Defining behavioral contrast for multiple schedules

Two different definitions of behavioral contrast have been used for multiple schedules. One, interschedule, definition identifies contrast as changes in the rates of responding which occur when subjects move from one multiple schedule to another. The other, intraschedule, definition emphasizes changes in the rates of responding which occur relative to a baseline rate of responding. The baseline is the rate of responding emitted during a multiple schedule that supplies equal rates of reinforcement in the two components. The distinction between these two definitions is important for empirical and theoretical reasons. For example, theoretical confusion has arisen when the interschedule definition has been used to test and reject theories which implicitly define contrast by the intraschedule definition.     

A quantitative analysis of extreme choice

Six homing pigeons were trained on a variety of concurrent variable-interval schedules in a switching-key procedure. Unlike previous work, reinforcer ratios of up to 160 to 1 and concurrent extinction variable-interval schedules were arranged in order to investigate choice when reinforcer-frequency outcomes were extremely different. The data obtained over 11 conditions were initially analyzed according to the generalized matching law, which fitted the data well. The generalized matching law was then fitted only to conditions in which the reinforcer ratios were between 1 to 10 and 10 to 1. The deviations of choice measures from the other four more extreme reinforcer-ratio conditions were significantly more towards equal choice than predicted by this second generalized matching fit. A contingency-discriminability model, which predicts such deviations, described the data more effectively than did the generalized matching law, and also correctly predicted the maintenance of responding on both alternatives when one was associated with extinction.     

Changeover delay and concurrent-schedule performance in domestic hens

Six domestic hens were exposed to a series of five pairs of two-key concurrent variable-interval schedules with a range of changeover delays from no delay to 15 s. Times spent responding on each alternative and total, within_, and post-changeover-delay response ratios were analyzed in terms of the generalized matching law. The sensitivity parameters, a, for response and time data were generally low when no changeover delay was programmed but were not 0.0. They were higher for all other changeover-delay values, with some tendency to increase as the changeover delay lengthened at very short delays. Within-delay responding was insensitive to reinforcement-rate differences at all changeover delays (a values close to 0.0). As a result of this insensitivity, post-changeover-delay responding was more sensitive to reinforcement-rate changes than was total responding. Interchangeover intervals increased systematically with changeover-delay duration. Responding, particularly after the changeover delay, was well predicted by an equation based on a reinforcer-loss model.     

The applied importance of research on the matching law

In this essay, we evaluate the applied implications of two articles related to the matching law and published in the Journal of the Experimental Analysis of Behavior, May 1994. Building on Mace's (1994) criteria for increasing the applied relevance of basic research, we evaluate the applied implications of basic research studies. Research by Elsmore and McBride (1994) and Savastano and Fantino (1994) involve an extension of the behavioral model of choice. Elsmore and McBride used rats as subjects, but arranged a multioperant environment that resembles some of the complex contingencies of human behavior. Savastino and Fantino used human subjects and extended the matching law to ratio and interval contingencies. These experiments contribute to a growing body of knowledge on the matching law and its relevance for human behavior.     

Behavioral economics and behavioral momentum

Some relations between elasticity of demand and the conditions of reinforcement are reanalyzed in terms of resistance to change, in ways suggested by the metaphor of behavioral momentum; some relations between resistance to change and the conditions of reinforcement are reanalyzed in terms of elasticity of demand, in ways suggested by behavioral economics. In addition, some data on labor supply in relation to variable-ratio schedules and alternative reinforcement are reanalyzed in terms of resistance to change and compared with steady-state resistance data for performance on multiple and concurrent interval schedules. The results of these studies can be summarized by two functions based on the behavioral momentum approach, relating relative behavioral mass to relative reinforcement per response or per unit time. The former is a relation between relative unit price and relative behavioral mass, suggesting the possibility of convergent measurement of a theoretical construct common to both approaches. However, the momentum and economic approaches differ fundamentally on whether it is preferable to construe discriminated operant behavior as selected and strengthened by its consequences or as part of a behavior–consequence bundle that maximizes utility.     

Behavioral economics without anomalies.

Behavioral economics is often conceived as the study of anomalies superimposed on a rational system. As research has progressed, anomalies have multiplied until little is left of rationality. Another conception of behavioral economics is based on the axiom that value is always maximized. It incorporates so-called anomalies either as conflicts between temporal patterns of behavior and the individual acts comprising those patterns or as outcomes of nonexponential time discounting. This second conception of behavioral economics is both empirically based and internally consistent.     

Correlation between self-reported rigidity and rule-governed insensitivity to operant contingencies

Adults were selected on the basis of their scores on the Scale for Personality Rigidity (Rehfisch, 1958a). Their scores served as a measure of hypothesized rule governance in the natural environment. Experiment 1 studied the effects of accurate versus minimal instructions and high versus low rigidity on performance on a multiple differential-reinforcement-of-low-rate (DRL) 4-s fixed-ratio (FR) 18 schedule. When the schedule was switched to extinction, accurate instructions and high rigidity were associated with greater perseveration in the response pattern subjects developed during the reinforcement phase. In Experiment 2, the effects of rigidity and of accurate versus inaccurate instructions were studied. Initially, all subjects received accurate instructions about an FR schedule. The schedule was then switched to DRL, but only half of the subjects received instructions about the DRL contingency, and the other half received FR instructions as before. Accurate instructions minimized individual differences because both high and low scorers on the rigidity scale earned points in DRL. However, when inaccurate instructions were provided, all high-rigidity subjects followed them although they did not earn points on the schedule, whereas most low-rigidity subjects abandoned them and responded appropriately to DRL. The experiments demonstrate a correlation between performances observed in the human operant laboratory and a paper-and-pencil test of rigidity that purportedly reflects important response styles that differentiate individuals in the natural environment. Implications for applied research and intervention are discussed.     

Limited matching on concurrent-schedule reinforcement of academic behavior

Three adolescent students with special educational needs were given a choice between completing one of two available sets of math problems. Reinforcers (nickels) across these alternatives were arranged systematically in separate experimental phases according to three different concurrent variable-interval schedules (reinforcement ratios of 2:1, 6:1, and 12:1). Time allocated to the two stacks of math problems stood in linear relationship to the reinforcement rate obtained from each stack, although substantial undermatching and bias were observed for all subjects. However, changes in the schedules were not followed by changes in allocation patterns until adjunct procedures (e.g., changeover delays, limited holds, timers, and demonstrations) were introduced. The necessity of adjunct procedures in establishing matching in applied situations is discussed as a limitation to quantitative applications of the matching law in applied behavior analysis.     

Effects of the discriminability of alternatives in three-alternative concurrent-schedule performance

Six pigeons were trained on two- and three-alternative concurrent schedules in which the alternatives were signaled by different wavelengths of light on the main pecking key. The schedules were arranged according to a switching-key procedure in which pecks on a white side key produced a 3-s blackout and, intermittently, a change in the variable-interval schedule of food programmed on the main (center) key after the blackout. In Part 1, a two-alternative concurrent variable-interval schedule was arranged in which the alternatives were signaled by 560 nm and 630 nm. Parts 2 and 3 arranged three-alternative concurrent variable-interval schedules with the alternatives signaled by 560 nm, 600 nm, and 630 nm (Part 2) and 560 nm, 623 nm, and 630 nm (Part 3). Within each part, the relative rate of food reinforcers available on the alternatives was varied across a wide range. In all parts of the experiment, the ratios of responses emitted between pairs of alternatives were more extreme than the ratios of reinforcers obtained on the pairs of alternatives, a result termed overmatching. In Parts 2 and 3, generalized matching sensitivities between pairs of alternatives were found to be higher when the reinforcer rate on the third alternative was low than when it was high—an apparent failure of the constant-ratio rule. The data were well described by an extension of the Davison and Jenkins (1985) model, which assumes differing discriminabilities between concurrent-schedule alternatives in combination with a punishing effect of blackout following changeovers.