Speech not a 1-sided affair in the human brain

We use both sides of our brain for speech, U.S. researchers report in a study they say alters previous conceptions about neurological activity. Researchers at New York University, writing in the journal Nature, say the findings offer insights into addressing speech-related inhibitions caused by stroke or injury and lay the groundwork for better rehabilitation methods. Many scientists have held that both speech and language are lateralized -- in other words, we use only one side of our brains for speech, which involves listening and speaking, and language, which involves constructing and understanding sentences. Not so, say the NYU researchers. "Our findings upend what has been universally accepted in the scientific community -- that we use only one side of our brains for speech," senior study author Bijan Pesaran of the university's Center for Neural Science said. "In addition, now that we have a firmer understanding of how speech is generated, our work toward finding remedies for speech afflictions is much better informed." The researchers examined brain functions of patients suffering from epilepsy with specialized electrodes placed directly inside and on the surface of the brain, a method that coincided with their medical treatment. "Recordings directly from the human brain are a rare opportunity," study co-author Thomas Thesen said. An analysis of brain activity as the patients engaged in speech tasks showed that both sides of the brain were used -- that is, speech is, in fact, bilateral. "Now that we have greater insights into the connection between the brain and speech, we can begin to develop new ways to aid those trying to regain the ability to speak after a stroke or injuries resulting in brain damage," Pesaran said.