SEQUENTIAL DEPENDENCIES OF THE LENGTHS OF CONSECUTIVE RESPONSE RUNS¹

Abstract

Three male albino rats, working under thirst drive in two-lever Skinner boxes, were trained under a procedure in which the reinforcement requirement was a minimum of eight consecutive responses on lever A followed by a response on lever B. The following aspects of the resulting performance were investigated: a.) sequential dependencies of the lengths of consecutive runs; b.) cyclic fluctuations in the length of successive runs; and c.) run-length changes during extinction. It was demonstrated that the length of a run is related to the length of the immediately preceding run, that there sometimes appear cyclic fluctuations in the length of successive runs, and that run-length variability increases under conditions of extinction.