History of response acquisition on a multiple FR-DRL schedule of reinforcement: Differentiation and stability of response rates

Abstract

Discrepancies in schedule performance are commonly observed between humans and non-humans. Three hypotheses are proposed to explain these discrepancies: verbal behavior, behavioral history and procedural variables. Various studies have been reported in which the effects of procedural variables on response rates have been assessed. One such variable is the history of acquisition of behavior in multiple schedules of reinforcement. With non-humans, the criterion generally used to change the components of the multiple schedule is the number of reinforcers, and with humans, components are generally changed after a fixed interval, independent of the organism’s performance. The goal of the present study was to assess the effects of different histories of acquisition in a multiple fixed-ratio(FR) differential-reinforcement-of-low-rate (DRL) schedule on (a) the differentiation in response rates and (b) on the time (measured in minutes and number of sessions) for stable response rates min each component to be achieved. Twenty undergraduates participated, and were distributed in four groups. The response was pressing a button on the screen with the mouse cursor. For participants in Group 1, the parameters of the DRL were incremented within sessions, from 2 s until 20 s, and subsequently the parameters of the FR were increased from 10 until 60. For the participants in Group 2, the parameters of both schedules were incremented simultaneously, within sessions. For participants in Groups 3 and 4, the increments in the parameters of the schedule components were always conducted across sessions and the difference between these groups was the criterion for changing the components of the multiple schedule. For participants in Group 3, schedules components changed after 10 points were earned and for those in Group 4, changes in components occurred after 3 minutes had elapsed. The differentiation in response rates between components of the multiple schedule was achieved with each of these ways of arranging the acquisition of responding. In general, the different ways in which acquisition was programmed did not affect the time necessary to achieve stability in responding in a multiple FR-DRL (behavior was stable for participants in each group within a maximum of 9 sessions). Maintenance of this stability, with continued exposure to the schedule of reinforcement, also was not a function of the history of acquisition.