Stroop (1935) noted that observers were slower to properly identify the color of ink when the ink was used to produce color names different from the ink. That is, observers were slower to identify red ink when it spelled the word blue. This is an interesting finding because observers are told to not pay any attention to the word names and simply report the color of the ink. However, this seems to be a nearly impossible task, as the name of the word seems to interfere with the observer's ability to report the color of the ink.
In this study pairs of conflicting stimuli, both being inherent aspects of the same symbols, were presented simultaneously (a name of one color printed in the ink of another color--a word stimulus and a color stimulus). The difference in time for reading the words printed in colors and the same words printed in black is the measure of the interference of color stimuli upon reading words. The difference in the time for naming the colors in which the words are printed and the same colors printed in squares (or swastikas) is the measure of the interference of conflicting word stimuli upon naming colors. The interference of conflicting color stimuli upon the time for reading 100 words (each word naming a color unlike the ink-color of its print) caused an increase of 2.3 seconds or 5.6% over the normal time for reading the same words printed in black. This increase is not reliable. But the interference of conflicting word stimuli upon the time for naming 100 colors (each color being the print of a word which names another color) caused an increase of 47.0 seconds or 74.3% of the normal time for naming colors printed in squares. Tests on the permanency of the interference of conflicting word stimuli are also described. (PsycINFO Database Record (c) 2005 APA, all rights reserved)
