694 THE CEREBRUM 



necting this organ with the cerebrum. This is shown by the fact that 

 its movements dm-ing respiration, mastication and deglutition are 

 executed with perfect precision, and may even be used for mimic ex- 

 pressions, singing and whisthng. Aphasia, therefore, is an intracere- 

 bral defect involving the spontaneity or power of phonetic expression 

 (Fig. 348). This implies that the aphasic person is no longer in a 

 condition to express his thoughts in words which form his principal 

 means of communication with his fellow-men. To be sure, man is 

 also subject to a number of conditions in which the intellectual facul- 

 ties are in abeyance, either from birth, as in idiots, or from disease, as 

 in coma, stupor, dementia and certain states of hysteria. This type of 

 speechlessness, although due to cerebral defects, cannot be classified 

 as aphasia. 



Motor aphasia is the result of an injury either to the efferent or motor 

 realm of the speech center or to the path connecting it with the motor 

 area situated along the fissure of Rolando. The motor area itself, 

 however, is not affected in cases of pure aphasia, as is evinced by the 

 fact that the muscles used in speaking are not paralyzed but have only 

 lost their central directing influence. For this reason, we must think 

 of the motor realm of the center of speech as a storehouse of those 

 memories which are directly concerned with articulation and the 

 phonetic construction of words. To be sure, an injury may be so 

 extensive that it also involves the motor area, in which case the aphasia 

 is associated with a hemiplegia. This is not at all uncommon. 



It is possible to amplify these associations and to impart to them 

 a specificity which in turn will tend to render the action of the laryn- 

 geal parts more and more effective. In other words, while the laryn- 

 geal parts may be fully developed, they cannot attain their greatest 

 functional efficiency unless the association realm is trained and made 

 to progress in a corresponding measure. 



An injury to this center most frequently results in consequence of 

 traumas and hemorrhages in the region of the middle cerebral artery. 

 These lesions may be very extensive or more or less restricted; hence, 

 the resulting motor aphasia or aphemia may be either complete or partial ' 

 in character. In the former case, the person loses his power of speech 

 absolutely, while in the latter he retains the faculty of uttering a limited 

 number of words. Thus, Broca has described a person suffering from 

 a loss of all numerical concepts with the exception of the term ^' three," 

 this number being employed by him constantly in referring to all nu- 

 merical values. Quite similarly, a person may lose the use of certaii 

 nouns and pronouns, or persistently employ words in wrong combina- 

 tions (paraphasia). The point to be emphasized is that these defects 

 in speech may be so specific that they may almost be compared to the 

 loss of one of the strings of a piano or other musical instrument. 



Another point to be noted is that the mental faculties of a persoi 

 afflicted with motor aphasia, are generally preserved, provided, of 

 course, that the injury is perfectly localized. This implies that hi 



