FACTORS IN LEARNING BY WHITE RATS 363 



" Between the sensory projection centers and the motor areas 

 are interpolated the association centers, and these are so ar- 

 ranged that all correlation, integration, and assimilation of 

 present sensory impulses with memory vestiges of past reac- 

 tions are completed, and the nature of the response to be made 

 is determined before the resultant nervous impulses are dis- 

 charged into the motor centers. Only such of the motor areas 

 will be excited to function as are necessary for evoking the 

 particular reaction which is the appropriate (that is, adaptive) 

 response to the total situation in which the body finds itself. 

 This arrangement of association centers in relation to a series of 

 distinct motor areas provides the flexibility necessary for complex 

 delayed reactions whose character is not predetermined by the 

 nature of the congenital pattern of the nervous connections." 



Through our inheritance from association psychology we seem 

 to have fallen into a narrow, mechanical view which in the case 

 of our own conduct belies our introspective reports, a view which 

 is narrow and untrue not because it attempts to be biological as 

 opposed to spiritualistic but because it so much neglects the 

 larger visceral reactions with which we are just now becoming 

 better acquainted. The reaction away from monotonous and 

 unprofitable repetitions, of which we have found so plentiful 

 illustrations in the rat's maze-learning, is similar to what we 

 find in our own conduct. Professor Dodge, in his presidential 

 address before the American Psychological Association, empha- 

 sizes a view in his treatment of the subject of fatigue which seems 

 to agree with our own. On the particular point in question, the 

 influence of general visceral demands, he says: ' In my own 

 case I have been interested in observing how every prolonged 

 period of monotonous work like correcting papers, for example, 

 finds before its close some insistent demand for interruption. 

 If I successfully suppress one demand, more insistent ones 

 arise, until finally effective voluntary reinforcement of the main 

 task suddenly ends." 22 



SUMMARY AND CONCLUSION 



Working 'on Professor Watson's suggestion, that probability 

 determines the early reactions of the rat in the maze and that 

 the principle of frequency finally determines which of the various 



22 Dodge Raymond. The Laws of Relative Fatigue. Psychol. Rev., 1917, 24, 

 89-113. Quotation is from page 111. 



