What Is the ImPACT Test? The Computerized Concussion Test Explained
The ImPACT test is a computerized concussion test comparing memory, speed, and reaction time after a head injury with a baseline or norms. It is not an IQ test.
Dr. Russell T. WarneChief Scientist
Share
The ImPACT test (Immediate Post-Concussion Assessment and Cognitive Testing) is a computerized battery that measures memory, processing speed, and reaction time so that clinicians can compare an athlete's scores after a suspected concussion with a preseason baseline or with age norms. It is an aid to concussion management, so it is not an IQ test and it cannot diagnose a concussion by itself.
This page covers what the battery measures, how baseline and post-injury testing work, what the reliability research shows, how athletes sometimes underperform at baseline and how the test tries to catch it, and where ImPACT sits in current return-to-play guidance.
What the ImPACT test measures
ImPACT runs on a computer and is built from six short tasks plus a symptom questionnaire. Kuhn and Solomon's description of the battery lists the modules and what each targets.
• Word Memory and Design Memory: Verbal and visual recognition memory, respectively, with both tasks also drawing on attention.
• X's and O's: Visual working memory, visual processing speed, and visual memory.
• Symbol Match: Visual processing speed along with learning and memory.
• Color Match: Response inhibition, scored partly by errors of commission.
• Three Letters: Working memory and visual-motor response speed.
The task scores are combined into five composites: Verbal Memory, Visual Memory, Visual Motor Speed, Reaction Time, and Impulse Control. A 22-item Post-Concussion Symptom Scale asks about headache, dizziness, nausea, and similar complaints.
The US Food and Drug Administration granted ImPACT and ImPACT Pediatric a De Novo classification in August 2016, creating a new Class II device type called a "computerized cognitive assessment aid for concussion." ImPACT is indicated for ages 12 to 59 and ImPACT Pediatric for ages 5 to 11. The FDA's summary states plainly that the device "does not identify the presence or absence of concussion" and is not intended as a stand-alone diagnostic device.
Baseline versus post-injury testing
The classic model is a two-step comparison. An athlete takes ImPACT before the season, and if a concussion is suspected the athlete takes it again, with the clinician asking whether the scores have dropped by more than chance would explain.
That judgment relies on a "reliable change index," a threshold built from the test's retest stability and its standard error of measurement. Iverson, Lovell, and Collins published reliable change confidence intervals for ImPACT using 56 uninjured adolescents and young adults tested twice, then applied them to 41 concussed amateur athletes tested preseason and within 72 hours of injury. A drop larger than the interval counts as reliable deterioration. Repeat testing also produces practice effects, which can mask a real decline if they are ignored.
When no baseline exists, post-injury scores are compared with normative data instead. Both consensus statements from the Concussion in Sport Group treat that as acceptable. The Berlin panel did not consider baseline neuropsychological testing "a mandatory aspect of every assessment" while allowing that it may add useful information, and the Amsterdam statement adds that baseline testing "is of limited use in younger athletes because of neurocognitive development."
How reliable are ImPACT scores?
A baseline comparison is only as good as the test's retest stability, and this is where the independent research is most sobering. Alsalaheen and colleagues' systematic review of ten studies found that every composite except processing speed showed poor to moderate reliability, with intraclass correlations below 0.80. Depending on the study, between 5% and 26% of people were misclassified as showing reliable change in verbal memory, and between 4% and 24% in processing speed, with no injury at all.
Resch and colleagues tested healthy college students on three occasions. Intraclass correlations ranged from 0.26 to 0.88 at one-week intervals and from 0.37 to 0.76 at longer intervals, and ImPACT classified between 22.2% and 46.0% of these uninjured participants as impaired at a follow-up session. Visual motor speed and reaction time held up better than the memory composites. For what those coefficients mean, see our article on test-retest reliability.
Accuracy estimates also depend on who runs the study. An early study coauthored by the test's developers reported sensitivity of 81.9% and specificity of 89.4% in 72 concussed and 66 uninjured high school athletes. A much larger independent analysis from the NCAA-Department of Defense CARE Consortium, with 1,414 concussed and 8,305 healthy athletes, found best-case sensitivity around 0.58 to 0.63 and specificity around 0.56 to 0.63. The authors concluded that the low values support a multidimensional assessment rather than reliance on any one computerized test.
Sandbagging the baseline and ImPACT's embedded validity indicators
Because a low baseline makes a later injury harder to detect, there has long been concern that some athletes "sandbag," deliberately underperforming before the season. ImPACT addresses this with embedded validity indicators, scores flagged when they fall outside the range that a person trying normally would produce. The default flags include an Impulse Control composite above 30, and Schatz and colleagues documented additional cutoffs on Visual Motor Speed, Reaction Time, and the X's and O's interference scores.
How often do baselines get flagged? In 3,769 high school and 2,130 college athletes, Schatz and colleagues found at least one invalid indicator on 11.9% of desktop and 6.3% of online high school baselines. Abeare and colleagues, using four published indicators on 7,897 athletes aged 10 to 21, found that 55.7% failed at least one, ranging from 83.6% of 10-year-olds to 29.2% of 21-year-olds. A 2020 review of 23 studies put the default indicator's rate near 6%, against 22.31% to 34.99% for alternative indicators, and found the default flag caught only 60% of people instructed to fake.
Deliberate sandbagging turns out to be harder than it sounds. When Erdal asked 75 college athletes to score lower than their baselines without tripping the indicators, 8 succeeded. Schatz and Glatts found ImPACT's automatic flags identified 60% of naive and 75% of coached fakers, and adding further ImPACT indicators raised that to 95% and 100%.
A flagged baseline does not prove intent. Flag rates climb steeply in younger children, and in the desktop version simple left-right confusion with the response keys accounted for many flags. The broader logic of these checks, and why failing one never equals lying, is covered in our explainer on the performance validity test.
Where ImPACT fits in return-to-play decisions
Current guidance treats ImPACT as one input among several. The Amsterdam 2022 consensus statement says computerized neurocognitive results "should be interpreted in the context of broader clinical findings and are not to be used in isolation to inform management or diagnostic decisions." Its recommendations for the sideline assessment tools also include adding procedures to assess the performance validity of baseline testing.
The return-to-sport strategy in that statement has six steps, from symptom-limited activity through full game play. Athletes may begin the first step within 24 hours of injury, each step typically takes at least 24 hours, and full return is expected to take at least a week and can take up to a month. ImPACT results can inform the clinician's judgment at points along that path, but clearance is a medical decision made by a licensed healthcare professional, not a test score.
A concussion battery is also a narrow instrument. It tracks short-term change in a handful of speeded and memory tasks against a person's own earlier performance, which is a different job from estimating general intelligence.
Frequently asked questions
Is the ImPACT test an IQ test?
No. ImPACT measures memory, processing speed, reaction time, and symptoms to track change after a suspected concussion. It produces no IQ score and was not designed to estimate general intelligence.
What age is ImPACT for?
The FDA's De Novo summary indicates ImPACT for ages 12 to 59 and ImPACT Pediatric for ages 5 to 11. The Amsterdam consensus notes that baseline testing is of limited use in younger athletes because their cognition is still developing.
Can ImPACT diagnose a concussion?
No. The FDA classifies it as an assessment aid that does not identify the presence or absence of concussion, and consensus guidance says results should not be used in isolation.
Is a baseline ImPACT test required?
Not under international consensus guidance. The Berlin panel did not consider baseline testing mandatory, and post-injury scores can be compared with normative data instead.
Can athletes fake a bad baseline on ImPACT?
Some try, but studies find that most people instructed to underperform are flagged, especially when several validity indicators are used together. A flagged baseline cannot serve as a trustworthy reference point for later comparison.
The takeaway
ImPACT is a computerized battery that turns six short tasks into memory, speed, reaction time, and impulse control composites, then compares them with a baseline or with norms after a suspected concussion. Its FDA classification and the international consensus statements agree on its role: an aid to clinical judgment, never a diagnosis or a clearance by itself. The independent evidence explains why. Most composites have only poor to moderate retest reliability, a meaningful share of healthy athletes look impaired on retest, and baseline validity flags fire far more often in young children than in adults. Read with those limits in mind, the test adds a structured cognitive data point to a multidimensional exam. If you want a measure of general reasoning ability rather than short-term change after an injury, you can take the RIOT IQ test.
References
1. Kuhn, A. W., & Solomon, G. S. (2014). Supervision and computerized neurocognitive baseline test performance in high school athletes: An initial investigation. Journal of Athletic Training, 49(6), 800-805. [doi.org/10.4085/1062-6050-49.3.66](. doi.org
2. US Food and Drug Administration. (2016). De Novo classification request for ImPACT and ImPACT Pediatric (DEN150037). [accessdata.fda.gov](. accessdata.fda.gov
3. Iverson, G. L., Lovell, M. R., & Collins, M. W. (2003). Interpreting change on ImPACT following sport concussion. The Clinical Neuropsychologist, 17(4), 460-467. [doi.org/10.1076/clin.17.4.460.27934](. doi.org
4. McCrory, P., Meeuwisse, W., Dvořák, J., Aubry, M., Bailes, J., Broglio, S., Cantu, R. C., Cassidy, D., Echemendia, R. J., Castellani, R. J., Davis, G. A., Ellenbogen, R., Emery, C., Engebretsen, L., Feddermann-Demont, N., Giza, C. C., Guskiewicz, K. M., Herring, S., Iverson, G. L., ... Vos, P. E. (2017). Consensus statement on concussion in sport: The 5th international conference on concussion in sport held in Berlin, October 2016. British Journal of Sports Medicine, 51(11), 838-847. [doi.org/10.1136/bjsports-2017-097699](. doi.org
5. Patricios, J. S., Schneider, K. J., Dvorak, J., Ahmed, O. H., Blauwet, C., Cantu, R. C., Davis, G. A., Echemendia, R. J., Makdissi, M., McNamee, M., Broglio, S., Emery, C. A., Feddermann-Demont, N., Fuller, G. W., Giza, C. C., Guskiewicz, K. M., Hainline, B., Iverson, G. L., Kutcher, J. S., ... Meeuwisse, W. (2023). Consensus statement on concussion in sport: The 6th International Conference on Concussion in Sport, Amsterdam, October 2022. British Journal of Sports Medicine, 57(11), 695-711. [doi.org/10.1136/bjsports-2023-106898](. doi.org
6. Alsalaheen, B., Stockdale, K., Pechumer, D., & Broglio, S. P. (2016). Measurement error in the Immediate Postconcussion Assessment and Cognitive Testing (ImPACT): Systematic review. Journal of Head Trauma Rehabilitation, 31(4), 242-251. [doi.org/10.1097/HTR.0000000000000175](. doi.org
7. Resch, J., Driscoll, A., McCaffrey, N., Brown, C., Ferrara, M. S., Macciocchi, S., Baumgartner, T., & Walpert, K. (2013). ImPACT test-retest reliability: Reliably unreliable? Journal of Athletic Training, 48(4), 506-511. [doi.org/10.4085/1062-6050-48.3.09](. doi.org
8. Schatz, P., Pardini, J. E., Lovell, M. R., Collins, M. W., & Podell, K. (2006). Sensitivity and specificity of the ImPACT Test Battery for concussion in athletes. Archives of Clinical Neuropsychology, 21(1), 91-99. [doi.org/10.1016/j.acn.2005.08.001](. doi.org
9. Czerniak, L. L., Liebel, S. W., Garcia, G. P., Lavieri, M. S., McCrea, M. A., McAllister, T. W., Broglio, S. P., & CARE Consortium Investigators. (2021). Sensitivity and specificity of computer-based neurocognitive tests in sport-related concussion: Findings from the NCAA-DoD CARE Consortium. Sports Medicine, 51(2), 351-365. [doi.org/10.1007/s40279-020-01393-7](. doi.org
10. Schatz, P., Moser, R. S., Solomon, G. S., Ott, S. D., & Karpf, R. (2012). Prevalence of invalid computerized baseline neurocognitive test results in high school and collegiate athletes. Journal of Athletic Training, 47(3), 289-296. [doi.org/10.4085/1062-6050-47.3.14](. doi.org
11. Abeare, C. A., Messa, I., Zuccato, B. G., Merker, B., & Erdodi, L. (2018). Prevalence of invalid performance on baseline testing for sport-related concussion by age and validity indicator. JAMA Neurology, 75(6), 697-703. [doi.org/10.1001/jamaneurol.2018.0031](. doi.org
12. Messa, I., Korcsog, K., & Abeare, C. (2022). An updated review of the prevalence of invalid performance on the Immediate Post-Concussion and Cognitive Testing (ImPACT). The Clinical Neuropsychologist, 36(7), 1613-1636. [doi.org/10.1080/13854046.2020.1866676](. doi.org
13. Erdal, K. (2012). Neuropsychological testing for sports-related concussion: How athletes can sandbag their baseline testing without detection. Archives of Clinical Neuropsychology, 27(5), 473-479. [doi.org/10.1093/arclin/acs050](. doi.org
14. Schatz, P., & Glatts, C. (2013). "Sandbagging" baseline test performance on ImPACT, without detection, is more difficult than it appears. Archives of Clinical Neuropsychology, 28(3), 236-244. [doi.org/10.1093/arclin/act009](. doi.org
Hero image: Evolution of Football Helmets, by Erik Drost, licensed CC BY 2.0 (creativecommons.org/licenses/by/2.0). Via Wikimedia Commons.
Take our professional IQ test
Want to know your IQ? Try the first ever professional online IQ test.
