Stroop interference and negative priming: problems with inferences from null results

The Stroop color-naming effect has often been taken as evidence for the automaticity of word processing (MacLeod, 1991). Recently, Besner, Stolz, and Boutilier (1997) reported that coloring a single letter instead of the whole word eliminated the Stroop effect. From this finding, they concluded that word processing could not be purely automatic, since it can be prevented. We asked whether the elimination of the Stroop effect is sufficient evidence for concluding that the word is not processed. Combining Besner et al.'s manipulation with a negative-priming procedure, we found intact negative priming from the prime color word in the absence of a Stroop effect. This result clearly indicates that the meaning of the prime word was processed. The findings highlight the importance of using converging methods to evaluate lack of processing.