RATE OF LEARNING IN THE WHITE RAT 37 



presented simultaneously. With the one, electric shock and 

 buzzer were used ; with the other, electric buzzer and light. The 

 previously discussed test trials were interpolated after each series 

 of 20 training trials in order to check the rate of learning. These 

 tests were not made with Nos. 2 and 9. These continued on the 

 regular learning series until they had had 100 trials before the 

 test series was entered. These animals do not appear to have had 

 any advantage over the other animals of this group where the 

 special tests were entered earlier. These special tests were not 

 expected to assist in learning the association, but they do not 

 appear to have hindered it. 



When the pain-buzzer group (Group I) had learned to respond 

 negatively to the first stimulus, pain, buzzer was sounded simul- 

 taneously with pain, and the problem was to transfer the negative 

 response from pain over to buzzer. In Table XIV the number 

 of trials necessary to master the problem and the strength of the 

 association are given. The number of test trials given is not 

 shown in this table, but is used in constructing the curve in Fig. 9. 



TABLE XIV 



Animal Training Trials % on Last 100 



2 120 91 



9 100 96 



14 100 91 



31 100 91 



32 120 90 



33 140 92 



Average 113.3 Qi-6 



No marked individual differences appear. Although the average 

 number of trials necessary to learn the association is 113.3, m 

 each case where the test trials were given the animal had so com- 

 pletely made the transfer that at the end of 60 trials he made 

 90 per cent on the test trials. However, because 90 per cent 

 on the last 100 trials had been adopted as a standard, each of the 

 animals was given additional trials on the training series. 



The four animals of Group VII had not only learned the 

 negative response to pain, but had transferred this response to 



