Page:Principles of Psychology (1890) v1.djvu/85

This page needs to be proofread.
65
HEADERTEXT.
65

FUirCTIOSS OF THE BRAIN. 65 whicii in turn excite others, nntil at last a motor discharge do"vvnwarcls of some sort occurs. When this is once clearly grasped there remains little ground for keeping up that old controversy about the motor zone, as to ■vhether it is in reality motor or sensitive. The whole cortex, inasmuch as currents run through it, is both. All the currents probably have feelings going with them, and sooner or later bring movements about. In one aspect, then, every centre is afferent, in another efferent, even the motor cells of the spinal cord having these two aspects inse]3ara- bly conjoined. Marique,* and Exner and Panethf have shown that by cutting round a ' motor ' centre and so sepa- rating it from the influence of the rest of the cortex, the same disorders are produced as by cutting it out, so that really it is only the mouth of the funnel, as it were, through which the stream of innervation, starting from else- where, pours ; X consciousness accompanying the stream, and being mainly of things seen if the stream is strongest occi]3itally, of things heard if it is strongest temporally, of things felt, etc., if the stream occupies most intensely the 'motor zone.' It seems to me that some broad and vague formulation like this is as much as we can safely venture on in the present state of science ; and in subsequent chapters I expect to give confirmatory reasons for my view. TVrATVr'S C0NSCI0USIO3SS LIMITED TO THE HEMISPHEBES. But is the consciousness ichich accompanies the activity of the coHex the only consciousness that man has ? or are his lower centres conscious as ivdl ? This is a difficult question to decide, how difficult one only learns when one discovers that the cortex-conscious- ness itself of certain objects can be seemingly annihilated in any good hypnotic subject by a bare wave of his opera- common to talk of an ' ideational centre ' as of something distinct from the aggregate of other centres. Fortunately this custom is already on the wane.

  • Rech. Exp. sur le Fonctionnement des Centres Psycho-moteurs (Brus-

sels, 1885). f Pflilger's Archiv, vol. 44, p. 544. X I ought to add, however, that Frangois-Franck (Fonctions Motrices, p. 370) got, in two dogs and a cat, a different result from this sort of ' cir- cumvallation.'