Abstract

Dose-response curves were determined for the effects of a series of sympathomimetic amines on the behavior of pigeons trained to peck a key under a multiple fixed-ratio fixed-interval schedule of food presentation. Mephentermine, d-amphetamine, hydroxyamphetamine and ephedrine all increased the rate of responding during the fixed-interval component of the schedule at low dosages. At higher dosages these drugs decreased the rate of responding during the fixedratio component of the schedule. Phenylephrine, metaraminol and norepinephrine had no effect on the rate of responding at low dosages and decreased the rate of responding during both components of the schedule at higher dosages. The effects of d-amphetamine and ephedrine on behavior were shown to be a function of the control rate of responding and the dosage.