764 OF THE FUNCTIONS OF THE NERVOUS SYSTEM. 



of Gloom may in like manner proceed alike from bodily or from mental uneasi- 

 ness. All these facts point, therefore, to the singleness of the centre from which 

 the Emotional movements immediately proceed; and to its identity with the 

 centre of the Sensori-motor actions. 



795. That the Emotional and Volitional movements, however, differ as to 

 their primal sources, is obvious, not merely from the fact that they are fre- 

 quently in antagonism with each other the Will endeavoring to restrain the 

 Emotional impulse, and either succeeding in doing so, or being vanquished by 

 the superior force of the latter but also from the curious fact, which Patho- 

 logical observation has brought to light, that muscles which will still act in 

 obedience to emotional impulses may be paralyzed to the volitional, and vice 

 versa. Thus, for example, the arm of a man affected with hemiplegia, which 

 no effort of his will could move, has been seen to be violently jerked under the 

 influence of the mental agitation consequent upon the sight of a friend. And 

 in the case of softening of the Spinal Cord already referred to ( 704, note), the 

 choreic movements, which were brought on by the mere approach of any one to 

 the patient's bed, and still more strongly by putting a question to him, were 

 most violent in the lower limbs, over which he had not the least voluntary 

 power. It is in the different forms of paralysis of the Facial nerve, however, 

 which is the one most peculiarly subservient to the movements of Expression, 

 that we have the best evidence of this distinctness. For it sometimes happens 

 that the muscles supplied by this nerve are paralyzed so far as regards the 

 Will, and yet are still affected by Emotional states of mind, and take their 

 usual part in the automatic actions of Respiration, &c., retaining also their usual 

 tension, so that no distortion is apparent unless Voluntary movements be at- 

 tempted : thus, to select an action which may be performed either consensually, 

 emotionally, or voluntarily, a patient affected with this form of paralysis can- 

 not close the eyelid by an act of his will, although he winks when he feels the 

 uneasy sensation that excites the action, and shuts the lids when the sudden ap- 

 proach of an object to the eye excites the fear of injury to that organ. On the 

 other hand, the paralyzed condition may exist in regard to the automatic and 

 emotional actions only, so that the muscles lose their tension, the mouth is 

 drawn to one side, the movements of expression are not performed, and there 

 is no involuntary winking : yet the Will may still exert its accustomed control, 

 and may produce that closure of the lids which does not take place in respond- 

 ence to any other impulse. 1 It has been inferred by Dr. M. Hall, 3 from cases 

 of this kind, that the Emotional actions are among those which are performed 

 by his " true spinal" system of nerves, as distinct from the sensori-volitional, 

 and that they therefore fall under the general category of excito-motor actions. 

 But it is obvious that they differ from these in their dependence, not merely 

 upon sensations, but also upon higher states of mind ; and there is no proof 

 whatever that the same nerve-fibres do not serve for the conduction of the mo- 

 tor impulses proceeding from the two different mental sources, Volition and 

 Emotion, as we have seen that they probably do for the volitional and automatic 

 impulses ( 753). 3 



1 See the detailed accounts of such cases in Sir C. Bell's work on "The Nervous Sys- 

 tem of the Human Body;" also "Brit, and For. Med. Rev.," vol. iv. p. 500, and vol. 

 xiii. p. 553. 



2 "Memoirs on the Nervous System," 1837, pp. 94, et seq. 



3 In former editions of this Treatise, the author maintained, upon the principles advo- 

 cated by Dr. M. Hall, that there must be distinct centres and conducting fibres for Voli- 

 tional, Emotional, and Reflex movements. Having since arrived at what he believes to be 

 a much simpler explanation of the phenomena, and one more in accordance with the 

 facts of the case, he does not hesitate to make known the change in his convictions ; and 

 would hope that he may induce those who may have adopted his previous opinions, to re- 

 consider the subject under the aspect in which he has now placed it. 



