Ronald M. Ruff

The Psychological Construct of Word Fluency

Measures of word fluency have been convincingly linked in the literature to damage in the left prefrontal lobe region. Yet, a reduction in word fluency has also been reported with diffuse, multifocal and nonfrontal lobe damage. Despite the undisputed neuropsychological application of multiple word fluency measures, the psychological construct underlying this measure is not well understood. In a sample of 360 normal adults stratified by age, gender, and level of education, we found that auditory attention and word knowledge were among the most important determinants. With respect to memory, short-term memory was not significantly correlated, but long-term memory was. Despite these three determinants, a large share of the variance of the multiple regression was still not accounted for, which underscores the partial independence of word fluency per se. Thus, we propose a distinction between (1) poor word fluency secondary to deficient verbal attention, word knowledge, and/or verbal long-term memory and (2) impaired word fluency without these three areas concurrently affected. Based on a review of the literature, it seems likely that in the latter condition, the profile is more associated with prefrontal lobe impairment, versus in the former condition, diffuse multifocal or nonfrontal lobe factors can play a role.

The ruff figural fluency test: A normative study with adults

Tests of verbal production, or fluency, have proved to be reliable and sensitive indices of brain dysfunction in a variety of clinical populations. Also, numerous studies suggest that disturbed verbal fluency can be linked to specific brain lesions. Less is known, however, about figural fluency performance in normal or in clinical groups. Although Jones‐Gotman and Milner (1977) tested an experimental figural, or design, fluency test in a circumscribed group of brain‐impaired patients, their test lacked psychometric sophistication. Presented herein is a new figural fluency test in a sample of 358 normal adults. The test proved to be reliable, and the data support that the performance depended not on sex, but on age and education. Moreover, figural fluency did not correlate with measures of motor speed or verbal fluency; modest correlations, however, were present with Performance IQ. Finally, the potential for neuropsychological applications of this new test are discussed.

Predictors of outcome following severe head trauma: follow-up data from the traumatic coma data bank

Outcome as a function of employment status or return to school was evaluated in severely head-injured patients. A priori we selected the most salient demographic, physiological, neuropsychological and psychosocial outcome predictors with the aim of identifying which of there variables captured at baseline or 6 months would best predict employability at 6 or 12 months. Based on the patients evaluated at 6 months, 18% of former workers had returned to gainful employment and 62% of former students had returned to school. For those not back to work or school at 6 months, 31% of the former workers and 66% of the former students had returned by 12 months. Age, length of coma, speed for both attending and motor movements, spatial integration, and intact vocabulary were all significantly related to returning to work or school. The three most potent predictors for returning to work or school were intactness of the patients verbal intellectual power, speed of information processing and age.

Self-rating versus neuropsychological performance of moderate versus severe head-injured patients

Head-injured patients frequently appear to be inaccurate in judging their cognitive functioning. To examine this clinical impression, self-ratings were compared with neuropsychological test performances. The sample was comprised of 28 patients with severe and 28 with mild-moderate head injuries, and these two groups were further subdivided according to chronicity, i.e. less than or equal to 1 year versus greater than 1 year between the date of injury and the evaluation. The control group of 31 adults was matched according to age and education. Head-injured patients rated themselves lower than normals regardless of severity of injury. Chronicity affected only the self-rating of learning and memory. The severely head-injured were generally less accurate when comparing self-ratings to test performance. However, this was not uniform across cognitive domains. Recommendations for self-assessment in neuropsychology are discussed.

Motivational Effects on Neuropsychological Functioning: Comparison of Depressed versus Nondepressed Individuals.

The neuropsychology of depression was examined in terms of organic and motivational hypotheses. Thirty medication-free depressed outpatients (selected according to Diagnostic and Statistical Manual of Mental Disorders [American Psychiatric Association, 1980] criteria for major depression) and 30 nondepressed normal controls were evaluated with a variety of neuropsychology measures. Prior to testing, subjects were assigned randomly to either a motivated or nonmotivated condition. A task measuring level of motivation demonstrated efficacy of the two motivation conditions. A 2 x 2 (Diagnosis x Motivational Level) multivariate analysis of variance of all the dependent measures revealed a significant main effect for depression, but no effect for motivation and no interaction. Univariate analyses demonstrated that the depressed group was impaired on visuospatial short-term memory and learning and on verbal learning. The finding of neuropsychological deficit in depressed subjects was not attributable to motivational factors. The problems with conceptualizing depression as a right-hemisphere dysfunction are discussed.

THE RUFF 2 AND 7 SELECTIVE ATTENTION TEST-A NEUROPSYCHOLOGICAL APPLICATION

The neuropsychological application of the Ruff 2 and 7 Selective Attention Test as a measure of visual selective attention was investigated. The instrument was constructed as a paper-and-pencil approach to evaluate sustained attention utilizing different distractor conditions in the study of voluntary or intentional aspects of attention. Four patient groups with cerebral lesions confined to either the right or left anterior or left or right posterior region (ns = 8, 8, 8, 6) were studied. Patients with right-hemispheric lesions showed a greater over-all reduction in processing speed independent of the serial or parallel processing mode in comparison to individuals with left-sided lesions. Furthermore, as predicted, the two groups with anterior brain damage showed a larger discrepancy between serial and parallel processing modes than patients with posterior lesions. Specifically, the right frontal cases showed the greatest differential of accuracy on the serial and parallel tasks.

Selective reminding tests: A normative study of verbal learning in adults

Verbal learning was assessed according to the Selective Reminding Test (SRT) in order to establish normative data and to provide a comparison with measures of immediate attention, verbal IQ, and verbal memory. The 392 subjects, stratified by sex (202 women, 190 men), age (4 groups: 16-70 years), and education (3 groups), were free of conflicting pathologies. Learning curves were established on centiles (75, 50, 25, 5). Sex differences favoring women were found in percent of finishers (those who reached criterion), and at all percentile levels of acquisition. Data were analyzed for group differences in performance on the SRT and related concurrent measures, but sex differences were not found on the VIQ or immediate attention tests. Also, assumptions of age and education stratification were not confirmed. However, those who completed the task were better able to form associational strategies than those who were unable to finish. The present data indicate that it is important to use detailed norms by gender and criterion level if clinical interpretations are to be valid.

The efficacy of structured memory retraining in a group comparison of head trauma patients

Empirically proven mnemonic techniques from the literature were assembled into a comprehensive treatment program for brain injured clients. Twenty head injured subjects with mild to moderate neuropsychological impairments were matched on the variables of age, sex, years of formal premorbid education, and elapsed time since insult. These patients were then randomly assigned to either the control or experimental remediation group. Both groups attended a six-week program and were blind as to what type of treatment they were receiving. Each followed identical daily schedules where the experimental group received the formal memory remediation and the controls received treatment focusing on psychosocial issues. Both groups improved on the neuropsychological memory measures over the course of the study. The experimental group did not improve significantly more than did the control group; however, once the groups were subdivided according to the severity of neuropsychological functioning at intake, significant treatment effects were observed. More specifically, only those patients with mild residual impairments seemed to benefit from rehabilitative efforts, and those with more moderate deficits did not respond to treatment. Clinical implications and future research are discussed.

Cognitive rehabilitation versus day treatment in head-injured adults: Is there an impact on emotional and psychosocial adjustment?

Emotional and psychosocial adjustments are typically the most challenging problems faced by the head injured, but there exists a paucity in research as to how affective problems are best ameliorated. In the present analysis, emotional and psychosocial adjustment were evaluated as part of a study comparing the efficacy of cognitive remediation versus day treatment. Out of 24 head-injured patients, half were randomly assigned into either treatment condition, each conducted 4 days a week over an 8-week span. A more favourable outcome for emotional adjustment was postulated for the day-treatment programme, since it was far more nurturing compared with cognitive remediation, which was thought to be more challenging if not confronting. However, our differential hypothesis for the two treatments was not confirmed, because in both groups there was a lessening of depression as measured by the Katz Adjustment Scale. The need is discussed for providing ongoing structured activities for the head injured in order to facilitate their emotional and psychosocial adjustment.

Construct validity of the San Diego Neuropsychological Test Battery.

A group of 259 normal adults were administered the San Diego Neuropsychological Test Battery. Factor analysis of the SDNB supported the construct validity of the battery according to a Luria-based functional systems assessment approach. Using expert ratings to interpret the obtained factor loadings, the following factors were identified: (a) arousal, (b) mnestic processes, (c) complex intelligence, and (d) planning. A second factor analysis of the SDNB, using a sample of 100 schizophrenic and head injured cases, achieved a factor structure very similar to that of the normal sample, offering further empirical support for a functional assessment approach with clinical populations. The clinical factor analysis yielded slightly different proportions of variance contributed by the test measures and two planning factors. The results are discussed as they relate to Lurias qualitative analysis of cortical organization applied to a quantitative methodology.