Stroop Color and Word Test
The Stroop Color and Word Test measures selective attention, processing speed, and executive inhibition by requiring a patient to name the ink color of a word while suppressing the impulse to read the word itself. It takes 5–15 minutes depending on the version administered and is scored against age-normed reference data, not a fixed pass/fail cutoff.
What the Stroop Test Measures
The Stroop task exploits a well-known interference effect: when the printed word and its ink color conflict (for example, the word "RED" printed in blue ink), most people are slower and more error-prone at naming the ink color than they are at simply reading words or naming color patches alone. That slowing — the interference effect — is the clinical signal. It reflects the brain's ability to inhibit an automatic, overlearned response (reading) in favor of a less automatic, task-relevant one (color naming), a core function of the executive-control network.
Clinically, the Stroop is used to assess:
- Selective attention — the ability to focus on a relevant stimulus dimension (ink color) while ignoring an irrelevant, competing one (word meaning).
- Processing speed — how quickly a patient can complete each trial condition.
- Executive inhibition / cognitive flexibility — the interference score, typically derived from the difference or ratio between color-word trial performance and the baseline color-naming or word-reading trials.
Administration
Several standardized versions exist, and they are not interchangeable:
- Golden version — the most widely used clinical format, presenting three timed trials (word reading, color naming, color-word interference) on separate cards.
- Victoria version — a shorter format using fewer stimuli per card, often preferred when testing time is limited or fatigue is a concern.
- D-KEFS Color-Word Interference Test — part of the Delis-Kaplan Executive Function System, which adds a switching condition to more directly isolate cognitive flexibility from simple inhibition.
Administration time runs roughly 5–15 minutes depending on which version is used. Because norms are version-specific, the same raw score means different things depending on which edition was administered — clinicians should always document which version was used alongside the results.
Scoring and Interpretation
Raw scores from each trial (word reading, color naming, color-word/interference) are converted to age-normed T-scores or scaled scores using the published normative tables for the version administered. The interference score — how much slower or more error-prone the color-word trial is relative to the baseline trials — is the primary metric of executive control.
There is no single universal cutoff that defines "impaired" performance on the Stroop. Interpretation depends on comparing the patient's normed scores to the reference sample for their age (and in some versions, education), and norms differ meaningfully between the Golden, Victoria, and D-KEFS versions. A lower-than-expected interference score in a patient with a documented head injury is a meaningful data point, but it should be interpreted alongside the rest of the neuropsychological battery and clinical history rather than in isolation.
Clinical Use Case
The Stroop is a standard component of neuropsychological batteries used to evaluate traumatic brain injury, concussion, ADHD, and general executive dysfunction. In concussion and post-concussion syndrome care, it is commonly included alongside other attention and processing-speed measures — such as the Trail Making Test A and Trail Making Test B — to characterize the specific cognitive domains affected by injury and to track recovery over serial administrations. It is also useful in differentiating attention/processing-speed deficits from broader memory impairment, which is better captured by instruments like the RAVLT.
Within the domain framework, the Stroop primarily maps to Attention and Executive Function, with a secondary contribution to Processing Speed.
CPT Billing for the Stroop Test
Administration and scoring of the Stroop as part of a neuropsychological battery is billed under the test administration and scoring codes, based on who administers the test:
- 96136 — test administration and scoring by a physician or qualified health professional, first 30 minutes (two or more tests, any method), with add-on code 96137 for each additional 30 minutes.
- 96138/96139 — the equivalent codes when a trained technician administers and scores the test.
The interpretation and report-writing component — integrating the Stroop's results with the rest of the battery into a clinical formulation — falls under 96132/96133 (neuropsychological testing evaluation services). The Stroop is not billed as a standalone test; it is virtually always administered as one component of a multi-instrument battery, and the applicable codes reflect the battery as a whole rather than the individual subtest.
Where the Stroop Sits in the Kavera Protocol
The Stroop Color and Word Test is one instrument within Kavera's assessment battery, most commonly deployed through the Concussion and Cognitive Health modules. It is typically paired with complementary attention and processing-speed measures so clinicians can distinguish inhibition-specific deficits from broader slowing or memory-driven impairment across a patient's recovery timeline.
How Kavera Handles This
Stroop runs in the Cognitive Health module on the cadence you set, scored and stored against baseline for executive inhibition and processing speed. Results plot with Trail Making B so executive function is read as a trend. The record supports 96136–96139 documentation. Self-Serve practices run this with their own staff. On Managed, Juliet Mott's team runs it and bills it under your credentials.