The effect of magnitude of reward and intertrial interval on the acquisition of a discrete trial lever press response



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This study examined the effect of regular patterns of reward and ITI on acquisition. 4 groups of 20 rat Ss were given 13 trials a day for 6 days. There were 2 schedules of reward (CRF and VRF), 2 lengths of ITI (15 and 60 sec.), and 2 values of reward (1 and 8 45 mg pellets). The rewards In the VRF groups and the ITI for all groups were presented In single alternation. A significant (alpha = .05) response decrement occurred on trials following a large reward and a short ITI. This decrement was present on the first and last days of training and did not appear to change over days and was independent of schedule of reward. It was concluded that the decrement was unconditioned and not the product of differential conditioning and therefore Is a serious source of confoundment in pattern learning experiments.



Reward (Psychology), Rats--Behavior