PHYSIOLOGY OF ATTENTION AND VOLITION. 233 



excessive, and in this way, again, the action of the whole encephalon 

 may be modified. 



The means usually adopted to induce the hypnotic state afford us an 

 illustration of a mode by which this condition may be brought about. 

 In the first place, the attention is so strained in one direction that 

 fatigue of a motor and of a sensory center has been induced. When 

 this has happened, the molecular agitation that accompanies activity 

 of function becomes more difficult. Repose is needed to restore its 

 former fitness for work. The structures immediately involved are re- 

 duced to a condition approaching that of sleep, and as a result they 

 have relaxed their hold on the circulation. The forces which sustain 

 its balance are therefore disturbed. The condition of the encephalic 

 circulation may now be considered analogous to that of the atmosphere 

 with a low barometic pressure ; it is mobile and disposed to storms. 

 If attracted in one direction, it is determined strongly. Then, the very 

 momentum with which the blood surges in that special direction re- 

 acts on and strengthens function. If it be toward an ideational center, 

 some particular idea may so monopolize the consciousness that the 

 judging faculty is almost as completely in abeyance as in ordinary 

 dreaming. Thus, when something bitter is put into the mouth of a 

 hypnotized subject, and he is told it is sweet, the notion of sweetness 

 becomes dominant because the circulation is so strongly focused 

 toward an ideational center that the gustatory center or track can 

 not respond to its natural stimulus. Its function is suspended on ac- 

 count of the failure of a necessary condition. 



In regard to volition, we need not here enlarge on the metaphysical 

 subtilties its discussion has given rise to. We have now to do with it 

 as a faculty subject to the tyranny of organic conditions, and our en- 

 deavor is, if possible, to catch at least a glimpse of its mechanism. 



The will is essentially a prospective faculty. It must have a goal 

 in view, whether a muscular movement, or an effort of memory, or a 

 process of reasoning be required to reach it. Some notion must pre- 

 cede action, and cerebration does its work without revealing to the 

 consciousness anything of the mechanism employed. 



Certain of the factors, however, may be specified with some pre- 

 cision. I, of course, must assume we have to do with an educated 

 brain, in which co-ordination has been established among its various 

 parts. 



Ideation, then, the initiatory stage of volition, involves, within a 

 limited ai*ea, molecular movement with corresponding vascular excite- 

 ment. The function of that area becomes active, and radiation of 

 energy must talce place in some direction. Strands for the purpose of 

 conduction branch off in innumerable lines to other centers. What 

 the immediate direction may be will of course depend on the circum- 

 stances of the moment and the results of previous association. 



In order that the outcome may correspond with the intention, the 



