A comparison of the WAIS and WAIS-R using T-score conversions that correct for age, education, and sex

A newly developed T score conversion system that corrects Wechsler Adult Intelligence Scale (WAIS) and Wechsler Adult Intelligence Scale-Revised (WAIS-R) subtest and IQ scores for appropriate demographic variables was used to compare subjects' performance on the two versions of the instrument. Using 428 pairs of subjects matched on age, education, and sex, with one person in each pair having taken the WAIS and the other the WAIS-R, we found no significant differences in level or pattern of performance when analyses were performed on the T scores. This was in contrast to highly significant differences when uncorrected scaled scores and IQ values were compared. Therefore, the T score system appears to provide a tool which may help clinicians make more direct comparisons between the results obtained on the WAIS and WAIS-R.     

Wais versus wais-r subtest patterns: A problem of generalization

Abstract

While the Wechsler Adult Intelligence Scale-Revised (WAIS-R) has gained considerable acceptance as a satisfactory successor to the WAIS as a measure of general intelligence, few studies have examined whether the two tests are comparable in terms of brain-behavior relationships. To evaluate the equivalence of profile interpretations of the WAIS and WAIS-R, the tests were given in a concurrent manner to 43 patients referred for neuropsychological evaluation. While subtest and summary IQ scores were highly correlated, the WAIS-R yielded significantly lower scores than did the WAIS, but not in a uniform manner. Subtest differences ranged from .56 to 2.42, indicating that the WAIS-R introduces a systematic profile bias. Ipsative correlations between profile patterns for each patient ranged from .233 to .986, with a mean correlation of .860. Finally, concordance rates for decisions based on three objective profile rules were examined for the WAIS and WAIS-R data. Concordance rates between tests for “positive” cases ranged from 41.7% to 65.5%. These results suggest that neuropsychological inferences derived from the patterning of WAIS-R subtest scores should be validated empirically and should not be assumed to be comparable with those previously established with the WAIS.     

Discrepancies between IQ and memory scores in alcoholism and aging

Standardized IQ and memory tests were administered to 30 alcoholic men (7 with Korsakoff's syndrome) and 29 nonalcoholic controls between 24 and 74 years of age, in order to evaluate alcohol-related discrepancies between IQ and memory scores (including those attributable to possible premature aging). Severity of amnesia often has been defined operationally as a large discrepancy between IQ scores on the Wechsler Adult Intelligence Scale (WAIS), and scores on memory tests such as the Wechsler Memory Scale (WMS). In the context of a normal WAIS Full Scale IQ or Verbal IQ, a low WMS memory quotient (MQ) signals the possibility of anterograde memory disorder. Revised and nonrevised versions of the WAIS and WMS were given to all of the subjects. As expected, the revised versions yielded lower scores than the non-revised versions; these differences were especially prominent in the older subjects (whether or not they had a history of alcoholism) and the Korsakoff patients. Korsakoff patients demonstrated the largest discrepancies between IQ and memory scores, regardless of the tests being used. Results indicated that measures used clinically to reveal amnesia, that is, large differences between IQ scores and memory scores, were effective in any combination (the WAIS or the WAIS-R with the WMS or the WMS-R).     

The National Adult Reading Test: restandardisation against the Wechsler Adult Intelligence Scale—Fourth edition

Since publication in 1982, the 50-item National Adult Reading Test (NART; Nelson, 1982; NART–R; Nelson & Willison, 1991) has remained a widely adopted method for estimating premorbid intelligence both for clinical and research purposes. However, the NART has not been standardised against the most recent revisions of the Wechsler Adult Intelligence Scale (WAIS-III; Wechsler, 1997, and WAIS-IV; Wechsler, 2008). Our objective, therefore, was to produce reliable standardised estimates of WAIS-IV IQ from the NART. Ninety-two neurologically healthy British adults were assessed and regression equations calculated to produce population estimates of WAIS-IV full-scale IQ (FSIQ) and constituent index scores. Results showed strong NART/WAIS-IV FSIQ correlations with more moderate correlations observed between NART error and constituent index scores. FSIQ estimates were closely similar to the published WAIS and WAIS-R estimates at the high end of the distribution, but at the lower end were approximately equidistant from the highly discrepant WAIS (low) and WAIS-R (high) values. We conclude that the NART is likely to remain an important tool for estimating the impact of neurological damage on general cognitive ability. We advise caution in the use of older published WAIS and/or WAIS-R estimates for estimating premorbid WAIS-IV FSIQ, particularly for those with low NART scores.     

Comparison of pervasive developmental disorder and schizophrenia by the Japanese version of the National Adult Reading Test

Abstract

Objective. In adults, it is sometimes difficult to discriminate between pervasive developmental disorder (PDD) and schizophrenia (SCH) when positive symptoms are not outstanding. We examined whether the Japanese version of the National Adult Reading Test (JART), is a valid scale for evaluating pre-morbid intelligence quotient (IQ) in patients with SCH, and the Wechsler Adult Intelligence Scale-Revised (WAIS-R) are useful for helping to discriminate between PDD and SCH. Methods. Sixteen patients with adult PDD and 16 age-, education- and sex-matched patients with SCH participated in the present study. In addition, two groups were matched for JART and GAF scores. All subjects were scored on the JART and WAIS-R after informed consent on the aim of this study. Examiners who were blind to the diagnoses measured JART and WAIS-R. Results. Significant diagnosis-by-IQ examination interactions were found (F[1,30] = 10.049, P = 0.003). Furthermore, WAIS-R scores of the PDD group were higher than those of the SCH group (P = 0.002) considering two groups were matched for JART. Conclusions. The comparison of IQ in the PDD group and in the SCH group by JART and WAIS-R might be an easy and useful method for helping to discriminate between PDD and SCH.     

Sex interaction of white matter microstructure and verbal IQ in corpus callosum in typically developing children and adolescents

BackgroundChildhood is an extremely important time for neural development that has a critical role in human intelligence. Efficient information processing is crucial for higher intelligence, so the intra- or inter-hemispheric interaction is vital. However, the relationship between neuroanatomical connections and intelligence in typically developing children, as well as sex differences in this relationship, remains unknown.MethodsParticipants were 253 typically developing children (121 boys and 132 girls) aged 5–18. We acquired diffusion tensor imaging data and intelligence using an age-appropriate version of the IQ test; Wechsler Intelligence Scale for Children (WISC) or Wechsler Adult Intelligence Scale (WAIS). We conducted whole-brain multiple regression analysis to investigate the association between fractional anisotropy (FA), which reflects white matter microstructural properties, and each composite score of IQ test (full-scale IQ, performance IQ, and verbal IQ).ResultsFA was positively correlated with full-scale IQ in bilateral inferior occipitofrontal fasciculus, genu, and splenium of corpus callosum (CC). FA in the right superior longitudinal fasciculus, bilateral inferior longitudinal fasciculus, and splenium of CC were also positively correlated with performance IQ. Furthermore, we found significant sex interaction between FA in the CC and verbal IQ. FA was positively correlated in boys, and negatively correlated in girls.ConclusionResults suggest that efficient anatomical connectivity between parietal and frontal regions is crucial for children’s intelligence. Moreover, inter-hemispheric connections play a critical role in verbal abilities in boys.     

Comparison of WAIS and WAIS-R scores of mildly and moderately mentally retarded adults

The Wechsler Adult Intelligence Scale (WAIS) and the Wechsler Adult Intelligence Scale-Revised (WAIS-R) were administered to 29 mildly and moderately mentally retarded adults. The WAIS Verbal and Full Scale IQs were significantly lower than were corresponding WAIS-R IQs. This difference is an exception to the general pattern of IQs being higher for tests that were standardized earlier. The present results suggest that WAIS-R IQs will be much higher than WISC-R IQs.     

Postdicting verbal iq of elderly individuals

abstract

we undertook a longitudinal crossvalidation of the Ryan and Paolo (1992) equation's ability to postdict Wechsler Adult Intelligence Scale-Revised (WAIS-R) Verbal IQ (VIQ) from National Adult Reading Test (NART) performance measured 5 years after VIQ scores were obtained, for a sample of 49 elderly normal individuals (mean age 71 years). Five-year interval postdiction accuracy agreed very well with the results of the original, concurrent study. Clinical utility is still limited, however, as VIQ must decline by 16.3 points for 95%-detection sensitivity. A new regression equation that utilizes a combination of NART errors and WAIS-R Vocabulary age-scaled scores (measured 3 years earlier) provided slightly better expected clinical sensitivity and accounted for 49% of the variance in VIQ scores.     

APPLICABILITY OF THE WAIS-R: its use with people with mental handicaps

Ever since the introduction of the Binet Simon Scale in 1905, psychologists have been involved in the quantitative assessment of intellectual handicaps through psychometric means. Although more recently decreasing emphasis has been placed on psychometric measurement of intelligence quotient (IQ) as the major variable in the assessment of mental handicap (Clark, 1974; Mittler, 1970), intelligence scales are still widely used as an assessment aid. Since introduction of the Wechsler Adult Intelligence Scale (WAIS) in 1955 it has been used by psychologists in addition to the Stanford-Binet Scale. Recent surveys attest to the continuing popularity of both (Porteaus, 1983). In 1981, the WAIS was revised, restandardised, and published as the Wechsler Adult Intelligence Scale – Revised (WAIS-R). This paper considers the usefulness of the WAIS-R to psychologists working with people who are mentally handicapped.     

Assessment of intellectual function in dementing disorders: Validity of WAIS-R short forms for patients with Alzheimer's,Huntington's,and Parkinson's disease

Abstract

While commonly administered in the neuropsychological assessment of dementia, the Wechsler Adult Intelligence Scale-Revised (WAIS-R) is excessively long (70–90 min) and difficult for many patients. The present study examined WAIS-R data from patients with clinically distinct dementing disorders, including those with Alzheimer's, Huntington's, and Parkinson's disease (N=148). The profiles of performance of these three patient groups across subtests were remarkably similar, suggesting that the use of a short form would not result in the loss of clinically significant information. The validity of several published short forms was reviewed. Although all of these systematically over- or underestimated Full Scale IQ for these patients, after a scaling table revision the Kaufman (1990) form appears to provide an accurate estimate of IQ. The use of this short form is therefore recommended to minimize frustration and fatigue on the part of the patient, and to allow the inclusion of other tests critical to the evaluation of dementia within a single assessment session.     

Value of ancillary testing in the diagnosis of pervasive developmental disorder in adults

Recently, there has been increasing interest in adults with pervasive developmental disorder (PDD) who seek general psychiatric services for various psychiatric problems. The diagnosis of PDD requires the careful collection of information about the patient's developmental history. A structured diagnostic interview is useful and should be performed, but has limitations now. The clinical value of the measurement of the Wechsler Adult Intelligence Scale, the Autism-Spectrum Quotient Japanese Version, and the Pervasive Developmental Disorders Autism Society Japan Rating Scale was demonstrated by a questionnaire survey that the authors conducted in 2010. These additional tests are useful if interpreted with caution. For example, a discrepancy between the performance intelligence quotient (IQ) and the verbal IQ in the Wechsler Adult Intelligence Scale does not by itself diagnose PDD. We examined whether the Japanese version of the National Adult Reading Test (Japanese Adult Reading Test; JART), a valid scale for evaluating pre-morbid IQ in patients with schizophrenia, and the Wechsler Adult Intelligence Scale-Revised (WAIS-R) are useful for discriminating between PDD and schizophrenia. Sixteen patients with adult PDD and 16 patients with schizophrenia matched for age, education and sex participated in this study. In addition, the two groups were matched for JART and the Global Assessment of Functioning scores. All subjects were scored on the JART and WAIS-R after giving informed consent for the study. The result was that significant diagnosis-by-IQ examination interactions were found (F [1, 30]=10.049, P=0.003). Also, the WAIS-R scores of the PDD group were higher than those of the schizophrenia group (P=0.002) when the two groups were matched for JART. In conclusion, the comparison of IQ in the PDD group and in the schizophrenia group by JART and WAIS-R might be an easy and useful method for helping to discriminate between PDD and schizophrenia. In addition, the difference in IQ scores measured by JART and by WAIS-R may be helpful in diagnosing PDD. The diagnosis of PDD in adults may be assisted by the use of these additional tests.     

Fine tuning of the digit symbol paired associate recall test for practitioner purposes in clinical and research settings

Guidelines are presented to facilitate the use of the WAIS Digit Symbol measure of paired associate recall as a neuropsychological instrument. Currently three formal variants of the test exist with accompanying normative data (the original WAIS-R-NI form; a WAIS-R Short Form; a longer WAIS-III form), providing a potential source of confusion which may limit its application. To circumvent this, the present article critically evaluates: (i) variations in test forms and their advantages; (ii) available norms in terms of age and education, with pointers for more differentiated guidelines in this regard; and (iii) the desirability of incorporating a delayed recall variant of the test. Finally, a synopsis of data is presented that supports the screening potential of Digit Symbol paired associate recall in cases of mild neurocognitive dysfunction. For the purposes of this paper, the term WAIS is used with broad reference to all variations of the original Wechsler Adult Intelligence Scale (1955) upon which they were based, including the WAIS-R (1981) and WAIS-III (1997) updated editions, and the South African WAIS (1969). The terms South African WAIS (South African Wechsler Adult Intelligence Scale), WAIS-R (Wechsler Adult Intelligence Scale - Revised), and WAIS-III (Wechsler Adult Intelligence Scale-III), refer to these specific versions of the test.     

Wechsler Intelligence Scale profiles, the cholinergic system, and Alzheimer's disease

Forty-one patients with putative Alzheimer's Disease (AD) were evaluated to determine the diagnostic utility of a profile of Wechsler Adult Intelligence Scale (WAIS) subtests which has been proposed by Fuld (1984) to identify cholinergic dysfunction. Only nine (21.9%) of these patients had positive Wechsler profiles. Half (n = 21) of the AD patients had been given the WAIS, and the other half (n = 20) the Wechsler Adult Intelligence Scale-Revised (WAIS-R). Positive profiles occurred more often in the AD subgroup given the WAIS-R, but this difference was not statistically significant. Specificity of the formula was evaluated using Wechsler results of 42 older normals and 30 patients who were being evaluated for dementia but who did not have AD. One of the 42 normals (2.4%) and five of the patient controls (16.7%) showed a positive Wechsler profile. Because of the Fuld formula's low sensitivity, a negative Wechsler profile cannot be used to help rule out AD. Although specificity of the formula is high, the diagnostic value of a positive Wechsler profile is modest even under the most favorable AD baserate conditions.     

A Brief Report on WAIS-R Normative Data Collection in Mayo's Older African Americans Normative Studies

ABSTRACT

Historically, neuropsychological measures such as the Wechsler Adult Intelligence Scale-Revised (WAIS-R) have yielded unacceptably high rates of misdiagnosis of impairment among cognitively normal African Americans, primarily due to poor test specificity and inadequate representation of ethnic minorities in the normative sample. In this report, we briefly review these issues and describe efforts by investigators in Mayo's Older African Americans Normative Studies (MOAANS) to develop more appropriate norms for African American elders on the WAIS-R. During MOAANS data collection, the third edition of the WAIS (WAIS-III) was introduced with updated representation of ethnic minorities in the normative database. More recently, specific demographic corrections for African Americans have been derived for WAIS-III subtest scores and indices. As such, WAIS-R normative estimates are not presented here. Interested readers who wish to obtain a full set of MOAANS WAIS-R norms, however, are invited to contact the authors for these data.     

Examiner judgment and actual stability of psychiatric inpatient intelligence quotients

Abstract

Despite the widespread use of the Wechsler Adult Intelligence Scale-Revised (WAIS-R; Wechsler, 1981) with psychiatric inpatients, little is known about the stability of the data obtained. Twenty-one psychiatric patients tested as inpatients were retested an average of 15 months later. Although 24% obtained FSIQ gains of at least 9 points (an increase of at least 14% over inpatient IQ), the stability data is essentially consistent with that reported for the WAIS-R standardization retest sample (Matarazzo & Herman, 1984). Statements pertaining to reliability gleaned from inpatient assessment reports bore little relationship to changes at retesting, and suggest that examiners may overcompensate for perceived negative influences on performance. Overreliance upon intersubtest scatter analysis may also be implicated. Certain characteristics of Digit Span performance appear be related to instability in this sample, but these potentially useful “red flags” of sub-optimal performance require cross-validation.     

IQ scores among homeless older adolescents: characteristics of intellectual performance and associations with psychosocial functioning.

Intellectual performance and the associations of IQ with the quality of psychosocial functioning were studied in a sample of homeless older adolescents. Fifty homeless older adolescents (ages 16-21) completed the Wechsler Adult Intelligence Scale-Revised (WAIS-R) and a questionnaire assessing psychosocial functioning and sexual risk factors. The WAIS-R scores were comparable to population means, with performance IQ scores tending to be higher than verbal IQ scores. The IQ was unrelated to the duration of homelessness. Higher IQ scores were significantly correlated with only a minority of the measures of psychosocial functioning, including less self-reported depression and lower reported delinquency, but also less self-control in high-risk sexual situations, less perceived peer support for safer sex, and a higher perceived likelihood of acquiring HIV.     

The relationship between IQ, memory, executive function, and processing speed in recent-onset psychosis: 1-year stability and clinical outcome

Studies commonly report poor performance in psychotic patients compared with controls on tasks testing a range of cognitive functions, but, because current IQ is often not matched between these groups, it is difficult to determine whether this represents a generalized deficit or specific abnormalities. Fifty-three first-episode psychosis patients and 53 healthy controls, one-to-one matched for sex, age, and full-scale current IQ, were compared on Wechsler Adult Intelligence Scale (WAIS) subtests representing indices of perceptual organization, verbal comprehension, processing speed, and working memory as well as other tests of executive function and episodic memory. The groups showed an equivalent pattern of performance on all WAIS subtests except digit symbol processing speed, on which the patients were significantly worse. Patients were also worse on measures where performance correlated with digit symbol score, namely working and verbal memory tasks. Standardized residual scores for each subtest were calculated for each patient using the difference between their actual subtest score and a predicted subtest score based on their full-scale IQ and the performance of controls. Scaled scores and residual scores were examined for relationships with clinical measures. Digit symbol-scaled score was significantly correlated with concurrent negative syndrome score at baseline, and digit symbol residual score significantly predicted residual negative symptoms at 1-year follow-up. In summary, our comparison of patients and controls precisely matched for IQ revealed that processing speed was attenuated in recent-onset schizophrenia, contributed significantly to working and episodic memory deficits, and was a prognostic factor for poor outcome at 1 year.     

The WAIS-III and major depression: absence of VIQ/PIQ differences

Poor Performance IQ (PIQ) relative to Verbal IQ (VIQ) is a standard finding in depressed patients administered the Wechsler Adult Intelligence Scale-Revised (WAIS-R). This study examined performance of depressed subjects on the instrument's latest revision, the WAIS-III, which provides a more detailed subdomain profile of intellectual functioning. WAIS-III IQ, index and subscale scores were compared between 121 unmedicated subjects in major depressive episode and 41 healthy volunteers, using demographically adjusted T-score conversions. Depressed subjects had significantly lower PIQ scores, but neither the absolute VIQ/PIQ difference nor prevalence of VIQ/PIQ discrepancies >1 SD differed between groups. Index score differences were exclusively in Processing Speed, and subtest differences only on timed tasks. WAIS-III scores did not differ between subjects with major depressive and bipolar disorders, nor between subjects with and without melancholia or history of suicidal behavior. Results suggest general intellectual performance in depression is best characterized by deficits in processing speed, rather than global nonverbal abilities, and that this deficit is consistent across depression subtypes.     

Neurological complications of vasculitis

Raw scores for cerebral blood flow (CBF), determined by xenon 133 inhalation, and for Wechsler Adult Intelligence Scale (WAIS) were measured in five groups of 12 subjects each: young normals, aged normals, and patients with cerebrovascular disease without dementia, dementia with cerebrovascular disease, and degenerative brain disease. Important differences were present in the raw data according to age and sex. When these were adjusted a quadratic model revealed a highly significant (p < 0.0001, r = 0.86) correlation between CBF and measured intelligence score. We interpret these findings to indicate that in dementing illnesses the WAIS raw score reflects the severity of the brain disorder, regardless of cause, and that CBF is reduced as a function of the severity rather than the cause of the abnormality.     

Bradykinesia in patients with obsessive-compulsive disorder

ObjectiveTo investigate the frequency of bradykinesia in patients with obsessive-compulsive disorder (OCD) and to see whether patients with OCD who also have bradykinesia display distinctive neuropsychological and neuropsychiatric features.MethodsWe studied 23 antipsychotic-free patients with OCD and 13 healthy controls. Bradykinesia was assessed with section III of the Unified Parkinson Disease Rating Scale. The Wechsler Adult Intelligent Scales-Revised (WAIS-R) was used to assess the Full Scale IQ and to measure visuospatial, visuoconstructional ability and psychomotor speed/mental slowness.ResultsOf the 23 patients with OCD studied, 8 (34%) had mild symptoms of bradykinesia. No relationship was found between bradykinesia and the sociodemographic variables assessed but this motor symptom was significantly associated with the severity of compulsions. Patients with bradykinesia differed from those without: they had a higher frequency of repeating compulsions, and lower IQ scores, performance scores, and WAIS-R subtest scores for similarities and picture completion. No significant differences were found between patients without bradykinesia and healthy controls in any test.ConclusionsClinical assessment of motor symptoms in adult patients with OCD often discloses mild bradykinesia sometimes associated with repeating compulsions and poor WAIS-R performance scores.