Wernicke, Carl (1848–1905)

German neurologist and psychiatrist. He is known for his study of aphasia. In The Aphasic Syndrome (1874), he described what later became known as sensory aphasia (that is, defects in, or loss of, speech and expression) as distinct from motor aphasia, first described by French surgeon Paul Pierre Broca (1824–1880).

Although both forms of aphasia result from brain damage, Wernicke found that the locus of the damage differed, sensory aphasia being induced by lesions to the left temporal lobe, motor aphasia by lesions to the left posterior frontal lobe. He used the differential clinical features of the two aphasias to formulate a general theory of the neural bases of language.

Wernicke also described a form of encephalopathy induced by thiamine deficiency which bears his name.