INTEGRATION OF MOVEMENTS IN LEARNING IN 

 THE ALBINO RAT 



A STUDY OF THE ADJUSTMENT OF AN ORGANISM TO AN 



ENVIRONMENT 



JOHN LINCK ULRICH 

 ITT. THE INCLINED-PLANE PROBLEM 



The extension of investigations similar to those made with 

 the latch-box problem, to another, the inclined-plane problem, 

 was necessary in order to substantiate the importance of all 

 reflex mechanisms interacting in learning. In the latch-box 

 problem, it was seen that a localized part of the rat's organiza- 

 tion, the neck reflex movement, was used in interacting with 

 other reflex parts. The sensory mechanism, that of extension 

 and flexion of the limbs, that for the production of reflex excit- 

 ability and other reflex parts was seen to condition in rats the 

 production of the neck reflex movement. Because of the exist- 

 ence of a mechanism to be- manipulated, but different from that 

 present in the latch-box problem, another localized reflex move- 

 ment interacting with other reflex parts will be used to solve the 

 inclined-plane problem. Since the development of interaction 

 of body parts is dependent upon the functional condition of the 

 reflex extensor thrusts and that for the production of reflex 

 excitability, these parts will again function. On the whole, 

 however, the same physiological changes for learning will exist. 



The inclined-plane problem, figure 3, consisted of a box cage 

 similar to that of the latch-box but somewhat higher. It was 

 31 cm. square and 33 cm. high, and in the center of one side was 

 a small door 11.5 by 12.5 cm. The inclined-plane, figure 4, was 

 made of two pieces of sheet aluminum 15.5 by 6.5 cm. hinged 

 together at one end. The upper inclined surface was covered 

 with black wood fiber. The plane supported by a bronze spring- 

 made an angle approximately 44 degrees with the base. To 

 the under surface of the plane was attached a freely moving 



455 



PSYCHOBIOLOGY, VOL. II, NO. 6 



