The maintenance of matching behavior when contrast occurs in multiple concurrent concurrent schedules of reinforcement

Abstract

Pigeons were trained on a multiple schedule of reinforcement in which each component was a concurrent schedule. The concurrent schedules were programmed by the changeover-key procedure. The primary purpose was to determine if the relative behavior allocated to two response alternatives is affected when absolute changes in these behaviors occur; i.e., to determine if matching is affected when positive behavioral contrast occurs. Results showed that (1) relative behavior in the unaltered component of the multiple schedule is not disrupted when positive contrast occurs in that component, (2) positive contrast occurred when the overall frequency of reinforcement in the reinforcement-correlated component(s) was high, but not when it was low, (3) changeover behavior was susceptible to positive contrast effects, and (4) changeover contrast and food-key contrast are independent phenomena.Studies of choice behavior in concurrent schedules of reinforcement have shown that there is a simple relationship between the subject's response rates and obtained reinforcement rates. This relationship, called the matching law (Herrnstein, 1961(Herrnstein, , 1970, states that pigeons' relative rate of responding in one component of the concurrent schedule matches the relative rate of reinforcement obtained in that component. Baum and Rachlin (1969) have suggested that this relationship may be best expressed as the proportional quantity: (1) where PI and P, and the total number of responses emitted during the first and second components, respectively, r, and r z are the total number of reinforcements obtained in the first and second components, respectively, and K is a constant describing the bias between the components.A great deal of research has documented the accuracy of the matching law, and shown that matching does occur when parameters of reinforcement such as frequency, magnitude, delay, and quality are manipulated (see de Villiers, 1977, Herrnstein, 1970) is that absolute and relative behaviors are independent of each other (i.e., one may change while the other remains constant). This notion has been confirmed in a number of situations (see Herrnstein, 1961;Holz, 1968;McSweeny, 1975McSweeny, , 1977 Wald & Cheney, 1975), but such research has been quite limited. Since the viability of any theory rests upon its consistency and applicability across as many conditions as possible, the focus of the present study was to test further the independent nature of absolute and relative rate of response in a manner different from that of past research. This was accomplished by modifying the prototypical paradigm that produces behavioral contrast in simple multiple schedules. In the prototypical paradigm, a change from multiple variable-interval variable-interval (mult VI VI) reinforcement to multiple variable-interval extinction (mult VI EXT) reinforcement results in a decrease in response rate during the second component because responding is no longer reinforced, while response rate in the first component increases above the baseli...

Contrast and Reallocation of Extraneous Reinforcers as a Function of Component Duration and Baseline Rate of Reinforcement

“…In these experiments the distribution of behavior between two concurrent response alternatives in a multipleschedule component, in which both reinforcement schedules were kept constant, was shown to be insensitive to variations in reinforcement in the other component (termed successive independence). Similar constancy of behavior allocation was reported by Marcattilio and Richards (1980). Successive independence cannot be assessed directly in the case of the present experiment because the extra-key reinforcers were allowed to vary in the constant component.…”