An Interresponse‐time Analysis of Responding Maintained by Schedules of Response‐produced Electric Shock

Abstract

The present study investigated ratio contingencies to evaluate factors that may determine the maintenance of responding when electric shock is the consequent event. Initially, squirrel monkeys (Saimiri sciureus) were exposed to a continuous-avoidance schedule to initiate bar pressing. Subsequently, a multiple random-interval variable-ratio yoked schedule of response-produced shock was used to maintain and to compare interval and ratio performance. A microcomputer recorded and stored the number of responses and interresponse times occurring between successive shock presentations during a given random-interval component, and these numbers determined the ratio requirements during the subsequent ratio component. Responding was maintained for more than 80 sessions in two of three monkeys under the multiple schedule with the ratio yoked to the interval component. Responding during the ratio component persisted in only one monkey, however, when the components were no longer yoked. An analysis of the interresponse times immediately preceding shock under the multiple yoked schedule revealed that the terminal interresponse times were longer under the interval schedule than under the ratio contingency. The interresponse-time analysis indicated that differential interresponse-time relationships may be major determinants of the maintenance of behavior controlled by schedules of electricshock presentation.

Selective Punishment of Interresponse Times: The Roles of Shock Intensity and Scheduling

“…Two of the three VI schedules they employed produced increases in response rate with low levels of shock but failed to maintain responding at higher levels. The similarity in these two sets of data supports the argument (Galbicka & Branch, 1981;Howell, Byrd, & Marr, 1983) that variableinterval shock schedules functionally target long IRTs. Further, the data of Filby and Appel, in conjunction with the current data, raise questions about the generality of response-rate increases produced by selective IRT shock schedules.…”

“…In their study, shocks were 1.0 mA in intensity and 200 ms in duration. Compared with other studies using monkeys as subjects and using 6.0-mA shock (e.g., Branch & Dworkin, 1981;Howell et al, 1983;Malagodi, Gardner, Ward, & Magyar, 1981), this intensity seems "low." In none of these studies was response suppression observed with schedules that functionally shocked long IRTs.…”

Differential Effects of Cocaine and Pentobarbital on Fixed‐interval and Random‐interval Performance

“…All were behaviorally experienced subjects (Howell, Byrd, & Marr, 1983), but none had been used previously in drug experiments.…”

“…Three adult male squirrel monkeys (Saimiri sciureus), S-74, S-75, and S-77, were housed individually and provided free access to food and water. All were behaviorally experienced subjects (Howell, Byrd, & Marr, 1983), but none had been used previously in drug exper-…”

“…A 650-V ac source was used to deliver a 6-mA electric shock of 200 ms duration, and electrode paste (EKG Sol) applied to the tail minimized changes in impedance between the tail and the electrodes. A TRS-80 Model I® microcomputer controlled experimental events, and recorded and analyzed data as described previously (Howell et al, 1983;Mapou, Borowiec, Richards, & Byrd, 1984). Sessions were conducted 5 days per week; each session lasted 2 hr during initial training and 1 hr during the experimental procedures.…”