CorsiCorsi block-tapping test

The Corsi test checks how many places in space a person can hold in mind at once. Identical blocks stand on a board, they light up one by one — and that "path" has to be repeated.

It is the spatial sibling of the well-known digit memory test. Words and numbers do not help here: it is visuospatial memory that does the work.

In BB Gym, Corsi is a trainer with three levels. The blocks are lamps that light up in turn. First you repeat the order forward, and at higher levels backward as well. Each part starts with a warm-up, and the result shows a score and a skill profile.

Where the test came from

The test was devised by the psychologist Philip Corsi in the early 1970s in the laboratory of the neuropsychologist Brenda Milner in Montreal. He wanted a spatial counterpart to the digit memory test.

The original board was a wooden board with nine cubes placed irregularly. The examiner tapped the cubes in a certain order, and the person had to repeat it. Since then the test has become one of the most common ways to study visuospatial memory.

How it works

First a short sequence is shown, for example two blocks. If it is repeated correctly, the next one is one block longer. Each length usually gets two tries, and the test ends when both fail.

The blocks stand in no particular pattern, so a sequence cannot be remembered as a row or a column. All that matters is which blocks lit up and in what order.

In BB Gym the blocks are lamps on a dark board: they do not dazzle and glow softly when they light up.

What the results show

The main measure is the span: the longest sequence repeated correctly at least once. In adults it is usually about five or six blocks.

The number of correct tries is counted separately. In 2000 Dutch researchers proposed multiplying the span by this number: such a "product" is steadier than the span alone, because it also reflects how confidently the shorter sequences went.

For a specialist the kinds of mistakes are useful too: swapped blocks or, in the "Backward" part, the forward order given instead of the reverse one.

Corsi and digits

The well-known working memory model of Alan Baddeley and Graham Hitch has separate "stores" for sounds and words and for images and spatial locations. The digit test loads the first, Corsi the second.

Interestingly, in Corsi the backward order is not always noticeably harder than the forward one, whereas with digits the difference is usually clear. A 1998 review discusses in detail what this may depend on.

What the trainer works on

The trainer loads visuospatial working memory and attention: you have to follow every lamp and hold the whole path to the end.

Results improve with practice, because people get used to the task and find their own tricks. But to be honest, there is little evidence that such exercises improve memory in everyday life. A 2013 meta-analysis found that working memory training helps mostly on similar tasks, and a 2016 review reached a similar conclusion about brain training in general.

So it is best to treat Corsi as an engaging memory warm-up and a way to track how sharp you are on different days.

How to play and what to watch for

Try to see a shape rather than separate lamps: join them with a line in your mind, as if drawing a path.

Long sequences are easier in chunks of two or three steps. In the "Backward" part, first recall the whole path, then walk it from the end.

There is no time limit for the answer, so do not rush the first tap.

Screen and lab: about norms

Published norms are tied to a wooden board, a particular block layout and presentation pace. On a screen everything is different, so compare results in BB Gym only between your own attempts.

Results in BB Gym are not a medical diagnosis or a neuropsychological assessment. If you are concerned about memory or attention, please see a specialist.

References

1. Berch D. B., Krikorian R., Huha E. M. (1998). The Corsi block-tapping task: methodological and theoretical considerations. Brain and Cognition, 38(3), 317–338
2. Kessels R. P. C. et al. (2000). The Corsi block-tapping task: standardization and normative data. Applied Neuropsychology, 7(4), 252–258
3. Baddeley A. D., Hitch G. (1974). Working memory. Psychology of Learning and Motivation, 8, 47–89
4. Melby-Lervåg M., Hulme C. (2013). Is working memory training effective? A meta-analytic review. Developmental Psychology, 49(2), 270–291
5. Simons D. J. et al. (2016). Do "brain-training" programs work? Psychological Science in the Public Interest, 17(3), 103–186
6. Corsi block-tapping test — Wikipedia