 Broca's patients could no longer speak but could understand language (non-fluent aphasia) while Wernicke's patients could no longer understand language but could produce jumbled speech (fluent aphasia).Post-mortems revealed lesions in separate areas of the brain in each case (now referred to as Broca's area and Wernicke's area respectively).Although the neurophysiology of language is now known to be more complicated than described by Broca or Wernicke, this classic double dissociation acted to begin modern neuropsychological investigation of language.