What it does
This page is a small battery of classic memory and attention tests for teaching cognitive psychology. A class can try each task, see their own scores at once, and download every trial to pool results and analyse them. It runs entirely in your browser: nothing is uploaded or kept after you close the page.
- Digit span: digits appear one per second and you type them back. Backward span asks for them in reverse, which also needs working memory to rearrange them.
- Corsi blocks: nine blocks, a few light up in turn, and you tap them in the same order. It is the visual-spatial partner of digit span.
- Visual search: find a T among Ls (hard) or an O among Xs (easy) in displays of different sizes. The tool fits a straight line of reaction time against the number of items and reports the search slope in milliseconds per item.
- Simple and choice reaction time: press as soon as a circle appears, or press left or right for the side it appears on.
It works well with the reaction time experiments, the signal detection calculator and the neural network toys.
How to use it
- Pick a task and its settings: direction and start length for the span tasks; target, set sizes and trials for search; simple or choice and number of trials for reaction time.
- Press Start. Use the keys shown, or tap on a phone or tablet. Stop or Esc ends a run without scoring it.
- Span tasks give each length twice and stop when both tries at a length are wrong, as in the usual paper versions.
- Read the results, then run another task. This session lists every completed run, and the CSV holds every trial from all of them.
What the numbers mean
- Span is the longest sequence you recalled correctly at least once. The Corsi total score is span × number of correct trials, which separates people more finely.
- Search slope: the extra time each added item costs. A flat slope means the target pops out; a slope of 20 to 40 ms per item or more means you checked the items one by one. Target-absent slopes are often about twice the present slopes. r² shows how straight the line is.
- Reaction time: the median is shown first because a single slow trial pulls the mean up. False starts (pressing before the signal) and anticipations (faster than 100 ms) are counted and left out.
- Browser timing is approximate. Screens, keyboards and touch screens add a delay of a few to tens of milliseconds that is similar on every trial, so compare people on the same device.
Worked example
Every run is random, so this example shows how scores are worked out rather than fixed numbers. Suppose a student gets both tries right at lengths 3 and 4, one of two at length 5, and both wrong at length 6. The test stops there: span = 5 and 5 of 8 tries are correct, so the Corsi total score would be 5 × 5 = 25. In a visual search run where mean RT rises from about 550 ms with 4 items to about 820 ms with 16 items on target-present trials, the slope is about 22 ms per item.
Tips
- Run the easy search (O among Xs) and the hard one (T among Ls) to show the difference between pop-out and serial search.
- Try forward then backward span to compare short-term storage with working memory.
- For a class data set, have everyone download the CSV and paste the files together.
Frequently asked questions
Are these clinical tests? No. They are for teaching and demonstration. No norms are given, and the block layout is made up.
Where are my results kept? Only in this page. Download the CSV before closing it.
Was the maths checked? Yes: search slopes against SciPy’s linear regression, and the reaction time summaries against NumPy.
Where the numbers come from
- Task designs: digit span (Jacobs 1887), Corsi block tapping (Corsi 1972) with a made-up block layout, visual search (Treisman and Gelade 1980), simple and choice reaction time (Donders 1868, Hick 1952). Corsi total score: Kessels et al. (2000).
- All sequences and displays are generated at random in the page; no norms or published data are included.
Standard scientific values, such as constants, atomic weights and melting points, are facts found in every textbook; we name where ours were checked. If you are an author or publisher and want a value, a credit or a table changed or removed, tell us and we will act quickly.
Last updated 2026-11-09.