A magnetoencephalographic study on Wisconsin Card Sorting Test
Using magnetoencephalography (MEG), we studied temporal and spatial processing during performance of the Wisconsin Card Sorting Test (WCST) in 12 normal subjects. The MEG responses were compared between the first wrong and the fourth correct feedback both at the period of presenting the cards and at the moment of presenting the feedback signals. We found that MEG activity differences between the wrong and the correct feedback occurred in the period of 190-220 ms (M190 and M200) and 300-440 ms (M300 and M370) after the presentation of cards, and at 460-640 ms (M460) after the presentation of the feedback signals. The differences were mainly located at the supramarginal gyrus (SMG), the dorsolateral prefrontal and the middle and inferior frontal gyrus after the presentation of cards, and at the dorsolateral prefrontal cortex and the middle frontal cortex after the presentation of feedback signals. Our results proved that the WCST task activates a broad frontal area and the parieto-frontal network across time streaming. Both shifting attention to the wrong feedback and enhanced visual working memory to the sorting shifting condition of the card presentation occur in the same areas at different time points. © 2002 Elsevier Science B.V.