THE CEREBRUM 595 



speech without there being any paralysis of these muscles. The lesion is 



usually in the third frontal convolution and most frequently associated with 



tight hemiplegia. In agraphic aphasia the patient is unable to communicate 



, his ideas by writing through an inability to arrange verbal signs for outward 



expression and hence to execute the movements of the hand and arm neces- 



sary for writing. In this form of aphasia the lesion is in the writing area, 



ijin the posterior half or third of the medi-frontal convolution. These two 



f Jorms of motor aphasia are not infrequently associated. 



Sensor aphasia or amnesia may be either visual or auditory. In visual 



.aphasia or amnesia the patient is unable to recognize a letter or word, printed 



or written (though capable of seeing other objects), a condition known as 



letter or word blindness. It is usually associated with lesions in the neighbor- 



hood of the supra-marginal convolution. In auditory aphasia or amnesia 



.the patient cannot understand articulate or vocal speech, though capable of 



hearing and understanding other sounds, through an inability to distinguish 



the associations of words and letters a condition known as word deafness. 



It is associated with lesions of the auditory area. 



Paraphasia is an inability to recall the proper words to associate with 

 ideas and necessary to their expression. 



Concept aphasia is the inability to recall the names of objects. It is 

 associated with lesions of the cortex of the mid-temporal or third temporal 

 convolution (Mills). This area is known as the concept or naming area. 



Many other forms of aphasia have been observed and described by 

 clinicians which are fully considered in works relating to diseases of the 



nerve system. 



The statements .regarding the mechanism of speech, the functions 



signed to the motor speech area (Broca's convolution) and the motor writing 



area though very generally accepted, have been questioned in recent years 



1 by Marie who on the basis of clinico-pathologic facts has presented a some- 



what different view which has found many adherents. 



Marie's Theory of Aphasia. Marie states that there is but one aphasia 

 and but one speech center, which he locates somewhere in the left temporo- 

 parietal lobe, and which he designates as a specialized intellectual center 

 speech. Motor aphasia in the accepted sense, he states is a combination of 

 word blindness and word deafness (both, however being defects of the speech 

 center) and defective articulation (anarthria) the result of a lesion of the 

 motor tracts necessary to the excitation of the muscles for articulation. Th 

 ksion causing the anarthria is in the lenticular zone, in close relation to the 

 enticular nucleus. This zone, in a horizontal section of the brain is limited 



uceus. , 



ba vertical plane level with the anterior sulcus of the ins, 

 by a similar plane level with the posterior sulcus of the insula; 

 tL^lrll ventricle and externally by the surface of the insula 

 This zone i< anatomically associated with the supra-marginal and angular 

 Jon^o utos and with tJposterior portions of the super and ^-touponj 



many others are at variance with it. 



