64 PSYCHOLOGY. 



Our knowletlj^e of this disease has liad three stages : we 

 may talk of the period of Broca, the jjeriod of Wernicke, 

 and the period of Charcot. What Broca's discovery was we 

 have seen. Wernicke was the first to discriminate those 

 cases in which the patient can not even tindersfand speech 

 from those in which he can understand, only not talk ; and 

 to ascribe the former condition to lesion of the temporal 

 lobe.* The condition in question is luord-deafness, and the 

 disease is auditory aphasia. The latest statistical survey of 

 the subject is that by Dr. Allen Starr, f In the seven cases 

 oipure word-deafness which he has collected, cases in which 

 the patient could read, talk, and write, but not understand 

 what was said to him, the lesion was limited to the first and 

 second temporal convolutions in their posterior two thirds. 

 The lesion (in right-handed, i.e. left-brained, persons) is 

 always on the left side, like the lesion in motor aphasia. 

 Crude hearing would not be abolished, even were the left 

 centre for it utterly destroyed ; the right centre would still 

 provide for that. But the linguistic use of hearing appears 

 bound up with the integrity of the left centre more or less 

 exclusively. Here it must be that words heard enter into 

 association with the things which they represent, on the one 

 hand, and with the movements necessary for pronouncing 

 them, on the other. In a large majority of Dr. Starr's fifty 

 cases, the power either to name objects or to talk coherently 

 was impaired. This shows that in most of us (as Wernicke 

 said) speech must go on from auditory cues ; that is, it 

 must be that our ideas do not innervate our motor centres 

 directly, but only after first arousing the mental sound of 

 the words. This is the immediate stimulus to articulation ; 

 and where the possibility of this is abolished by the de- 

 struction of its usual channel in the left temporal lobe, the 

 articulation must suffer. In the few cases in which the 

 channel is abolished with no bad effect on speech we must 

 suppose an idiosyncrasy. The patient must innervate his 

 speech-organs either from the corresponding portion of the 

 other hemisj)here or directly from the centres of ideation, 



* Der aphasische Symptoraencomplex (1874). See in Fig. 11 the con- 

 volution marked Wernicke. 



f ' The Pathology of Sensory Aphasia,' 'Brain,' July, 1889. 



