PROCESSING IN THE STROOP TASK - MENTAL SET AS A DETERMINANT OF PERFORMANCE

Subjects took part in a Stroop experiment in which they responded to t he print color of an irrelevant word that spelled a congruent or incon gruent color word. In the CLASSIFY condition, subjects were instructed to map one color to one response button and the other color to anothe r response button. In the DETECT condition, subjects were instructed t o signal the presence of a target color with one response button, and its absence with another response button. The CLASSIFY instructions pr oduced 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 s et 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.