Content area
Full Text
Abstract Subjects took part in a Stroop experiment in which they responded to the print color of an irrelevant word that spelled a congruent or incongruent color word. In the CLASSIFY condition, subjects were instructed to map one color to one response button and the other color to another response button. In the DETECT condition, subjects were instructed to signal the presence of a target color with one response button, and its absence with another response button. The CLASSIFY instructions produced the standard result: The incongruent condition was slower than the congruent condition. In contrast, there was no Stroop effect given DETECT instructions. These results are discussed in terms of mental set as an important determinant of processing, and contrasted with the received view that reading the irrelevant word is largely "automatic" and virtually always results in a Stroop effect. In many variants of Stroop's (1935) classic experiments, subjects are asked to identify the color of a word while ignoring the word. The standard result is that the time to identify the color when it is paired with an incongruent color word is slower than when it is paired with a congruent color word or a neutral word. The most widely accepted view is that reading the irrelevant word is, in some sense mandatory, with interference in identifying the color a common consequence (see MacLeod, 1991, for a review). Is the Stroop effect inevitable, or can it be circumvented? Surely, there are trivial manipulations that may reduce or eliminate the Stroop effect: making the words too small (or too large), too briefly presented, or permitting the subjects to squint or defocus. However, these techniques do not inform us as to the underlying psychological processes. Manipulations that tax the limits of visual resolution aside, are there instructional manipulations that alter the subject's mental set, and thus protect against the proclivity to read the word, or against the impact of this reading? Further, and most central here, can such an effect be demonstrated under conditions where the stimuli and the overt response required are the same as those that produce the Stroop effect? There have been a number of previous attempts to reduce the effect of an incongruent word with procedural manipulations; some of these are discussed...