A 2-STATE ANALYSIS OF FIXED-INTERVAL RESPONDING IN PIGEON

The behavior of pigeons on six geometrically spaced fixed‐interval schedules ranging from 16 to 512 sec is described as a two‐state process. In the first state, which begins immediately after reinforcement, response rate is low and constant. At some variable time after reinforcement there is an abrupt transition to a high and approximately constant rate. The point of rapid transition occurs, on the average, at about two‐thirds of the way through the interval. Response rate in the second state is an increasing, negatively accelerated function of rate of reinforcement in the second state. 1969 Society for the Experimental Analysis of Behavior