DETECTION OF ACQUIRED DEFICITS IN GENERAL INTELLIGENCE USING THE NATIONAL ADULT READING TEST AND RAVEN STANDARD PROGRESSIVE MATRICES

A multiple regression equation for estimating premorbid Raven's Standa rd Progressive Matrices (RSPM) scores on the basis of age and the Nati onal Adult Reading Test (NART) was derived. A sample of patients with confirmed cerebral lesions was examined to determine the proportion of patients with significant discrepancies between their predicted and o btained RSPM performance. The sensitivity of the procedure was modest (52 per cent), although a comparison with discrepancies between premor bid and current performance on the Wechsler scales indicated that the RSPM was more sensitive to neuropathology. These findings suggest that when NART-intelligence test comparisons are used to diagnose cerebral impairment, the likelihood of a false-negative diagnosis is high.