Reading proficiency affects the construct validity of the Stroop Test interference score

The Stroop Color and Word Test is used clinically to assess a specific aspect of executive function, that is, selective inhibition. It requires a subject to inhibit an automatized reading response in favor of a less well-rehearsed, competing color-naming response. Although it is necessary to the interpretation of the Stroop effect observed during the interference condition, the degree of automaticity of the reading response is usually assumed in an adult population rather than being defined by any standard reading measures. The present investigation demonstrated that, in a group of 306 parents of children with learning disabilities, the best indicator of reading automaticity was not simply a standard word-reading score within normal limits, but rather a score that was at least equal to the individual's Full Scale IQ. In those subjects who satisfied this reading criterion, the Stroop Interference score correlated significantly with other measures of response inhibition. No such correlation was observed in subjects who did not satisfy the reading automaticity criterion.