The most pervasive brain network model of spoken language processing is Wernicke-Lichtheim's classical view, which was revived by Geschwind in 1965 as the 'disconnexion' account. This has been established through various neuropsychological observations of language disorders of patients with aphasia, alexia and so on. The recent development of brain imaging techniques, e.g., PET (positron emission tomography), fMRI (functional MRI), MEG (magneto-encephalography) and NIRS (near infrared spectroscopy), has enabled us to directly investigate normal brain activities, and studies using these techniques challenge the disconnexion view. In this paper a brief summary of the classical view is given, and recent brain imaging studies are reviewed, primarily focused upon neural substrates of speech perception, the semantic system, phonological/phonetic encoding and motor programming.
