A reappraisal of localization theory with reference to aphasia. Part 2: Language theories from outside neurology.

Part 1 of this series explored various historical writings about aphasia in order to understand the current scope of the field and the prevailing neuroanatomical model. This paper will examine the contexts from which key aphasiologists mentioned in Part 1 wrote, with particular attention to influential language theories from outside neurology. Some biases of the Standard Average European languages used by these authors have shaped aphasia theories indirectly and will also be discussed. This analysis reveals an historical shift in the subject matter of aphasiology, from speech behaviors to "language," defined quite broadly. This shift in subject has serious implications for attempts to localize language in the brain.