DISTRIBUTION OF EFFORT IN LEARNING IN WHITE RAT 49 



SOME GENERAL REMARKS ON THE INTEGRATION OF 

 MOVEMENTS 



Rats are endowed with the physiological predisposition to 

 display, upon the application of a stimulus, movements both 

 native and acquired. Many of these, which the rats make when 

 first confronted with a new situation or problem, appear, because 

 of their sharpness, to be more or less impulsive and primal. 

 They are all integrated movements. Some of them are useful 

 and some of them are possibly of indifferent value. While they 

 do not follow one another in any predictable manner, never- 

 theless there is some interconnection among the movements. 

 The close study of Sherrington (13) on the reflexes from a spinal 

 animal has yielded information on the linkage of the separate 

 movements involved in very complex co-ordination. He also 

 makes clear some of the conditions involved in both native and 

 acquired integrations. It is probably safe to say that both 

 types (native and acquired) of integrations have the same con- 

 structive mechanism or structural basis. 



It is well known that for the accurate learning of any problem 

 such as we have been considering a new or acquired integration 

 must be established. In this process of acquisition the animal 

 displays numerous sporadic movements. These are scarcely 

 produced de novo by the situation. They must be native re- 

 flexes, or modifications at least, of previously existing integra- 

 tions. From this mass of movement there slowly emerges the 

 new and desired integration. In a sense, then, an acquired 

 integration is a growth. It is usually said, further, that in 

 this growth, or in learning, there is a process of stamping in of 

 the useful movements, and stamping out of the useless move- 

 ments. It has often been maintained that the movements giv- 

 ing pleasure are the ones maintained and those giving pain are 

 eliminated. But this addition to the trial and error theory 

 often leads to a form of anthropomorphism. While I am unable 

 to advance any serviceable explanation of the stamping in and 

 stamping out process, I wish to mention some objective changes 

 in the types of movement displayed during the learning process. 



The animal passes from an excitable state, during the early 

 trials, to a less excitable one as learning is completed. The 

 excitable state is very evident in the early trials, and is the 

 "emotional" one so often mentioned. Many profound bodily 



