REDINTEGRATION IN ALBINO RAT— A STUDY IN RETENTION 25 



It is quite true that to turn either way from the start 

 would be equally easy. But when the rat has finally begun 

 to run the correct pathway from the start the more easily 

 integrated movement by which to enter alley 2, through 

 turn 1, is in the direction which leads to a minus " error," 

 i.e., straight away into the cul-de-sac. It is easier for the 

 rat to continue straight ahead, past any turn, in the direc- 

 tion in which it is running, or straight ahead through the 

 turn into the cul-de-sac. These " errors " are indicated by 

 a minus sign in the turns 1, 3, and 5; and plus at the other 

 turns. All figures show that many more " errors " are 

 made here, both in learning and redintegration, than in 

 making the more acute turns, which require established 

 integration to be made continuously in a perfect manner. 

 Thus it is clearly seen that the integrated movement at 

 the respective turns must be learned before the habit can 

 be established. 



Some authors have attempted to show by logic rather 

 than by research in the laboratory that this question is a 

 mere matter of chance — which way a rat will go through a 

 turn. But experimental observation clearly proves that it 

 is a hard and fast question in experiment on the establish- 

 ment of perfect integration of movement. It is not a 

 matter of chance but of difficult integration versus easy 

 integration. The minus " error " at turn 1 is thus dominant 

 over the plus " error "; at turn 2, the plus over the minus, 

 etc., as far as already limited. In other words, as already 

 stated, the weak link in the chain of the habit — the domi- 

 nant error or the integration difficult to acquire — appears 

 in the process of learning and reappears after retention in 

 redintegration. 



(2) Effect of Distribution of Trials on Redintegration 



It has been shown quite conclusively in animal experi- 

 mentation that the wider the distribution of effort, within 

 certain limits as yet undefined, the greater will be the 

 economy [Yerkes (3), Hunter (12), Ulrich (18)]. Any 

 attempt to ascertain the effect upon retention of different 

 distributions of effort in learning should be begun with 

 full cognizance of these conclusions. 



