SOME PHYSIOLOGICAL ASPECTS OE HYPNOTISM. 521 



summed effect is generally inhibition. 7.c\, increased resist- 

 ance of the lower gaps. The physiological proofs of this 

 are numberless. I need only cite one : the reflex actions 

 of such an animal as the frog are always aroused with far 

 more ease if the higher centres are not present. The 

 higher centres thus rein in the others, and by paralysing 

 these the reins are cut, the resistance of the gaps is 

 diminished, and they are rendered easier to force. 



It is this last phase of central physiological activity 

 which has been assumed by Heidenhain and others to 

 come into play in Hypnotism, and to cause some of those 

 profound alterations in the whole nervous system which are 

 striking characteristics of hypnotic phenomena. 



I have already pointed out that the simple method used 

 to hypnotise in man is that of fixed gaze in a slightly 

 strained attitude of vision, necessitating concentrated at- 

 tention and a prolonged effort of the will. In animals the 

 simple method is forced inactivity and uniform sense im- 

 pression. A definite view as to the physiological basis of 

 will is beyond modern physiology, but it has been already 

 stated that physiologically it includes capacity to modify the 

 paths of nervous impulses; and it appears probable there- 

 fore that the agencies afiecting such modification are the 

 play of other impulses upon the resistance of the gaps. It 

 may further be stated that this is probably efi"ected by a 

 specific combination of co-ordinated impulses emerging 

 from the highest parts of the nervous organism, the cere- 

 bral hemispheres. Some physiologists (Wundt,' for in- 

 stance) localise these in one portion, the apperception 

 centres of the Frontal Lobes. The process of forced and 

 persistent attention demands continued play of this kind 

 inhibiting some, augmenting other gap resistances in the 

 brain and cord. Physiological investigation shows plainly 

 that continued activity of nerve-fibres is not accompanied 

 by deleterious changes in the nerve-fibres. These are in- 

 defatio-able, but it is quite otherwise with the structures 

 which surround the endings of nerve-fibres. Here continued 

 activity is deleterious, producing increased resistance to the 

 1 Wundt, Hypnotisine et Si/i^xes/iofi, 1893. 



