Abstract

Although the Wisconsin Card Sorting Test (WCST) has been widely used to evaluate the frontal lobe functioning, there is no published data on normal children in Korea which results in limitation of its clinical validity in children. The present study was conducted to investigate developmental trends of normal children`s performance on the WCST. The computerized version of WCST (Heaton, 1991) was administered to 160 elementary school children aged 7 to 11 years. Their Full Scale IQs measured by the Korean version of WISC-R ranged from 80 to 138 (M=111.02, SD=11.77). Children did not differ in FSIQ, VIQ, and PIQ when compared based on age. However, very moderate correlations were found between FSIQ, VIQ, and PIQ scores and the scoring variables. Out of the 10 WCST scoring variables, 9 variables except Failure to Maintain Set showed age effect, but sex difference was not found in any variables. There was also no significant interaction effect between age and sex. Important differences in developmental trends were found among the 10 WCST scoring variables. The nature of these differences was effectively explained by the three factors. From the principal axis analysis with oblique rotation using the 10 WCST scoring variables, three factors with eigenvalue greater than 1 emerged, interpreted as conceptual formation (Factor Ⅰ: accounted for 60.24% of variance), perseveration (Factor Ⅱ: 18.52% of variance), and ability to sustain attention (Factor Ⅲ: 12.12% of variance). The growth curves for the 5 scoring variables constituting Factor Ⅰ(Total Number of Corrects, Nonperseverative Errors, Conceptual level Responses, Number of Categories Completed, and Trials to Complete First Category) showed significant improvement from age 7 to 8, suggesting a developmental spurt during that period. By contrast, Perseveration Errors included in Factor Ⅱ significantly decreased from age 9 to 11, while Failure to Maintain Set included in Factor Ⅲ showed no age effect. These results suggest that the WCST performance requires multiple cognitive functioning with different developmental trends.