FRACTIONATING FRONTAL-LOBE FUNCTIONS - FACTORS OF THE MILWAUKEE-CARD-SORTING-TEST

The Milwaukee Card Sorting Test (MCST), a modification of the Wisconsi n Card Sorting Test (WCST), was administered to 71 geriatric, orthoped ic or neurologic patients. The MCST requires that participants verbali ze prior to sorting, thus enabling quantification of separate, element al executive abilities needed for card sorting performance. A prelimin ary factor analysis yielded three factors, corresponding to elemental executive abilities of forming, maintaining, and switching mental set. Results are discussed as they apply to understanding the cognitive st ructure of card sorting tasks to revealing different performances asso ciated with behaviorally distinct executive deficits. and to suggestin g anatomical substrates underlying the three factors.