Simon Task
Conflict task: Irrelevant spatial location influences response. Press keys based on the color of the box, ignoring where it appears.
Frequently Asked Questions
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What is the Simon Effect?
The Simon effect is the finding that reaction times are significantly faster when the stimulus occurs in the same relative location as the response, even if the stimulus location is irrelevant to the task. It reflects the ability to inhibit interference in executive control.
How is the conflict effect calculated?
Conflict effect = Mean RT (Incongruent) - Mean RT (Congruent). A larger difference indicates a greater impact of the position-response conflict.
Why does location matter at all?
Stimulus position automatically activates the spatially matching response, so a left keypress to a right-side stimulus must override that activation — first reported by Simon and Rudell in 1967.
How large is a typical Simon effect?
Tens of milliseconds. It shrinks with practice and with longer preparation intervals but rarely disappears entirely.
How does it differ from flanker and Stroop effects?
All are conflict effects, but the Simon effect arises from stimulus location, the flanker effect from distractor identity, and Stroop from overlearned reading — dissociable in both behavior and brain imaging.
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About Implementation
This Simon task includes a practice phase and a formal experiment phase. The practice phase provides immediate feedback to help learning, while the formal phase records data for analysis. It includes standard design elements like fixation crosses and inter-trial intervals.
Metrics
Key metrics include: Mean Reaction Time and Accuracy for congruent/incongruent trials, and the Simon Effect (RT difference). Data can be exported as JSON or CSV for further analysis.
References
- Simon, J. R., & Rudell, A. P. (1967). Auditory S-R compatibility: The effect of an irrelevant cue on information processing. Journal of Applied Psychology, 51(3), 300-304.
- Simon, J. R., & Wolf, J. D. (1963). Choice reaction times as a function of angular stimulus-response correspondence and age. Ergonomics, 6(1), 99-105.
- Simon, J. R. (1969). Reactions toward the source of stimulation. Journal of Experimental Psychology, 81(1), 174-176.
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About This Experiment
This experiment is an educational adaptation for demonstration purposes. It is not a clinical diagnostic tool. Results reflect your performance in this specific session and should not be interpreted as an assessment of your cognitive abilities.
Data Privacy
Your experiment data is processed and stored locally in your browser. No data is uploaded to any server unless you explicitly export it.
