Neuropsychological information in the Wechsler Adult Intelligence Scale-Revised.

The relationships among Wechsler Adult Intelligence Scale-Revised profiles (WAIS-R), Luria-Nebraska Neuropsychological Battery (LNNB) profiles and Halstead Retian Neuropsychological Battery (HRNB) profiles were examined in two samples of patients referred for neuropsychological evaluation. Canonical correlation analysis suggested that the average level of WAIS-R profiles was related to the average level and scatter of LNNB profiles, Overall performance on the HRNB was less strongly related to overall performance on the WAIS-R than was the LNNB. Patients who were similar to a WAIS-R modal profile characterized by relative deficits on performance subtests were more likely to be similar to LNNB modal profiles characterized by relative impairments on sensorimotor subtests. Patients who were similar to a WAIS-R modal profile characterized by relative deficits on verbal subtests were more likely to be similar to LNNB modal profiles characterized by relative impairments on either language subtests or conceptual subtests. Patients classified into an HRNB profile type characterized by strengths on the Aphasia Screening subtest were more likely to show strengths on WAIS-R verbal subtests. However, less than 8 % of the total samples could be jointly classified into both the requisite WAIS-R profile clusters and one of the associated LNNB or HRNB profile clusters. WAIS-R subtest profile level may be a useful statistic to screen for neuropsychological deficits, but WAIS-R patterns are essentially useless for neuropsychological screening. Discussion focuses on the role of the WAIS-R in neuropsychological evaluations.     

The recognition of facial affect in autistic and schizophrenic subjects and their first-degree relatives

BACKGROUND: Autism and schizophrenia are considered to be substantially influenced by genetic factors. The endophenotype of both disorders probably also includes deficits in affect perception. The objective of this study was to examine the capacity to detect facially expressed emotion in autistic and schizophrenic subjects, their parents and siblings. METHOD: Thirty-five subjects with autism and 102 of their relatives, 21 schizophrenic subjects and 46 relatives from simplex (one child affected) and multiplex (more than one child affected) families, as well as an unaffected control sample consisting of 22 probands completed a 50-item computer-based test to assess the ability to recognize basic emotions. RESULTS: The autistic subjects showed a poorer performance on the facial recognition test than did the schizophrenic and the unaffected individuals. In addition, there was a tendency for subjects from multiplex families with autistic loading to score lower on the test than individuals from simplex families with autistic loading. Schizophrenic subjects and their relatives as well as siblings and parents of autistic subjects did not differ from the sample of unaffected subjects in their ability to judge facial affect. CONCLUSIONS: Findings corroborate the assumption that emotion detection deficits are part of the endophenotype of autism. In families with autistic children, the extent of facial recognition deficits probably indexes an elevation in familial burden. It seems unlikely that problems in emotion perception form a consistent part of the endophenotype of schizophrenia or the broader phenotype in relatives of patients with psychosis or autism.     

The reliability of score differences on the WAIS,WISC-R,and WAIS-R

Analyzed data from the WAIS, WISC-R, and WAIS-R manuals to determine the reliabilities of the differences between Verbal and Performance IQs, of subtest comparisons, and of differences between subtest and IQ scores. The differences between the Verbal and Performance IQs were moderately reliable: 0.76 (WAIS and WISC-R) and 0.81 (WAIS-R). The means of the reliability coefficients of the differences between the 55 pairs of subtests were appreciably lower: 0.58 (WAIS), 0.62 (WISC-R), and 0.65 (WAIS-R). The most consistently reliable subtest differences were between Block Design and Vocabulary and the least reliable differences between Block Design and Object Assembly. The means of the reliability coefficients of the differences between subtest scores and the Full Scale IQs were 0.53 (WAIS), 0.58 (WISC-R), and 0.62 (WAIS-R). It was concluded that caution should be exercised when interpreting configurations on Wechsler protocols.     

Predictive validity of two short-forms of the WPPSI: a 3-year follow-up study

An equally weighted WPPSI short-form (Comprehension, Arithmetic, Block Design, and Picture Completion) was administered to 64 prekindergarten children, while a verbally weighted WPPSI short-form (Comprehension, Arithmetic, Block Design, and Vocabulary) was administered to 63 prekindergarten children. All subjects subsequently were administered school achievement tests at the end of the first- and second-grade years. Low, but significant correlations between the FSIQ and achievement test scores were obtained; the Arithmetic and Block Design subtests were the best subtest predictors of school achievement in grades one and two. The predictive validities of the two WPPSI short-forms were found to be essentially equivalent.     

Autonomic arousal explains social cognitive abilities in high-functioning adults with autism spectrum disorder

Empirical research into behavioural profiles and autonomic responsivity in individuals with autism spectrum disorders (ASDs) is highly variable and inconsistent. Two preliminary studies of children with ASDs suggest that there may be subgroups of ASDs depending on their resting arousal levels, and that these subgroups show different profiles of autonomic responsivity. The aim of the present study was to determine whether (i) adults with high-functioning ASDs may be separated into subgroups according to variation in resting arousal; and (ii) these ASD arousal subgroups differ in their behavioural profiles for basic emotion recognition, judgements of trustworthiness, and cognitive and affective empathy. Thirty high-functioning adults with ASDs and 34 non-clinical controls participated. Resting arousal was determined as the average skin conductance (SCL) across a 2 min resting period. There was a subgroup of ASD adults with significantly lower resting SCL. These individuals demonstrated poorer emotion recognition, tended to judge faces more negatively, and had atypical relationships between SCL and affective empathy. In contrast, low cognitive empathy was a feature of all ASD adults. These findings have important implications for clinical interventions and future studies investigating autonomic functioning in ASDs.     

Variability in Wechsler Adult Intelligence Scale-IV subtest performance across age

Normal Wechsler Adult Intelligence Scale (WAIS)-IV performance relative to average normative scores alone can be an oversimplification as this fails to recognize disparate subtest heterogeneity that occurs with increasing age. The purpose of the present study is to characterize the patterns of raw score change and associated variability on WAIS-IV subtests across age groupings. Raw WAIS-IV subtest means and standard deviations for each age group were tabulated from the WAIS-IV normative manual along with the coefficient of variation (CV), a measure of score dispersion calculated by dividing the standard deviation by the mean and multiplying by 100. The CV further informs the magnitude of variability represented by each standard deviation. Raw mean scores predictably decreased across age groups. Increased variability was noted in Perceptual Reasoning and Processing Speed Index subtests, as Block Design, Matrix Reasoning, Picture Completion, Symbol Search, and Coding had CV percentage increases ranging from 56% to 98%. In contrast, Working Memory and Verbal Comprehension subtests were more homogeneous with Digit Span, Comprehension, Information, and Similarities percentage of the mean increases ranging from 32% to 43%. Little change in the CV was noted on Cancellation, Arithmetic, Letter/Number Sequencing, Figure Weights, Visual Puzzles, and Vocabulary subtests (<14%). A thorough understanding of age-related subtest variability will help to identify test limitations as well as further our understanding of cognitive domains which remain relatively steady versus those which steadily decline.     

Some cognitive correlates of schizophrenic illnesses

A battery of tests was developed to assess verbal, non-verbal and mixed cognitive functions. Interest was based on pattern of response rather than absolute scores. The subjects were 167 men held in prison on criminal charges or in a maximum security hospital after conviction. The present paper deals exclusively with two subgroups: the 61 schizophrenic men and the 41 men with no psychiatric disorder. The schizophrenic group as a whole presented a very different cognitive pattern from the 'normal' men. First, with the exception of the vocabulary subtest of the WAIS, the schizophrenics were inferior on all tests, whether verbal, non-verbal or mixed function. Secondly, they showed considerably more variation within subtests. The schizophrenic sample was therefore subdivided into four clinical groups. Each showed a distinctive cognitive profile. It is argued that these cognitive differences reflect real differences in the disorder and type of illness being experienced by members of these subgroups.     

Factor structure of the Chinese version of the WAIS-R for Chinese adults in the lowest percentiles of IQ

The Chinese version of the WAIS-R was factor analyzed for a sample of 130 Chinese adults in Hong Kong who had low intellectual abilities. All subtests except the Vocabulary subtest were included for analyses. Results supported a three-factor solution composed of Verbal Comprehension, Perceptual Organization, and Memory/Freedom from Distractibility Factors, as well as a two-factor solution of classic Verbal-Perceptual dichotomy. Comparison of present two- and three-factor structure with individuals having low or normal IQ in Mainland China and North America revealed satisfactory congruence coefficients. However, our general factor accounted for only a small portion of common and total variance (28.5% and 35.3% respectively). Error variances of our subtests were large when compared to normative samples of Mainland China and US. Results were discussed in terms of clinical interpretation of the WAIS-R subtests, danger of using short-forms to assess IQ and need for normative studies of WAIS-R in Chinese-speaking countries. © 1996 John Wiley & Sons, Inc.     

Cognitive impairment in schizophrenia is the core of the disorder

Patients with schizophrenia exhibit an exceedingly wide range of symptoms from a variety of domains. The cardinal features are abnormal ideas (such as delusions); abnormal perceptions (such as hallucinations); formal thought disorder (as evidenced by disorganized speech); motor, volitional, and behavioral disorders; and emotional disorders (such as affective flattening or inappropriateness). In addition to these diverse, and sometimes bizarre symptoms, it has become increasingly apparent that the disorder is, to variable degrees, accompanied by a broad spectrum of cognitive impairments. This review addresses the question of whether the cognitive deficits seen in schizophrenic patients are the core features of the disorder. In other words, we explore whether schizophrenia is best characterized by symptoms or cognitive deficits (we suggest the latter) and moreover, whether there is a specific cognitive deficit profile that may assist in diagnosis. First, we discuss what the cognitive deficits are. Then we address in turn the reality, frequency, predictive validity, specificity, course and susceptibility to neuroleptic effects of these cognitive impairments. In brief, we argue that various cognitive deficits are enduring features of the schizophrenia illness, that they are not state-related and are not specific to subtypes of the illness, and, more specifically, that working memory and attention are characteristically impaired in patients with schizophrenia, irrespective of their level of intelligence. Last, we conclude that problems in these cognitive domains are at the very core of the dysfunction in this disease.     

Short form of the WPPSI and WPPSI-R

A short form of the WPPSI, which consisted of the Block Design, Vocabulary, Arithmetic, and Comprehension subtests, was administered to 426 applicants to kindergarten at a private school. The following year a short form WPPSI-R, which consisted of the same subtests, was administered to 372 applicants to kindergarten at the same school. The FSIQs and subtest scores of the two short forms were nearly identical. The findings varied from the results of previous studies that found the complete WPPSI FSIQ to be 6 to 8 points higher than the WPPSI-R FSIQ. Limitations of the present study and of short form Wechsler IQs are discussed.     

The profile of memory function in children with autism

A clinical memory test was administered to 38 high-functioning children with autism and 38 individually matched normal controls, 8-16 years of age. The resulting profile of memory abilities in the children with autism was characterized by relatively poor memory for complex visual and verbal information and spatial working memory with relatively intact associative learning ability, verbal working memory, and recognition memory. A stepwise discriminant function analysis of the subtests found that the Finger Windows subtest, a measure of spatial working memory, discriminated most accurately between the autism and normal control groups. A principal components analysis indicated that the factor structure of the subtests differed substantially between the children with autism and controls, suggesting differing organizations of memory ability.     

Is the WAIS-R an acceptable test for the elderly? opinions of examinees 75 years and older

Two hundred twenty-four healthy volunteers, 75 years of age and older (M = 80.67 years; SD = 4.99), completed the WAIS-R and a post WAIS-R questionnaire. The questionnaire gathered information about the subjects' perceptions of the Wechsler Scale across five categories. The vast majority of subjects (over 92%) experienced the WAIS-R as interesting, challenging, motivating, and within their endurance. Only two subtests were rated negatively; Picture Arrangement and Block Design were experienced as tricky by 17% and 22% of the subjects, respectively. There were no significant differences on IQ and subtest scores between subjects who perceived the WAIS-R in a negative manner and those who viewed it positively.     

Short-term memory and cognitive variability in adult fragile X females

We investigated the possibility that adult fragile X [fra(X)] heterozygotes have a distinct or specific cognitive profile, with a particular focus on visuospatial and/or memory deficits. With a sample of 13 adult fra(X) female carriers (2 fra(X) positive) and age-matched control women, we performed 2 tests: Wechsler Adult Intelligence Scale-Revised (WAIS-R) and the Revised Visual Retention Test (RVRT). An identifiable cognitive profile was not evident in the study group, but significant differences were evident in RVRT performance in number correct and number of errors when compared to controls and normative data. The combination of the WAIS-R and RVRT data suggests that the short-term memory component of the tasks may be of more significance than visuospatial performance in the deficits observed.     

Quantifying qualitative features of Block Design performance among healthy older adults.

Block Design tasks are neuropsychologically valuable, but standard scoring sacrifices potentially useful information that could elucidate the cognitive processes underlying performance failures. Qualitative indices that were proposed in the WAIS-R-NI [Kaplan, E., Fein, D., Morris, R., & Delis, D. (1991). The WAIS-R as a neuropsychological instrument [Manual]. San Antonio, TX: Psychological Corporation] should help to remedy this situation but have received little research attention. We present WAIS-R Block Design data for 177 healthy older adults (aged 50-90) incorporating several qualitative measures, outlining normative ranges and examining age differences. Proportional scoring, counts of single-block placement and rotation errors, counts of parameter-violating errors such as breaking configuration, and availability of implicit grid information all offer potentially valuable supplementary data that can enrich clinical interpretation of Block Design protocols.     

Evidence of a divided-attention advantage in autism

People with autism spectrum disorders appear to have some specific advantages in visual processing, including an advantage in visual search tasks. However, executive function theory predicts deficits in tasks that require divided attention, and there is evidence that people with autism have difficulty broadening their attention (Mann & Walker, 2003). We wanted to know how robust the known attentional advantage is. Would people with autism have difficulty dividing attention between central and peripheral tasks, as is required in the Useful Field of View task, or would they show an advantage due to strengths in visual search? Observers identified central letters and localized peripheral targets under both focused- and divided-attention conditions. Participants were 20 adults with high-functioning autism and Asperger's syndrome and 20 adults matched to the experimental group on education, age, and IQ. Contrary to some predictions, individuals with autism tended to show relatively smaller divided-attention costs than did matched adults. These results stand in stark contrast to the predictions of some prevalent theories of visual and cognitive processing in autism.     

Application of the four-subtest WAIS-R short form with an older clinical sample

Investigated the validity of the Arithmetic + Vocabulary + Picture Arrangement + Block Design subtest combination as an estimate of the WAIS-R Full Scale IQ in a sample of 55 elderly patients. The correlation between the short-form IQ and the WAIS-R Full Scale IQ was highly significant, r(53) = .95, p less than .001. A pairwise t-test computed between the mean IQs for the two forms was nonsignificant, t(54) less than 1. Approximately one-fourth of the Ss showed changes in intelligence classification levels when the short form was used. The short form does not provide a precise estimate of IQ; however, it appears to have clinical utility as a screening device to identify patients with atypical cognitive functioning. The short form correctly categorized 84% of the current sample with respect to the presence or absence of abnormalities on the full WAIS-R.     

Screening for rare epigenetic variations in autism and schizophrenia

While many studies have led to the identification of rare sequence variants linked with susceptibility to autism and schizophrenia, the contribution of rare epigenetic variations (epivariations) in these disorders remains largely unexplored. Previously we presented evidence that epivariations occur relatively frequently in the human genome, and likely contribute to a subset of congenital and neurodevelopmental disorders through the disruption of dosage‐sensitive genes. Here we extend this approach, studying methylation profiles from 297 samples with autism and 767 cases with schizophrenia, identifying 84 and 268 rare epivariations in these two cohorts, respectively, that were absent from 4,860 population controls. We observed multiple features associated with these epivariations that support their pathogenic relevance, including (a) a significant enrichment for epivariations in schizophrenic individuals at genes previously linked with schizophrenia, (b) increased brain expression of genes associated with epivariations found in autism cases compared with controls, (c) in autism families, a significant excess of epivariations found specifically in affected versus unaffected sibs, (d) Gene Ontology terms linked with epivariations found in autism, including “D1 dopamine receptor binding.” Our study provides additional evidence that rare epivariations likely contribute to the mutational spectra underlying neurodevelopmental disorders.     

Base rates of intersubtest scatter in the old age standardization sample of the WAIS-R

The Wechsler Adult Intelligence Scale-Revised (WAIS-R) old-age standardization sample was analyzed to ascertain normal base rates of intersubtest scatter. The range and number of scaled scores that deviated by +/- 3 points from the mean were calculated for each subject on the Verbal, Performance, and Full Scale subtests. Mean ranges for the total sample were 4.4, 3.4, and 6.5, respectively. Ranges were larger for men than women; whites demonstrated more scatter than blacks. An increase in scatter emerged on the Verbal and Full Scales as one moved from the lowest to the highest education and IQ groups. Over 75% of individuals had two, one, or zero subtests that deviated significantly from their WAIS-R mean score. Finally, the scatter range for the elderly sample was compared to the original WAIS-R standardization sample.     

Predicting WAIS-R IQ premorbid ability: combining subtest performance and demographic variable predictors.

The WAIS-R standardization sample was used to develop regression formulas designed to predict WAIS-R IQ scores. In contrast to previous approaches that focused on either "hold" measures or demographic variables as predictors of premorbid functioning, these two domains were used conjointly in the present study. WAIS-R subtests served as measures of present ability, whereas age, race, sex, education, and occupation served as the demographic predictors. Because any WAIS-R subtest may be impaired following brain injury, no subtest(s) were determined a priori to be "hold" measure(s). Instead, 33 regression formulas were developed each combining 1 of the 11 WAIS-R subtests with demographic variables, to predict IQ scores. The current equations generally doubled the amount of variance accounted for by demographic variables alone and accounted for more variance in WAIS-R IQs than any other currently available method of predicting premorbid cognitive functioning. Regression to the mean was not a significant problem. The regression equations are reported to aid in the estimation of premorbid WAIS-R IQ. Tables of predictive accuracy are also presented.     

The effects of unilateral and multifocal lesions on the WAIS-R: a factor analytic study of stroke patients.

An exploratory maximum likelihood factor analysis of the inter-correlations among the 11 subtests of the WAIS-R was undertaken for 167 patients who had a primary diagnoses of cerebrovascular accident (right hemisphere, n = 79; left hemisphere, n = 55; diffuse or multifocal, n = 33). On the WAIS-R, this sample performed below normative standards (average scaled score = 7.1), but demonstrated a pattern of variability among subtests similar to the normative groups. Interestingly, VIQ-PIQ discrepancy analyses revealed V > P profiles for patients with lesions in either or both hemispheres. The best fit for the WAIS-R matrix was an oblique two-factor model comprised of the Verbal and Performance subtests. This factor solution, which was moderately correlated (.52), accounted for 58.8% of the total variance. The stability of a two-factor structure in this neurologic impaired population suggests that the WAIS-R is a robust measure, even when used within such a rehabilitation population. Only two of the eleven subtests (i.e., Comprehension and Picture Arrangement), however, were related to lesion site. Rehabilitation settings may need to rely more on neuropsychological procedures that measure the more "fluid" areas of neurocognitive ability, in contrast to the WAIS-R which appears less sensitive to the neurological impairment associated with stroke.