HABIT FORMATION IN THE DOG 53 



APPENDIX II 



CONTROL EXPERIMENT ON DISCRIMINATION TO NOISE, AFTER 



LEARNING 



In commenting on Rothmann's experiment (page 14) I em- 

 phasized the desirability of having all stimuli presented when 

 the animal is occupying the same position relative to the food. 

 The following record is more spectacular than some others 

 which my animals have made, but I have noted numerous other 

 instances which illustrate the pokit almost as well. 



It has already been said that this dog had learned the prob- 

 lem. On the second day of her tra'ning she showed an nvariable 

 tendenc}" to turn to the right food-compartment (F')- Each time 

 on the second day and twice on the third day, immediateh^ after 

 the animal had made the wrong turn, the experimenter sounded 

 the left buzzer the second t me. When the control-test was 

 made, eight days had elapsed since this had been done. This 

 day's record, which follows, shows clearly how strong and 

 pers'stent was the association. 



Problem 8, Dog 2, April 22, 1912 

 Trial Proper choice Actual choice 



1 R Rt 



2 R Rt 



3 L L 



4 R Rt 



5 L L 



6 L L 



7 R L* 



8 L L 



9 R L* 



10 R L* 



11 R L* 



12 L L 



13 R L* 



14 R Rf 



15 L L 



Correct reactions 10 



Incorrect reactions 5 



Total 15 



Percentage of accuracy 66t 



* Turned R; operator sounded (r) buzzer again; dog reversed choice, 

 t Stimulus presented only once. 



