss. An individualized reward structure could help motivate patients to learn new movements during rehabilitation. “If we give people the right rewards, we may improve how well they learn and retain a new movement.”
The team has already shown that electrical stimulation may be a valuable therapy tool to help people relearn how to walk following a stroke or other brain injury. Their findings suggest that the best rehabilitation may be a combination of physical therapy and brain stimulation.