EXECUTIVE FUNCTIONS IN SCHOOL-AGED CHILDREN - POTENTIAL EFFICACY OF TASKS IN DISCRIMINATING CLINICAL GROUPS

The performance of three groups of children on a battery of executive function tasks was investigated. A double dissociation paradigm was us ed, including six executive function tasks (Wisconsin Card Sorting Tes t, Matching Familiar Figures Test, visual search, verbal fluency, Towe r of Hanoi, and males) and two vocabulary tasks (Peabody Picture Vocab ulary Test-Revised and the Boston Naming Test). Executive function was defined as goal-directed behavior including strategic planning, impul se control, organized search, and flexibility of thought and action. O ne hundred and fifteen children, aged 6.0 to 12.11 years, participated in the study (36 children with attention deficit hyperactivity disord er, 34 children with developmental language disorder, and 45 nondisabl ed children). Four main results were found: (a) groups differed on thr ee of the executive function tasks, (b) groups differed on both of the nonexecutive function tasks, (c) the relationship between age and per formance was linear, and (d) discriminant function analysis revealed 7 7% of the cases were correctly classified. Implications of the results for the development of executive functions and the construct validity of executive function tasks are discussed.