182 



THE CEREBRUM. 



special sense. Large parts of the cerebral cortex possess no 

 projection fibers; they are believed to be associative in function. 

 Association Centers of Flechsig. Flechsig describes three as- 

 sociation centers, the anterior, middle, and posterior. Anterior 

 Association Center (Fig. 54). According to Flechsig, that part 

 of the frontal cortex which is anterior to the motor region deter- 

 mines the temperament and individuality of the person; and as 

 Mills declares, is the center of inhibition, self control, attention, 

 concentration, volition. It is the center of "the abstract concept" 



CONCRETE CONCEPT 



Fig. 56. Cortical areas after C. K. Mills. Convex surface of cerebral hemisphere. 

 (Brubaker's Physiology.) 



(Fig. 56). J. S. Bolton says of this association center that "it 

 is the last part of the cerebrum to be developed, and is the first 

 to undergo dissolution; it is under-developed in amentia of all 

 grades and atrophied in dementia, according to its degree." "It 

 possesses the highest (mental) function" (Brain, Vol. 29). The 

 posterior association center, composed of those portions of cortex 

 situated between the sensory region of the equatorial zone, in 

 front, and the visual cortex of the occipital lobe, behind, deter- 



