Joseph J. Ryan, Anthony M. Paolo, Jay N. Van Fleet; Neurodiagnostic implications of abnormal verbal-performance IQ discrepancies on the WAIS-R: A comparison with the standardization sample. Arch Clin Neuropsychol 1994; 9 (3): 251-258. doi: 10.1093/arclin/9.3.251
The neurodiagnostic value of Wechsler Adult Intelligence Scale-Revised (WAIS-R) Verbal-Performance IQ (VIQ-PIQ) discrepancies was evaluated in a brain-damaged sample. The VIQ-PIQ differences of 260 neurologically impaired patients was compared to the WAIS-R standardization sample. The average VIQ-PIQ discrepancy of the patients was significantly larger than the mean IQ difference for normals. Comparison of the number of subjects whose VIQ-PIQ discrepancy equaled or exceeded 95% of the controls revealed no differences for the total sample and for individuals with low average or average intelligence. Conversely, the frequency of abnormal VIQ-PIQ differences was significantly greater among patients with Full Scale IQs ≤ 79. The occurrence of an abnormal VIQ-PIQ discrepancy in persons with IQs ≤ 79 should serve as a stimulus for further assessment.