Stroop interference with response, comparison, and encoding stages in a sentence-picture comparison task

The paper discusses a Stroop variant of the word-picture comparison task analyzed by Chase and Clark (1971). The locatives above or below were printed at the center of a reference square, and Ss reported "Yes" if there was a word or an array of Xs in the location specified and "No" if there was not. Under the control (Xs) conditions, above displays were classified faster than below displays and true displays faster than false displays. These effects were unaltered when the words "yes" or "no" or "right" or "wrong" were printed in place of the Xs, although there was a small overall increase in response latency under these Stroop conditions that was independent of agreement or disagreement between the distractor and the response to be made. When the locatives up and down were printed on the display, a substantial Stroop effect was observed, and the above-below and true-false effects were eliminated. These results are discussed in relation to theories about the nature of Stroop interference and processes involved in sentence-picture comparisons.