A new study reveals that the brains speech processing center is “miles away in terms of brain architecture and function” from where it was previously thought to reside, changing scientists’ understanding about the origins of language.
Carl Wernicke, a German neurologist, determined the location of the brain’s speech processing center in 1874, called the Wernicke’s Area, by studying the effects of brain injuries on a person’s ability to understand language and speak. The development of medical imaging techniques like Functional Magnetic Resonance Imaging (fMRI) revealed that of the brain’s speech processing center is actually located 3cm closer to the front of the brain.
The results of study, published this week in Proceedings of the National Academy of Sciences (PNAS), which are considered definitive, mean that “textbooks will now have to be rewritten”, according to Josef Rauschecker , a professor in the department of neuroscience at Georgetown University Medical Center (GUMC) , and the study’s senior author.
“Other researchers have found what we have, as well, which has caused a lot of controversy in the field as to where Wernicke’s area really is. This study provides a definitive, irrefutable answer,” said Rauschecker.
The study analyzed the results of more than 1,900 participants in more than 100 imaging studies of the brain using techniques like fMRI and Positron Emission Tomography (PET) scans. The research resulted in over 800 coordinates for speech processing in the brain, which was then analyzed to pinpoint the location of Wernicke’s area: in the left temporal lobe, within the superior temporal gyrus, in front of the primary auditory cortex.
The study was supported by National Science Foundation grants, and a National Institute on Deafness and Other Communications Disorders grant, and will be published online this week in the Early Edition of the Proceedings of the National Academy of Sciences (PNAS).