[Madrid adaptation of the Wisconsin card sorting test: a comparative study of internal consistency].

INTRODUCTION WCST (Wisconsin Card Sorting Test) is still a widely used neuropsychological test for evaluation of disorders of the frontal lobes. Recent studies have cast doubt on the validity of WCST as a marker for frontal dysfunction. OBJECTIVES We present a simplified version of WCST specially designed to evaluate the capacity to change the criteria for attention. Our objectives were to examine the difference in standards and in internal consistency between our adaptation and the conventional WCST. SUBJECTS AND METHODS The two tests were applied to a group of 60 young persons with no cerebral disorders. The principal components of both tests were analysed for determine their internal structure. RESULTS We found statistically significant differences between the scores of Spanish persons and the standard data for WCST. Analysis of the main components showed a solution of two components in the conventional WCST and a solution of three components in our adaptation. CONCLUSIONS The American rating system underestimated the level of performance in the Spanish sample. Analysis of the internal consistency showed the excessively redundant and simple factorial structure of the conventional WCST. Our adaptation was shown to have a richer internal structure, with the order of error scores more in accord with the type of cognitive process involved. These advantages may be attributed to more exact analysis of non perseverant errors, subclassified as efficient errors (i.e. linked to comparison of hypotheses) and random errors (i.e. linked to loss of criteria for attention).