DISCRIMINATIVE AND REINFORCING PROPERTIES OF TWO TYPES OF FOOD PELLETS¹

Abstract

In Experiment I some discriminative functions of food pellets were studied by developing a multiple schedule of reinforcement (mult FR 30 Fl 3) in which the delivery of a standard laboratory food pellet as a reinforcer set the occasion for reinforcement on every 30th response (FR 30), and the delivery of a sucrose food pellet as a reinforcer set the occasion for reinforcement after a 3-min interval (Fl 3). Discriminative stimulus control by the type of pellet was also demonstrated by reversing the operant discrimination and having the standard pellet control the FI 3 and the sucrose pellet control the FR 30. In Experiment II a mult FR 30 FR 30 with two bars was developed; a standard food pellet was followed by an FR 30 on Bar 1 and extinction (ext) on Bar 2, while a sucrose pellet was followed by an FR 30 on Bar 2 and ext on Bar 1. A control rat was placed, for comparison, on a mixed (mix) FR 30 FR 30 schedule with two bars, but neither bar correlated with the type of food pellet. In Experiments I and II the similarity between pellet controlled multiple schedules and multiple primed schedules was discussed, as was the comparability of transitions and effectiveness of control between pellet controlled multiple schedules and multiple schedules providing continuous exteroceptive stimuli.The purpose of this study was to investigate some discriminative functions of reinforcing stimuli by using two types of food pellets as reinforcers and following each with a different schedule of reinforcement. These procedures involve the differential reinforcement of responses as a consequence of the prior type of pellet. If the discrimination is effective the process results in changes in the rate of responding occasioned by stimuli correlated with presentation of the reinforcer and with the appropriate consummatory behavior.EXPERIMENT I A multiple schedule of reinforcement is characterized by programming reinforcements on two or more schedules, each schedule being correlated with an appropriate controlling stimulus (Ferster and Skinner, 1957). The first two-ply multiple schedule developed in this study involved presenting a standard formula (St) pellet and following it with a reinforce-

Determinants of Human Fixed-Interval Performance Following Varied Exposure to Reinforcement Schedules

“…The demonstration of discriminative control of response rate by stimulus features of the schedules themselves is consistent with work by Cerutti (1991) and extends the demonstration to the more typically studied response-contingent situations. Furthermore, these data contribute to the generally under-researched area of discriminative control by reinforcing stimuli (e.g., Cruse, Vitulli, & Dertke, 1966;Reid, 1958), to the literature on reinforcement density as it affects human operant behavior (e.g. , Flora & Pavlik, 1992;Sonuga-Barke, Lea, & Webley, 1989), and to the body of research on factors affecting human FI performance (e.g.…”

Response‐independent Events in the Behavior Stream

“…When a response is reinforced, the reinforcer can function as a discriminative stimulus that evokes further responding (cf. Cruse, Vitulli, & Dertke, 1966). When an identical food presentation to the reinforcer is intruded as a response-independent event, it too may evoke the operant response.…”

Effects of Magnitude of Food Reinforcement on Free‐operant Response Rates

“…Such conditioning can, for example, create different patterns of lever approach (Carlson & Wielkiewicz, 1976; see also Burns, 1976, for an example of differential patterns of behavior in the runway after different reinforcement magnitudes). The suggestion that different magnitudes of reinforcement can act as discriminative stimuli for the emission of different specific patterns of responding is also documented in the operant conditioning literature (Cruse, Vitulli, & Dertke, 1966). If the structure of behavior interacts with reinforcement magnitude, molar contingency theories of the action of reinforcement, such as those proposed by Baum (1973), may have to be modified to consider the effect of reinforcement on the local structure of behavior.…”