Processing Speed Test

A cognitive processing speed test: match symbols to digits as fast as you can for 90 seconds. It is modelled on the coding task in IQ batteries. This is about your brain, not your computer's CPU.

90 seconds · symbol-digit matching

Match each symbol to its digit

For each symbol shown, click or type the digit it has in the key. You have 90 seconds. Keyboard keys 1 to 9 work too.

Symbol key

★
1
▲
2
●
3
■
4
♦
5
◆
6
○
7
□
8
△
9

What is cognitive processing speed?

Processing speed is how quickly you take in simple information, decide and respond. This page tests your mental speed. It does not test your computer's processor.

In the Wechsler Adult Intelligence Scale (WAIS-IV), the Processing Speed Index is one of four index scores, alongside Verbal Comprehension, Perceptual Reasoning and Working Memory. It combines two subtests, Coding and Symbol Search. In Coding you copy symbols that match digits against a time limit. This test follows the same idea with a 90-second limit.

How to read your score

Our own rough guide for this web task. Not standardised norms.
Correct matches in 90 secondsBand
Fewer than 25Slower end
25 to 44Middle range
45 or moreFaster end

The bands are a guide for comparing your own attempts. Screen size, mouse or keyboard, and practice all move the number. Aim for high accuracy first, then speed.

Processing speed and age

Processing speed is one of the abilities that changes most with age. Salthouse (1996) proposed that slower processing across adulthood explains much of the age difference in other thinking tasks. The slowing is gradual, and people differ a lot.

Processing speed is only one part of IQ. Some people reason very well at a moderate pace, and others are quick but less accurate. That is why we show speed and accuracy separately.

Frequently asked questions

What is processing speed?

Cognitive processing speed is how quickly you can take in simple information, decide and respond. It is not about how fast your computer is. In the Wechsler adult IQ test (WAIS-IV) it is one of four index scores, the Processing Speed Index.

What is the Processing Speed Index?

The Processing Speed Index in the WAIS-IV is built from two subtests, Coding and Symbol Search. Coding asks you to copy symbols paired with digits against a time limit. This page uses the same idea.

What is a good score on this test?

There are no standardised norms for this web version. As our own rough guide, fewer than 25 correct matches in 90 seconds is the slower end, 25 to 44 is a middle range and 45 or more is the faster end. Device, input method and practice all change the number.

Does processing speed decline with age?

On average, yes. Research on adult ageing, including Salthouse (1996), finds that processing speed slows gradually across adulthood and that this slowing accounts for much of the age difference in other thinking tasks. Individual differences are large.

Should I trade accuracy for speed?

No. Wrong answers do not add to your correct matches, so guessing quickly can lower your score. We show speed and accuracy separately so you can see both.

How is this different from a reaction time test?

A reaction time test measures how fast you respond to one signal. This task asks you to look up a symbol, choose the matching digit and repeat, so it also uses visual search, short-term memory and decision making.

Is this a clinical test?

No. It is modelled on coding tasks used in IQ batteries, but it is not a clinical administration. It cannot diagnose any condition or give an IQ score.

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Sources

  1. Salthouse, T. A. (1996). The processing-speed theory of adult age differences in cognition. Psychological Review, 103(3), 403 to 428.
  2. Wechsler, D. (2008). Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV). Pearson.
This is an informal web task, not a clinical test.