What is the Stroop Effect?
Named after John Ridley Stroop, who published the groundbreaking paper in 1935, the Stroop Effect remains one of the most famous and reliable neuropsychological findings in history. It reveals the natural conflict that occurs in your brain when the visual prefrontal prefrontal cortex process names of colors printed in mismatching hues (e.g., the word 'RED' written in blue ink).
Literate adults read automatically. However, identifying an ink color requires active cognitive flexibility. When these two pathways clash (known as an incongruent trial), your brain slows down to resolve the interference conflict, revealing critical insights about your executive gating and attention metrics.
Key Performance Metrics of the Test
Congruent Reaction Time
Evaluating trials where visual cues match textual labels (e.g., the word "BLUE" in blue ink). Tracks maximum basic motor speed.
Incongruent Reaction Time
Evaluating trials where textual names clash with visual hues (e.g., the word "GREEN" in red ink). Measures selective attention latency.
Interference Latency Index
The exact millisecond difference between matching and mismatched trials. A lower index represents faster cognitive processing and ADHD-related target suppression filters.