Choice as a Function of Local Versus Molar Reinforcement Contingencies

Abstract

Rats were trained on a discrete-trial probability learning task. In Experiment 1, the molar reinforcement probabilities for the two response alternatives were equal, and the local contingencies of reinforcement differentially reinforced a win-stay, lose-shift response pattern. The win-stay portion was learned substantially more easily and appeared from the outset of training, suggesting that its occurrence did not depend upon discrimination of the local contingencies but rather only upon simple strengthening effects of individual reinforcements. Control by both types of local contingencies decreased with increases in the intertrial interval, although some control remained with intertrial intervals as long as 30 s. In Experiment 2, the local contingencies always favored win-shift and lose-shift response patterns but were asymmetrical for the two responses, causing the molar reinforcement rates for the two responses to differ. Some learning of the alternation pattern occurred with short intertrial intervals, although win-stay behavior occurred for some subjects. The local reinforcement contingencies were discriminated poorly with longer intertrial intervals. In the absence of control by the local contingencies, choice proportion was determined by the molar contingencies, as indicated by high exponent values for the generalized matching law with long intertrial intervals, and lower values with short intertrial intervals. The results show that when molar contingencies of reinforcement and local contingencies are in opposition, both may have independent roles. Control by molar contingencies cannot generally be explained by local contingencies.

Concurrent VR VI schedules: Primacy of molar control of preference and molecular control of response rates

“…One question to ask is whether the opposed primacy of each of these complementary factors is absolute (e.g., Williams, 1991Williams, , 1993. That is, is IRT reinforcement irrelevant to measures of preference and preference irrelevant to the determination of local response rates to a schedule?…”

Polymorphic response patterns under frequency-dependent selection

“…A possible answer is suggested by experiments that show that the magnitude of the difference in reinforcement probability across competing response patterns determines whether subjects learn the momentary maximizing sequence of the schedule (e.g., Williams, 1972Williams, , 1991. Then consider how, in the three items listed above, a response pattern changes the momentary payoff probabilities.…”

“…Another possibility is that the pigeons did not learn the stable patterns because frequency-dependent schedules are intrinsically challenging. To see this, consider the discrete-trials schedules commonly designed to test momentary maximizing (e.g., Hiraoka, 1984;Shimp, 1966;Silberberg & Williams, 1974;Williams, 1972Williams, , 1991. In most of these schedules, a salient event such as food or a response occurrence resets the reinforcement contingencies (Staddon, Hinson, & Kram, 1981), whereas in frequency-dependent schedules there is no such event.…”

Scientific Peer Review: A Case Study From Local and Global Analyses

“…I partly make this recommendation in recognition of the fact that one's own personal belief about a paradigm, no matter how strongly held, may be sadly mistaken (Shimp, 1999). Perhaps, for example, we should consider the possibility that local and global analyses complement each other, and that it makes perfectly good sense to ask, not which of the two analyses is universally correct for all important problems, but what each means and in what contexts each applies (see also Hawkes & Shimp, 1998;Hineline, 2001;Williams, 1991). My reading of Staddon's book suggests he, too, sees potential value in both kinds of analysis.…”