The Corsi block‑tapping test (CBTT) is a neuropsychological assessment tool used to evaluate visuo‑spatial short‑term memory and working memory capacity. It was first described by Italian neuropsychologist Phillip C. Corsi in 1972 as a non‑verbal analogue of the digit span test, which assesses auditory memory.
Purpose and construct
The primary construct measured by the Corsi block‑tapping test is the ability to temporarily store and reproduce sequences of spatial locations. Performance on the test is commonly interpreted as an index of visuo‑spatial short‑term memory span, and it is also employed to explore executive functions such as sequencing, attention, and planning.
Administration
The standard version employs a set of nine wooden blocks (or a computerized interface) arranged irregularly on a board. The examiner taps a sequence of blocks, and the examinee must replicate the sequence in the same order (forward condition). After a series of successful trials, the sequence length is increased by one block. The test continues until the participant fails to correctly reproduce two consecutive sequences at a given length. The longest correctly reproduced sequence length is recorded as the Corsi span. Variants of the test include:
- Backward condition – the examinee repeats the sequence in reverse order.
- Dual‑task condition – the participant performs the Corsi task concurrently with a secondary verbal or motor task to assess divided attention.
- Computerized versions – these present stimuli on a screen and record response times with higher precision.
Scoring
The primary score is the forward Corsi span, expressed as the number of blocks in the longest correctly reproduced sequence. Additional scores may include the total number of correct trials, error types (e.g., anticipatory errors, perseverations), and reaction times in computerized formats. Normative data are available stratified by age, education level, and clinical population.
Reliability and validity
Research indicates moderate to high test‑retest reliability (coefficients typically ranging from .70 to .90) and good internal consistency. Construct validity is supported by moderate correlations with other visuo‑spatial memory measures (e.g., visual pattern test) and lower correlations with purely verbal memory tasks, confirming its non‑verbal nature. The backward and dual‑task versions show stronger associations with executive function measures.
Clinical and research applications
The Corsi block‑tapping test is widely used in clinical neuropsychology, neurology, and cognitive neuroscience. Typical applications include:
- Assessment of memory deficits in traumatic brain injury, stroke, multiple sclerosis, and neurodegenerative disorders (e.g., Alzheimer’s disease, Parkinson’s disease).
- Evaluation of developmental disorders such as attention‑deficit/hyperactivity disorder (ADHD) and autism spectrum disorder.
- Monitoring of cognitive changes over time or in response to therapeutic interventions.
- Experimental investigations of spatial memory processes, brain‑imaging studies of the dorsal visual stream, and studies of age‑related cognitive decline.
Neuroanatomical correlates
Functional imaging and lesion studies associate performance on the Corsi block‑tapping test with activity in the posterior parietal cortex, dorsal premotor areas, and the cerebellum. Damage to these regions, particularly the right parietal lobe, often results in reduced Corsi spans.
Limitations
While the test is robust for assessing visuo‑spatial short‑term memory, it may be influenced by factors such as attention, motivation, and motor planning. Cultural and educational differences can affect performance, necessitating appropriate normative references. Additionally, the test does not directly assess long‑term memory or complex spatial navigation abilities.
References
- Corsi, P. M. (1972). Human memory and the medial temporal region of the brain. Brain, 95(1), 81–90.
- Kessels, R. P., et al. (2000). The Corsi Block-Tapping Task: Standardization and normative data. Applied Neuropsychology, 7(4), 252–258.
- Baddeley, A. (1992). Working memory. Science, 255(5044), 556–559.
Note: The information presented reflects established scholarly sources up to the knowledge cutoff date of September 2021.
