Effect of a signalled delay between an action and outcome on human judgement of causality

Three experiments examined the influence of a stimulus inserted between an action (pressing the space bar of a computer) and an associated delayed outcome (a triangle lighting up on the screen) on ratings of the causal effectiveness of that action. In Experiment 1, subjects rated an action that produced an outcome immediately as more causally effective than an action that produced a delayed outcome. The rating of the causal effectiveness of an action that produced a delayed outcome in which the delay was filled by a stimulus was higher than the rating of actions that produced the outcome after an unsignalled delay. In Experiment 2, the effect of a stimulus presented uncorrelated with the action or the outcome was examined and found not to enhance the rating of causal effectiveness of an action that produced a delayed outcome. In Experiment 3, the degree of correlation between the stimulus and the consequence was examined. Ratings of the causal effectiveness of the action were greater the higher percentage of delay intervals that were signalled.