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Full-Text Articles in Psychology

The Midsession Reversal Task With Pigeons: Effects Of A Brief Delay Between Choice And Reinforcement, Megan Ashley Halloran Jan 2020

The Midsession Reversal Task With Pigeons: Effects Of A Brief Delay Between Choice And Reinforcement, Megan Ashley Halloran

Theses and Dissertations--Psychology

During a midsession reversal task, the session begins with a simple simultaneous discrimination in which one stimulus (S1) is correct and the alternate stimulus (S2) is incorrect (S1+/S2-). At the halfway point, the discrimination reverses and S2 becomes the correct choice (S2+/S1-). When choosing optimally, a pigeon should choose S1 until the first trial in which it is not reinforced and then shift to S2 (win-stay/lose-shift). With this task pigeons have been shown to respond suboptimally by anticipating the reversal (anticipatory errors) and continuing to choose S1 after the reversal (perseverative errors). This suboptimal behavior may result from a pigeon’s …


Chlordiazepoxide Increases Risky Choice, Devin Andrew Galdieri Jan 2020

Chlordiazepoxide Increases Risky Choice, Devin Andrew Galdieri

Graduate Theses, Dissertations, and Problem Reports

Probability discounting is a measure of risky choice that is correlated with maladaptive behavior and psychological disorders. Benzodiazepines are a class of drug on which relatively little risky-choice research has been conducted, particularly under conditions of chronic drug exposure. Chlordiazepoxide, a standard benzodiazepine, was administered to rats that had been trained to respond on a risky-choice task in which a choice was available between a single food pellet with 100% certainty or three food pellets with probabilities of delivery that decreased across each experimental session. During baseline, responding was sensitive to the programmed contingencies and larger-reinforcer choice decreased as the …