Wechsler Adult Intelligence Scale-Revised Performance Research Articles

Neurocognitive indices of executive hypercontrol in obsessive–compulsive disorder

Cognitive impairment, more often involving memory and/or executive functions, has been reported in obsessive-compulsive (OC) patients. The present study aimed at: i) replicating, in an independent sample, previous findings by our group showing neurocognitive slowness limited to executive tasks; ii) assessing the influence of deficit in general cognitive abilities on executive dysfunction. A comprehensive neuropsychological battery was administered to 30 drug-free OC patients and 30 healthy controls. Obsessive-compulsive patients performed worse on visuospatial tests, were slower on executive tasks, and performed worse on the Wisconsin Card Sorting Test. After covarying for Wechsler Adult Intelligence Scale-Revised performance Intellectual Quotient, a lesser degree of executive dysfunction was observed. Obsessive-compulsive patients exhibit an impairment of executive functions, especially when tasks also require visuospatial abilities. The impairment might reflect a hyperactivity of the executive control.

Voxel-based morphometry and stereology provide convergent evidence of the importance of medial prefrontal cortex for fluid intelligence in healthy adults

We investigated whether a relationship exists between frontal lobe volume and fluid intelligence as measured by both Cattell's Culture Fair test and the Wechsler Adult Intelligence Scale-Revised (WAIS-R) Performance scale, but not with crystallized intelligence as measured by the WAIS-R Verbal scale, in healthy adults, using two well-established image analysis techniques applied to high-resolution MR brain images. Firstly, using voxel-based morphometry (VBM), we investigated whether a significant relationship exists between gray matter concentration and fluid intelligence on a voxel-by-voxel basis. Secondly, we applied the Cavalieri method of modern design stereology in combination with point counting to investigate possible relationships between macroscopic volumes of relevant brain regions defined as dorsolateral, dorsomedial, orbitolateral, and orbitomedial prefrontal cortex on the basis of neuroanatomical landmarks, and fluid intelligence. We also examined the effect on these relationships of normalizing regional brain volumes to intracranial volume. VBM analysis revealed a positive correlation between gray matter concentration in the medial region of prefrontal cortex and Culture Fair scores (corrected for multiple comparisons), and also WAIS-R Performance Intelligence sum of scaled scores (SSS) (uncorrected for multiple comparisons before controlling for age, and this converges with the stereological finding of the positive correlation between volume of dorsomedial prefrontal cortex normalized to intracranial volume and Culture Fair scores after controlling for age. WAIS-R Verbal Intelligence SSS showed no correlations. We interpret our findings, from independent analyses of both VBM and stereology, as evidence of the importance of medial prefrontal cortex in supporting fluid intelligence.

Olfactory identification and WAIS-R performance in deficit and nondeficit schizophrenia

Introduction: An expanding database supports the notion that the deficit syndrome (DS) is a discrete condition within schizophrenia and recent data argues that Smell Identification Deficits (SID) may have a primary relationship with its pathophysiology. If so, then the relationship of University of Pennsylvania Smell Identification Test (UPSIT) scores with other neurocognitive measures in DS patients may point to the neural substrate of the deficit syndrome. Method: We examined the relationship of UPSIT scores and Wechsler Adult Intelligence Scale-Revised (WAIS-R) performance in 46 DSM-IV schizophrenia patients. The Schedule for the Deficit Syndrome (SDS) interview was used to subgroup the sample into 13 DS and 33 nondeficit syndrome (NDS) patients. Results: DS and NDS groups had similar mean ages, age of onset, and GAF scores, but DS patients had fewer years of education. DS and NDS patients also did not differ in full scale, verbal or performance IQ or in any WAIS-R subtest. However, UPSIT scores were significantly worse in the DS patients, most of whom met criteria for a clinically meaningful olfactory impairment. In DS patients, UPSIT scores were significantly correlated with Performance IQ, Block Design, and Object Assembly, all of which are associated with complex visual–motor organizational function thought to be mediated by parietal circuitry. UPSIT scores in NDS patients were significantly related with Vocabulary, Similarities, and Digit Symbol subtests, which are indicative of verbal functioning. Conclusion: These preliminary data support previous findings suggesting that in addition to frontal neuropsychological abnormalities, DS patients may have greater performance impairments on tasks associated with parietal functioning. Our findings furthermore suggest that the parietal circuitry may be a conspicuous substrate for impaired odor identification ability in these patients. The lesser abnormalities in UPSIT ability in NDS patients may be attributed to verbal ability. These data are preliminary and further investigations with larger samples are needed to support our findings.

Apolipoprotein-e influences aspects of intellectual ability in type 1 diabetes.

The epsilon4 allele of the apolipoprotein-E (APOE) gene is associated with poor outcome following various cerebral insults. The relationship between APOE genotype and cognitive function in patients with type 1 diabetes is unknown. In a cross-sectional study of 96 people with type 1 diabetes, subjects were APOE genotyped, previous exposure to severe hypoglycemia was estimated by questionnaire, and cognition was assessed by neuropsychological testing. Cognitive abilities were compared using multivariate general linear modeling (multiple analysis of covariance, MANCOVA) in those with (n = 21) and without (n = 75) the APOE epsilon4 allele. APOE epsilon4 selectively influenced cognitive ability in a sex-specific manner (F = 2.3, P = 0.044, Eta(2) = 0.15); women with APOE epsilon4 performed less well on tests of current, nonverbal intellectual ability (Wechsler Adult Intelligence Scale-Revised performance test score, P = 0.001, Eta(2) 0.26) and frontal lobe and executive function (Borkowski verbal fluency, P = 0.016, Eta(2) = 0.15). Previous exposure to severe hypoglycemia did not interact with APOE epsilon4 to produce cognitive disadvantage. The APOE epsilon4 genotype is associated with specific cognitive disadvantage in young women with type 1 diabetes. APOE epsilon4 is unlikely to mediate susceptibility to hypoglycemia-induced cognitive disadvantage.

Apolipoprotein E epsilon 4 and the pattern of regional brain atrophy in Alzheimer's disease.

Although the APOE epsilon 4 allele increases the risk of developing AD, the effects of the epsilon 4 allele on brain atrophy in clinical AD patients are controversial. To investigate a possible relationship between the genetic variants of APOE and brain atrophy in patients with AD. Using MRI-based volumetry techniques, the authors compared the volumes of the hippocampal formation, amygdaloid complex, and whole brain in probable AD patients (based on criteria of the National Institute for Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association) with different APOE alleles. One group (n = 46) had the epsilon 3/3 allele, one group (n = 46) had the epsilon 3/4 allele, and one group (n = 46) had the epsilon 4/4 allele. The three groups were matched for age, sex, disease duration, education level, and severity of dementia represented by their score of the Mini-Mental State Examination. A possible difference in pattern of cognitive deficits with dose of the APOE epsilon 4 allele was also examined. The normalized hippocampal volume was correlated with the number of APOE epsilon 4 alleles (r = -0.285, p = 0.0007). The amygdalar volume was also correlated with the number of APOE epsilon 4 alleles (r = -0.178, p = 0.037). The number of APOE epsilon 4 alleles was positively correlated with the whole-brain volume (r = 0.185, p = 0.030). It was also correlated with Wechsler Adult Intelligence Scale-Revised performance IQ (r = 0.203, p = 0.017) and with Wechsler Memory Scale-Revised attention/concentration score (r = 0.191, p = 0.025). Different patterns of regional brain atrophy were found among patients of different APOE genotypes. The effect of APOE epsilon 4 allele on the brains of AD patients may have regional specificity.

Discrepancy between predicted and obtained WAIS–R IQ scores discriminates between traumatic brain injury and insufficient effort.

This study examines how well the discrepancy between predicted and obtained Wechsler Adult Intelligence Scale--Revised (WAIS-R) scores discriminate between insufficient effort (IE) and traumatic brain injury (TBI). The 27 IE patients performed significantly more poorly on the WAIS-R than the 48 moderate-severe TBI patients. Premorbid IQs were calculated with formulae that use demographics (Barona Index) or demographics and WAIS-R performance (Best-3 and the Oklahoma Premorbid Intelligence Estimation). Predictions were similar on the Barona, but IE patients' predicted IQs were lower than TBIs for measures with a performance component. IE patients demonstrated a greater discrepancy score (i.e., predicted IQ--obtained IQ) than TBIs; variable levels of sensitivity and specificity were obtained when discriminate functions were developed on these scores. The potential advantage of using discrepancy scores versus performance-based measures to detect insufficient effort is discussed.

The Executive Decline Hypothesis of Cognitive Aging: Do Executive Deficits Qualify as Differential Deficits and Do They Mediate Age-Related Memory Decline?

This paper reports the results of two studies which investigated whether aging is associated with a differential deficit in executive function, compared with deficits in general cognitive ability (Wechsler Adult Intelligence Scale-Revised performance). Further, the studies investigated the specificity of the executive decline hypothesis of memory and aging by examining whether declines in executive function mediate age-related memory decline over and above the variance in memory accounted for by general cognitive ability. The results of Study 1 showed no consistent evidence of a differential decline in executive function among a sample of participants aged between 18 and 75 years. The results of Study 2 indicated a differential decline in one indicator of executive function, the Modified Card Sorting Test, among an older sample aged between 60 and 89 years. Both studies demonstrated that measures of executive function accounted for age-related variance in free recall, recognition, and serial recall, even after controlling for general cognitive ability. However, in Study 1, once variance attributed to speed of processing was taken into account, executive function did not contribute further to the age-related variance.

PASAT and Components of WAIS-R Performance: Convergent and Discriminant Validity

The Paced Auditory Serial Addition Task (PASAT) (Gronwall, 1977), a full length Wechsler Adult Intelligence Scale—Revised (WAIS-R) (Wechsler,1981), and the National Adult Reading Test (NART) (Nelson, 1982) were completed by a sample of 152 healthy participants. Principal components analysis revealed that PASAT's loading on general intelligence (g) was substantial (.72) and exceeded that of many WAIS-R subtests. Following rotation, PASAT loaded highly (.75) on the WAIS-R attention/concentration factor. Evaluation of nested confirmatory factor analytic models confirmed that, although PASAT is not independent of general intellectual ability, it still loaded significantly on attention/concentration (.44) when it was permitted to load simultaneously on g. Conventional normative data were provided for three age bands. In addition, regression equations were built to permit a quantitative comparison of individuals' obtained PASAT scores with their estimated premorbid PASAT scores (using NART and age as predictors) and with scores predicted from their current general level of intellectual ability (using WAIS-R IQ and age as predictors). Both these sets of predictorvariables accounted forhighly significant proportions of PASAT variance; Multiple R was .52 for the former and .66 for the latter.

Longitudinal and psychometric profiles of two cognitive status tests in very old adults.

Forty-four nondemented adults, over the age of 75 years, were tested at six-month intervals spanning two years. Study goals were to examine the validity of the Mini-Mental State Examination (MMSE) and the Wechsler Adult Intelligence Scale-Revised (WAIS-R), to assess the long-term reliability of these instruments, and to examine the longitudinal profile of this sample. Results showed that the MMSE was moderately correlated with the WAIS-R. The MMSE had low internal consistency, although the total score behaved reliably across the five occasions. The WAIS-R scales showed a high degree of internal consistency and test-retest reliability. WAIS-R performance remained stable across occasions; however, decline was evident in the MMSE subtests of Attention and Language.

Relationship of iq to verbal learning and memory: Test and retest

The relationship between Wechsler Adult Intelligence Scale-Revised (WAIS-R) IQ and performance on measures of memory was examined in 64 adults tested twice at a 2-week interval. Repeated measures analyses of variance revealed that individuals with Low-Average WAIS-R Full Scale IQ scores performed significantly more poorly than did individuals with Average and High-Average Full Scale IQs on memory measures including the Wechsler Memory Scale-Revised (WMS-R) General Memory and Delayed Recall indices, as well as California Verbal Learning Test (CVLT) Total Words, Learning Slope, and Discriminability. Although all three groups demonstrated significant practice effects on each memory measure, group differences in performance persisted at retest. Multiple regression analyses revealed that WAIS-R factor scores Verbal Comprehension and Freedom from Distractibility accounted for up to 42% of the variance in WMS-R and CVLT indices. Moreover, WAIS-R performance at initial testing accounted for 22–41 % of the variance in memory performance at retest These results are discussed in the context of the construct stabilities of intelligence and memory, as well as the psychometric precision of the tests used to measure these constructs.

Memory and intellectual deficits do not decline with age in schizophrenia

Cognitive deficits in schizophrenia are reported to be more consistent with a static encephalopathy than a dementing disorder. This study investigates memory and intellectual decline in 62 chronic schizophrenic subjects using the Wechsler Adult Intelligence Scale—Revised (WAIS-R), the Rivermead Behavioural Memory Test and the National Adult Reading Test (NART) in a cross-sectional study using five age cohorts (18–29, 30–39, 40–49, 50–59 and 60–69 years of age) and then by two cohorts (young: 18–39; older: 40–69). A second method of investigating intellectual decline was implemented by estimating the discrepancy score between WAIS-R (current IQ) and NART (premorbid IQ) for each subject. No significant differences were found in WAIS-R Full Scale, Verbal and Performance IQ and memory functioning across the five age cohorts (and when using two age groups). A significant difference in test scores was found using the Picture Completion and Digit Symbol subtests of the WAIS-R. The differences were not related to age or duration of illness. No significant difference in scores were evident in the remaining WAIS-R subtests. These results support previous findings that schizophrenia is more consistent with a static encephalopathy than a dementing disorder and that intellectual and memory function does not markedly decline with age.

A comparison of the NART (restandardized) and the NART‐R (revised)

The ability of the National Adult Reading Test (NART; Nelson & Willison, 1991) and the revised NART (NART-R; Crawford, 1990) to estimate IQ was examined in a healthy sample (N = 47) using the Wechsler Adult Intelligence Scale-Revised (WAIS-R) scores as the criterion. Mean estimated IQs from the NART-R were not significantly different from the WAIS-R Full Scale and Performance IQ, but the NART-R significantly overestimated Verbal IQ by 2.5 points. Nelson & Willison's (1991) NART equations significantly overestimated Full Scale and Verbal IQ by 5.3 and 5.5 IQ points respectively. The NART-R had significantly higher correlations with Full Scale and Verbal IQ than the NART.

Inspection time and WAIS-R IQ subtypes: A confirmatory factor analysis study

Eighty-seven subjects from a diabetic outpatients' clinic were tested on the Wechsler Adult Intelligence Scale-Revised (WAIS-R) and on a test of visual inspection time (IT). The correlation between WAIS-R Full-Scale IQ and IT was −.250( p<.05). The between the square root transformation of IT scores and the sum of WAIS-R performance subtests was −.421 ( p < .001), and with the sum of WAIS-R Verbal subtests was −.192 (n.s.). Principal components analysis indicated that IT had only a very modest loading on general intelligence. After Varimax rotation, two factors were obtained with eigenvalues greater than 1; IT had a high loading on the Performance factor but a near zero loading on the Verbal factor. Confirmatory factor analysis revealed that a two-factor model of intelligence, with correlated Performance and Verbal factors and IT loaded on the Performance factor only, had a better fit to the data than a single latent factor model. This analysis also showed that IT had loadings significantly greater than zero on general and performance-ability factors, but the loading of IT on the Verbal factor was not distinguishable from zero. IT appears to be significantly related to performance IQ but only weakly to Verbal IQ.

Relationship between Intelligence and Criterion Task Set Performance

Intelligence has been shown to be a mediating factor in the performance of many tasks. The purpose of this study is to examine the relationship between Wechsler Adult Intelligence Scale-Revised (WAIS-R) scores and performance on a multi-task performance battery, the USAF Criterion Task Set (CTS). Performance scores for high and low WAIS-R groups (N=26/group) were compared across each task component of the CTS. Results of this study indicate that there is a fairly strong relationship between intelligence, as measured by WAIS-R, and performance on the CTS central processing tasks. Subjects scoring high on the WAIS-R are likely to be more accurate and faster in their responses than subjects who scored low on the WAIS-R. Verbal and performance subscales of the WAIS-R did not appear to mediate task performance differentially. In general, WAIS-R performance does not seem to be related to perceptual input tasks or motor/output tasks of the CTS battery.

WAIS-R and MMPI profiles of men who have sexually assaulted children: evidence of limited utility.

Wechsler Adult Intelligence Scale-Revised (WAIS-R) data were compiled on 101 male sexual offenders of children, and Minnesota Multiphasic Personality Inventory (MMPI) profiles were compiled for a subsample of 81 of these subjects in a replication and extension of the Hall, Maiuro, Vitaliano, and Proctor (1986) MMPI study. The MMPI profiles were heterogeneous and had multiple elevations. No significant relationships between the WAIS-R Full Scale IQ, WAIS-R Performance IQ Minus Verbal IQ Index, or the MMPI scales, and offense characteristics were obtained. These results support the hypothesis of Hall et al. (1986) that psychometric instruments may be of limited utility in characterizing or differentiating among sexual offenders on the basis of criminological variables.

Relationship between the Wechsler Adult Intelligence Scale-Revised and the Wide Range Achievement Test-Revised in a Sample of Normal Adults

The Wechsler Adult Intelligence Scale-Revised (WAIS-R) and the Wide Range Achievement Test-Revised (WRAT-R) were administered as part of a psychological assessment battery. Data were collected from 121 adults and correlations calculated between WRAT-R subtests and WAIS-R Verbal, Performance, and Full Scale IQs; and WAIS-R scaled scores. A Multiple Regression Analysis was carried out using the WRAT-R subtests as independent variables and Full Scale IQ as the dependent variable. Verbal IQ and Full Scale IQ were found to be better predictors of WRAT-R scores than Performance IQ. Results replicate the patterns observed by other researchers, found in samples with differing characteristics, being also similar to those found for the unrevised Wechsler Scales and the unrevised WRAT. The correlations, however, were generally lower.

Comparison of the PPVT-R and WAIS-R in state hospital psychiatric patients.

This study examined the relationship between the Peabody Picture Vocabulary Test-Revised (PPVT-R) and Wechsler Adult Intelligence Scale-Revised (WAIS-R) in 40 adult psychiatric inpatients. The tests were administered to the patients in counterbalanced order as part of their overall psychological evaluation. Mean scaled scores were obtained for both tests. There were no significant differences between PPVT-R scores and WAIS-R Verbal, Performance, and Full Scale IQ scores. Significant correlations between the PPVT-R and all three WAIS-R scores also were obtained. However, further analysis indicated a great deal of variability between individual PPVT-R and WAIS-R Full Scale scores. In addition, the PPVT-R was found to underestimate significantly the WAIS-R IQ scores of a subgroup (N = 13) of mildly mentally retarded subjects. A tendency for the PPVT-R to overestimate the WAIS-R as IQ improved also was noted.

Factor structure of the WAIS-R for an incarcerated population

The factor structure of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) for a large sample of incarcerated individuals (N = 234) was investigated. A principal components analysis followed by Varimax rotation identified the familiar Perceptual Organization and Verbal Comprehension factors. Coefficients of congruence between the current factors and those of the WAIS-R standardization sample indicate a high degree of correspondence. Thus, empirical support was provided for interpretation of WAIS-R Performance and Verbal IQs in this population.