STUDIES OF CEREBRAL FUNCTION. IX 19 



of the mazes, but in general they indicate that our mazes do 

 not provide a trustworthy index of individual differences 

 among normal animals. 



In contrast to this, the correlations for the operated cases 

 are uniformly high and significantly greater than their prob- 

 able errors. The most consistent results are obtained from 

 errors and from total trials less errorless runs, with cor- 

 relation coefficients ranging from 0.84 to 0.91. They indicate 

 that there is some common factor involved in the learning 

 of all five mazes by operated animals which is reliably 

 measured by the criteria which we have adopted. 



The nature of this factor is not clearly indicated. The 

 lower correlations for time show that it is not mere activity 

 or speed of running. Whether it is motivation, ekphorie, or 

 some sort of insight into the problem is not revealed by these 

 figures. The previous results of Lashley ('29) for learning 

 in the double platform box and in the maze show that there 

 is no correlation in the learning of these two problems, al- 

 though the same incentives are used, so differences in motiva- 

 tion seem improbable as a cause of the correlations. 



This throws us back upon some mechanism directly in- 

 volved in the learning process itself as the function measured 

 in our study. The divergent results with the double platform 

 box (Lashley, '20), the learning of which was unaffected by 

 any cortical lesion, indicate that mere fixation in memory or 

 ekphorie is not the factor involved. Our knowledge of the 

 actual factors responsible for maze learning, such as the in- 

 fluence of thwarting in blind alleys, the formation of associa- 

 tions with specific cues in the maze, maintenance of the sense 

 of direction, symbolization of the maze pattern and the like, 

 is too slight to justify any further conclusions concerning the 

 nature of the function which is being measured. Lashley 

 ('29) has attempted to relate it to general intelligence, but 

 such speculation can be'justined only by showing a high cor- 

 relation of maze learning with tests known to involve some 

 general capacity which can be termed intelligence by common 

 consent. All that we can justifiably conclude is that our mazes 



