“ Scientists from the Center for Innovation in Science and Technology, University of Washington placed an array of 64 electrodes on the scalp of four people suffering from severe epilepsy. The initial aim of this study was to examine what is happening in the brain of these patients and thereby is causing seizures. At the same time the electrodes controlled the brain areas which are considered to be responsible for speech. These are motor cortex, Wernicke’s area and Broca’s area. These brain regions produce 40 phonemes (distinguished vocal sounds in speech) which structure the English language.”
Source: learning-mind.com
