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Cocaine And Timing: Drug Effects Under A Mixed Fixed-Interval Extinction Schedule, Vincent O. Hodge

Masters Theses

The effects of cocaine hydrochloride (3.2-56.2 mg/kg) were determined in rats performing under a mixed fixed-interval 60-seconds extinction 120-seconds schedule of food delivery. Responses were recorded in successive 5-second bins. With the exception of the highest dose (56.2 mg/kg), cocaine did not significantly affect rate of responding under the fixed-interval component or extinction component, or the time of peak responding under the extinction component. The highest dose significantly reduced response rates and shifted the time of peak responding leftward to quicker and earlier moments. Results are discussed in terms of possible rate- and time-dependent effects of stimulant drugs.