DISCRIMINATION EXPERIMENT WITH WHITE RATS 163 



per trial for A, B, and D on this day was 1.7 seconds, for C 

 4 seconds. 



Time 

 or 



TOO 



1° 



tc 



Still 



A 



Moving 



20 



10 



t*~ 2~> j" v* s* 



/•*- IT* JW< ,< /* 6t ? t £ , 



100 



« , 



5*^ y *> s* «* ; 



* /*- /**- a^ jw /* j-x <*■ ;■ 





Figure 3. — Curves showing first responses of four white rats to stationary and 



moving lights. Per cent of correct choices for each successive ten 



trials. Average time in tenths of seconds. 



