Stroop Color–Word Test

The Stroop Color–Word Test measures selective attention and cognitive control across three short blocks.

Block 1 — colour naming (neutral). You name the ink colour of neutral symbols. This establishes your baseline colour-naming speed before any competing word information is introduced.

Block 2 — word reading (congruent). You respond to colour words printed in matching ink. This captures the automatic, prepotent reading response that the final block must override.

Block 3 — interference (incongruent). You name the ink colour while ignoring a conflicting colour word. The slowing relative to the congruent block is the Stroop interference effect — an index of how much effort it takes to suppress the automatic reading response.

The interference effect is reported within-person in milliseconds (incongruent minus congruent reaction time). No population norm is applied: results are indicative of one session, not diagnostic, and are sensitive to sleep, caffeine, and distraction.

These figures describe this respondent's own within-session performance — reaction-time differences and accuracy across conditions. Where a published reference distribution exists, a percentile within that sample is shown alongside the raw value; otherwise only the raw effect is reported.

• Stroop, J. R. (1935). Studies of interference in serial verbal reactions. Journal of Experimental Psychology, 18(6), 643–662.
• MacLeod, C. M. (1991). Half a century of research on the Stroop effect: An integrative review. Psychological Bulletin, 109(2), 163–203.