Effect of Deprivation Level and Overtraining on Differential Conditioning and Reversal

Abstract

60 rats received 60 or 204 differential instrumental conditioning trials under 3-, 19- or 43-hr. water deprivation, followed by 60 reversal trials. In early acquisition speeds to both S+ and S—were greater with increased deprivation, but the subsequent onset of differentiation was most rapid in groups run at 43-hr. deprivation, this produced by their slower running to S—. Reversal performance was but little affected by deprivation, not was there any interaction between deprivation level and amount of prior training in the determination of reversal performance. Reversal performance was related to amount of prior training in a complicated fashion depending on the stimulus, the point of response measurement and the stage of training: First, number of prior reinforcements increased both start and run speeds to the old positive stimulus in early reversal but had no effect on start speeds and decreased run speeds in later reversal; second, number of prior non-reinforcements did not affect speed acquisition to the new positive stimulus.