Color-Word Stroop Task

Background

The Color-Word Stroop Task is among the oldest and most well-known neuropsychological tests in psychology. The "Stroop Effect" was first noted by Erich Rudolf Jaensch at Philipps-University of Marburg in 1929. The effect was first operationalized by John Ridley Stroop in the 1930s, who developed the eponymous Stroop Task while working on his doctoral thesis at George Peabody College for Teachers (now part of Vanderbilt University). In 1935, Stroop published his findings from the task in his classic paper, "Studies of interference in serial verbal reactions". Stroop spent most of his professional career teaching psychology and biblical studies at David Lipscomb College (now Lipscomb University), passing away before his dissertation made him famous.

With the shift from behaviorism to cognitive psychology in the 1960s, the Stroop Task gained prominence for providing one of the most robust, replicable, and easy to understand demonstrations of automatic verses controlled cognitive processing. The task gained further recognition when Charles Golden published a standardized version for clinical applications in 1978, and has since become a staple in psychological research and neuropsychological assessment.

Task Procedure

Participants are presented, one at a time, a series of color names (red, green, blue, or black) and simple rectangles, each of which is displayed in one of the four colors represented by the names (red, green, blue, or black). Their task is to name the color in which each stimulus is displayed. Stimuli remain on the screen until a response is made. The display color can be congruent (green) or incongruent (blue) with the color name, or neutral if the stimulus is a rectangle. Typically, speed and/or accuracy of color naming is impaired on incongruent relative to congruent trials, which demonstrates the Stroop effect.

The Color-Naming Stroop Task runs a single block of 84 test trials, representing 7 repetitions of each combination of display color (red, green, blue, black) and congruency (congruent, incongruent, control). Error feedback is provided for incorrect responses.

What it Measures

The Color-Word Stroop Task is a measure of response inhibition.

Psychological Domains

• Executive Function
• Inhibitory Control: Ability to suppress dominant automatic response in favor of a weaker one
• Selective Attention: Ability to focus on the relevant stimulus dimension
• Processing Speed: Overall reaction times reflect psychomotor and perceptual speed

Main Performance Metrics

• Stroop Effect: Difference in speed and accuracy between congruent and incongruent trials
• Inhibition Effect: Difference in speed and accuracy between control and incongruent trials

Psychiatric Conditions

Performance on the SST tends to be impaired in patients with the following psychiatric conditions:

• Attention Deficit Hyperactivity Disorder (ADHD)
• Dementia
• Traumatic Brain Injury (TBI)
• Schizophrenia
• Autism Spectrum Disorder
• Obsessive Compulsive Disorder (OCD)
• Major Depressive Disorder
• Bipolar Disorder
• Substance Use Disorder