Relative time effect in signaled and unsignaled delays of reinforcement

Abstract

One purpose of this study was to determine if by correlating each component of a multiple schedule with delays-of-reinforcement of either 0, 2, 4, or 8 s, a within-session delay-of-reinforcement gradient could be obtained. Reinforcement was delivered on each component using a tandem schedule composed by a random interval that added to each nominal delay yielded a constant interreinforcement interval (IRI) of either 32 or 128 s. Three pigeons were assigned to each IRI. Response rates in each component of the multiple schedules decreased gradually as the reinforcement delay was lengthened. A second purpose was to determine the point on a continuum defined by the probability of signaling the delay period p(signal) at which frequency-of-reinforcement effects become relative-time effects in a reinforcement-delay procedure. The p(signal) was either 0.00, 0.33, 0,66 or 1.00. When p(signal) was 0.00, global response rates for any given delay were higher with the 32 s than with the 128 s IRI, showing a frequency-of-reinforcement effect. When p(signal) was increased from 0.33 to 1.00 global response rates for any given delay were higher with the 128 s than the 32 s IRI, showing a relative-time effect.