Date of Award:


Document Type:


Degree Name:

Doctor of Philosophy (PhD)



Committee Chair(s)

J. Grayson Osborne


J. Grayson Osborne


The present study was designed to analyze the transfer of stimulus control in temporal fading procedures. Several aspects of temporal fading procedures were manipulated including sources of inhibitory stimulus control, delays of reinforcement, and rates of increase in the temporal parameter of a fading procedure. In Experiment I, previous research producing transfer of stimulus control in a temporal fading procedure was directly replicated and controls were implemented for the operation of inhibition. The results showed that inhibitory stimulus control is not necessary in order to produce a transfer as participants with neutral stimulus backgrounds also transferred from one dimension to another without errors. However, positive stimulus backgrounds in the fading procedure prohibited the participants from achieving an errorless transfer of discrimination learning. In Experiment II, a fixed trial duration was employed with a constant and equal delay of reinforcement for both new and original stimulus dimensions. In this condition, participants did not transfer from one dimension to another with up to 30-second delays. Control participants were yoked to participants exposed to delayed and fading procedures to examine response latencies under delayed reinforcement for a simultaneous discrimination. There were no discernible response patterns under this condition except that participants continued to emit relatively short response latencies with a 40-second delay of reinforcement. In Experiment III, the effects of different steps of temporal fading on transfer were examined. The results showed that as the step of delay increased (10 sec. per trial), subjects transferred earlier in the fading series. Also, subjects with extremely low steps of delay (.1 sec. per trial) tended to remain with the original stimulus dimension. Experiments I through III demonstrated the necessity of either inhibitory or neutral stimulus backgrounds, differential delays of reinforcement correlated with each stimulus dimension, and relatively rapid increments in delay of the original stimulus dimension to obtain transfers of stimulus control in temporal fading procedures. When excitatory stimulus backgrounds were employed, or no differential delay of reinforcement was present, or the delay of the original stimulus dimension increased slowly, errorless transfers were not obtained.

Overall, the results indicate that temporal fading procedures are a reliable, although complexly controlled, means of obtaining transfer between two stimulus dimensions.



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