Judging up and down.

In Experiment I subjects were asked to judge whether an arrow was pointing up or pointing down at various heights inside a surrounding rectangle. They were faster on an arrow pointing up the higher it was in the rectangle, and they were faster on an arrow pointing down the lower it was in the rectangle. Experiments 2, 3, and 4 were designed to test sources for this"congruity effect." The intrusive height information for each arrow was assumed to facilitate or interfere with (a) the activation of the correct motor response; (b) the maintenance of the implicit instruction "Is it pointing up, or is it pointing down?"; or (c) the selection of the criterial perceptual information as a basis for the response. All three experiments were consistent with c, but not with a or b. Indeed, the results contrasted with previous demonstrations of the Stroop effect in certain critical features.