Properties Of Simultaneous Discrete Occasion Setters

This series of experiments used 80 to 120 day old water-deprived rats (Rattus norvegicus) to investigate whether simultaneously presented discrete occasion setters shared two properties of serially presented discrete occasion setters. Results of Experiment 1 revealed that all groups showed a strong reinstatement effect. In the second experiment a target stimulus was first trained as a predictor of shock and then paired with a simultaneously presented occasion setter to inhibit responding to the target stimulus. The occasion setter was then paired with a shock. Due to a limitation of the procedures, results from Experiment 2 were inconclusive. The third experiment tested whether simultaneously presented occasion setters would only transfer to other targets that underwent occasion setting training. Results from Experiment 3 revealed strong contextual control over behavior that overshadowed the ability of the features to modulate responding to the targets. A fourth experiment addressed limitations from Experiment 3. Results from Experiment 4 revealed that simultaneous discrete occasion setters were unable to transfer to another target stimulus. Overall results from this experiment indicate that simultaneously presented cues do not act as occasion setters.