PSYCHOMETRICALLY MATCHED TASKS FOR ASSESSMENT OF HEMISPHERIC ASYMMETRIES OF FUNCTION

One of the best methods for studying subtle lateralizing signs of brai n dysfunction is the use of psychometrically matched tasks. The curren t study reports the development and psychometric matching of two pairs of measures of language and visual-spatial functioning. We expanded a nd modified four existing neuropsychological measures in order to deve lop tasks with a wide range of item difficulty that could be administe red to subjects with impaired attention or extreme fatigue. Using 413 subjects, a Word Finding and a Dot Localization task were matched on t heir distributions of item difficulty and item-scale correlations. Mea sures of Similarities and Line Orientation were matched similarly. The psychometric matching for both pairs of tests was cross-validated usi ng an additional 413 subjects. The matched measures of Word Finding an d Dot Localization have been used in several studies to date and have proven valuable for identifying subtle lateralized impairment that mig ht otherwise be obscured by psychometric artifacts. (C) 1995 Academic Press, Inc.