University Times

Pitt researcher Connie A. Tompkins has received a $1.2 million grant to study language comprehension deficits in adults who have suffered right hemisphere brain damage as the result of stroke.

That might sound irrational to anyone who has bought into the popular misconception that the left side of the brain controls language functions, while artistic and visual abilities come from the right hemisphere.

“It’s a part of pop psychology that is still widely promulgated, this false idea that there is a strict dichotomy between the right and left parts of the brain,” says Tompkins, a professor of communication science and disorders in the School of Health and Rehabilitation Sciences. But contrary to common belief (even among many physicians, Tompkins laments) and best-selling books such as “Drawing on the Right Side of the Brain,” both hemispheres of the brain control language functions. For example, research over the last 20 years by Tompkins and other scientists has shown that it is actually the right side of the brain — traditionally believed to be the spatially oriented, non-linguistic half — that enables people to understand nuances of language.

That’s why people recovering from right hemisphere strokes often have difficulty comprehending words and phrases that have more than one meaning, Tompkins says. “This can be quite socially handicapping — for example, when someone tells a joke or makes a sarcastic comment, and the person who has right-hemisphere stroke damage doesn’t get it or misses the point.”

Scientists used to believe that patients who had suffered right-hemisphere strokes lost knowledge of different interpretations of some language forms, especially words (“bat,” for example) or phrases (such as “Can you open the door?”) that have more than one meaning.

But research by Tompkins and her colleagues indicates that this isn’t true. “We’ve found that when multiple interpretations can be made — for example, when there is a literal as well as an intended, humorous interpretation of the punch line of a joke — the person with right hemisphere brain damage is still able to entertain all of the possible interpretations,” Tompkins says.

What they can’t do very well is zero in on which interpretation is appropriate within the context of the conversation.

“If they follow up on the wrong interpretation, that can be very problematic. They could get messages wrong at work, for instance.”

Tompkins’s $1.2 million grant from the National Institute on Deafness and Other Communication Disorders will fund a study in which adults with right hemisphere brain damage (RHD) will be asked to complete comprehension tasks; their results will be compared with results from adults who have not had strokes. The study also will use MRI scans to determine if the locations of brain lesions affect patients’ communication deficits. For more information or to enroll in the study, call 412/383-6624. The study is enrolling individuals with RHD as the result of stroke, as well as older people who have not had a stroke.

A stroke occurs when the brain does not get enough oxygen either because of a prolonged lack of oxygen-rich blood (cerebral ischemia) or bleeding in or around the brain (cerebral hemorrhage). Stroke is the third-leading cause of death in the United States, behind heart disease and cancer, and each year about 600,000 people in this country suffer a stroke, according to the American Heart Association.

“There are as many people who suffer right-brain strokes as there are with left-brain strokes, and probably half of the people with right-brain strokes have language comprehension problems to a moderate-to-severe degree,” Tompkins says. “Many others have subtle communication issues that aren’t so problematic until they’re in difficult situations — maybe with lots of people talking at once, or when they have lots of messages they have to keep up with.”

Tompkins’s research team includes co-investigators Julie Fiez, of psychology, and Carolyn Cidis Meltzer, of radiology and psychology, who also is chief of neuroradiology and medical director of the PET Facility at UPMC.

— Bruce Steele