288 PSYCHIATRY 



ciations is that between vaso-motor alterations and the seat of the 

 emotions, which are thus intimately involved with the viscera 

 and vessels in their minute connection with the sympathetic system. 

 This association has a most important influence in the mental 

 sphere, though beyond this fact little is yet known of the physio- 

 logical basis of these reactions. 1 



The intimate connection of mental states and the physical re- 

 actions of the whole body is well recognized by both physiologists 

 and psychologists; it is of fundamental importance in psychiatry. 

 Lombard 2 describes the cells of the central nervous system, dur- 

 ing waking hours, as continually under the influence of a shower 

 of weak nervous impulses, coming from the sensory organs all over 

 the body; moreover, activity of brain-cells, especially emotional 

 forms of activity, leads to an overflow of nervous impulses to the 

 spinal cord and an increased irritability, or, if stronger, excitation 

 of motor nerve-cells. There is a constant inflow from the environ- 

 ment of a vast number of excitations ordinarily disregarded by 

 the mind but all the time influencing the nerve-cells; the effect 

 of this multitude of afferent stimuli, in spite of their feebleness, 

 is to cause the motor cells continually to send delicate motor stimuli 

 to the muscles and to keep them in the state of slight but continued 

 contraction or tension of muscle-tonus. In these mechanisms is 

 the seat of the kinesthetic sensations and the functional altera- 

 tions that play so essential a part in contributing to the well-known 

 symptom-factors of the "sense of effort" and "inadequacy," and 

 motor "retardation" and "excitation." 



Some of the physiologists have given much study to the rela- 

 tion of mental and physical states. Sherrington's 8 discussion of 

 common and organic sensation and the contributing cutaneous 

 sensations has an extraordinary interest for psychiatry. Com- 

 mon sensation is understood to mean that sum of sensations re- 

 ferred, not to external agents but to the processes of the animal 

 body, and these sensations possess strong affective tone. Total 

 common sensation is the result of many component sensations, 

 and those that arise in internal organs and viscera contribute a 

 great deal to the total sum. Affective tone is the constant accom- 

 paniment of sensation; every form of common sensation is based 

 on perception of an altered condition of the body itself. In con- 

 nection with this comes the fact that all forms of common sensa- 

 tion present significantly preeminent attributes of physical pleas- 

 ure or physical pain; and all are linked closely to emotion. 



1 Cf . Baldwin's Diet, of Philosophy and Psychology. 



1 Lombard, W. P., The General Physiology of Muscle and Nerve, Am. Text-Book 

 of Phys., vol. n, p. 143. 



3 Sherrington, C. S., Cutaneous Sensations, Schafer's Text-Book of Physiology, 

 vol. n, p. 969, et seq. 



