Both sides of brain are used in speech: study

In a discovery that goes against prevailing concepts of brain activity involved in speech, Bijan Pesaran, an associate professor in New York University's Center for Neural Science, and Thomas Thesen, director of the New York University ECoG (Electrocorticography) Center and associates have shown that all parts of speech are functional in both sides of the brain.

The researchers conducted the study directly measuring brain activity, according to an article published in the 15, January, issue of the journal Nature.

They recorded the brain activity of people who had electrodes directly implanted in both hemispheres of the brain in those areas that are known to be associated with speech.

The patients repeated words that were not really words. The researchers found that the electrical signals produced in the brain were essentially the same in both hemispheres of the brain.

The discovery means that both sides of the brain could function in listening, speaking, interpreting language, and understanding sentences, as against accepted thought that the functions were distinctly separated between the two hemispheres of the brain.

According to experts in the field, the discovery could open up ways of improving speech in people who had suffered strokes or had lost one of the speech regulating regions of the brain due to disease or accident.

According to Pesaram the team's findings upended what had been universally accepted in the scientific community, that only one side of our brains was used in speech.

"Since we have a firm understanding of how speech is generated, our work toward finding remedies for speech afflictions is much better informed," he wrote in the study in the journal Nature.

The researchers examined brain functions of patients suffering from epilepsy testing the parts of the brain that were used during speech.

The participants were asked to repeat two non-words - 'kig' and 'pob', which served as a prompt to gauge neurological activity.

IANS quoted Thomas Thesen, director of the NYU Langone Medical Centre in Manhattan, NY as saying recordings directly from the human brain were a rare opportunity.

According to Pesaran, now that there were greater insights into the connection between the brain and speech, new ways could be developed to aid those trying to regain the ability to speak after a stroke or injuries resulting in brain damage.