FREQUENCY AND RECENCY FACTORS IN MAZE 

 LEARNING BY WHITE RATS 



JOSEPH PETERSON 



University of Minnesota 



Let us assume that the number of previous runs in any unit 

 of the maze (frequency) determines the direction a rat running 

 the maze in the process of learning will take at any bifurcation 

 encountered, and that probability alone governs the early 

 " choices " at such positions. 1 On these assumptions an inter- 

 esting explanation of maze-learning by rats has been made. 

 Let us start an imaginary rat in a ten-cul-de-sac maze and de- 

 termine its course at each bifurcation by nipping a coin: 

 " heads," it keeps its direction — forward or return, in which- 

 ever it happens at the time to be going; " tails," it enters the 

 blind alley. On emergence from the blind alley, " heads " again 

 takes it in the direction it had when the blind alley was encoun- 

 tered and " tails " means a return, the reverse of that direction. 



The results of one such trial are here given to make more 

 concrete the method. F in the lower line means movement 

 toward the food box (forward) and R signifies a return, the 

 reverse direction. An R underscored means that the return is 

 complete and that the direction of movement is reversed, put- 

 ting the animal again at the first bifurcation — at the first blind 

 alley. The figures represent blind alleys entered. 



hththttththhhthtththhh 

 F2F3F4R3R2R#F2F3RR1 R F F 



htththhhttthtthhhhthth 

 F4RR2RAF2R1 R I KFFFF5F6F 



tttthhhh 



7 R6 FFFFF(to food box). 



1 Throughout this discussion the word "choice" is used in the sense of going 

 into one of two possible alleys open to the animal at any given bifurcation in the 

 maze, not as implying any voluntary selection. 



338 



