Date of Graduation
Eberly College of Arts and Sciences
David W. Schaal.
Two experiments examined the effects of morphine and d-amphetamine on behavior that was temporally organized under several schedule arrangements. Two body weights were assessed for each experiment. Experiment 1 made use of fixed-interval (FI) schedules, the peak procedure, and a two-key (free-operant psychophysical) procedure. Indexes of timing performance under each of these schedules were assessed and compared. Timing indexes were decreased by both drugs in the two-key procedure, but were not reliably altered in the peak procedure. Both drugs produced clear rate-dependent effects on behavior in both procedures. In Experiment 2, FI performance was assessed both alone and with a concurrently available variable-interval (VI) schedule to determine whether drugs would cause a pigeon to leave a potential source of reinforcement early in order to respond to a future source of reinforcement. Although reductions in the index of curvature were obtained, there was no clear difference in FI performance based on whether or not a VI schedule was concurrently available. The results of Experiment 1 are inconsistent with the theory of a sped-up pacemaker, but are consistent with explanations involving a decrease in attention. The data also are consistent with the rate-dependency hypothesis, which states that rates of responding following drug administration tend to be determined in large part by rates of responding under baseline conditions.
Knealing, Todd William, "Effects of morphine, d-amphetamine, and food deprivation on temporally organized behavior" (2002). Graduate Theses, Dissertations, and Problem Reports. 1593.