A BRIEF ASSESSMENT OF EXECUTIVE CONTROL DYSFUNCTION - DISCRIMINANT VALIDITY AND HOMOGENEITY OF PLANNING, SET SHIFT, AND FLUENCY MEASURES

The current study evaluated the discriminant validity and homogeneity of category fluency, Stroop interference, and planning measures of exe cutive dysfunction and introduced a new measure of planning behavior: We compared performance of patients with schizophrenia, Parkinson's di sease, and Huntington's disease, which are disorders associated with s ome impairment of executive function. Findings indicated that all thre e measures successfully discriminated between patient groups and contr ols. Correlational analysis suggested a strong association between tes t scores on these measures, which were only moderately related to perf ormance on nonexecutive function measures. It is concluded that the th ree tasks are sensitive and relatively homogeneous in their recruitmen t of executive functions.