Elbert W. Russell

MMPI profiles of closed head trauma patients: Impact of neurologic complaints

The MMPI is used commonly with neurologic patients despite concerns about its validity with this population. The basis for this concern--possible artifactual effects due to neurologic-related MMPI items (NRIs)--was assessed in this study of 58 closed head trauma (CHT) patients. The MMPI profiles of these patients were analyzed before and after statistical correction was made for 42 NRIs that were identified by three neurologists. Significant effects occurred on Scales 1 (HS), 2 (D), 3 (HY), 7 (PT), and 8 (SC) in regard to their T scores, frequency of pathological elevation (T greater than 69), and representation in configural codes. The results suggest that MMPI content scales and subscales may help to distinguish the relative contribution of neurologic and emotional complaints on MMPI profiles.

The accuracy of automated and clinical detection of brain damage and lateralization in neuropsychology

The validity of both computer programs and clinical judgment in neuropsychology for determining the existence and lateralization of brain damage is reviewed. Computerized interpretation in neuropsychology, after a propitious beginning, was largely abandoned due to severe criticism, essentially based on only three studies. Only one of these studies compared clinical judgment with computer programs. A thorough examination of the literature located many more studies assessing the accuracy of computer programs, clinical judgment, and discriminant analysis. When reviewed, these studies found that the computer programs, especially the Neuropsychological Key, were quite accurate though not as accurate as clinical judgment. Computer programs and especially the Lateralization Index are potentially as accurate as expert clinical judgment. The rationale related to computer programs is also discussed. This includes the implications of impairment, criterion adequacy, and methods used in designing the neuropsychological Key and the Lateralization Index. Since computer programs are completely reliable across studies, they can be used to examine the differences between sample populations and criterion accuracy. Factors contributing to reduced accuracy in both clinical judgment and computer programs are also explicated.

Factor analysis of the revised Wechsler Memory Scale Tests in a neuropsychological battery.

The Revised Wechsler Memory Scale (4 scales) along with 13 subtests from the WAIS and Halstead-Reitan battery were subjected to a principal components factor analysis. 9 tests of memory loaded on 5 of the 6 factors indicating that 5 types of memory were isolated. These were immediate verbal memory, recent verbal memory, recent figural memory, figural learning, verbal learning storage. Loading of memory and nonmemory tests on the same factors indicates a closer relationship between some memory and nonmemory processes than between kinds of memory.

FLUID AND CRYSTALLIZED INTELLIGENCE: EFFECTS OF DIFFUSE BRAIN DAMAGE ON THE WAIS

In the 1940s two forms of intelligence, fluid and crystallized, were postulated. Active mental processing (WAIS performance subtests) were fluid while well learned abilities (WAIS verbal subtests) were crystallized. Brain damage was considered to affect fluid abilities more than crystallized. WAIS scores comparing normal and diffusely organically damaged subjects indicated that, as hypothesized, the verbal subtests were more affected than the performance subtests.

Left temporal lobe brain damage pattern on the wechsler adult intelligence scale

This study supports an association of left temporal brain damage with the unusual WAIS subtest pattern of more impaired Information and Vocabulary than Similarities scores. Temporal lesions may impair well-learned verbal memory more than reasoning skills. Thirty-six patients with localized left hemisphere brain damage in the frontal, parietal or occipital, and temporal lobe were compared using an index in which Information and Vocabulary were contrasted to Similiarities. Index scores were adjusted for age. Seventy-five percent of the temporal patients had negative index scores, and 75% of the frontal patients had positive index scores. Temporal patients tended to score more negatively on the index than did frontal patients, p less than .05.

Developments in the Psychometric Foundations of Neuropsychological Assessment

The last decade for neuropsychology has been a fruitful period for developing a new psychometric methodology. The major development in methodology has also initiated a significant theoretical advance. The methodological development has been the creation of computerized scoring programs. The construction of these programs utilized new methods to norm large test batteries. These methods, in turn, required the perfection of a methodology theory related to groups or batteries of tests. The theory may be called a test set theory. While there have been many developments in regard to individual tests, this chapter will concentrate on those aspects of neuropsychology that are related to this development of computerized assessment batteries.

Validation of a brain-damage vs. schizophrenia MMPI key

Since neuropsychologic tests largely have failed to separate schizophrenic from brain-damaged patients, an MMPI key was constructed to make such a separation. When cross-validated, this key provided a 76% correct separation and achi2 significant beyond the .001 level for 50 schizophrenic and 50 brain-damaged profiles. Neuropsychologic tests should be used to separate normals from brain-damaged patients and the MMPI to separate schizophrenic from brain-damaged patients.

MMPI correlates of verbal-intellectual deficits in patients with left hemisphere lesions

This study investigated the emotional adjustment of patients (N = 31) with left hemisphere damage (LHD) as a function of the degree of impairment in verbal intelligence as measured by the Wechsler Adult Intelligence Scale. A multivariate comparison was made of the composite MMPI profiles of three groups of LHD patients classified according to Verbal IQ. The three groups produced fairly similar composite profiles, which indicated the presence of mild dysphoria, dissatisfaction, withdrawal, decreased initiative, and mild somatic preoccupations. Significant correlations emerged between the degree of verbal-intellectual disability and MMPI F, PT, SC, and SI. However, when the variance in MMPI scores due to premorbid status (education) was partialled out, these correlations dropped to nonsignificant levels. These findings failed to support previous studies that linked verbal deficits with emotional disturbance, and they underscore the importance of premorbid intelligence in the psychological adjustment to organic impairment.

Memory and attention

The effect of attention on memory was examined in three studies. In all three, the subjects were instructed to remember the items of one color from an array that contained items of two colors. Subsequently, the subjects were asked to reproduce items of both colors. Almost all of the items that the subjects remembered were those to which they had attended. The parameters of sex, color, and mode of presentation (verbal and drawing) were not significant. Head injury did not disrupt this effect. On the basis of this effect, it was theorized that the strength of a memory store is related directly to the strength of attention.

MMPI correlates of Performance intellectual deficits in patients with right hemisphere lesions

This study investigated the emotional adjustment of 50 patients with focal brain damage in the right hemisphere (RHD). The impact of functional loss (as assessed by the WAIS Performance IQ) was assessed by a multivariate comparison of the composite MMPI profiles of these patients as classified into three groups: Below Average, Average, and Above Average Performance IQ. Regardless of the extent of decline in Performance-related abilities, right hemisphere impairment was associated with symptoms of mild depression, loss of initiative, anxiety, denial, and somatic preoccupations. MMPI scores were not correlated significantly with their WAIS Performance IQs. Implications for neuropsychological assessment are discussed.