Temporal Constraint on Choice: Sensitivity and Bias in Multiple Schedules

Abstract

In multiple schedules of reinforcement, ratios of responses in successive components are relatively insensitive to ratios of obtained reinforcers. An analysis is proposed that attributes changes in absolute response rates to concurrent interactions between programmed reinforcement and extraneous reinforcement in other components. The analysis predicts that ratios of responses in successive components vary with reinforcer ratios, qualified by a term describing the reinforcement context, that is, programmed and extraneous reinforcers. Two main predictions from the analysis were confirmed in an experiment in which pigeons' responses were reinforced in the components of a multiple schedule and analog extraneous reinforcement was scheduled for an alternative response in each component. Sensitivity of response and time ratios to reinforcer ratios in the multiple schedules varied as a function of the rate of extraneous reinforcers. Bias towards responding in one component of the multiple schedule varied as an inverse function of the ratios of extraneous reinforcer rate in the two components. The data from this and previous studies of multiple-concurrent performance were accurately predicted by our analysis and supported our contention that the allocation of behavior in multiple-schedule components depends on the relative values of concurrently-available reinforcers within each component.

Adaptive Behavior and Learning

“…That is, in the absence of competition from "other" behavior, responding in each component will expand to fill all the time available. But as R O increases, t i → R i /ΣR j , i.e., when R O is large, there is perfect matching for all components, which is what the data show (e.g., McLean & White, 1983;Nevin, 1974). That is, when neither response is able to "saturate" (take up all the time in its component), there will be matching, as on the corresponding concurrent schedule.…”

Component duration effects in multiple schedules

“…Previous studies have typically varied both the relative and the absolute reinforcement rates simultaneously, so that it has been unclear whether changes in absolute reinforcement rate may playa significant role on its own, as is suggested by some theoretical models (McLean & White, 1983). In the present study, the total reinforcement rate summed over both components, maintained at either a high or low level, was held constant for a given series of conditions.…”

Remembering: The role of extraneous reinforcement

“…For example, White, McLean, and Aldiss (1986) programmed a constant rate of reinforcement for left-leverpressing by rats and varied the concurrently available variable-interval (VI) reinforcement rate for right-leverpresses across a series of conditions. Reinforcers obtained by left responses were construed as being analogous to extraneous reinforcement, although they effectively added to whatever true extraneous reinforcement might have been available (McLean & White, 1983). White et al demonstrated that the rate of right responses increased as a hyperbolic function of an increasing rate of reinforcers for right responses, as hypothesized by Hernnstein's (1970) law of effect.…”

“…At first glance, part of this prediction might appear to be disconfirmed, because the effect of reinforcer probability still emerged even when no reinforcers were arranged for center key pecking. In evaluating this claim, it is important to consider that even when center key pecking was not explicitly reinforced, R o was still present (McLean & White, 1983;Williams, 1988). Among other possibilities, the center key was still illuminated in EXT, not only providing the opportunity to peck (which the pigeons did), but also providing a source of light that could occasion other behaviors.…”