Deborah Wolfson

Category test and trail making test as measures of frontal lobe functions

Abstract A brief review of the literature reveals that many psychologists believe that certain tests measure frontal lobe deficits. However, recent carefully controlled studies suggest that neuropsychological deficits are far from specific for frontal versus nonfrontal lesions. In this study, we compared groups with frontal and nonfrontal cerebral lesions that were approximately equivalent for types of lesions and other variables. No intergroup differences were found on the Category Test and Part B of the Trail Making Test. The results suggest that neuropsychologists should adopt a more critical attitude concerning so-called “frontal lobe deficits.”

A selective and critical review of neuropsychological deficits and the frontal lobes

Presumptions about the functions of the frontal lobes, and the sensitivity and specificity of certain tests to measure frontal lobe functions, are having a substantial influence on both clinical and research conclusions. In this paper the authors examine the details of the studies that have contributed to these presumptions, and find that the evidence to support these conclusions is weak. A detailed evaluation of the evidence relating to the Wisconsin Card Sorting Test and the Thurstone Word Fluency Test is also presented. Finally, the development of the belief that frontal lobe functions can be specifically measured is reviewed. The authors of this paper conclude that the “bewildering array” of deficits attributed to frontal lesions still seems to prevail.

The Trail Making Test as an initial screening procedure for neuropsychological impairment in older children.

This study was designed to explore the possibility of using a brief neuropsychological test for broad-band initial screening of children with academic problems who might have neuropsychological deficits that should be more completely evaluated. Part B of the Trail Making Test was selected as the instrument for investigation. Three groups of children, aged 9-14 years, were composed for this study to represent (1) children with diagnosed brain damage or disease, (2) children who were medically normal but who were of serious concern to parents and teachers because of inadequate academic progress, and (3) a normal control group. The Brain-Damaged group required more than three times the number of seconds needed by the controls to complete the test, and the group with academic difficulties required more than twice the time of the controls. Using the limits set by the distributions of the Brain-Damaged and control groups, it was possible to identify a cutoff point that may be used for preliminary identification of children with academic difficulties who might benefit from further neuropsychological evaluation. The results of this study stand in need of cross-validation and, obviously, much additional outcome research is necessary to evaluate the efficacy and validity of the findings for screening purposes.

Influence of age and education on neuropsychological test results

Abstract Attribute variables of age and education were evaluated with relation to the General Neuropsychological Scale (GNDS), a comprehensive measure of neuropsychological functions. A brain-damaged group and a control group, each composed of 50 subjects, were studied. The GNDS clearly differentiated the two groups, and was significantly related to age and education among the controls. However, the effects of age and education were minimal among brain-damaged subjects. These results suggest that adjusting raw scores according to age and education may not be a clinically valid procedure for brain-damaged subjects, and may only tend to invalidate the raw scores of neuropsychological tests.

Emotional disturbances and their interaction with neuropsychological deficits.

The interaction and relationships between neuropsychological tests (which are principally oriented to intellectual and cognitive abilities) and tests of personality and emotional status are complex, but nevertheless important in the clinical assessment of brain-damaged persons. Are indications of emotional disturbances to be expected as a direct consequence of brain damage? If so, how can the indications of emotional disturbances be differentiated from results obtained with psychiatrically disturbed (non-brain-damaged) subjects? Some authors have presumed that emotional disturbances, such as depression, acute anxiety, etc., in their own right cause impaired performances on neuropsychological tests, whereas other authors have proposed that brain damage predisposes the individual to demonstrate evidence of emotional disturbances. If emotional disturbances cause impairment on neuropsychological tests, why is it that so many emotionally disturbed persons without brain damage tend to perform normally on neuropsychological tests? This review of relevant publications considers (1) different general approaches to these questions and their implications for neuropsychology, (2) evidence of differential sensitivity to brain damage of neuropsychological and emotional instruments, (3) the sensitivity and specificity of self-assessments and complaints of head-injured subjects, (4) MMPI findings among head-injured subjects and in interaction with neuropsychological measurements, and (5) principles and guidelines that may be of value in clinical application of findings reported in the literature.

The Two Faces of Mild Head Injury

The research literature indicates that the great majority of persons who sustain any initial neuropsychological impairment from a mild head injury recover in 1 to 3 months. Nevertheless, clinicians report that some persons with a mild head injury demonstrate signs and report symptoms suggesting that they have sustained permanent brain damage. Although this latter group contains the participants of principal clinical interest, our literature review did not identify any research that provided a comprehensive description of the neuropsychological characteristics of this important subgroup of mild head-injured persons. The present investigation compared four groups: (1) controls, (2) persons with definite traumatic brain tissue damage, (3) persons with mild head injuries routinely accessed into a research study, and (4) persons with mild head injuries who had persisting clinical signs and symptoms. The same comprehensive neuropsychological test battery was used to evaluate all four groups. All pairs of groups differed significantly in neuropsychological status, with Group 3 showing only mild impairment (approaching the level of the controls) and Group 4 showing significant impairment (approaching the level of the group with definite brain tissue damage). The results emphasize the need for a comprehensive neuropsychological examination of persons with mild head injuries who have persisting clinical problems.

Conventional intelligence measurements and neuropsychological concepts of adaptive abilities

The concept of intelligence and its representation by the Intelligence Quotient have been difficult to define and the subject of criticism for various reasons. Matarazzo and Kaufman have reviewed intelligence measurements and brain functions, but a biologically based explication of intelligence has not been explicitly proposed since the theories presented more than 40 years ago by Halstead and Hebb. The present study explored the overlap and differential sensitivity of intelligence measures (VIQ, PIQ, and FSIQ) and neuropsychological measures (Impairment Index and Category Test) to cerebral damage and educational attainment. The results indicated that neuropsychological measures may serve to broaden the concept of intelligence and that a brain-related criterion may contribute to a fuller understanding of its nature.

Consistency of neuropsychological test scores of head-injured subjects involved in litigation compared with head-injured subjects not involved in litigation: Development of the retest consistency index

Abstract Neuropsychological test scores earned by a group of 20 head-injured subjects involved in litigation were compared with the test scores of 20 head-injured subjects not involved in litigation. The tests were taken from either the WAIS or the WAIS—R and the Halstead-Reitan Battery. The comparisons were based on intraindividual consistency of performances (difference scores) for each subject over two testings. On the second examination, the group of litigants earned lower means on each test and the group of non-litigants earned higher means on each test. The contrasting direction of change produced highly significant findings in comparing intergroup difference score distributions (Testing 2 minus Testing 1 for each group). These difference score distributions were used to develop the Retest Consistency Index, a measure that correctly classified 90% of the litigants and 95% of the non-litigants. As in any study of this type, these results require cross-validation.

Verbal processing by the brain

Reitan and Wolfson (1985) have proposed a model of brain-behavior relationships which postulates a three-part organization of higher-level aspects of central processing: Verbal and related language functions (mainly left hemisphere), visual-spatial and related abilities (mainly right hemisphere), and conceptual abilities (both hemispheres). Three groups of subjects (controls, left cerebral lesions, and right cerebral lesions) and two strictly verbal tests (the Word Finding Test and the Vocabulary subtest from the Wechsler Scale) were used as a partial test of this model. Left cerebral lesions impaired Vocabulary scores but right cerebral lesions had little if any impairing effect. However, on the Word Finding Test, which has a strong conceptual requirement in addition to the verbal requirement, the group with left cerebral lesions continued to show striking impairment but the group with right cerebral lesions also showed significant impairment as compared to the control group. Additional studies are needed to test the proposed model in more detail.

The seashore rhythm test and brain functions

Abstract The neuropsychological literature contains many statements about the brain correlates of the Seashore Rhythm Test, with the prevailing contention being that the test is principally dependent upon the integrity of the right temporal lobe. However, the only published empirical investigation that we could find (Milner, 1962) reported no significant differences between groups with right and left temporal-lobe excisions. In the present study we compared a number of groups with right, left, and generalized cerebral lesions, varying with regard to type of lesion, and found no differences among them on the Seashore Rhythm Test. Age and gender differences did not approach statistical significance. However, control subjects performed much better than did brain-damaged subjects. Our results indicate that the Seashore Rhythm Test is a general indicator of brain functions.