Studies on behavior. I. Differential sensitivity to pentobarbital of pecking performance in pigeons depending on the schedule of reward.

Pigeons working in a Skinner box developed different rates of pecking depending on the schedule of reward. When every 50th peck was rewarded (FR5O) the rate of response was high and constant. When the first peck after an interval of fifteen minutes was rewarded (15'FI) the average rate of pecking was low and there was a steady increase in rate through the interval. Pecking of the birds on 15'FI was markedly reduced by doses of pentobarbital...