Men Listen With Half of Brain

Tuesday November 28 1:54 PM ET
Men Listen With Half of Brain - Study

By LINDSEY TANNER, AP Medical Writer

CHICAGO (AP) - Score one for exasperated women: New research suggests men really do listen with just half their brains.

Composites of brain activity from 10 males (top row) and 10 females (bottom row) showing both anterior and posterior temporal lobe views when they underwent functional magnetic resonance imaging while listening to excerpts from a popular novel. The images reflect blood flow to the areas of the brain activated by the exercise. (A larger view is available here.) Image: IU School of Medicine Department of Radiology.

In a study of 20 men and 20 women, brain scans showed that men when listening mostly used the left sides of their brains, the region long associated with understanding language. Women in the study, however, used both sides.

Other studies have suggested that women ``can handle listening to two conversations at once,'' said Dr. Joseph T. Lurito, an assistant radiology professor at Indiana University School of Medicine. ``One of the reasons may be that they have more brain devoted to it.''

Lurito's findings, presented Tuesday at the Radiological Society of North America's annual meeting, don't necessarily mean women are better listeners.

It could be that ``it's harder for them,'' Lurito suggested, since they apparently need to use more of their brains than men to do the same task.

``I don't want a battle of the sexes,'' he said. ``I just want people to realize that men and women'' may process language differently.

In the study, functional magnetic resonance imaging - or fMRI - was used to measure brain activity by producing multidimensional images of blood flow to various parts of the brain.

Inside an MRI scanner, study participants wore headphones and listened to taped excerpts from John Grisham's novel ``The Partner'' while researchers watched blood-flow images of their brains, displayed on a nearby video screen.

Listening resulted in increased blood flow in the left temporal lobes of the men's brains. In women, both temporal lobes showed activity.

The findings tend to support previous suggestions that women's brains are ``either more bilaterally dominant'' or more right-side dominant in doing certain tasks than men's, said Dr. Edgar Kenton of the American Stroke Association, a neurologist at Thomas Jefferson University in Philadelphia.

Though preliminary, the study could help doctors treating stroke victims better understand how men's and women's brains differ, Kenton said.

It suggests that in a stroke affecting the brain's left side, women might recover language ability more quickly than men, though that remains to be proven, Kenton said.

Indiana University School of Medicine Press Release follows:

NEWS FLASH: Men Do Hear -- But Differently Than Women, Brain Images Show

INDIANAPOLIS -- Research conducted at the Indiana University School of Medicine may help resolve an age-old dilemma between the sexes. Men listen with only one side of their brains, while women use both, according to information on brain imaging presented Tuesday, Nov. 28, at the 86th Scientific Assembly and Annual Meeting of the Radiological Society of North America (RSNA).

The study may add fuel to the females' argument, but researchers say the findings don't address whether women are better listeners than men.

"Our research suggests language processing is different between men and women, but it doesn't necessarily mean performance is going to be different," said Joseph T. Lurito, M.D., Ph.D., assistant professor of radiology at IU School of Medicine. "We don't know if the difference is because of the way we're raised, or if it's hard-wired in the brain."

In the study, 20 men and 20 women underwent functional magnetic resonance imaging (fMRI) while listening to a passage from "The Partner," a John Grisham novel. A majority of the men showed exclusive activity on the left side of the brain, in the temporal lobe, which is classically associated with listening and speech. The majority of women showed activity in the temporal lobe on both sides of the brain, although predominantly on the left. The right temporal lobe traditionally is associated with non-language auditory functions.

"As scientists, we're figuring out what normal is, and more and more often it seems we're finding that normal for men may be different than normal for women," said Michael Phillips, M.D., assistant professor of radiology and co-author of the study. "That doesn't mean one is better or more capable than the other."

The finding may help with research regarding how men and women recover from stroke and brain tumors, said Dr. Lurito. It also may help guide brain surgeons in avoiding certain areas of the brain, depending on whether they're operating on men or women, he said.

"Also, scientists working on improving imaging technologies, such as fMRI and PET (positron emission tomography), need to be aware of potential gender differences," said Dr. Phillips.

Co-authors of a paper on the topic being presented at RSNA by Drs. Lurito and Phillips are Mario Dzemidzic, Ph.D., assistant professor of radiology; Mark J. Lowe, Ph.D., assistant professor of radiology; Yang Wang, M.D., assistant scientist of radiology, and Vincent P. Mathews, M.D., associate professor of radiology.

The research was funded by the IU School of Medicine Department of Radiology.

The RSNA is an association of 31,000 radiologists and physicists in medicine dedicated to education and research in the science of radiology. The society's headquarters is located in Oak Brook, Ill.

The Indiana University School of Medicine, the state's only medical school, has nine regional campuses with more than 1,000 full-time faculty teaching nearly 2,000 medical students and residents annually.

NEWS FLASH: Men Do Hear -- But Differently Than Women, Brain Images Show