The HED Task Catalog is under development. IDs are not stable until formal release. Comments are welcome at github.com/hed-standard/hed-task/issues.

Stroop Color-Word Task

HED task ID: hedtsk_stroop_color_word

Family: Conflict and interference tasks

Also known as: Stroop, Color-Word Interference Test, CWIT

Naming the ink color of color words while ignoring word meaning; RT and error costs on incongruent trials index selective attention and conflict control.

Description

The Stroop Color-Word Task is a classic measure of selective attention and cognitive control that requires participants to identify the ink color of printed words while ignoring the semantic content. In the standard version, participants view color names (e.g., “RED,” “BLUE”) printed in incongruent ink colors and must respond with the ink color rather than reading the word. The task measures reaction time and accuracy across congruent trials (word and color match), incongruent trials (word and color conflict), and neutral trials. Performance reflects the ability to overcome automatic word-reading processes and requires engagement of executive control mechanisms. The Stroop interference effect (slowed RT on incongruent trials) is one of the most robust findings in cognitive psychology.

Inclusion test

An experiment is an instance of this task when its procedure matches, it manipulates at least one of the listed variables, and it records at least one of the listed measures.

Procedure

Color words (RED, BLUE) are printed in incongruent ink colors; participants name the ink color while ignoring the word.

Manipulation

Congruency (congruent, incongruent, neutral); proportion congruent; response modality (vocal, manual); stimulus type (classic, spatial, numerical).

Measurement

Stroop interference effect (incongruent − congruent RT); facilitation (neutral − congruent); error rate; conflict adaptation (Gratton effect).

Variations

Named versions that change what the participant experiences or does. The identifier of a variation is hedvar_<task>__<variation>.

Variation

Description

Justification

Classic Color-Word Stroop

hedvar_stroop_color_word__classic_color_word_stroop

Name ink color of incongruent color words; the canonical interference paradigm.

Canonical color naming of congruent/incongruent color words

Manual (Button-Press) Stroop

hedvar_stroop_color_word__manual_button_press_stroop

Responses via key press rather than vocal naming; preferred in neuroimaging to reduce motion artifacts.

Button press instead of vocal response; different response modality

Vocal Response Stroop

hedvar_stroop_color_word__vocal_response_stroop

Original format with spoken color-naming responses; produces larger interference due to response-channel overlap with word reading.

Vocal naming; distinct from manual version

Counting Stroop

hedvar_stroop_color_word__counting_stroop

Count the number of items displayed while ignoring the number word printed; used extensively in fMRI.

Count number of words instead of naming color; different task dimension

Spatial Stroop

hedvar_stroop_color_word__spatial_stroop

Conflict between stimulus location and directional word content (e.g., “LEFT” on right side).

Spatial word/location conflict; different conflict dimension

Numerical Stroop

hedvar_stroop_color_word__numerical_stroop

Conflict between numerical magnitude and physical size of digits.

Number magnitude vs. physical size conflict; different domain

Reverse Stroop

hedvar_stroop_color_word__reverse_stroop

Read the word while ignoring ink color; reverses the typical control demand.

Name the word rather than the color; reversed task demand

Proportion-Congruent Manipulation

hedvar_stroop_color_word__proportion_congruent_manipulation

Varying the ratio of congruent-to-incongruent trials to study context-driven control adjustments.

Conflict frequency variation; adaptation context per §5.2

Face-Word Stroop

hedvar_stroop_color_word__face_word_stroop

Emotional face images paired with congruent/incongruent emotion labels.

Face emotion vs. color word conflict; different stimulus domain

Color-Shape Stroop

hedvar_stroop_color_word__color_shape_stroop

Shapes printed in colors that conflict with shape-color associations (e.g., a blue banana).

Color word/shape conflict instead of ink color; different conflict structure

Priming Stroop

hedvar_stroop_color_word__priming_stroop

Preceded by neutral, congruent, or incongruent primes to study anticipatory control.

Prime precedes Stroop item; temporal context manipulation

Negative Priming Stroop

hedvar_stroop_color_word__negative_priming_stroop

Measures inhibitory aftereffects when a previously ignored color word becomes the target on the next trial.

Previously ignored item becomes target; tests ignored repetition effect

Cognitive processes

This task is designed to engage the following processes:

Key references

  • Stroop, J. R. (1935). Studies of interference in serial verbal reactions. Journal of Experimental Psychology, 18(6), 643-662. (DOI)

  • MacLeod, C. M. (1991). Half a century of research on the Stroop effect: An integrative review. Psychological Bulletin, 109(2), 163-203. (DOI, PubMed)

  • Wager, T. D., Sylvester, C. Y. C., Lacey, S. C., Nee, D. E., Franklin, M., & Jonides, J. (2005). Common and unique components of response inhibition revealed by fMRI. NeuroImage, 27(3), 323-337. (DOI, PubMed)

Further references

  • Egetemeyer, J., Rehme, A. K., Liebhaber, N., Eickhoff, S. B., & Grefkes, C. (2024). Not all Stroop-type tasks are alike: Assessing the impact of stimulus material, task design, and cognitive demand via meta-analyses across neuroimaging studies. Neuropsychology Review, 34, 687–714. (DOI, PubMed)

  • Servant, M., Montagnini, A., & Burle, B. (2014). Conflict tasks and the diffusion framework: Insight in model constraints based on psychological laws. Cognitive Psychology, 72, 162–195. (DOI, PubMed)

  • Algom, D., & Chajut, E. (2019). Reclaiming the Stroop effect back from control to input-driven attention and perception. Frontiers in Psychology, 10, 1683. (DOI, PubMed)

  • Neumann, J., Lohmann, G., Derrfuss, J., & von Cramon, D. Y. (2005). Meta-analysis of functional imaging data using replicator dynamics. Human Brain Mapping, 25(1), 165–173. [Stroop neuroimaging meta-analysis] (DOI, PubMed)