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Judy Perkins Walker
Research into how the brain processes communication functions is critical to helping stroke survivors recover lost language skills

Bob Lundstrom had just finished speaking on the phone with a lawyer and with the head of his company in Sweden when a strange feeling came over him. It was as if his brain “was going down.”

Unaware of what was happening or of the severity of his condition, the Georgetown, Maine, resident tried to continue his normal morning routine. He stopped at the local post office, but left abruptly when he was unable to communicate with the postmaster. Although Lundstrom was unaware of it, his speech was incomprehensible, something of a “word salad.”

Lundstrom, a physicist and founder of his own wire-making company, then drove to Bath to meet his wife for lunch–driving, he recalls, “as though I was drunk,” the road appearing to him as though he was looking backward through binoculars. By the time he arrived, it was clear something was wrong, but Lundstrom could not articulate what he was experiencing.

Such a sudden inability to communicate is one of the symptoms of stroke, the nation’s third leading cause of death. Those who survive strokes often are unable to read, write or talk. Others like Lundstrom, who had a stroke in 1996, may only be able to express part of their message, without the appropriate or logical arrangement of words.

Their inability to process or produce language because of brain damage is known as aphasia, which affects more than a million people in the United States, according to the National Aphasia Association. People with aphasia lose the ability to process and produce language in the part of the brain that is damaged by stroke, says Judy Perkins Walker, a University of Maine researcher and associate professor of communication sciences and disorders.

Walker, who would eventually meet Lundstrom at a stroke survivors’ support group meeting, understands what happens when a stroke or brain injury causes aphasia. She has spent 20 years working in hospitals with patients who have brain damage and researching the complex effects of such trauma. Patients who volunteer to cooperate with Walker in her research are struggling to understand stroke damage and its effects. Lundstrom agreed to participate in Walker’s research and served as a test subject.

Walker’s research is contributing to new understanding of how the brain processes certain aspects of language. Her work blends scientific and medical theory with research results and communication performance by survivors.

Walker is an internationally recognized authority on an area of neurolinguistics concerning prosodic deficits in brain-damaged subjects, and has published numerous articles in scientific journals on her research. She speaks on the topic throughout Maine, nationally and internationally. With response-time experiments and acoustic analyses of speech production, Walker currently is focusing on how language is processed and produced by people who have had strokes.

Specifically, Walker studies prosody, or the melody of speech that helps us understand language through more than mere words. She concentrates on injuries to the left hemisphere of the brain, the area that controls our ability to understand and produce language, including intonation and accenting on specific words or syllables to assist in recognizing nouns and verbs.

Patients with right hemisphere damage also are part of Walker’s research. The right hemisphere is responsible for spatial and perceptual functioning, including a person’s ability to decipher emotion and non-verbal communications that may be conveyed through prosody.

Walker’s research expands on existing theory that explains how the left and right hemispheres work together to process the overall meaning of sentences. The left hemisphere processes prosody that conveys linguistic meaning; the right hemisphere processes aspects of prosody that convey emotional information.

To understand the linguistic distinctions that Walker asks her research subjects to make, consider words like “suspect,” “convict” or “permit” that carry multiple meanings as nouns or verbs, depending on which syllables are stressed. Aphasic subjects may hear the tonal distinction, but may be unable to understand it when the message reaches the damaged left hemisphere of the brain.

In a similar example, consider the parsing, or grammatical interpretation of a sentence like, “The man who hunts, ducks out in winter.” Aphasic subjects may overlook the comma or not register the pause, parsing the sentence incorrectly: “The man who hunts ducks, out in winter.”

Linguistically, people tend to associate words that naturally go together, like “hunts ducks,” according to Walker. But prosodic cues can direct a listener to parse the sentence differently.

Perhaps more troubling for an aphasic subject is the inability to understand whether a question is being asked or statement being made by the rise or drop in tone at the end of a sentence. They hear the change in intonation, but they do not process what it means.

Conversely, a subject with right hemisphere damage may have trouble distinguishing emotional meaning in a sentence that is conveyed through varying intonation.

In her work with people who have brain damage, Walker measures response times and accuracy as they decipher words and sentences. With the latest acoustic equipment in her laboratory, Walker also can measure the features of prosody, such as increased syllable duration–components of speech that can be altered by stroke damage.

The complexity of language processing and production often is taken for granted, Walker says, but it is important in determining what communication functions have been compromised by the damage and what therapy will be most effective in treatment. That’s why she and other researchers are trying to establish the degree to which prosody affects understanding and production of meaningful sentences in people with brain damage.

Using her findings, she hopes to help develop more effective therapies so people with aphasia can recover communication skills or at least compensate for them sooner.

Students in the Department of Communication Sciences and Disorders find Walker’s research and classes particularly insightful and memorable. Research assistants under her supervision often work with aphasic subjects. Recent UMaine graduate student Rebecca Pelletier, now a speech pathologist working at a rehabilitation center and a hospital in Bangor, studied under Walker in courses and as a research assistant. She says Walker’s anecdotal teaching methods introduce students to the realities of patients’ symptoms and struggles. They also learn about the importance of family support in a stroke survivor’s recovery, she says.

Before joining the University of Maine faculty in 1997, Walker spent many years as a clinician and researcher working with patients with neurological disorders in such settings as the Veteran’s Administration Hospital in Houston, Massachusetts General Hospital and Spaulding Rehabilitation Hospital in Boston, and Dartmouth-Hitchcock Medical Center.

“My focus is really to teach students to become future speech-language clinicians who will work in medical settings, helping patients get back on their feet and start living a life as normal as possible after a stroke.”

Bob Lundstrom’s stroke wiped out an entire vocabulary in English and German languages, and his grasp of Morse code.

“It was a powerful thing for me in the hospital for a long time,” Lundstrom says. “I couldn’t (verbalize that) I wanted a glass of water. You can’t imagine the frustration a patient has. I couldn’t read, write or spell. I couldn’t understand what they were saying on TV.”

In the months of therapy designed to get him to use other parts of his brain, Lundstrom began memorizing words again. He practiced them one by one, with his speech therapist and his wife– all part of the support team Walker says is important for recovery.

“Someone’s got to look you in the eye and say–You can do it,'” says Lundstrom, 67, who now speaks about his experiences in Walker’s classes. “It’s going to be somebody like Dr. Walker or someone she’s taught.”

After his stroke, even Lundstrom’s then 4-year-old grandson was part of the therapy. He told his grandfather: “Papa, you taught me the names of the trees. Now I’ll teach them back to you.”

by George Manlove

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