HIGHER FUNCTIONS OF THE CEREBRUM IN MAN; APHASIA 863 



movements of the laryngeal and tongue muscles. Pierre Marie, as a 

 result of very extensive experience in Paris, has shown that this classifi- 

 cation is unjustified. He maintains that there is only one true form of 

 aphasia, and that such a thing as pure motor aphasia as above defined 

 does not exist, the condition being invariably accompanied by intellectual 

 impairment. 



Marie points out that the various claims that aphasia may exist without 

 intellectual impairment have been made without sufficient investigation of 

 the intellectual status of the patient. He shows that many patients suf- 

 fering from aphasia if asked to do ordinary things, such as cough or spit 

 or raise the hand, can do them as well as a normal individual, but that 

 these after all are very crude acts in the ordinary performances of a normal 

 individual. To test the intellectual powers it is necessary to require the 

 patient to perform acts which entail a considerable amount of cerebral 

 integration. We must ask him to perform some sequence of events such 

 as walking several times in one direction, then in another, touching cer- 

 tain objects, etc., or better still we should observe the patient closely in his 

 business transactions and everyday routine of life to see whether he does 

 things exactly as he did them before. It is always possible by such tests 

 to show that in aphasia the mental powers have become distinctly de- 

 preciated. 



The portion of the cerebral cortex affected in aphasia is always in the 

 neighborhood of the so-called area of Wernicke, which is closely related to 

 the visual and auditory centers. In making this sweeping conclusion, 

 Marie admits that cases of pure word-blindness but not of word-deafness 

 may exist ; that is, a patient still retaining his intellectual powers may lose 

 his ability to interpret correctly what he sees, although he can still interpret 

 accurately what he hears. 



This conclusion conforms exactly with those of the psychophysiologists 

 regarding the difference in the language mechanisms of educated and un- 

 educated persons. Language is learned through the sense of hearing, and 

 it is only by later education that more is learned by the sense of sight; 

 that is to say, a person learns to read only after he has learned to under- 

 stand spoken language. Word-blindness may therefore occur as a pure 

 symptom, and is less likely than word-deafness to be associated with ab- 

 normal integrative functions of the cerebrum. Word-deafness however de- 

 pends upon a lesion involving the auditory center; it necessarily means 

 disturbance in the association functions of the cerebrum, and is always 

 accompained by a certain amount of mental derangement. 



In corroboration of these facts may be cited the well-known fact that 

 a deaf-mute is mentally far inferior to one that is congenitally blind. 

 Loss of hearing leads to more serious cerebral disability than loss of sight. 



