Wist, E. R. (1962). Amount, delay, and position of delay of reinforcement as parameters of runway performance. Journal of Experimental Psychology, 63(2), 160-166.
http://dx.doi.org/10.1037/h0046759
2 reinforcement concentrations (8% and 32% sucrose solutions), 2 delay intervals (3 and 45 sec.), and 3 delay positions (2, 6, and 10 ft. from the goal box) were factorially combined in a study of rat performance and consummatory behavior in a runway. Running occurs "at rates determined by its consequences such as the concentration of reinforcement, and it occurs everywhere at the same rate independent of its temporal or spatial distance from its climax. Factors such as fatigue or habituation may result in declines in rate over long distances. Factors such as obstacles and distracting stimuli may produce local disturbances in running, but do not manipulate its basic rate. Time and distance factors, important in the classical treatment of performance gradients do not readily account for the effects obtained." (PsycINFO Database Record (c) 2016 APA, all rights reserved)