Processing Speed Test (Symbol–Digit Matching)

Symbol–digit tasks are among the most widely used measures of processing speed: how quickly you can take in what you see, compare it with a key and respond. A large review of one such test, the Symbol Digit Modalities Test, found it reliable and sensitive enough to be used as a speed measure in medical research [1].

This page is our own game in the same family, with our own symbols. It is not that test, it has none of its norms, and it can't tell you anything about your health.

• A key at the top pairs 9 symbols with the digits 1 to 9. The key changes every run.
• One symbol appears at a time. Tap its digit on the number pad or press the key; the next symbol comes right away. Wrong answers are counted.
• 6 practice symbols with feedback come first (you can skip them), then 90 seconds. Leaving the page ends the run, because the test is timed.

Your score is the number of symbols matched correctly in the time. We also show your average time per symbol and how many you got wrong; going faster usually costs some accuracy. Over the first few runs you will remember more of the key and get faster, so compare with your own runs once the scores settle. For a pure speed test without a key, try the reaction time test.