PLEASURE, PAIN AND INTELLIGENCE 157 



the experiments give no support to the view that pleasant sensations are 

 accompanied by a diminution of blood suppl} r to the brain, and unpleas- 

 ant sensations by the reverse effect. 



Angell and Thompson express themselves as 1 allows concerning 

 the physiological concomitants of pleasant and unpleasant re- 

 actions : 



It is in the case of the emotions, where the agreeable and disagreeable 

 experiences are most intense, that we should expect to find the most 

 marked and constant correspondence of agreeable states with one set of 

 physiological processes and of disagreeable states with an antithetical set . 

 if any such relationship existed. But our curves show not the slightest 

 evidence of such an interconnection. None of the various factors 

 involved, vaso-motor level, rate and amplitude of the pulse curve, posi- 

 tion and emphasis of the dicrotic notch, or rate and amplitude of the 

 breathing, changes uniformly in one direction for agreeable experiences, 



and in opposite direction for disagreeable experiences 



Almost all of our emotional experiences, whether agreeable or disagree- 

 able, produced vaso-constrictions. 



The results yielded by the study of affective states, by means of 

 instruments for recording changes in circulation, pulse, and respir- 

 ation and other physiological manifestations do not afford at pres - 

 ent a very encouraging outlook for the solution of our problem, 

 for in so far as pleasurable and painful experiences are not asso- 

 ciated with uniform outward expressions it is difficult to obtain 

 clear evidence of the accompanying internal physiological states. 

 It is commonly assumed that there is something in pleasure and 

 pain or their physiological correlates that reinforces or inhibits, 

 as the case may be, the responses from which these states result. 

 What this something is and how it produces its effects are prob- 

 lems for which a satisfactory solution has not been offered. 

 There has been a bewildering variety of theories of the nervous 

 correlates of pleasure and pain and of pleasantness and unpleasant- 

 ness but there has been little attempt to apply these theories 

 to explain the mechanism of profiting by experience, and it is 

 difficult to see how most of these theories would help us in regard 

 to this matter even were the} established. 



