Brain speed
Match symbols to numbers for 90 seconds. Slower scores went with higher death and disability rates.
How to do it
- A key at the top pairs nine symbols with the numbers 1 to 9. It's shuffled each time.
- For each symbol shown, tap its number, or type it on a keyboard.
- Practice on five first, then go as fast as you can for 90 seconds without guessing.
Your result
You'll get 5 practice symbols first, then 90 seconds for real.
Nothing you enter leaves this page unless you save your result.
What the research found
Matching symbols to numbers against the clock tests how fast you think, focus and hold things in mind, all at once. It's one of the most sensitive checks for changes in thinking, though it can't say which ability changed. In 3,156 older adults in a large US heart study, lower scores on the paper version went with more deaths and disability over 8.4 years. That held after taking age, education, heart disease and brain scans into account. People with both a low score and slow walking had the highest death rate. This on-screen version isn't the same test, so use it to track your own speed over time.
Studied in: 3,156 adults around 70 in a large US heart study, followed for 8 years.
- Rosano C et al. Association between lower digit symbol substitution test score and slower gait and greater risk of mortality and of developing incident disability in well-functioning older adults. J Am Geriatr Soc. 2008;56(9):1618-25. PubMed
- Jaeger J. Digit Symbol Substitution Test: the case for sensitivity over specificity in neuropsychological testing. J Clin Psychopharmacol. 2018;38(5):513-9. PubMed