Subitizing
Count the targets in a split second
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What is the Subitizing?
Subitizing is the ability to tell at a glance how many items are in a small group, without counting them one by one. E. L. Kaufman and colleagues introduced the term in 1949. For sets of up to about four items, people judge the number quickly and accurately. Beyond that range, judgements become slower and less reliable, because people have to count or estimate instead.
Researchers study subitizing to understand how we perceive number and how attention limits what we can take in from a brief glance. The Neuroptimize game, Subitizing, flashes a scatter of coloured shapes for a moment. Your job is to count only the ones that match a named colour and shape, such as blue stars, among distractors, then pick how many you saw.
How to play the Subitizing
- Each session has 12 rounds. Every round starts by showing you the target, for example "Count the blue stars", with a picture of the shape in its colour.
- A scatter of coloured shapes then flashes on screen for a short time. Count only the shapes that match both the colour and the shape of the target.
- The shapes disappear and four number choices appear. Tap the number of targets you saw.
- The answer is then revealed: the targets are ringed and the other shapes fade out. A correct answer scores more when there were more targets to count.
- At low levels the shapes stay up for over two seconds, there are only a few targets and the distractors look quite different. As your level rises the flash gets shorter, the number of targets and distractors grows, and more distractors share either the colour or the shape of the target.
Strategies and tips
Fix the target in mind
Use the cue screen to picture exactly what you are looking for, both the colour and the shape. Saying it to yourself, such as "red hearts", helps you ignore everything else once the flash begins.
Look for the colour first
Colour usually stands out faster than shape. Let your eyes find all the shapes in the target colour, then check which of those have the right shape. This helps when distractors share one of the two features.
Count in small groups
Small sets can be judged at a glance, but larger ones cannot. When there are many targets, split them into little clusters of two or three and add the clusters together, rather than counting each shape.
Use the reveal to learn
After each answer the targets are ringed. Check which ones you missed or counted wrongly, such as a same-coloured distractor, or a target in a corner. You will soon notice your own habits.
Hold the image briefly
The shapes vanish before the choices appear, so keep a mental snapshot of the display. Often you can finish counting from that brief image in the moment after the flash, especially at higher levels where the exposure is short.
The science behind the Subitizing
Subitizing is the rapid, confident and accurate judgement of the number of items in a small set, usually up to about four. The term was introduced by E. L. Kaufman and colleagues in 1949. Larger sets require counting or estimation, which is slower and more prone to error.
Frequently asked questions
What is subitizing?
Subitizing is the fast, accurate recognition of how many items are in a small set without counting. It usually works for up to about four items. The word comes from the Latin for "sudden".
What is the subitizing range?
The subitizing range is commonly given as up to about four items. Within it, answers are quick and nearly error-free. Above it, people rely on counting or estimation, which takes longer and leads to more mistakes.
Is subitizing the same as counting?
No. Counting means going through items one at a time, and it gets slower with every extra item. Subitizing is an immediate judgement that feels effortless for small sets.
Why do the counts go above four in the game?
At higher levels Subitizing shows more targets than can be judged at a glance, which turns each round into a quick counting and grouping challenge as well. Fewer targets appear at lower levels.