Reward magnitude and partial reinforcement effects in a single runway.

The partial reinforcement acquisition effect (PRAE) in running speeds and the frustration effect (activity following nonreward compared with reward) were measured simultaneously in an alley whose goal-box floor was a stabilimeter. Experimental groups of 9 male Charles River albino rats each received 50 or 100% reinforcement combined factorially with 3 magnitudes of reward (1, 3, or 9 pellets). A control group of 18 Ss was never rewarded. The size of the PRAE was a direct function of reward magnitude, and crossing of 50 and 100% curves was found for all alley segments, including the goal segment. The frustration effect (FE) was present by the 2nd day of training for the 3- and 9-pellet groups, and the size of the FE was directly related to reward magnitude. The present study is unique in that (a) the findings were free from the effects of reward contrast, (b) behavior antecedent to the goal indicated that incentive was effectively manipulated, and (c) an unrewarded control group was used. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)