THE RELATION OF STRENGTH OF STIMULUS TO 

 RAPIDITY OF HABIT-FORMATION IN THE KITTEN 



J. D. DODSON 



Central College, Pella, Iowa 



For this study of the relation of strength of stimulus to rapidity 

 of learning I have used the method which Yerkes and I found 

 satisfactory in our similar study of the dancing mouse. 1 But 

 instead of requiring the kitten to choose between white and 

 black, as in the case of the mouse, I required it to discriminate 

 between light and dark — that is the kitten had to choose in 

 the Tight-dark series instead of the white-black series. Irre- 

 spective of the relative positions of the two boxes the subject 

 had to choose the light one. Should the kitten enter the dark 

 box it received an electric shock, and was never allowed to 

 escape by passing through the same. 



The apparatus was very much the same as that used with 

 the dancer (for general construction see figures 1 and 2, page 

 460, of the article referred to above). The experiment box 

 was divided into a nest box, an entrance chamber and two 

 electric boxes. The entrances and exits to the electric boxes 

 were 9 by 9 cm. each. The electric boxes were placed in the 

 circuit of a constant electric current. In this circuit was a 

 double key by which the experimenter could direct the current 

 through either box he might wish. The inductorium and re- 

 sistance coil were placed in an adjoining room thus eliminating 

 all the noise of the constant buzz of the inductorium. The 

 current was furnished by a storage battery which was kept 

 constant at a voltage of 19.5 and amperage of 4. To govern 

 the amount of light entering the electric boxes, the entire end 

 of the experiment box containing the electric boxes was covered, 

 and two openings cut in the cover, one directly over each electric 

 box. In order to prevent the kitten from seeing the opening 

 in this cover as it entered the electric box, a platform 25 cm. 

 wide was placed 12 cm. from the top of the box and directly 



1 Jour, of Comp. Neurol, and Psy., 1908, 18, 459-482. 



330 



