Purpose of the Questionnaire (Scale)

The WCST is a neuropsychological test that assesses executive functions, with an emphasis on cognitive flexibility, abstract thinking, and problem-solving ability. It is intended for patients with frontal lobe lesions, individuals diagnosed with conditions such as schizophrenia, ADHD, or neurodegenerative disorders, as well as for neuropsychologists and researchers studying cognitive functions.

Questionnaire (Scale) Analysis

The test was developed by Grant and Berg in 1948 and consists of 128 cards with different shapes, colors, and numbers, along with 4 reference cards. Examinees sort the cards using trial-and-error, while the sorting rule changes unexpectedly after 10 correct responses. During the process, immediate feedback is provided (“correct”/”wrong”).

Scoring of Questions

The main measures of the WCST include perseverative errors, i.e., applying an old rule after the category has changed, the number of completed categories (maximum of 6), and the trials to the first correct category, which reflect learning speed.

Statistical Analysis

The test completion time is 20–30 minutes, with test-retest reliability (r = 0.82). The WCST demonstrates high validity, with strong correlations to other tests such as the Tower of London (r = 0.71), and significant clinical utility, as it differentiates schizophrenia (d = 1.3) and detects frontal lobe lesions with 89% sensitivity.

Validity & Reliability

The WCST has been shown to be valid through correlations with functional (fMRI) studies of the frontal lobe and reliable with stable measurements across repeated testing.

References

Grant, D.A. & Berg, E.A. (1948). A behavioral analysis of reinforcement and ease of shifting. JCP, 12(1), 32–40.
Heaton, R.K. (1981). WCST Manual. PAR.
Nyhus, E. & Barceló, F. (2021). WCST and prefrontal dynamics. Neuropsychologia, 150, 107713.

Keywords

Executive Functions, Cognitive Flexibility, Frontal Lobe, WCST, Neuropsychological Assessment.