Toward an explanation of Dodrill's observation: high neuropsychological test performance does not accompany high IQs.

Dodrill demonstrated that many neuropsychological tests correlate poorly with intelligence in the above-average intelligence range, while correlating adequately throughout the total range. The most parsimonious explanation for this observation is that most neuropsychological tests have a low ceiling with a constricted range at their upper limits precluding the possibility of high correlations. This explanation is examined through various examples. Interpretation should take this constricted range into consideration for people with above-average premorbid ability, by supplementing neuropsychological tests with intellectual ability tests. Also, the future construction of neuropsychological tests should extend the upper range.

In defense of the Halstead Reitan Battery: a critique of Lezak's review.

Since many neuropsychologists utilize the Halstead Reitan Battery (HRB), it is important to answer a critical review contained in Lezak's (1995) book. Lezak understands hypothesis testing but not HRB pattern analysis or the use of fixed batteries. A fixed battery provides a constant background, which reveals individual characteristics of the patient. Issues discussed include, types of batteries, legitimate review methods, and Reitan's method. This writing demonstrates that almost all of Lezak's criticisms of either the HRB or the Halstead Russell Neuropsychological Evaluation System (HRNES) are either incomplete, misleading or erroneous. Her critique of the Reitan method involved a confusion of terms. In spite of attempts to discredit the HRB not a single sound study questioning the validity of the HRB was presented, while many studies have demonstrated its validity. The fallacy of nonrefutation asserts that it is a fallacy to condemn methods that have been validated while recommending procedures that have not been validated. Lezak questions Reitan's method, the HRB and the HRNES, which have been thoroughly validated, while presenting no validating studies of her own recommended methods.

A partial cross-validation of a Halstead-Reitan Battery malingering formula.

Using the Halstead-Reitan Battery profiles of 796 people, a formula for the detection of malingering was partially cross-validated to assess the false positive rate. Subjects included normals, psychiatric cases, and persons with all major types of brain disorder. The formula incorrectly designated 32% of the sample as fakers (i.e., as false positives). Of the 120 head-trauma cases, 39 (32%) obtained Fake scores, whereas 81 (67%) were correctly assessed as not malingering. The correlation of the results of the formula and the severity of the profile (as measured by the Average Impairment Rating) was 67, p < .0001.

Detection of malingering on the Halstead-Reitan Battery: a cross-validation.

Using the Halstead-Reitan Battery profiles of 796 people, a formula for the detection of malingering was cross-validated to assess the false positive rate. Subjects included normals, psychiatric cases, and all major types of organics. The formula incorrectly designated 27% of the sample as fakers (i.e., as false positives). Of the 120 head trauma cases, 27 (22.5%) obtained Fake scores, while 93 (77.5%) were correctly assessed as not malingering.

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.

Neuropsychological test patterns in men for Alzheimer's and multi-infarct dementia.

This paper examined three patterns of test performance on the Halstead Reitan Battery (HRB) and the Wechsler Adult Intelligence Scale-Revised (WAIS-R), including Fuld's formula, that differentiated Alzheimer's Disease (AD) from cerebrovascular disease, especially Multi-Infarct Dementia (MID). Study 1 and 2 utilized 12 AD subjects and 13 subjects who had transient ischemic attacks (TIAs). All of the subjects in this study were male. The severity of impairment was equated. A WAIS-R deterioration pattern was found for the AD subjects, from which a formula was derived that correctly identified 84% of the subjects. The Fuld formula identified 76%. In regard to the HRB, Motor tests especially were less impaired for AD subjects and the HRB formulas correctly identified about 92% of the subjects. A third study, using an entirely new sample, applied these formulas to 11 AD and 28 MID subjects. The same rate of separation for the HRB formulas was found. Neither the WAIS formula, with the original cutting points, nor did the Fuld formula quite reach significance.

Left temporal lobe brain damage pattern on the WAIS, addendum.

This study added Digit Span to an index investigated in a previous study. An index score, in which the WAIS Vocabulary and Information were more impaired than Similarities and Digit Span, indicated left temporal lobe damage. Using subjects with damage restricted to a single lobe of the brain, the index was found to be significantly more related to the left temporal lobe than to any other part of the brain.

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.

Comparison of two methods for converting the WAIS to the WAIS-R.

Two methods for converting WAIS scores to WAIS-R scores were investigated. One method subtracted the mean differences between the WAIS and WAIS-R IQs and subtests means from the WAIS scores. The other method converted the WAIS and WAIS-R scores to T scores. Theoretically, the two methods should produce equivalent results. Because the SDs for the WAIS and WAIS-R were quite similar, the only components that remained to produce the difference were the means. Using 52 pairs of WAIS and WAIS-R scores, matched by age and education, both methods were compared. There was no statistically significant difference between the methods. Two new norming methods were discussed in terms of these results.

Fluidity theory and neuropsychological impairment in alcoholism.

In order to determine whether the "classic" alcoholic WAIS pattern is the result of right hemisphere damage or the loss of fluid intelligence abilities, right-hemisphere damaged, left-hemisphere damaged, alcoholic, and control groups of 40 subjects each were matched on the variables of age and education. They were administered the WAIS-Revised (WAIS-R) and four sensory and motor measures that were sensitive to lateralized damage but not to fluidity. The alcoholic group showed the "classic" pattern of a lower performance than verbal WAIS IQ. Although the left hand scores on the sensory and motor tests were significantly more impaired than the right hand scores for the right-hemisphere damaged group they were not for the alcoholic group. These results did not support the right hemisphere theory. Rather, as indicated by further analysis, the pattern is most adequately explained by the fluidity theory.

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.

Lateralized anterior and posterior lesions and performance on Digit Span and Russell's revision of the Wechsler Memory Scale.

Performance on the Russell (1975) revision of the Wechsler Memory Scale and the Digit Span subtest of the Wechsler Adult Intelligence Scale by subjects with lateralized anterior and posterior lesions was investigated. Ss were right-handed men whose brain lesions were identified on the basis of neurodiagnostic tests as being lateralized to either the left or right hemisphere and restricted to either the anterior or posterior side of the central sulcus. A normal comparison group was formed of Ss suspected of having neurological damage and referred for neuropsychological testing but who had normal neurodiagnostic examinations. It was predicted that both the laterality and caudality of lesions would affect memory task performance. This prediction was fully supported for the logical memory task and partially supported for the figural memory and digit span tasks.

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.

Renorming Russell's version of the Wechsler Memory Scale.

Several studies of Russell's version of the Wechsler Memory Scale found that the Logical Memory Scales appeared to be normed too high, indicating a need for renorming. This study produces such a renorming by developing new scale scores and age/education corrections. The scaling used a new method, "reference scale norming". The z scores for 12 tests in the Rennick version of the Halstead-Reitan Battery were averaged and used to establish a reference scale. Scale scores for the memory tests were derived from this scale. The results of this study demonstrated that the earlier Logical Memory Scale norms were in fact too high; this error is corrected.

Verbal and figural Gestalt Completion Tests with lateralized occipital area brain damage.

Verbal and figural forms of the Gestalt Completion Test were administered to 8 subjects with left or near left occipital, 12 with right or near right occipital, 12 with left anterior-lateral and 9 with right anterior-lateral lesions. Z score indices of verbal vs. figural scores were constructed. The indices for these groups were compared. Damage to the left occipital area did not impair the figural score more than the verbal, while damage to the right occipital area impaired the figural considerably more than the verbal. The anterior-lateral groups had no lateralized impairment. This supports the concept that the left occipital area perceptually transforms verbal visual data, while the right occipital area transforms figural visual data.

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.

A reference scale method for constructing neuropsychological test batteries.

Scaling of neuropsychological test variables requires knowledge of test parameters. This is a study of the parameters for 12 tests in the Rennick Index of the Halstead-Reitan Battery, using 732 subjects. z-score distributions were plotted. Great variability among test distributions indicated that, for brain-damaged subjects: the range is much greater than for normals; maximum z scores ranged from 3.8 to 27.3 for different tests; the form of the distributions was highly variable, ranging from normal to highly skewed distributions. Thus, the same z scores indicated quite different amounts of impairment on different tests. This raises questions regarding the applicability of z and T scores to a brain-damaged population. The second part of this study demonstrated how scaled scores, indicating equal amounts of impairment, could be constructed. This method used a reference scale produced by averaging control subjects' z scores on 12 tests. Individual scaled scores were obtained through a linear regression prediction.