D-01 · Executive Control
Name the ink, ignore the word. A lock that opens only when your executive control overrides sixty thousand hours of reading practice.
Experimental design
Within-subjects repeated measures; color-word Stroop task
Stroop interference
Slowing (and errors) when ink color conflicts with the word's meaning
Automaticity
Overlearned reading proceeds without deliberate control, competing with color naming
Response conflict
Simultaneous activation of incompatible response tendencies
Stroop effect
Classic interference when naming ink color of incongruent color words (Stroop, 1935).
Anterior cingulate cortex (ACC)
Conflict monitoring region engaged when competing responses are co-activated.
Dorsolateral prefrontal cortex (DLPFC)
Implements top-down biasing toward task-relevant dimensions (color, not word).
Difficulty
IntroEstimated time
8 minutes
Paradigm
Stroop interference
First published
1935
Reading is so overlearned it is automatic, it happens whether you want it to or not. When the word RED is printed in blue ink, naming the ink color requires actively suppressing the automatic response. The delay is pure, measurable executive control.
John Ridley Stroop published the effect in 1935, and it remains one of the most replicated findings in experimental psychology. Naming ink colors of incongruent color words is reliably slower, often by 100–200 ms, and more error-prone than naming colors of neutral stimuli. The task became the canonical probe of inhibitory control, and its neural signature centers on anterior cingulate conflict monitoring and dorsolateral prefrontal control.
Stroop, J. R. (1935). Studies of interference in serial verbal reactions. Journal of Experimental Psychology, 18(6), 643–662.