Variable Interval Response Rate as a Function of Prior Partial Reinforcement of a Running Response

Abstract

Two groups of 8 rats were given 60 trials of 100% reward followed by 80 trials of 50% random reward in the first goal box (GB) of a double alley. The effects of non-reward in GB₁ were measured in a second alley, where Ss bar-pressed on a 30-sec. VI reward schedule. Two control groups of 8 Ss received identical training except that they were never rewarded in GB₁. For all Ss Alley 1 and GB₁ were white, for one experimental and one control group Alley 2 was white, for the other two black. A significant frustration effect was obtained for the two experimental groups; however, this effect was not significant when compared to the bar-pressing rate of the control groups. None of the effects of brightness of Alley 2 were significant.