Stroop Interference
Strictly speaking, Stroop Interference refers to impaired performance (higher error rates and longer reaction times) when Ss are asked to name the ink color in which a word is printed when the word itself (which is irrelevant to the task) is the name of a different color rather than the same color, a word unrelated to color, or a string of random letters. For example, it takes longer to say "red" to the word blue printed in red ink, compared to when the word is red. More generally, Stroop-like Interference is that same impaired performance when the irrelevant dimension (element) of a stimulus calls for a different (or the opposite) response from the relevant. So it takes longer to say "top" to a word appearing at the top of a screen when the word itself is bottom rather than top. This Stroop-like Interference is related to the Eriksen & Eriksen flanker effect, in which it is harder to decide which of two stimuli is present in the center of the screen when it is flanked by (irrelevant) copies of the alternative letter. Stroop Interference is perhaps the most common measure of selective attention. See also Garner Interference. (JRP, February 1, 2007).