Modifiability of neuropsychological dysfunction in schizophrenia.

Schizophrenia is often characterized by compromised neuropsychological functioning, especially on tasks sensitive to frontal and temporohippocampal functions but the extent to which cognitive dysfunction can be modified in schizophrenics remains unclear. Twenty-four inpatient schizophrenics and 24 intellectually and demographically matched, inpatient mood-disordered controls were randomly assigned to one of two conditions. Subjects assigned to the cued condition received instructional cues on measures of visual and semantic memory, executive function, and constructional ability. Subjects in the standard condition performed the same neuropsychological measures without cues. The present study revealed some degree of plasticity of neurobehavioral function in schizophrenia.

Effect of instructional cues on schizophrenic patients' performance on the Wisconsin Card Sorting Test.

OBJECTIVE: Schizophrenic patients are particularly deficient on measures of executive functioning, notably the Wisconsin Card Sorting Test. This study was conducted to determine the efficacy of a cuing strategy in facilitating performance on this cognitive measure of the integrity of prefrontal brain structures and functioning. METHOD: Twenty-four schizophrenic inpatients and 24 demographically matched inpatients with mood disorders were administered the Wisconsin Card Sorting Test either with instructional cues at the beginning of the task or with the standard administration procedure. RESULTS: There was a significant benefit of cues for the patients with affective disorders as well as for the schizophrenic patients. The schizophrenic subjects in the uncued condition maintained poor but stable performance throughout the course of the task. CONCLUSIONS: The study suggests that the deficit in executive functioning of schizophrenic patients may lie in the formation of concepts, not in their application.

Training novice raters on the Negative Symptom Assessment Scale.

The Negative Symptom Assessment (NSA), a scale for rating negative symptoms of schizophrenia, has been shown to have high interrater and test-retest reliabilities as well as high concurrent validity with similar instruments. In this study, the facility of clinicians unfamiliar with the NSA to learn this scale was evaluated. After attending a 30-min training lecture, 27 experienced researchers, who had never previously used the NSA, viewed and rated a videotaped, semi-structured NSA interview of a schizophrenic patient. These ratings were compared with those of an experienced rater. Scores for most items met our criteria for learning with this level of training. These data demonstrate that high levels of agreement with experienced raters can be achieved on the NSA after brief periods of training.

Validation of the 16-item Negative Symptom Assessment.

The dimensional structure of the 16-item Negative Symptom Assessment (NSA-16) was validated in a sample of 223 unmedicated schizophrenic inpatients and cross-validated on an independent sample of 276 patients with schizophrenia. Using a confirmatory factor analytic procedure, a five factor model was found to best characterize the structure of this rating instrument. These factors include: Communication, Emotion/Affect, Social Involvement, Motivation, and Retardation. The latent structure of the NSA-16 is similar to the larger instrument from which it was derived. The findings provide support for a multidimensional model of negative symptoms in schizophrenia and offer a useful measure for their assessment.

Factor structure of the negative symptom assessment.

The factor structure of the Negative Symptom Assessment (NSA), a standardized negative symptoms rating scale, was systematically evaluated in a group of 223 inpatients with schizophrenia. Confirmatory factor analyses found that a six-factor model best described the NSA. More specifically, the domains of Communication, Emotion/Affect, Social Involvement, Motivation, Gross Cognition, and Retardation characterized the rating scale. This latent structure of the NSA is consistent with a multidimensional conceptualization of negative symptoms.

Administration duration for the Wechsler Adult Intelligence Scale-III and Wechsler Memory Scale-III.

The administration times for each of the subtests from the Wechsler Adult Intelligence Scale-III (WAIS-III) and Wechsler Memory Scale-III (WMS-III) were recorded for a clinical sample of 81 patients. The findings revealed that the time needed to administer the WAIS-III subtests to generate the summary scores, index scores, and both scores were 58, 51, and 65 min, respectively. The time required to complete the primary subtests on the WMS-III was 21, 15, and 6 min for Immediate Memory, General Memory, and Working Memory, respectively, resulting in a total administration time of 42 min. The time necessary to administer most of the subtests was unrelated to age, education, or performance level. These data demonstrate a shorter than expected administration time for the WAIS-III and a longer than anticipated administration for the WMS-III. Results for other clinical settings will be impacted by examiner familiarity and patient composition.

Comparing methods for estimating premorbid intellectual functioning.

Efforts to determine premorbid intellectual functioning for a patient prior to their current evaluation has been attempted using demographic information, current performance data, or a combination of both. Five of these premorbid intellectual prediction methods were assessed in a sample of 104 neurological patients referred for neuropsychological evaluation and a matched control sample. Predicted Full-Scale Intelligence Quotient (FSIQ) scores of patients did not differ from the true FSIQ scores of the matched controls. Logistic regression analyses found no difference in classification accuracy among the prediction methods. The findings of this study found combined demographic and performance methods developed by Vanderploeg and Schinka (1995), Vanderploeg, Schinka, and Axelrod (1996), Krull, Scott, and Sherer (1995) and Williamson, Krull, and Scott (1996) to be accurate estimates of premorbid functioning. This study found estimates of premorbid functioning based on demographic data alone (Barona, Reynolds, & Chastain, 1984) not to differ from the other methods, which is at odds with prior studies. Prospective studies employing all of these methods are recommended to clarify the utility of demographically based estimates.

Concurrent validity of the MAE visual naming test.

Deficient confrontation naming has been observed in a number of neurological illnesses, as well as in aphasia and normal aging. The Visual Naming Test (VNT) of the Multilingual Aphasia Examination (MAE) is a standardized measure of confrontation naming. One hundred patients, consecutively referred for neuropsychological evaluation, were administered the VNT, Boston Naming Test (BNT), and WAIS-R. Concurrent validity of the two confrontation naming measures was demonstrated by their high intertest agreement. Performance on the VNT was found to be related to a unique ability separate from general intellectual functioning. Suggestions regarding the clinical use of the VNT are discussed.

Evaluation of seven-subtest short forms of the Wechsler Adult Intelligence Scale-III in a referred sample.

The application of seven-subtest short forms of the Wechsler Adult Intelligence Scale-III (WAIS-3) was evaluated in a sample of 281 mixed clinical patients from three Veterans Affairs Medical Centers. Short-form summary scores were derived from deviation quotient tables and from prorating. They included either Block Design or Matrix Reasoning. Short-form summary scores for Full-Scale IQ (FSIQ) and Verbal IQ (VIQ) demonstrated good alternate-forms reliability with the full WAIS-3 scores, whereas Performance IQ (PIQ) summary scores were less accurate. Short forms derived from deviation quotients and prorating did not differ from each other. However, the inclusion of Matrix Reasoning resulted in somewhat better accuracy with WAIS-3 PIQ than did Block Design. The results of this study support the use of the seven-subtest short form of the WAIS-3 in estimating full WAIS-3 summary scores, especially for FSIQ and VIQ.

WAIS-R verbal-performance IQ discrepancies in persons with lateralized lesions: utility of a seven subtest short form.

WAIS-R Verbal-Performance IQ difference scores for Ward's (1990) seven subtest short form and the complete WAIS-R were examined in patients with lateralized and diffuse lesions. For both versions, the expected Performance > Verbal pattern was observed in the right hemisphere lesion group, while no summary score differences were seen in the left hemisphere group. Verbal-Performance IQ discrepancies for the short form fell within +/- 5 points of the WAIS-R discrepancy scores in about 75%of the cases, regardless of lesion location. Statistically reliable IQ differences between the complete and abbreviated WAIS-R attained 66%, 91%, and 89% agreement for the left, right, and diffuse groups, respectively. The results support the clinical utility of the seven subtest short form.

Construct validity of the WCST in normal elderly and persons with Parkinson's disease.

Separate principle component analyses of the WCST were conducted on 187 normal elderly and 181 persons with Parkinson's disease (PD). Adequate construct validity was found for "conceptualization/problem solving" and "failure to maintain set" factors in both groups. Perseverative and nonperseverative errors were related for the normal group, but not for the PD subjects. This may reflect the frontal systems deficit observed in PD. Additional principle component analyses were conducted with the WCST and measures of memory and attention. In neither the normal nor the PD group did the WCST significantly load with the memory and attention measures. This suggests that the WCST provides information about problem solving relatively independent of memory and attention functions for elderly persons.

Application of the Postconcussive Syndrome Questionnaire with medical and psychiatric outpatients.

The Postconcussive Syndrome Questionnaire (PCSQ; Lees-Haley, 1992) was previously found (Axelrod, Fox, Lees-Haley, Earnest, Dolezal-Wood, & Goldman, 1996) to produce four factors, named Psychological, Somatic, Cognitive, and Infrequency. These four factors of the questionnaire were evaluated across five groups of medical and psychiatric outpatients. The patients were from neurology, mental health, family practice, and internal medicine clinics as well as from a clinic that evaluated new patients to a health maintenance organization. Mental health patients had greater psychological symptoms and fewer health concerns than the other groups. Neurology patients differed from the other groups by having greater Infrequency symptoms. Patients who were referred for their screening evaluation or were seen by internal medicine had fewer overall symptoms than the other three patient groups. The data from this study provide support for the use of the PCSQ as a multifactorial self-report measure of symptom presentation.

Parsimonious prediction of Wechsler Memory Scale--III memory indices.

Equations for prorating the Wechsler Memory Scale--III (WMS-III) Index scores were derived and validated on a sample of 252 mixed clinical cases. Regression equations were performed using age-scaled scores as predictors and the sum of age-scaled scores for Immediate Memory (IM) and General Memory (GM) as the criteria. Including Logical Memory and Verbal Paired Associates with either Faces or Family Pictures resulted in estimated scores that accounted for 95% to 97% of the variance for IM and GM. Over 80% of these cases had estimated sum of scaled scores that fell within 3 points of actual sum of scaled scores, within 1 standard error of measurement. When only Logical Memory and Verbal Paired Associates were included, estimations accounted for only 87% of the variance, and only 60% of the estimated scores fell within 3 points of actual sum of scaled scores. The regression equations are presented, as are the confidence intervals derived from a bootstrapping procedure that created 15,000 different samples.

Estimating Full Scale IQ While Minimizing the Effects of Practice.

The present study attempted to ascertain the best estimate of true Wechsler Adult Intelligence Scale-Revised (WAIS-R) Full Scale IQ (FSIQ) when confronted with an individual who recently had been administered the WAIS-R. Sixty-five college undergraduate participants were administered the WAIS-R twice within 14 days. WAIS-R summary scores, factor scores, and short-form estimates obtained from the second assessment were compared to FSIQ at the first evaluation. The results indicated that Verbal IQ, the Verbal Comprehension factor score, and subtracting 6 points from the current FSIQ are the least affected by repeat assessment and the most accurate estimates of FSIQ at the first evaluation. Use of these estimates of FSIQ are encouraged when evaluating an individual who has been administered the WAIS-R in the recent past.

Cross-validation of prediction equations for Wechsler Memory Scale-III Indexes.

Six prediction equations were previously found to predict to Wechsler Memory Scale-III (WMS-3) Immediate Memory Index (IM) and General Memory Index (GM) using two- or three-subtest combinations. The equations were cross-validated on a sample of 214 mixed clinical patients from an entirely different location in the Midwest. The two three-subtest prediction equations (including Logical Memory, Verbal Paired Associates, and either Faces or Family Pictures) better estimated IM and GM than did the two-subtest equations (Logical Memory and Verbal Paired Associates). Correlations for the former equations correlated .97 and .96 with full WMS-3 IM and GM, respectively. In addition, at least 95% of the predicted scores were within two SEMs of obtained IM and GM scores. The two-subtest equations correlated only .89 for IM and .92 for GM. The predicted scores that fell within two SEMs captured 78% and 88% of the cases for IM and GM, respectively. The results provide support for the use of the three-subtest prorated forms of the WMS-3 to estimate IM and GM.

Observations on the factor structure of the WAIS-R.

Confirmatory factor analyses (CFAs) revealed 2 important characteristics of the standardization data of the Wechsler Adult Intelligence Scale Revised. One finding was that Digit Symbol fit better on an attentional factor in younger groups, but fit was better when Digit Symbol loaded on a visual-perceptual factor in older groups. A second observation was that specifying correlated errors or a fourth factor to explain covariance between Block Design and Object Assembly improved model fit in all age groups except 70- to 74-year-olds. The results illustrate the value of CFA and have implications for investigating other samples and other Wechsler tests.

Effects of practice in repeated administrations of the Wechsler Memory Scale Revised in normal adults.

Practice effects were examined over four administrations of the immediate (I) and delayed (II) portions of three subtests of the WMS-R: Logical Memory (LM), Verbal Paired Associates (VPA), and Visual Reproduction (VR). A repeated measures ANOVA revealed that large and significant (p < .001) increases occurred in the General Memory (GM) and Delayed Recall (DR) indices and in the LMI, LMII, and VPAI subtests (Effect Sizes [ESs] = 0.70-0.87). Small but significant (p < .001) increases occurred in VRI (ES = 0.24) and VRII (ES = 0.43). The greatest increase in scores occurred at the first retest session, whereas increases of smaller magnitudes occurred at Sessions 3 and 4. Ceiling effects occur in subtests (VPAII, VRI, and VRII) on which individuals score most of the total possible points at the first testing session; this makes interpretation of practice effects difficult. Test-retest reliability coefficients, mean change scores from Session 1 to Session 2, standard errors of prediction, and 95% confidence intervals are presented. These score changes need to be taken into consideration when interpreting performance at retest.

Estimation of Wechsler Adult Intelligence Scale-III index scores with the 7-subtest short form in a clinical sample.

A 7-subtest short form of the Wechsler Adult Intelligence Scale-III (WAIS-III) previously demonstrated good comparability in estimating Full Scale and Verbal IQ summary scores, with adequate comparability in estimating Performance IQ. In a mixed clinical sample of 295 patients, the current study assessed the equivalence of the index scores generated from the full and prorated WAIS-III. The results revealed correlations corrected for redundancy of .90, .86, .87, and .75 for the Verbal Comprehension (VCI), Perceptual Organization (POI), Working Memory (WMI), and Processing Speed (PSI) indexes, respectively. Although the 7-subtest short form of the WAIS-III was not designed to estimate index scores, adequate estimates are viable for VCI, POI, and WMI when the goal is to obtain group, rather than individual, data points.

Minnesota Multiphasic Personality Inventory-2 validity patterns: an elucidation of Gulf War syndrome.

The potential effects of psychological distress on physical symptoms observed in Persian Gulf War veterans were evaluated in 48 veterans using neuropsychological evaluation that included personality assessment (the Minnesota Multiphasic Personality Inventory-2). Cluster analysis of the validity scales resulted in a solution with two viable subgroups. Members of cluster 1 had significantly higher scores on five Minnesota Multiphasic Personality Inventory-2 clinical scales, a measure of trait anxiety, and a number of subjective complaints, as well as lower scores on a task of attention. Neuropsychological functioning did not otherwise differ between the groups, Contributions of personality style in coping with physical and mental health stressors were indicated. Experience of distress appeared to be attributable to individual differences rather than factors that have been associated with the elusive Gulf War syndrome. Persian Gulf War veterans' emotional reactions to clinical laboratory findings, perceptions of exposure risks, war experience, and stress may represent a variation of post-traumatic stress disorder.

Cognitive and motor deficits in selected unilateral brain-injured patients.

16 right hemisphere and 16 left hemisphere, nonaphasic brain-injured stroke patients were compared with 16 matched normal controls on the verbal and visuospatial paired-associate tasks developed by Stark in 1961 as a partial replication to a more severely impaired population. Right brain-injured patients showed a significant visuospatial deficit and contralateral motor impairment; while left brain-injured patients, screened for aphasia, showed contralateral motor impairment but did not show impairment on the verbal task. Examination of the areas of infarct resulting from the cerebrovascular accident in the left-hemisphere patients suggested that the presence of a contralateral motor deficit without verbal impairment results from specific focal occlusions of branches of the middle cerebral artery in this selective group of patients.