Information effects on the response-reinforcer association

Abstract

Pigeons were trained on a discrete-trial delayed reinforcement procedure with respect to one response key that was periodically illuminated. In some conditions, a second response key, or a tone, both previously paired with reinforcement, was interpolated in the delay-ofreinforcement interval. In comparison to a control condition with neither stimulus in the delay interval, the interpolated stimulus attenuated (blocked) the amount of responding that was maintained by the delayed reinforcement contingency. The degree of blocking was unaffected by whether the interpolated stimulus was the tone or keylight, in spite of the fact that the keylight evoked responding and the tone did not. A second study showed that the blocking effects involved the response-reinforcer association in that blocking occurred when the delayed reinforcement was response-dependent but did not occur when reinforcement was responseindependent. The results thus show that response-reinforcer associations are affected by informational variables in the same manner as has been shown for stimulus-reinforcer associations. They also demonstrate that preexisting stimulus-reinforcer associations can block response-reinforcer associations, thus suggesting that both types of association depend upon the same associative process.Research during the past 10 years has shown that "informational" variables are an important determinant of whether conditioning will occur. Perhaps the simplest, and most compelling, demonstration of an informational effect is the phenomenon of "blocking" (cf. Kamin, 1%9). The typical procedure for producing blocking is to pair some compound stimulus (AB) with reinforcement. Normally, both elements gain stimulus control, as shown when they are tested separately. If pretraining is given with one of the elements (A) alone, however, acquisition of stimulus control by the other element (B) during compound AB training is much weaker. Thus, pretraining with A blocks control by B. The importance of the finding is its demonstration that temporal contiguity between element B and the reinforcer is not sufficient to cause conditioning to occur. Instead, the stimulus also must provide information about the occurrence of the reinforcer that is not already provided by other events in the situation.The process underlying information effects like blocking currently is a matter of dispute (cf. Mackintosh, 1975). The experiments to be reported are not concerned with this theoretical issue, however, but instead are addressed to defining the domain over which blocking effects occur. More specifically, do informational variables determine the effects of

Context Specificity of Conditioned‐reinforcement Effects on Discrimination Acquisition

“…That is, learning occurred more readily in Condition -G than in the no-signal condition. This effect is perhaps surprising, given the findings in other studies that have examined the effects of delay of reinforcement on simple response rate, in that stimuli occurring only at the end of a delay interval reduced response rate relative to a no-stimulus condition, an effect that has been interpreted as showing "blocking" of the response-reinforcer association (Williams, 1975(Williams, , 1978Williams, Preston, & DeKervor, 1990). Apparently, such blocking effects do not occur in simultaneous discrimination procedures, a finding we have replicated in several other unpublished studies.…”

Incentive Theory: Ii. Models for Choice

“…Another way of verbalizing Equation 1 is to say that reinforcement of a target response may be blocked by intervening responses (Williams, 1978) and that this occurs with constant probability during the delay. is an approximation to a more exact expression…”

Effects of signaled reward in instrumental conditioning: Enhanced learning on DRL and DRH schedules of reinforcement

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