Nervous and mental diseases . hqualities to the third frontal or Brocas convolution. It seems prob-ably true that all the cortex and subcortex associated with speech maybe affected by a lesion in any part of it. Such lesions produce a generalreduction of speech power which takes on various phases, depending tosome extent on the location and extent of the lesion or lesions, andnumerous variations are determined by the personal characteristics ofthe patient and the lapse of time. Schematically, we may say that as one or another of these majorspeech-centers is diseased we have corresponding varie
Nervous and mental diseases . hqualities to the third frontal or Brocas convolution. It seems prob-ably true that all the cortex and subcortex associated with speech maybe affected by a lesion in any part of it. Such lesions produce a generalreduction of speech power which takes on various phases, depending tosome extent on the location and extent of the lesion or lesions, andnumerous variations are determined by the personal characteristics ofthe patient and the lapse of time. Schematically, we may say that as one or another of these majorspeech-centers is diseased we have corresponding varieties of corticalspeech defect, or aphasia. They are : (1) Auditory aphasia, or word-deafness ; (2) visual aphasia, or word-blindness ; (3) motor aphasia, oraphemia, and (4) graphic motor aphasia, or agraphia. Disturbance ofthe connecting fibers also disturbs speech, giving rise to a number ofsecondary or connectiny aphasias. Again, more than one center may besimultaneously affected, causing combined aphasias. The four primary. Fig. 72.—Diagram showing receptive and emissive speech-route, and the primarv interrela-tions of the major cortical representations for speech. A, B, C, D, correspond to the cortical partssimilarly indicated in the preceding figure (after Wyllie). so-called word-centers are, to a large degree, mutually dependent. Word-blindness is often attended by agraphia, as the mind is unable to recallthe visual image of the word, which is to be copied, as it were, throughthe action of the graphic center. Again, if there is word-deafness, thepatient cannot write to dictation, though he may copy perfectly. Individuals vary greatly in the quality of their verbal faculties. Asfirst emphasized by Charcot, one may have his words priucipallv asso-ciated with the auditory area (auditif), another with the motor area(moteur), and a third with the visual area. If w^e learn a new languageby ear its memories are mainly auditory, and if by the book, they arevisual. It is only wh
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