Interpreting change on the WAIS-III/WMS-III in clinical samples.

Clinicians should note that there is considerable variability in the reliabilities of the index and subtest scores derived from the third editions of the Wechsler Adult Intelligence Scale (WAIS-III) and the Wechsler Memory Scale (WMS-III). The purpose of this article is to review these reliabilities and to illustrate how they can be used to interpret change in patients' performances from test to retest. The WAIS-III IQ and Index scores are consistently the most reliable scores, in terms of both internal consistency and test-retest reliability. The most internally consistent WAIS-III subtests are Vocabulary, Information, Digit Span, Matrix Reasoning, and Arithmetic. Information and Vocabulary have the highest test-retest reliability. On the WMS-III, the Auditory Immediate Index, Immediate Memory Index, Auditory Delayed Index, and General Memory Index are the most reliable, in terms of both internal consistency and test-retest reliability. The Logical Memory I and Verbal Paired Associates I subtests are the most reliable. Data from three clinical groups (i.e., Alzheimer's disease, chronic alcohol abuse, and schizophrenia) were extracted from the Technical Manual [Psychological Corporation (1997). WAIS-III/WMS-III Technical Manual. San Antonio: Harcourt Brace] for the purpose of calculating reliable change estimates. A table of confidence intervals for test-retest measurement error is provided to help the clinician determine if patients have reliably improved or deteriorated on follow-up testing.     

Comparison of the Peabody Picture Vocabulary Test-Third Edition and Wechsler Adult Intelligence Scale-Third Edition with university students

This study examined the relationship between the Peabody Picture Vocabulary Test-Third Edition (PPVT-III) and Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) using 40 adults who ranged in age from 18 to 41 (mean age of 22 years). Participants were administered the PPVT-III and WAIS-III in counterbalanced fashion to control for order effects. Results revealed that the PPVT-III score was related to the WAIS-III Verbal IQ (VIQ) and Full Scale IQ (FSIQ) scores but unrelated to the Performance IQ (PIQ) score. In addition, analyses indicated that, while there were no significant differences between the PPVT-III score and WAIS-III mean FSIQ and PIQ scores, the PPVT-III mean score was significantly lower than the WAIS-III VIQ. Further analysis indicated that the PPVT-III adequately estimated WAIS-III FSIQ and VIQ scores for participants who were classified as Average or High Average on the WAIS-III. However, for participants in the Superior range, the PPVT-III tended to underestimate FSIQ and VIQ scores by approximately 10 points.     

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.     

The relationship between premorbid intelligence and symptoms of severe anorexia nervosa restricting type

The purposes of this study were as follows: to compare premorbid IQ with present IQ in patients with more severe anorexia nervosa restricting type (AN-R) and to investigate the relationship between decreasing IQ and symptoms in patients with severe AN-R. Twenty-two participants were recruited (12 were AN-R patients; 10 were healthy controls). The average BMI in AN-R patients and healthy controls was 12.65 and 19.82, respectively. We assessed the outcomes using the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III), the Japanese Adult Reading Test, The Eating Disorders Inventory-2 (EDI-2), Beck Depression Scale-2 (BDI-2) and State-Trait Anxiety Index. In two-way ANOVA, there were significant interactions for the FIQ and PIQ. Only in the AN-R group, a significant single main effect of time was evidenced for the FIQ and PIQ. In the AN-R group, a significantly high positive correlation was found between changes in the PIQ and the body dissatisfaction subscale of the EDI-2. These findings raise the possibility that in patients with severe AN-R, an excessive decrease in body weight induces decreased PIQ; as a result, they have worse dissatisfaction with their body shape.     

Detecting malingering on the WAIS-III. Unusual Digit Span performance patterns in the normal population and in clinical groups.

In several studies, suppressed Digit Span performance has been proposed as a potential marker for deliberately poor performance in a neuropsychological evaluation. The purpose of this study was to document Digit Span performance patterns in the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III; ) standardization sample and selected clinical groups. Base rate tables were generated for the Digit Span scaled score, longest span forward, longest span backward, and the Vocabulary-Digit Span difference score. Cut-off scores for suspecting negative response bias were proposed, and clinical case examples were used to illustrate these scores.     

Wechsler Adult Intelligence Scale-III inter-subtest scatter: a comparison of brain-damaged patients and normal controls

This study assessed the validity of Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) inter-subtest scatter (as measured by the scaled score range) as an indication of cognitive impairment due to brain dysfunction. Participants were 174 individuals with documented brain damage. Means for age, education, and WAIS-III full-scale IQ were 49.19 years (SD = 15.33), 12.57 years, (SD = 2.78), and 88.45 (SD = 17.78). The scatter ranges for brain-damaged participants were compared with those of the WAIS-III standardization sample. Results indicated that the full-scale IQ is significantly correlated with amount of scatter, r(172) = .42, p < .0001, so that a definitive answer to the question requires control of full-scale IQ. In the present analyses, inter-subtest scatter among the individuals for the sample as a whole was no greater than that for persons in the standardization sample, but subtest scatter was significantly greater for participants with IQs > or = 90. This finding suggests that there may be small differences in scatter between brain-damaged persons and normal controls, but that scatter is relatively insensitive to the presence of brain damage or dysfunction. Therefore, interpretation of marked inter-subtest variability as a sign of brain damage appears unwarranted.     

Superior temporal gyrus, language function, and autism

Deficits in language are a core feature of autism. The superior temporal gyrus (STG) is involved in auditory processing, including language, but also has been implicated as a critical structure in social cognition. It was hypothesized that subjects with autism would display different size-function relationships between the STG and intellectual-language-based abilities when compared to controls. Intellectual ability was assessed by either the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) or Wechsler Adult Intelligence Scale-Third Edition (WAIS-III), where three intellectual quotients (IQ) were computed: verbal (VIQ), performance (PIQ), and full-scale (FSIQ). Language ability was assessed by the Clinical Evaluation of Language Fundamentals-Third Edition (CELF-3), also divided into three index scores: receptive, expressive, and total. Seven to 19-year-old rigorously diagnosed subjects with autism (n = 30) were compared to controls (n = 39; 13 of whom had a deficit in reading) of similar age who were matched on education, PIQ, and head circumference. STG volumes were computed based on 1.5 Tesla magnetic resonance imaging (MRI). IQ and CELF-3 performance were highly interrelated regardless of whether subjects had autism or were controls. Both IQ and CELF-3 ability were positively correlated with STG in controls, but a different pattern was observed in subjects with autism. In controls, left STG gray matter was significantly (r = .42, p ≤ .05) related to receptive language on the CELF-3; in contrast, a zero order correlation was found with autism. When plotted by age, potential differences in growth trajectories related to language development associated with STG were observed between controls and those subjects with autism. Taken together, these findings suggest a possible failure in left hemisphere lateralization of language function involving the STG in autism. Superior Temporal Gyrus, Language Function, and Autism     

A Retrospective Neurocognitive Study in Children With Spastic Diplegia

The study presents the results on neonatal cranial ultrasonography (US) and later intelligence (Wechsler Intelligence Scale-Third Edition and Wechsler Preschool and Primary Scale of Intelligence-Revised) and Neuropsychological assessments of 15 children with spastic diplegia. The assessments were undertaken when the children were 5 to 12 years of age. The children's IQ scores were, as a group, at the lower end of the normal distribution. The neuropsychological assessment indicated that deficits in visuomotor and visuospatial processing were characteristic of the children. No association was found between the neonatal cranial US findings and the IQ and neurocognitive scores. However, the cranial US findings strongly predicted functional motor limitations of the children.     

A retrospective neurocognitive study in children with spastic diplegia

The study presents the results on neonatal cranial ultrasonography (US) and later intelligence (Wechsler Intelligence Scale-Third Edition and Wechsler Preschool and Primary Scale of Intelligence-Revised) and Neuropsychological assessments of 15 children with spastic diplegia. The assessments were undertaken when the children were 5 to 12 years of age. The children's IQ scores were, as a group, at the lower end of the normal distribution. The neuropsychological assessment indicated that deficits in visuomotor and visuospatial processing were characteristic of the children. No association was found between the neonatal cranial US findings and the IQ and neurocognitive scores. However, the cranial US findings strongly predicted functional motor limitations of the children.     

Utility of a clinically derived abbreviated form of the WAIS-III

The Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) often poses problems for many populations due to the length of administration. Twenty geriatric subjects were administered the full WAIS-III. Three abbreviated forms of the WAIS-III (Satz-Mogel abbreviation; seven-subtest short form; and a clinically derived abbreviation) were evaluated by rescoring original full WAIS-III protocols. Results showed that the abbreviated WAIS-III protocols were highly correlated with complete protocols, and classification rules were the highest for the clinically derived abbreviation. The clinically derived abbreviation was reevaluated in a college LD/ADHD population yielding similarly high correlations. Results support the use of abbreviated forms of the WAIS-III in the evaluation of elderly patients and young adults, and point to the clinically derived abbreviation as providing the smallest discrepancies from FSIQ.     

Validity of two selected-item short forms of the WAIS-III in an intellectually deficient sample

Various short forms of the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III; D. Wechsler, 1997) have been investigated, but limited information is available regarding the usefulness of any WAIS-III abbreviation with intellectually deficient individuals. Our study compared the validities of two WAIS-III selected-item short forms in a sample of 59 individuals with full scale IQs (FSIQs) of 79 or lower. The performance of both short forms was adequate, but the results gave a consistent edge to an adapted version of the Satz-Mogel (1962) short form in comparison to the abbreviated form by J. H. Wymer, K. Rayls, and M. T. Wagner (2003). The correlation (r = .98) of Satz-Mogel estimates with WAIS-III FSIQ scores was slightly higher than the correlation (r = .97) for estimates from Wymer et al.'s abbreviated form, and Satz-Mogel estimates did not differ significantly from actual FSIQs. In comparison to individual classification (FSIQ > 70 versus FSIQ < or = 70) obtained with the full WAIS-III, the misclassification rate was somewhat lower for the Satz-Mogel short form. Although both short forms performed reasonably well, practitioners should be cautious when utilizing any short form to make decisions about individuals.     

Estimating the percentage of the population with abnormally low scores (or abnormally large score differences) on standardized neuropsychological test batteries: a generic method with applications

Information on the rarity or abnormality of an individual's test scores (or test score differences) is fundamental in interpreting the results of a neuropsychological assessment. If a standardized battery of tests is administered, the question arises as to what percentage of the healthy population would be expected to exhibit one or more abnormally low test scores (and, in general, j or more abnormally low scores). Similar issues arise when the concern is with the number of abnormal pairwise differences between an individual's scores on the battery, or when an individual's scores on each component of the battery are compared with the individual's mean score. A generic Monte Carlo simulation method for tackling such problems is described (it requires only that the matrix of correlations between tests be available) and is contrasted with the use of binomial probabilities. The method is then applied to Index scores for the Wechsler Adult Intelligence Scale--Third Edition (WAIS-III; D. Wechsler, 1997) and Wechsler Intelligence Scale for Children--Fourth Edition (WISC-IV; D. Wechsler, 2003). Three computer programs that implement the methods are made available.     

Prorating Wechsler Adult Intelligence Scale-III summary scores

The application of the nine-subtest prorated version of the Wechsler Adult Intelligence Scale-III (WAIS-III) in estimating Verbal, Performance, and Full-Scale IQ scores was evaluated in a sample of 278 mixed clinical patients from two Department of Veterans Affairs Medical Centers. The composite reliabilities of the three prorated summary scores, which excluded Comprehension and Picture Arrangement, did not differ from reliabilities from the full WAIS-III. All three prorated IQ summary scores demonstrated good alternate forms reliability with the standard WAIS-III summary scores. Verbal Performance discrepancy scores were accurate for 86% of the cases. The results of this study appear to support the regular use of prorated WAIS-III summary scores in estimating full WAIS-III summary scores. The benefit of this system is that by giving all of the subtests required for the index scores, not only are the index scores derived, but a very close estimation of the summary scores are generated.     

Quantitative measures of memory malingering on the Wechsler Memory Scale--Third edition in mild head injury litigants.

Wechsler Memory Scale-Third edition (WMS-III) performance in 25 mild traumatic brain injury (TBI) litigants who met the criteria for probable malingered neurocognitive dysfunction (MND) was compared with 50 nonmalingering subjects. The base rate for probable MND in the population studied was 27%. Overall, malingerers showed globally depressed memory function. They returned significantly poorer scores than nonmalingerers on all WMS-III indexes and subtests, and on selected WMS-III index difference scores and intelligence-memory difference scores. Using the minimum score returned in the nonmalingerers as the cut-off for malingering, the delayed auditory recognition memory tasks were highly effective in detecting malingering. Raw scores below 43 on the auditory recognition-delayed (AR-D) subtest or below 18 on word list II-recognition, identified around 80% of the malingerers. In a group of 50 severe TBI litigants, only a very small proportion (i.e., <10%) returned scores below the cut-offs for malingering for the mild TBI subjects.     

The estimation of premorbid intelligence levels among Portuguese speakers: the Irregular Word Reading Test (TeLPI)

Information regarding cognitive abilities in earlier stages of life is essential to ascertain if and to what extent these may have declined. When unavailable, clinicians rely on estimate methods. One of the contemporary methods used worldwide combines performance on irregular word reading test with demographics since it has shown to provide reliable estimates of premorbid ability. Hence, a reading test portuguese irregular word reading test (TeLPI) was developed, filling an important gap in the neuropsychological evaluation of Portuguese speakers. Using 46 irregular, infrequent Portuguese words, TeLPI was validated against Wechsler Adult Intelligence Scale (WAIS)-III (N = 124), and regression-based equations were determined to estimate premorbid IQ considering TeLPI scores and demographic variables. TeLPI scores accounted for 63% of the variance of WAIS-III Full-Scale IQ, 62% of Verbal IQ, and 47% of Performance IQ and thus were considered valid for premorbid intelligence estimation.     

Ethnic and sex differences on the test of nonverbal intelligence, Quick Test of intelligence, and Wechsler Intelligence Scale for Children-Revised

This study investigated the performance of 89 students on the Test of Nonverbal Intelligence, Quick Test, and Wechsler Intelligence Scale for Children-Revised IQ scores for ethnic and sex differences. The sample consisted of 61 males, 28 females (37 Black, 52 White). A two-way analysis of variance and the new Duncan's Multiple Range Test were used to identify significant differences between the mean scores. The findings did not indicate any significant differences between the IQ scores with regard to ethnicity or sex. Implications of these findings are discussed in terms of assessing minority group members with the Wechsler Intelligence Scale-Revised, Test of Nonverbal Intelligence, and Quick Test.     

Comparison of the Kaufman Brief Intelligence Test and the Wechsler Intelligence Scale for Children-Third Edition in economically disadvantaged African American youth

The Kaufman Brief Intelligence Test (K-BIT; Kaufman & Kaufman, 1990) and the Wechsler Intelligence Scale for Children-Third Edition (WISC-III; Wechsler, 1991) are compared in 35 economically disadvantaged African American youth presenting for treatment in a community mental health setting. Significant correlations were found between K-BIT Composite and WISC-III Full Scale IQ scores. Results revealed significant differences between K-BIT and WISC-III scores; K-BIT Composite and Matrices mean scores were found to be 6 and 11 points higher than respective WISC-III Full Scale IQ and Performance IQ mean scores. No significant differences were obtained between K-BIT Vocabulary and WISC-III Verbal IQ scores. Our findings support the authors' recommendations for use of the Matrices subtest alone with African American youth from economically disadvantaged backgrounds (Kaufman & Kaufman, 1990).     

Speed and memory in the WAIS-III Digit Symbol--Coding subtest across the adult lifespan.

The primary role of speed in determining Digit Symbol scores is well established. Among the important questions that remain to be resolved are: (1) whether speed accounts for all of the age-related decline in Digit Symbol scores, and (2) whether memory ability makes any significant contribution to Digit Symbol performance, especially after controlling for speed. We analyzed data from the WAIS-III/WMS-III standardization sample to resolve these issues. As expected, speed (Digit Symbol-Copy) correlated very strongly with Digit Symbol--Coding. Memory (Digit Symbol--Incidental Learning or WMS-III index scores) correlated more moderately with Digit Symbol-Coding. Even after controlling for variance in Coding explained by Copying, a statistically significant proportion of the residual variance was explicable in terms of memory functions. The contribution of memory to Digit Symbol--Coding, while relatively small, is real. In addition, a small portion of the age-associated decline in Coding scores cannot be accounted for by Copying scores.     

The Guide to the Assessment of Test Session Behavior: Validity in Relation to Cognitive Testing and Parent-Reported Behavior Problems in a Clinical Sample

Examined the validity of the Guide to the Assessment of Test Session Behavior (GATSB) in a clinical sample. The GATSB is a structured and standardized measure that was normed on the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) standardization sample. The purpose of this study was to extend validity research on the GATSB to cognitive measures other than the WISC-III and to parent-reported child behavior problems. Test observations were taken for 122 children ages 6 to 16 years who were referred to an outpatient psychology clinic for psychoeducational evaluations. GATSB scores demonstrated a moderate relation with general indexes from the WISC-III, the Woodcock-Johnson Psychoeducational Battery-Revised (WJ-R), and the Wide Range Assessment of Memory and Learning (WRAML), but displayed low magnitude correlations with the Child Behavior Checklist (CBCL). These results expand existing data supporting the validity of the GATSB and suggest that it may be fruitfully adopted into a clinic setting.     

MMPI-2 indices of psychological disturbance and attention and memory test performance in head injury

A number of studies have investigated the relationship between psychological disturbance and neuropsychological (NP) test performance. The current study is a replication and extension of who found that MMPI-2 indices of psychological disturbance are related to performance on NP tests of attention and memory in psychiatric and head-injured patients. In a large sample (N=381) referred for evaluation after sustaining presumed head injury, we examined the relationship between MMPI-2 indices of psychological disturbance and measures of attention and memory from the Wechsler Memory Scale-Revised (WMS-R), Wechsler Adult Intelligence Scale-Revised (WAIS-R), California Verbal Learning Test (CVLT), and the Memory Assessment Scales (MAS). Although related to other domains, MMPI-2 variables were most consistently related to measures of attention and List Learning. Even when demographic variables, injury severity, and litigation status were controlled, MMPI-2 indices significantly predicted performance on six out of eight tests. However, the correspondence between similar indices on the WMS-R and MAS were relatively low, especially for Verbal Memory and Visual Reproduction. Further, litigation was significant in predicting only 2 of 8 attention and memory indices.