Neural basis of speech and language
Elucidating the neural basis of speech and language has been one of the greatest challenges in cognitive neuroscience. Much of what we know today about the neural basis of language is based on careful studies of language disturbances with neuropsychological test batteries in patients who have suffered circumscribed brain lesions due to neurological conditions. For instance, it has been shown in patient studies that the various language skills, speaking, comprehending, reading, and writing are governed by partly distinct underlying neural mechanisms; each of these abilities can be separately severed following brain damage. For instance, there are brain-damaged patients who can write their thoughts on a piece of paper but are not able to read what they themselves just wrote. During the last few decades it has been possible to investigate the underlying neural mechanisms in healthy subjects using non-invasive brain imaging. In the following, key findings from patient and neuroimaging studies will be described.