Actuarial Assessment of Wechsler Verbal-Performance Scale Differences as Signs of Lateralized Cerebral Impairment

Abstract

Long-standing clinical lore holds that a discrepancy between Wechsler-Bellevue (W-B) Verbal/Performance Scale weighted scores is a more sensitive sign of lateralized brain damage than a discrepancy between Verbal/Performance Scale IQ. To assess this question, two step-wise discriminant functions using W-B Verbal and Performance Scale weighted scores (Function 1) and IQs (Function 2) as independent variables were derived and cross-validated on right- and left-hemisphere-lesioned subjects. Cross-validation hit rates were statistically comparable though disappointingly low (Function 1–67%, Function 2–64 %). These results do not support the clinical lore which favors a weighted discrepancy score over an IQ-discrepancy as a sign of lateralized cerebral impairment.