Temporal control in chained fixed-ratio, fixed-interval schedules.

João Claudio Todorov,Lucas Couto De Carvalho,Kalliu Carvalho Couto

doi:10.3922/j.psns.2013.1.15

Abstract

Four rats were subjected to chained fixed-ratio (FR), fixed-interval (FI) schedules of reinforcement (chain FR 5 FI). A FR schedule at one lever produced a discriminative stimulus (i.e., light) associated with an FI schedule of primary reinforcement (water) at the second response lever. The FR schedule was kept constant, whereas the FI length was changed from 10 to 60 s under five different experimental conditions. Increases in the FI length resulted in increases in pre-ratio pauses, but pauses in the FI tended to be a constant percentage of FI length. Data from this experiment indicate that pre-ratio pauses are also a function of the interreinforcement interval (IRI). Data from three experiments with chained FR 5 FI 60-s schedules indicate that pausing in the FI component of chained FR FI schedules with the FI as the second component of the chain may tend to disappear as the IRI duration increases.

Highlights

Research that involves fixed-interval (FI) schedules of reinforcement began serendipitously (Skinner, 1956) but opened a new area of investigation in experimental psychology
Pausing in an FI has been attributed to the fact that the period after reinforcement is a signal for the absence of response reinforcement (Skinner, 1938; Ferster & Skinner, 1957; Catania, 1991)
Temporal control in chained schedules appears to be a function of the interreinforcement interval (IRI) and not a function of the fixed time to the opportunity for reinforcement signaled by a discriminative stimulus

Summary

Introduction

Research that involves fixed-interval (FI) schedules of reinforcement began serendipitously (Skinner, 1956) but opened a new area of investigation in experimental psychology. Pre-ratio pauses and work time are features of the pattern of responding in this schedule; both measures increase with increases in the size of the FR requirement. When the pre-pause and work times are increased, the interreinforcement interval (IRI) is extended. At least three variables can influence the pre-pause length in this schedule: FR requirement, interreinforcement interval, and work time (e.g., Neuringer & Schneider, 1968; Shull, 1970a; Crossman, Heaps, Nunes, & Alferink, 1974). Temporal control in chained schedules appears to be a function of the IRI and not a function of the fixed time to the opportunity for reinforcement signaled by a discriminative stimulus. The present study manipulated the IRI by increasing the size of the FI length while keeping the FR requirement constant

Methods

Procedure

Results and Discussion