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The Lumleian Lectures on the Pathological Relations of the Voice and Speech

1879; BMJ; Volume: 1; Issue: 958 Linguagem: Inglês

10.1136/bmj.1.958.691

0959-8138

J. S. Bristowe,

Phonetics and Phonology Research

LECTURRE III.MR.PRESIDENT AN-D GENTLEMEN,-I propose in to-day's lecture to confine my attention to those affections of speech which are dependent on lesions of the higher nerve-centres-affections which are commonly included under the term " aphasia".I need not repeat the well-worn story of how Gall first localised the faculty of speech in the anterior cerebral lobes; how MIM.Dax, father and son, demonstrated, as the result of long-continued observation, that disturbances of speech oc- curred mainly, if not wholly, in dependence on lesions of the left cerebral hemisphere; how M. Broca, at a later period, identified the posterior part of the left third frontal convolution, together with, perhaps, a portion of the adjoining second frontal convolution, as the special centre for articulate speech.Yet notwithstanding the remarkable observations on which the last conclusion was based, and the rapid accumulation of facts which, on the whole, tended strongly to confirm its truth, many distinguished physicians, having regard to the important exceptions which occasionally presented themselves, and from a disinclination to believe in the localisation of cerebral functions, hesitated for a time to accept it.But this localisation, to which many pathological as well as physiological considerations had long pointed-on which Hughlings Jackson had especially insisted, and which Bastian and Broadbent had assumed in their writings on aphasia-has, during the last few years, been established beyond the possibility of doubt by the experimental researches of Fritz and Hitzig, and of Ferrier; and some, at any *rate, of the apparent exceptions have been in the case of left-handed persons, in whom we have reason to believe that the functional importance of the cerebral hemispheres, as well as that of the limbs, is trans- posed.There are few, therefore, now who, in the main, do not acquiesce in Broca's generalisation, that the posterior part of the left third convo- lution, together with some neighbouring tracts, is the special centre for the expression of the thoughts in language; and who do not also accept his explanation, that the predominance of the left side of the brain over the other side is connected with the predominant use of the right arm and leg, and is due to a special aptitude of the left hemisphere to take the lead in self-education, in determining actions requiring special skill, and in the higher mental operations.Broca did not regard the spot here indicated as the intellectual centre of speech, but as the supreme centre for the motor processes of speech ; as the agent of the mind for the automatic expression of the thoughts in articulate language and in writing-a view which Hughlings Jackson adopts when he speaks of it as being " the way out" for speech.Apart from the pathological consequences of disease of this area, there are several considerations tending to establish the truth of Broca's inference.,One is the discovery that, in the case of many of the lower animals, experimental injury of the posterior part of the third frontal, and the lower part of the ascending frontal, convolution on one side, causes, according to its character, paralysis or spasm of the opposite side of the tongue and lips-a fact which implies direct connection through the motor tract between this particular part of the brain and the muscles which are concerned in articulation.