Resistance to Change in Schedules of Avoidance and Timeout from Avoidance

Abstract

Galizio (1999) reported that responding that produced a timeout from avoidance was more resistant to extinction than avoidance responding itself. The present study sought to extend this finding. Six times during each session, a signaled fixed-ratio 10 schedule was superimposed on a variable-cycle 60-s shock deletion schedule. By completing the ratio, rats produced a signaled 5- or 8-min timeout. Response rates maintained by avoidance and timeout were compared by analyzing responding during each FR presentation (timeout) and in the 5-min period before it (avoidance). Resistance to change was assessed by (a) increasing the variable-cycle parameter from 60 s to 120 s (Experiment 1), and (b) shock-omission extinction (Experiment 2). In both cases, timeout responding was more resistant to change than avoidance responding.