ABSTRACT
There is firstly an account of the areas of the cerebral cortex that are concerned in speech, the anterior speech area of Broca, and the large posterior speech area of Wernicke (Fig. E4–1). These areas were originally defined by astute inferences from cortical lesions in patients that suffered various kinds of aphasia. The remarkable discovery was that about 95% of aphasics have lesions in their left cerebral hemisphere. Experiments on exposed human brains have confirmed these earlier clinical studies and sharpened the localizations of the speech area, showing in particular that the Wernicke area extended up into areas 39 and 40 of the parietal lobe (Fig. E4–3).
