Bradley N. Axelrod

Validity of the Wechsler abbreviated scale of intelligence and other very short forms of estimating intellectual functioning.

Performance on the Wechsler Adult Intelligence Scale—III (WAIS-III) was compared to performance on the Wechsler Abbreviated Scale of Intelligence (WASI), as well as short form estimations of intellectual functioning derived from WAIS-III performance, in a mixed clinical sample of 72 participants. The WASI verbal IQ (VIQ) score was significantly higher than the WAIS-III VIQ, whereas performance IQ (PIQ) estimates all differed from actual WAIS-III PIQ and full scale IQ (FSIQ). Correlations of WAIS-III scores with WASI scores were consistently lower than were correlations between the WASI-III and all other short forms. Although maintaining administration times of 15 minutes for a two-subtest FSIQ and 30 minutes for a four-subtest FSIQ, the WASI did not consistently demonstrate desirable accuracy in predicting scores obtained from the WAIS-III. The results suggest that clinicians should use the WASI cautiously, if at all, especially when accurate estimates of individuals’WAIS-III results are needed.

Detecting Incomplete Effort with Digit Span from the Wechsler Adult Intelligence Scale—Third Edition

The current study evaluated the utility of the Digit Span subtest in discriminating patients with mild head trauma from individuals referred for independent neuropsychological evaluation with objective evidence of poor effort. Various indices from the Digit Span subtest were evaluated to determine the best discriminator of brain injury from poor motivation patient groups: Digit Span Forward, Digit Span Backwards, Reliable Digit Span, Digit Span Age-Corrected Scaled Score, and the difference score between the Vocabulary and Digit Span scaled scores. The Digit Span scaled score was found to be the best discriminating index. A cutoff score of less than or equal to 7 accurately classified 75% of persons in the incomplete effort group and 69% of persons in the TBI group. Application of this cutoff score to a non-litigating mild brain injury group yielded a 77% correct classification rate. However, Digit Span scaled score accounted for a modest amount of variation and it is not recommended as a stand-alone validity measure.

Full scale IQ as mediator of practice effects: The rich get richer

Abstract Differential effects of practice over four administrations of the WAIS-R were examined as a function of Full Scale IQ at initial testing (N = 36). Twelve education-matched normal adults represented each of three groups: Low-Average (80—90), Average (95—105), and High-Average (110—120) Full Scale IQ. Participants were tested at 2-week intervals. Repeated measures analysis of variance indicated that Average and High-Average groups made greater gains across retest intervals than did the Low-Average group (p < .002). Across groups, gains were greater at the first retest than at the second or third retest (p < .001). A Scale × Time interaction indicated disproportionate gain in Performance IQ versus Verbal IQ, particularly at the first retest (p < .001). Previous exposure to the WAIS-R dramatically alters performance: Traditional interpretations regarding expected gain and profile analysis are not valid at retest.

Analysis of an Oral Paradigm for the Trail Making Test

Performance on the Trail Making Test is dependent upon multiple factors (e.g., motor speed, visual search, symbolic set shifting, capacity to sustain effort), many of which are difficult to assess differentially using the tests traditional administration, or with certain clinical populations (e.g., blind or grossly motor-impaired individuals). The present study investigated a motor-free, vision-free, oral version of the Trail Making Test in two groups of younger adults and one group of elderly adults. The results demonstrated that although there were age-associated differences in raw performance times, the comparability of oral and written performances, as assessed by oral-to-written ratios, was consistent across age groups. These results suggest that the oral version of the Trail Making Test yields results consistent with an individuals written performance in normal subjects, regardless of age. Findings are discussed with regard to the potential clinical application of this measure as an alternative for specific populations, and as a useful way of interpreting written Trail Making performances.

Embedded Symptom Validity Tests and Overall Neuropsychological Test Performance

A sample of 314 consecutive clinical and forensic referrals with mild traumatic brain injury was evaluated using the Meyers Neuropsychological Battery (MNB). A comparison was made of the test performance and performance on the embedded Symptom Validity Tests (SVTs) with a control for multicolinearity utilized. Using the nine embedded SVTs in the MNB, the incidence of poor effort fell at 26% of the total sample. Involvement in litigation was related to more failures on the individual SVTs. The correlation between failed effort measures and the Overall Test Battery Mean (OTBM) was consistently negative, regardless of litigation status, in that more failures were associated with lower OTBM scores. The correlation between the number of SVTs failed and the OTBM was -.77. Our results are similar to those presented by Green, Rohling, Lees-Haley, and Allen (2001); who reported a .73 correlation with the failure on the Word Memory Test and performance on the OTBM. The results of the current study also indicate that 50% of the variance in neuropsychological testing can be accounted by failures on internal SVTs.

Age-related performance on the Wisconsin card sorting, similarities, and controlled oral word association tests

Abstract Clinical psychologists and neuropsychologists are frequently called upon to assist other health professionals in distinguishing normal age-related cognitive changes from abnormal neurocognitive changes likely to be associated with pathological processes of the aging brain. Such distinctions are made more difficult in the absence of normative data from clinical tests considered sensitive to normal age-related changes. Three tests of conceptualization skills, the Wisconsin Card Sorting Test (WCST), Similarities from the WAIS-R (WAIS-R-SML), and the Controlled Oral Word Association Test (COWAT), were given to 80 healthy independently living individuals, ages 50 through 89 years, grouped into four age decades. Results revealed a progressive age-related decline in performance on these tasks. Changes in these executive functioning skills were found to be unrelated to intellectual competence, educational experience, or the general health status of the participants.

Discriminability of the Wisconsin Card Sorting Test using the standardization sample.

The four neurological patient groups and the normals from the Wisconsin Card Sorting Test (WCST) standardization sample were used to examine the discriminability of the WCSTs indices. Results reveal consistent differentiation of normals from the patient groups on all WCST variables, with classification rates averaging 71% accuracy. However, patient groups with frontal, diffuse, and nonfrontal lesions were not consistently discriminable from each other. The results suggest that the WCST is most usefully conceptualized as a measure of executive abilities that involves the frontal lobes, but should not be considered solely as a marker of isolated frontal lobe pathology.

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.

Utility of a Wisconsin card sorting test short form in persons with Alzheimer's and Parkinson's disease

The utility of administering only the first deck of 64 cards from the Wisconsin Card Sorting Test (WCST-64) in persons with Alzheimers (AD) and Parkinsons disease (PD) was evaluated. There were 35 elderly subjects matched for gender, age, and education in each of four groups: controls, PD without dementia (PDN), PD with dementia (PDD), and AD. Additionally, the control and PDN subjects were matched for level of cognitive functioning as were the PDD and AD groups. Results revealed that demented persons performed significantly worse than nondemented subjects. The WCST-64 was also sensitive to the subtle executive deficits demonstrated by persons with PD without dementia. The findings support the use of the WCST-64 in elderly persons with AD and PD.

Neuropsychological Prediction of Treatment Efficacy and One-Year Outcome in Schizophrenia

The present study was conducted to establish the degree of interrelationship between neuropsychological functioning in the acute phase of the schizophrenic illness, clinical measures of treatment response (positive and negative symptoms), and 1-year outcome. Nineteen SADS/RDC schizophrenic inpatients were clinically rated during a 2-week drug washout period and again following 4 weeks of neuroleptic treatment. The findings revealed that reduced attentional ability in the baseline phase significantly predicted the presence of higher residual negative symptoms following 4 weeks of treatment, while neurocognitive status was unrelated to positive symptom response. With respect to prediction of the 1-year outcome, poor functional status of this schizophrenic population was significantly associated with the presence of baseline memory dysfunction.