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Trait analyses of the Luria-Nebraska's Intellectual Processes, Motor Functions, and Memory Scales were performed using multitrait-multimethod procedures and confirmatory factor analysis. Three measures each of intellectual, motor, and memory functions were administered to 161 neuropsychiatric patients. Intellectual scales (viz., Luria-Nebraska and WAIS-R) were found to have convincing discriminant properties, but motor and memory measures demonstrated visibly less such robustness. Confirmatory factor analyses supported a three-factor model of the 9×9 matrix, in which each of the three Luria-Nebraska scales serves as a marker for the factors. Issues related to the neuropsychological constructs, test construction, and construct validity of measurement procedures employed in clinical neuropsychology are discussed.

An exploratory maximum likelihood factor analysis of the inter-correlations among the 11 subtests of the WAIS-R was undertaken for 167 patients who had a primary diagnoses of cerebrovascular accident (right hemisphere, n = 79; left hemisphere, n = 55; diffuse or multifocal, n = 33). On the WAIS-R, this sample performed below normative standards (average scaled score = 7.1), but demonstrated a pattern of variability among subtests similar to the normative groups. Interestingly, VIQ-PIQ discrepancy analyses revealed V > P profiles for patients with lesions in either or both hemispheres. The best fit for the WAIS-R matrix was an oblique two-factor model comprised of the Verbal and Performance subtests. This factor solution, which was moderately correlated (.52), accounted for 58.8% of the total variance. The stability of a two-factor structure in this neurologic impaired population suggests that the WAIS-R is a robust measure, even when used within such a rehabilitation population. Only two of the eleven subtests (i.e., Comprehension and Picture Arrangement), however, were related to lesion site. Rehabilitation settings may need to rely more on neuropsychological procedures that measure the more “fluid” areas of neurocognitive ability, in contrast to the WAIS-R which appears less sensitive to the neurological impairment associated with stroke.

One hundred seventy-nine psychiatric inpatients were administered the WAIS-R and several neuropsychological and academic achievement tests. All subjects were assigned to three groups based on their WAIS-R's VIQ-PIQ discrepancy scores: (i) Low Verbal (Verbal IQ < Performance IQ. by at least 13 points); (ii) Low Performance (Performance IQ < Verbal IQ by at least 13 points); and (iii) Equal (Verbal IQ-Performance IQ within 13 points). The Low Verbal group made significantly more errors on the Speech Sounds Perception Test, demonstrated lower spelling scores, evinced more aphasic signs, and had had more special education placements than did the Equal or Low Performance groups. The Low Performance subjects demonstrated significantly more signs of constructional dyspraxia and performed more poorly on the Grooved Pegboard test. The neuropsychiatric patients who had Verbal-Performance IQ discrepancies of at least one standard deviation may be at risk for specific, subtle neuropsychological deficits.

The pattern and level of WISC-R performances were examined for 113 younger (ages 6–12) and 124 older (ages 12–16) epileptic children. Although these youngsters performed more poorly than the norm group on all 10 subtests, as do adult epileptics on the WAIS (Fowler, Richards, & Boll, 1980), only the younger subjects showed a definite tendency to be more variable in their performance. Factor analyses demonstrated the presence of highly similar Verbal Comprehension and Perceptual Organization dimensions for both groups but, in the case of the 3-factor solutions, an additional freedom-from-distractibility dimension was found for only the older subjects. These results suggest that Kaufman's (1975, 1979) 3-factor model of the Wechsler scales is more strongly approximated as the age of the epileptic respondents increases.

One hundred eight epileptic patients (59 men, 49 women; 55% partial seizures, 45% generalized) were examined on 45 indices comprising a modified Halstead Neuropsychological Test Battery. Factor analyses identified five dimensions: Verbal Comprehension, Perceptual Organization, Selective Attention, Motor Skills, Abstract Reasoning. These factors are similar to those previously reported for neurocognitive abilities in several different populations. Relative deficits on Verbal Comprehension and Abstract Reasoning were related, as predicted, to left hemispheric dysfunction as indexed by EEG localization. Perceptual Organization demonstrated a further, predictable relationship to right hemispheric function. Deficits on Selective Attention were not clearly lateralized, being correlated with a wide variety of electroencephalographic abnormalities. The implications of these findings for the use of neurocognitive profiles in treatment planning for this population are discussed.

The pattern and level of WAIS performance for 118 epileptic adults (65 men and 53 women) were compared to those of the standardization sample. As expected, epileptic subjects performed more poorly on all 11 subtests (from .61 to 1.17 SD below the norm group). Contrary to expectation, epileptic subjects were neither more variable nor were the inter-correlations of the subtests lower than those of the norm group. Overall, strong similarities in the patterns of performance on the tests were found for the two groups. As in previous research, factor analysis revealed the presence of a verbal comprehension factor, a perceptual organization dimension, and, in the instance of the three-factor solutions, an additional freedom-from-distractibility dimension for both groups.

The current study examines the sensitivity of the Wechsler Adult Intelligence Scale in predicting performance on a modified Halstead Neuropsychological Test Buttery for lower-functioning neuropsychiatric inpatients (97 men, 54 women). Regression analyses support earlier-reported findings that the WAIS's subtests more accurately predict neuropsychological test performance than do the WAIS IQ's alone. The IQ's and scaled scores respectively predicted 27% and 39% of the variance in the Halstead's measures. The overall relationship between neurocognitive and WAIS indices is somewhat greater than previous reports and is apparently due to the fact that the lower the overall level of cognitive ability, the lower is neuropsychological functioning in general. However, since most of the variance in the modified Halstead Battery was not common with the WAIS's indices, these findings continue to support the practice of including both sets of measures as part of a comprehensive neuropsychological assessment paradigm for such patients. The importance of developing instruments and procedures which more precisely measure “fluid” neurocognitive abilities is underscored.