ASSO CIA TION AREAS OF FLE CHSIG. 7 7 3 



faculties, and by a change for the worse in the general disposition of the 

 individual, that it is important to ascertain what the clinical evidence on this 

 point really amounts to. Welt l has collected fifty-nine cases of lesions confined 

 to the frontal region in man ; of these, forty-seven (or about 80 per cent.) showed 

 no changes in intellectual capacity or in character ; and only twelve of the total 

 number (or 20 per cent.) had such changes recorded against them. It is clear, 

 therefore, that the doctrine of special localisation of the intellectual faculties in 

 the latent or inexcitable portion of the frontal lobe rests on no sufficient basis. 



We cannot, therefore, say that the intellectual faculties reside in this 

 part more than in another ; they are apparently bound up with the 

 integrity of the whole organ. But what part of the changes of which they 

 are the manifestation take place in the " sensory areas," what part in the 

 "motor areas," and what part in what Flechsig has termed the 

 " association areas," there is no evidence to show. That there is, however, 

 some localisation in connection with the expression of intellectual 

 processes in the association areas, is evidenced by the phenomena of 

 aphasia to which attention will immediately be directed. 



It must be borne in mind that although the inexcitable regions of 

 the cortex yield no obvious result on stimulation, at least in the direction 

 of the production of movement, they may nevertheless be concerned 

 in the production of inhibitory phenomena, which are no less important 

 in neural physiology than the phenomena of movement. For, after 

 they are extirpated, and especially is this said to be the case with 

 the prefrontal lobes, the time and intensity of spinal reflexes is stated 

 to become shortened ; while, on the other hand, stimulation of these 

 regions, and especially of the prefrontal, is said, in the dog, to cause 

 prolongation of latency and diminution in intensity of spinal reflex 

 responses. 2 It is further stated that these inhibitory influences travel 

 both by the lateral and the anterior columns of the cord. Fario found 

 that much more influence was exerted upon the reflex movements of 

 the anterior than of the posterior limb, but that strong induced currents 

 had in any case to be employed to obtain the inhibitory results. Very 

 little effect was got by stimulating the occipital region, and none from 

 the parieto-temporal. Neither ablation nor excitation of the motor 

 region appeared to influence the spinal reflexes. This last statement 

 appears improbable, and there can be little doubt that before drawing 

 inferences of a general nature from these experiments they should be 

 repeated, with every precaution to avoid fallacy, upon the monkey. 8 



It is noteworthy, confining our attention to the primates, although the 

 statement appears to be one of general applicability to mammals, that as we 

 ascend the scale of organisation we find the projection areas (both sensory and 

 motor) of the cortex becoming relatively smaller and more concentrated, and 

 the non-excitable or association areas occupying a larger proportion of the 

 surface. This concentration is very obvious if we compare the Rolandic or 

 motor areas of the monkey with those of the anthropoid ape and of man (Figs. 

 336, 339, and 340), and it applies not only to the whole motor area, but also to 

 its individual components. It is also manifested in the auditory projection area, 



1 Deutsches Arch. f. klin. Med., Leipzig, 1888, Bd. xlii. S. 339. 



2 Fano, Atti d. r. Accad. d. Lincei, Roma, 1895, tomo ccxcii., Rendiconti, p. 115 ; Oddi, 

 ibid., p. 118 ; Libertini, Arch, per le sc. med., Torino, 1895, tomo xix. 



a Goltz had long previously noted that dogs with the anterior half or fronto-parietal 

 regions of the brain bilaterally removed, became much more excitable and restless, and 

 showed a complete absence of self-control and an exaggeration of many reflex movements ; 

 but there was of course much more than the prefrontal lobes lacking in these cases. 



