Great Adaptations

Diagram

The left panel captures the brain’s response for neurologically intact individuals when reading words in a functional magnetic resonance imaging scanner. In people with brain lesions (right panel, black regions), the brain’s response while reading is quite different.

Brenda Rapp, a professor in the Department of Cognitive Science, began her professional life in education, trying to help children with dyslexia and dysgraphia boost their reading and writing skills. The work was a joy, but it was also somewhat of a mystery.

“Kids were getting better, but I didn’t really know why they were getting better,” Rapp says. “It felt like a bit of an art form, and what I wanted was a real scientific base of understanding of how the brain does these things. What are the processes? What are the mechanisms?”

Such questions remain at the heart of Rapp’s work today. The chair of the Department of Cognitive Science studies stroke victims in an attempt to understand what’s happening in their brains as they recover and regain a measure of their lost skills in spoken and written language.

“When you have a stroke and you lose skills like these, the parts of the brain where those skills used to be are just gone—the neurons are no longer there,” she says. “But people do get better, and they can continue to keep getting better for an incredibly long time. We’re trying to understand how that happens.”

What part of the brain do speaking and writing skills move to after a stroke? Does the process vary from person to person? Or is something systematic about the human brain at work?

Firm answers to such questions are a long way off. “There has been very little research in this area,” Rapp says. “It’s only in the last 10 years that anyone has started to look seriously at questions like these.”

The fact that every stroke is different, inflicting a unique pattern of damage, complicates the research process. A key component of Rapp’s research strategy involves focusing on conducting in-depth case studies of the brains of individual stroke victims.

Research subjects come in once every couple of weeks over the course of many months to undergo functional magnetic resonance imaging (fMRI) while engaged in spelling, reading, and speaking tasks.

“We’re measuring the changes in their skills and abilities over time,” Rapp says. “And we’re looking to see how those changes in skills relate to the changes the fMRI shows in brain activity over time.”

A couple of hypotheses are in play at this early stage. One holds that the brain moves lost skills to areas adjacent to where the damage occurred, perhaps because those areas retain some fragmentary familiarity with the skills. Another hypothesis has the lost skills moving to the comparable area in the opposite hemisphere of the brain, perhaps because such “homologous” regions share structural similarities appropriate to the lost skills.

To advance progress in this area, the National Institute on Deafness and Other Communication Disorders recently awarded a $12 million, five-year grant to support research on stroke victims in three cities. In Baltimore, Rapp will be focusing on written language, with colleagues at Northwestern University focusing on understanding sentences, and colleagues at Boston University and Harvard examining skills involved in producing spoken words.

“Up until now, different researchers have used a lot of different methodologies and measured different things,” Rapp says. “With this study, we’re going to focus on testing patients in similar ways across all three locations so that we can begin building up a systemic and comprehensive database of cases for the first time.”

Developing such a foundation of basic knowledge is the essential first step on the road toward turning this young field of research into genuine help for stroke victims. If scientists do gain a better understanding of what’s happening in the post-stroke brain, that may open the door for effective therapies.

“There may be ways to target the areas of the brain that turn out to be critical for stroke victims,” Rapp says. “Are there pharmacological interventions? Would some method of electrical stimulation help?”

That possibility is what drives many of Rapp’s subjects to participate in her research. “People who have a stroke, they feel like this terrible thing happened to them, and their life just went off in a new direction,” Rapp says. “A lot of them tell me that if maybe someone could just learn something from what they’re going though, they’d be able to be a part of helping other stroke victims in the future.”

—Jim Duffy