TEST

Corsi Block-Tapping Test

Visuospatial memory and spatial working memory

The reference paradigm for visuospatial memory, in digital form. Forward and backward sequences across nine blocks, with an exact record of the order tapped and the latencies between taps.

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WHAT THE TEST IS

What verbal memory cannot see

Unlike verbal tests of immediate memory, the Corsi task examines the ability to encode, hold and manipulate spatial information: the component underpinning orientation, navigation, route following and the planning of actions in space.

The difference between the two conditions is not a gradation of difficulty but a functional separation. The forward version measures visuospatial temporary storage; the backward version adds active manipulation and sequential reorganisation. Neuroimaging supports that dissociation: posterior parietal networks for maintenance, dorsolateral prefrontal cortex for manipulation (Wager & Smith, 2003; Owen et al., 2005).

The digital version keeps the principles of the classic paradigm and adds what the tabletop format cannot give: recording precision, a standardised presentation rhythm, and the exact sequence the patient tapped — not merely whether they got it right.

HOW IT IS ADMINISTERED

Reproduce the sequence; then do it backwards

Nine blocks appear on screen in an irregular layout and stay visible throughout. The system highlights them one by one at a steady rate of one per second, with a colour change and a hand pointing to each. Once the sequence ends, the person reproduces it by tapping the blocks: first in the same order and, in the second condition, in reverse order. Sequences start at two elements and grow until two consecutive trials fail at the same level.

WHAT THE TEST MEASURES

Indicators and their interpretation

Forward span

Longest sequence reproduced correctly on at least one trial. It is the upper limit of immediate visuospatial storage capacity.

High: sound visuospatial storage, attentional efficiency and effective spatial encoding; preserved functioning of posterior parietal networks.
Low: difficulty with visuospatial storage, an attentional deficit or problems with perceptual encoding. Fatigue and anxiety can also weigh in and are worth ruling out.

Forward hits

Total number of correct sequences across the whole forward subtest. It measures consistency, not just capacity: a high span with few hits is fragile performance.

High: stable, efficient performance with consistent maintenance of visuospatial information.
Low: inconsistent execution, attentional fluctuation or fatigue, even when the maximum span is not especially low.

Mean latency (forward)

Average time between taps while reproducing the sequence. Reports on the speed of sequential retrieval and on motor planning.

High: cognitive slowing, uncertainty about the response, overload, or excessive checking strategies.
Low: efficient processing; but if they come with errors, they point to impulsivity or a failure of inhibitory control.

Backward span

Longest sequence reproduced correctly in reverse order. Storing is no longer enough here: the sequence has to be reorganised while it is held.

High: good executive capacity, cognitive flexibility and efficient manipulation of visuospatial information.
Low: difficulty with the executive component — manipulation, updating and inhibition — even where basic storage is intact.

Backward hits

Total correct sequences in the backward condition. It measures whether executive control holds up across many demanding trials.

High: sustained executive control and efficient manipulation, not just an isolated peak of performance.
Low: executive difficulty, cognitive fatigue or an inability to keep the strategy going. With an acceptable backward span, it reveals an inconsistency that shapes overall performance.

Tapped sequence

A record of the exact order of blocks selected, in both conditions. This is what makes qualitative error analysis possible.

High: organised sequences: sound sequential encoding and retrieval, good attentional control.
Low: systematic order errors, omissions, intrusions or perseverations; in the backward condition, incomplete reversal or fragmentation of the sequence.

REFERENCES

Bibliography

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.
Kessels, R. P. C., van den Berg, E., Ruis, C., & Brands, A. M. A. (2008). The backward span of the Corsi Block-Tapping Task and its association with the WAIS-III Digit Span. Assessment, 15(4), 426–434.
Brunetti, R., Del Gatto, C., & Delogu, F. (2014). eCorsi: Implementation and testing of the Corsi block-tapping task for digital tablets. Frontiers in Psychology, 5, 939.
Baddeley, A. D. (2000). The episodic buffer: A new component of working memory? Trends in Cognitive Sciences, 4(11), 417–423.
de Paula, J. J., Malloy-Diniz, L. F., & Romano-Silva, M. A. (2016). Reliability of working memory assessment in neurocognitive disorders: A study of the Digit Span and Corsi Block-Tapping tasks. Brazilian Journal of Psychiatry, 38(3), 262–263.
Baddeley, A. D., Hitch, G. J., & Allen, R. J. (2019). From short-term store to multicomponent working memory: The role of the modal model. Memory & Cognition, 47, 575–588.