4 K. S. LASHLEY AND L. E. WILEY 



The bimodality of distribution of these constants is good 

 evidence that the positive correlations are not merely the 



TABLE 1 



The relation between extent of lesion and efficiency of performance in previous 



studies of the effects of cerebral injury. The constants are for error 



scores where these are available, otherwise for trials 



L. = initial learning, P. E. = postoperative retention. 



1 Correlations not computed, but no suggestion of a correlation from inspection 

 of the data. 



result of some error in sampling, in which case they would 

 show a normal distribution around zero, but express a genuine 

 relation between the variables studied. All of the constants, 

 however, have been determined from relatively small numbers 



