680 PROBLEMS IN REGARD TO LOCALIZATION OF 



incitations in ' imitative ' Speecli do not, like those in 

 Voluntary Speech, also find their ' way out ' through the 

 third frontal gyrus. In fact, we have every reason to 

 believe that the route from the Auditory Perceptive Centre 

 to the Corpus Striatum is one and the same for every 

 kind of Speech, whether its mode of in citation may be 

 strictly 'imitative,' Ideo-motor, or distinctly Volitional. 



This latter conclusion is found to be in accordance 

 with the evidence derived from disease. No fact has been 

 more certainly established in regard to Aphasic patients, 

 than that there is in them a loss not only of Voluntary, 

 but of Ideo-motor, and, to just as marked an extent, a 

 loss of ' imitative ' Speech. A really Aphasic patient 

 cannot copy the simplest word or vowel sound, which he 

 has just heard, nor does he even do it unbidden and echo- 

 like, in the most purely imitative reflex style. 



Others again have assumed that a separate route exists 

 by which Emotional stimuli may be transmitted to the 

 lower centres for Articulation in the Pons and Medulla, 

 without passing through the Corpus Striatum, simply 

 because Aphasic patients occasionally utter new words of 

 an interjectional order — as oaths, or such phrases as 'Oh 

 dear!' 'Thanks!' and other simple exclamations, under 

 the influence of a strong emotional stimulus. Even for 

 this kind of connection, however, no independent evidence 

 exists (see p. 580) ; and perhaps the facts can be equally 

 well explained by the supposition that Emotional stimuli 

 of greater energy, or which emanate from a wider area, 

 may occasionally force their way through damaged tracks, 

 the resistance in which could not be overcome by mere 

 Volitional stimuli. 



As to the causes which have determined the greater or 

 almost exclusive influence of the left Hemisphere in 

 inciting Speech-movements, only conjectures can be 



