Role of a stimulus filling an action-outcome delay in human judgments of causal effectiveness.

Experiments examined the effect of a stimulus filling a response-outcome delay on human judgments of causal effectiveness. In Experiment 1, subjects rated the effectiveness of 2 concurrently available responses. One response led to the outcome with a 75% probability, the other never led to the outcome. Ratings were higher for the former compared to the latter key, and for immediate compared to delayed outcomes. A signal presented during the delay ameliorated this deficit. Experiments 2 and 3 examined conditioned reinforcement and perceptual catalysis accounts of this effect. In both experiments, 50% of responses on each of 2 keys led to an outcome. Ratings were high, relative to an unsignaled condition, when a stimulus filled the outcome delay, and when the same stimulus followed the response but did not precede the outcome. This result is not consistent with the operation of perceptual catalysis and was shown to be the result of secondary-reinforcement-like processes rather than outcome-confusion or generalization between responses (Experiments 3, 4).