Stroop Effect

Slower, error-prone naming of ink color when the word spells an incompatible color, the classic interference task.

Specifications & Metrics

Stroop's 1935 paper showed that reading interferes with color naming, but not the reverse order of tasks.
The task is a standard index of attentional control and is sensitive to aging, fatigue, and clinical conditions.
It has been reproduced thousands of times, making it one of psychology's most robust phenomena.