Prueba De Wisconsin

Wisconsin card sort
From Wikipedia, the free encyclopedia
The Wisconsin Card Sorting Test (WCST) is a neuropsychological test of "set-shifting", i.e. the ability to display flexibility in the face of changing schedules of reinforcement.[1][2] The WCST was written by David A. Grant and Esta A. Berg. The Professional Manual for the WCST was written by Robert K. Heaton, Gordon J. Chelune, Jack L.Talley, Gary G. Kay, and Glenn Curtiss.
Contents [hide]
1 Method
2 Clinical use
3 Use in research
4 Legal ownership of trademark
5 References
6 External links
[edit]Method



Screenshot from a computerized version of the Wisconsin Card sort
Initially, a number of stimulus cards are presented to the participant. The shapes on the cards are different in color, quantity, and design.The cards are to be matched first by color, then by design and then by quantity. The participant is given a stack of additional cards and asked to match each one to one of the stimulus cards, thereby forming separate piles of cards for each. The participant is not told how to match the cards; however, he or she is told whether a particular match is right or wrong. During the course of the test thematching rules are changed and the time taken for the participant to learn the new rules, and the mistakes made during this learning process are analysed to arrive at a score.
The original WCST used paper cards and was carried out with the experimenter on one side of the desk facing the participant on the other.[2] Since the early 1990s, however, computerized versions of the task have beenavailable, the most recent version being the Microsoft Windows-compatible version 4.0.[3] The latter has the advantage of automatically scoring the test, which was quite complex in the manual version. The test takes approximately 12–20 minutes to carry out and generates a number of psychometric scores, including numbers, percentages, and percentiles of: categories achieved, trials, errors, andperseverative errors.
[edit]Clinical use

Clinically, the test is widely used by neuropsychologists, clinical psychologists, neurologists and psychiatrists in patients with acquired brain injury, neurodegenerative disease, or mental illness such as schizophrenia. It has been considered a measure of executive function because of its reported sensitivity to frontal lobe dysfunction. As such, the WCSTallows the clinician to assess the following "frontal" lobe functions: strategic planning, organized searching, utilizing environmental feedback to shift cognitive sets, directing behavior toward achieving a goal, and modulating impulsive responding. The test can be administered to those 6.5 years to 89 years of age.
Although successful completion of the test relies upon a number of intact cognitivefunctions including attention, working memory, and visual processing, it is loosely termed a "frontal lobe" test on the basis that patients with any sort of frontal lobe lesion generally do poorly at the test. In particular, patients with lesions of the dorsolateral frontal lobe make a higher number of perseverative errors than control participants.[4] A recent factor analysis of the WCST has shownthese perseverative errors to be the most useful outcome measure in assessing cases.[5] A more sophisticated description of deficits of this type is "executive dysfunction".
[edit]Use in research

The WCST has been used in neuroimaging paradigms such as PET and fMRI. As predicted by the acquired brain injury literature, early PET studies have shown the task involves significant activation ofthe dorsolateral prefrontal cortex.[6][7] However, more recent fMRI studies have shown that the ventrolateral prefrontal cortex (Konishi et al., 1998, Nature Neuroscience) together with the caudate nucleus (Monchi et al., 2001, J. Neuroscience) may be the regions most important for the set-shifting process required in the WCST. These regions are also associated with working memory functions...