Effects of the Intensity of Electric Shock on Response Suppression During Multiple and Mixed Schedules of Signalled and Unsignallei Electric-Shock Delivery

Abstract

In three experiments, food-rein forced responding was studied during multiple schedules of signalled and unsignalled electric-shock delivery. Depending upon the shock intensity employed, responding was (a) similarly suppressed in each component, (b) reduced primarily in the component associated with unsignalled shock, or (c) reduced considerably in both components of the multiple schedule. Mild shock intensities, which initially failed to produce differential response suppression, did so when they were reintroduced following exposure to more intense signalled and unsignalled shock. Food-maintained responding was studied during mixed as well as multiple schedules of signalled and unsignalled electric-shock delivery in Experiment 3. During the mixed schedules of food-and-shock delivery, the components were not distinguished by correlated stimuli, remaining either light or dark. While the multiple schedule readily led to differential response suppression, similar levels of response suppression were found in both components during the mixed schedule of signalled and unsignalled shock delivery. These experiments show that differential response suppression during signalled and unsignalled shock is a function of shock intensity and the discriminability of shock and shock-free occasions.