Wechsler Adult Intelligence Scale-III Research Articles

Verbal Fluency in Schizophrenia

Verbal fluency is impaired in patients with schizophrenia, but the association with other cognitive domains remains unclear. Forty-seven patients with schizophrenia (DSM-IV) and 47 controls matched by age, gender, years of education, and vocabulary (Wechsler Adult Intelligence Scale-III) were assessed in terms of sociodemographic, clinical, and cognitive variables. Healthy controls performed significantly better than patients with schizophrenia in all cognitive measures. However, the way these cognitive domains were related differed across groups. Semantic fluency (SF) and phonological fluency (PF) were predicted by working memory (WM) in patients with schizophrenia, whereas the predictor in the healthy controls was processing speed (PS). Moreover, after dividing the sample of patients according to their performance on fluency tests, we found that a worse performance on SF or PF was predicted by WM. However, for patients with a better performance on fluency, the pattern was similar to that of healthy controls. Cognition may show a different pattern of interaction in schizophrenia, with less impaired patients showing a closer pattern to healthy controls. Therefore, we suggest that, depending on the severity of cognitive deficits, performance on neuropsychological tests may not reflect the same underlying mechanisms.

Escitalopram and Enhancement of Cognitive Recovery Following Stroke

Adjunctive restorative therapies administered during the first few months after stroke, the period with the greatest degree of spontaneous recovery, reduce the number of stroke patients with significant disability. To examine the effect of escitalopram on cognitive outcome. We hypothesized that patients who received escitalopram would show improved performance in neuropsychological tests assessing memory and executive functions than patients who received placebo or underwent Problem Solving Therapy. Randomized trial. Stroke center. One hundred twenty-nine patients were treated within 3 months following stroke. The 12-month trial included 3 arms: a double-blind placebo-controlled comparison of escitalopram (n = 43) with placebo (n = 45), and a nonblinded arm of Problem Solving Therapy (n = 41). Change in scores from baseline to the end of treatment for the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and Trail-Making, Controlled Oral Word Association, Wechsler Adult Intelligence Scale-III Similarities, and Stroop tests. We found a difference among the 3 treatment groups in change in RBANS total score (P < .01) and RBANS delayed memory score (P < .01). After adjusting for possible confounders, there was a significant effect of escitalopram treatment on the change in RBANS total score (P < .01, adjusted mean change in score: escitalopram group, 10.0; nonescitalopram group, 3.1) and the change in RBANS delayed memory score (P < .01, adjusted mean change in score: escitalopram group, 11.3; nonescitalopram group, 2.5). We did not observe treatment effects in other neuropsychological measures. When compared with patients who received placebo or underwent Problem Solving Therapy, stroke patients who received escitalopram showed improvement in global cognitive functioning, specifically in verbal and visual memory functions. This beneficial effect of escitalopram was independent of its effect on depression. The utility of antidepressants in the process of poststroke recovery should be further investigated. Trial Registration clinicaltrials.gov Identifier: NCT00071643.

Attentional Control Activation Relates to Working Memory in Attention-Deficit/Hyperactivity Disorder

Attentional control difficulties in individuals with attention-deficit/hyperactivity disorder (ADHD) might reflect poor working memory (WM) ability, especially because WM ability and attentional control rely on similar brain regions. The current study examined whether WM ability might explain group differences in brain activation between adults with ADHD and normal control subjects during attentional demand. Participants were 20 adults with ADHD combined subtype with no comorbid psychiatric or learning disorders and 23 control subjects similar in age, IQ, and gender. The WM measures were obtained from the Wechsler Adult Intelligence Scale-III and Wechsler Memory Scale-Revised. Brain activation was assessed with functional magnetic resonance imaging (fMRI) while performing a Color-Word Stroop task. Group differences in WM ability explained a portion of the activation in left dorsolateral prefrontal cortex (DLPFC), which has been related to the creation and maintenance of an attentional set for task-relevant information. In addition, greater WM ability predicted increased activation of brain regions related to stimulus-driven attention and response selection processes in the ADHD group but not in the control group. The inability to maintain an appropriate task set in young adults with combined type ADHD, associated with decreased activity in left DLPFC, might in part be due to poor WM ability. Furthermore, in individuals with ADHD, higher WM ability might relate to increased recruitment of stimulus-driven attention and response selection processes, perhaps as a compensatory strategy.

Validation study of a French version of the modified telephone interview for cognitive status (F‐TICS‐m) in elderly women

To evaluate the performance of a French version of the modified Telephone Interview for Cognitive Status (F-TICS-m) in identifying cognitive decline among elderly women. All women aged 72-86 participating in the 'Etude Epidémiologique auprès de Femmes de l'Education Nationale' (E3N) cohort and living in or near Paris constituted the target population of the validation study. Volunteer women (n = 120) underwent both a 20-min telephone interview and a face-to-face neuropsychological examination at an interval of few days (median interval: 10 days). The telephone interview included F-TICS-m, as well as a recall of key elements of a short story, arithmetic/verbal problems and two verbal fluency tests. Neuropsychological examination consisted of a standardized battery of cognitive tests (including the Mini-Mental State Examination (MMSE), the Free and Cued Selective Reminding Test-FCSRT, Trailmaking tests A and B, the similarities subtest of the Wechsler Adult Intelligence Scale-III, etc.) the Instrumental Activities of Daily Living questionnaire, and the Geriatric Depression Scale. Neuropsychological examination led to classification of each subject as cognitively normal (n = 92) or impaired/demented (n = 28). F-TICS-m showed satisfactory internal consistency (Cronbach's alpha = 0.69). It correlated linearly with MMSE (Pearson's r = 0.72). Concurrent validity against the gold-standard classification was satisfactory, with an area under the ROC curve (AUC) of 0.83. The combination of F-TICS-m and the other telephone tests had no additional effect on discrimination power in our sample (AUC = 0.81). F-TICS-m is a valid instrument for assessing the overall cognitive status of French elderly women. Its validity in men and its reproducibility warrant further studies.

The contribution of the cerebellum to cognition in Spinocerebellar Ataxia Type 6.

This study sought evidence for a specific cerebellar contribution to cognition by characterising the cognitive phenotype of Spinocerebellar Ataxia Type 6 (SCA-6); an autosomal dominant genetic disease which causes a highly specific late-onset cerebellar degeneration. A comprehensive neuropsychological assessment was administered to 27 patients with genetically confirmed SCA-6. General intellectual ability, memory and executive function were examined using internationally standardised tests (Wechsler Adult Intelligence Scale-III, Wechsler Memory Scale-III, Delis and Kaplan Executive Function System, Brixton Spatial Anticipation test). The patient group showed no evidence of intellectual or memory decline. However, tests of executive function involving skills of cognitive flexibility, inhibition of response and verbal reasoning and abstraction demonstrated significant impairment at the group level with large effect sizes. The results demonstrate an executive deficit due to SCA-6 that can be conceptualised as parallel to the motor difficulties suffered by these patients: the data support a role for the cerebellum in the regulation and coordination of cognitive, as well as motor processes that is relevant to individual performance.

The Contribution of the Cerebellum to Cognition in Spinocerebellar Ataxia Type 6

This study sought evidence for a specific cerebellar contribution to cognition by characterising the cognitive phenotype of Spinocerebellar Ataxia Type 6 (SCA-6); an autosomal dominant genetic disease which causes a highly specific late-onset cerebellar degeneration. A comprehensive neuropsychological assessment was administered to 27 patients with genetically confirmed SCA-6. General intellectual ability, memory and executive function were examined using internationally standardised tests (Wechsler Adult Intelligence Scale-III, Wechsler Memory Scale-III, Delis and Kaplan Executive Function System, Brixton Spatial Anticipation test). The patient group showed no evidence of intellectual or memory decline. However, tests of executive function involving skills of cognitive flexibility, inhibition of response and verbal reasoning and abstraction demonstrated significant impairment at the group level with large effect sizes. The results demonstrate an executive deficit due to SCA-6 that can be conceptualised as parallel to the motor difficulties suffered by these patients: the data support a role for the cerebellum in the regulation and coordination of cognitive, as well as motor processes that is relevant to individual performance.

Effects of education and cultural background on performance on WAIS-III, WMS-III, WAIS-R and WMS-R measures: Systematic review

The literature on the effects of education and cultural background on Wechsler Adult Intelligence Scale-III (WAIS-III), Wechsler Memory Scale-III (WMS-III), WAIS-R and WMS-R performances was reviewed. The electronic databases PsycINFO, MEDLINE and PubMed were searched over the period 1980–2008 and reference lists from papers identified were examined for relevant articles. Of 3,081 papers identified, 19 met criteria including English language, group research, adult sample, quantitative data published and focus on relationship between culture and/or education and performances on WAIS-III, WMS-III, WAIS-R or WMS-R measures. There was converging evidence that both education and culture showed significant relationships with test performances, particularly on the WAIS-III and WAIS-R in control and clinical groups. The limited research available did not demonstrate improved diagnostic efficiency with the application of demographic corrections for the WAIS-III. Clinical implications were discussed, including the issue of compromised validity when assessing people from diverse cultural backgrounds for whom relevant normative data are not available. Suggested research directions included the development of culturally and linguistically specific normative data, the modification and validation of “culture-free” tests and the examination of cultural effects in clinical groups in the Australian context.

Diagnostic efficiency of demographically corrected Wechsler Adult Intelligence Scale-III and Wechsler Memory Scale-III indices in moderate to severe traumatic brain injury and lower education levels

Despite the sensitivity of neuropsychological tests to educational level, improved diagnostic accuracy for demographically corrected scores has yet to be established. Diagnostic efficiency statistics of Wechsler Adult Intelligence Scale-III (WAIS-III) and Wechsler Memory Scale-III (WMS-III) indices that were corrected for education, sex, and age (demographically corrected) were compared with age corrected indices in individuals aged 16 to 75 years with moderate to severe traumatic brain injury (TBI) and 12 years or less education. TBI participants (n = 100) were consecutive referrals to an outpatient rehabilitation service and met careful selection criteria. Controls (n = 100) were obtained from the WAIS-III/WMS-III standardization sample. Demographically corrected indices did not provide higher diagnostic efficiency than age corrected indices and this result was supported by reanalysis of the TBI group against a larger and unmatched control group. Processing Speed Index provided comparable diagnostic accuracy to that of combined indices. Demographically corrected indices were associated with higher cut-scores to maximize overall classification, reflecting the upward adjustment of those scores in a lower education sample. This suggests that, in clinical practice, the test results of individuals with limited education may be more accurately interpreted with the application of demographic corrections. Diagnostic efficiency statistics are presented, and future research directions are discussed.

The impact of vascular comorbidities on qualitative error analysis of executive impairment in Alzheimer’s disease

Recent evidence suggests that patients with Alzheimer's disease (AD) and vascular comorbidities (VC) perform worse across measures of verbal reasoning and abstraction when compared to patients with AD alone. We performed a qualitative error analysis of Wechsler Adult Intelligence Scale-III Similarities zero-point responses in 45 AD patients with varying numbers of VC, including diabetes, hypertension, and hypercholesterolemia. Errors were scored in set if the answer was vaguely related to how the word pair was alike (e.g., dog-lion: "they can be trained") and out of set if the response was unrelated ("a lion can eat a dog"). AD patients with 2-3 VC did not differ on Similarities total score or qualitative errors from AD patients with 0-1 VC. When analyzing the group as a whole, we found that increasing numbers of VC were significantly associated with increasing out of set errors and decreasing in set errors in AD. Of the vascular diseases investigated, it was only the severity of diastolic blood pressure that significantly correlated with out of set responses. Understanding the contribution of VC to patterns of impairment in AD may provide support for directed patient and caregiver education concerning the presentation of a more severe pattern of cognitive impairment in affected individuals.

Change in Cognitive Functioning Following Acute Antidepressant Treatment in Late-Life Depression

Selective Serotonin Reuptake Inhibitors (SSRIs) are the most commonly prescribed medications for geriatric depression. The association of late-life depression and cognitive impairment has been well documented. However, there have been few placebo-controlled trials examining the impact of SSRIs on cognitive functioning. Prepost neuropsychological (NP) data collected as part of an 8-week, double-blind, placebo-controlled trial of citalopram in depressed patients aged 75 years and older were used to examine change in cognitive functioning. University-affiliated outpatient psychiatry clinics. One hundred seventy-four community-dwelling men and women aged 75 years or older with nonpsychotic unipolar depression. NP assessments included mental status (Mini-Mental State Examination), psychomotor speed (Wechsler Adult Intelligence Scale-III Digit Symbol Subtest), reaction time (Choice Reaction Time), visual-spatial skill (Judgment of Line Orientation), executive functioning (Stroop Color/Word Test), and memory (Buschke Selective Reminding Test). Differences in the pattern of change by treatment group depended on responder status. Citalopram nonresponders were the only group to decline on verbal learning and psychomotor speed. Citalopram responders showed significant improvement in visuospatial functioning, when compared with nonresponders in either condition, but their improvement was not greater than responders on placebo. Citalopram responders showed greater improvement on psychomotor speed than citalopram nonresponders, but their improvement was not greater than placebo responders or nonresponders. Medication may have a deleterious effect on some aspects of cognition among patients aged 75 years and older who have not responded. This suggests that patients should not be maintained on a medication if they have not had an adequate response.

Does Greater Phonological Storage Capacity Correlate with Levels of Intentionality and Theory of Mind?

Greater phonological storage capacity may be associated with levels of intentionality, and therefore by assumption, Theory of Mind. The participants were 34 high school students in the Midwest (15 girls, 19 boys; age range= 15 to 17 years). The measures were digits forward and digits backward from the Digit Span subtest of the Wechsler Adult Intelligence Scale-III and a measure purporting to assess Theory of Mind and Levels of Intentionality (Kinderman, Dunbar, & Bentall, 1998). There was found to be a weak nonsignificant correlation between digits forward and Levels of Intentionality, and a moderate and significant correlation between digits backward and Levels of Intentionality. The latter correlation was significantly larger. The digits backward test requires not only greater phonological storage capacity but also appears to tap working memory resources. Findings suggest that greater phonological storage capacity is associated with higher intentionality, and by implication, perhaps more elaborate Theory of Mind, but only when the phonological task requires working memory functions.

Serious Problems with the Mexican Norms for the WAIS-III when Assessing Mental Retardation in Capital Cases

A Spanish-language translation of the Wechsler Adult Intelligence Scale-III (WAIS-III), normed in Mexico, is sometimes used when evaluating Spanish-speaking defendants in capital cases in order to diagnose possible mental retardation (MR). Although the manual for the Mexican test suggests use of the U.S. norms when diagnosing MR, the Mexican norms—which produce full-scale scores on average 12 points higher—are sometimes used for reasons that are similar to those used by proponents for “race-norming” in special education. Such an argument assumes, however, that the Mexican WAIS-III norms are valid. In this paper, we examined the validity of the Mexican WAIS-III norms and found six very serious problems with those norms: (1) extremely poor reliability, (2) lack of a meaningful reference population, (3) lack of score normalization, (4) exclusion of certain groups from the standardization sample, (5) use of incorrect statistics and calculations, and (6) incorrect application of the true score confidence interval method. An additional problem is the apparent absence of any social policy consensus within Mexico as to the definition and boundary parameters of MR. Taken together, these concerns lead one to the inescapable conclusion that the Mexican WAIS-III norms are not interpretable and should not be used for any high-stakes purpose, especially one as serious as whether a defendant should qualify for exemption against imposition of the death penalty.

Is Psychopharmacologic Treatment Associated With Neuropsychological Deficits in Bipolar Youth?

To evaluate the impact of psychopharmacologic treatments on neuropsychological functioning in bipolar youth. Participants were 173 children (aged 6-17 years) with DSM-IV bipolar disorder. Participants were comprehensively assessed using structured diagnostic interviews (Schedule for Affective Disorders and Schizophrenia for School-Age Children) and neuropsychological measures (eg, subtests of the Wechsler Intelligence Scale for Children-III and Wechsler Adult Intelligence Scale-III) during the years 2001-2006. Comparisons were made in neuropsychological functioning between medicated and unmedicated youth with bipolar disorder. Children who were treated with mood stabilizers performed significantly (P < .05) more poorly than untreated children on measures of processing speed and working memory. Treatment with other classes of medication, including second-generation antipsychotics, was not significantly associated with neuropsychological impairments. Treatment with mood stabilizers may be associated with specific neuropsychological impairments. Cognitive side effects may need to be considered in selecting particular psychopharmacologic treatments for children with bipolar disorder.

Relationship Between Processing Speed and Executive Functioning Performance Among OEF/OIF Veterans

Comorbid mild traumatic brain injury (mTBI) with posttraumatic stress disorder (PTSD) is a common clinical presentation among troops returning from Operation Enduring Freedom and Operation Iraqi Freedom (OEF/OIF). This study examined processing speed and executive functioning in a sample of OEF/OIF veterans who had sustained mTBI, a subset of whom also had comorbid PTSD. Fifty-three OEF/OIF veterans with a history of mTBI completed Wechsler Adult Intelligence Scale-III Symbol Search and Digit Symbol-Coding subscales, Stroop Word, color and color-word trials, and Trail Making Test, Parts A and B as part of a comprehensive neuropsychological test battery. Excluding from analysis those who scored poorly on effort testing, multiple regression showed that measures of processing speed accounted for 43% of the variance in performance on the Trail Making Test, Part B and 50% of the variance in performance on the Stroop task. Significant differences in processing speed and executive functioning were found on the basis of presence of comorbid PTSD. Stroop Color (F = 9.27, df = 52, P < .004) and Stroop Color Word (F = 7.19, df = 52, P < .01) scores differed significantly between the groups. Those having comorbid PTSD (+TBI/+PTSD) scored significantly poorer than the mTBI-only group (+TBI/-PTSD). Implications for treatment of the comorbid conditions are discussed.

A comparison of laboratory and clinical working memory tests and their prediction of fluid intelligence

The working memory (WM) construct is conceptualized similarly across domains of psychology, yet the methods used to measure WM function vary widely. The present study examined the relationship between WM measures used in the laboratory and those used in applied settings. A large sample of undergraduates completed three laboratory-based WM measures (operation span, listening span, and n-back), as well as the WM subtests from the Wechsler Adult Intelligence Scale-III and the Wechsler Memory Scale-III. Performance on all of the WM subtests of the clinical batteries shared positive correlations with the lab measures; however, the Arithmetic and Spatial Span subtests shared lower correlations than the other WM tests. Factor analyses revealed that a factor comprising scores from the three lab WM measures and the clinical subtest, Letter-Number Sequencing (LNS), provided the best measurement of WM. Additionally, a latent variable approach was taken using fluid intelligence as a criterion construct to further discriminate between the WM tests. The results revealed that the lab measures, along with the LNS task, were the best predictors of fluid abilities.

Neuropsychological performance is related to current social and occupational functioning in veterans with posttraumatic stress disorder

Several studies have reported deficits in both immediate and delayed recall of verbal memory in patients with posttraumatic stress disorder (PTSD). However, most of these studies had several methodological disadvantages. None of these studies assessed parameters related to social or occupational functioning. Fifty Dutch veterans of UN peacekeeping missions (25 with PTSD and 25 without PTSD) were assessed with a comprehensive neuropsychological test battery consisting of four subtests of the Wechsler Adult Intelligence Scale-III, California Verbal-Learning Test, and the Rey Auditory Verbal-Learning Test. Veterans with PTSD were free of medication and substance abuse. Veterans with PTSD had similar total intelligence quotient scores compared to controls, but displayed deficits of figural and logical memory. Veterans with PTSD also performed significantly lower on measures of learning and immediate and delayed verbal memory. Memory performance accurately predicted current social and occupational functioning. Deficits of memory performance were displayed in a sample of medication- and substance abuse-free veterans with PTSD. Deficits in memory performance were not related to intelligence quotient, length of trauma exposure, or time since trauma exposure. This study showed that cognitive performance accurately predicted current social and occupational functioning in veterans with PTSD.

Cognitive Dysfunctions Associated With PTSD: Evidence from World War II Prisoners of War

The authors aim to delineate cognitive dysfunction associated with posttraumatic stress disorder (PTSD) by evaluating a well-defined cohort of former World War II prisoners of war (POWs) with documented trauma and minimal comorbidities. The authors studied a cross-sectional assessment of neuropsychological performance in former POWs with PTSD, PTSD with other psychiatric comorbidities, and those with no PTSD or psychiatric diagnoses. Participants who developed PTSD had average IQ, while those who did not develop PTSD after similar traumatic experiences had higher IQs than average (approximately 116). Those with PTSD performed significantly less well in tests of selective frontal lobe functions and psychomotor speed. In addition, PTSD patients with co-occurring psychiatric conditions experienced impairment in recognition memory for faces. Higher IQ appears to protect individuals who undergo a traumatic experience from developing long-term PTSD, while cognitive dysfunctions appear to develop with or subsequent to PTSD. These distinctions were supported by the negative and positive correlations of these cognitive dysfunctions with quantitative markers of trauma, respectively. There is a suggestion that some cognitive decrements occur in PTSD patients only when they have comorbid psychiatric diagnoses.

Compromised fronto-striatal functioning in HIV: An fMRI investigation of semantic event sequencing

The human immunodeficiency virus (HIV) damages fronto-striatal regions, and is associated with deficits in executive functioning. We recently developed a semantic event sequencing task based on the Picture Arrangement subtest of the Wechsler Adult Intelligence Scale-III for use with functional magnetic resonance imaging (fMRI) and found recruitment of dorsolateral prefrontal cortex and basal ganglia in healthy participants. To assess the impact of HIV on the functioning of the basal ganglia and prefrontal cortex, we administered this task to 11 HIV+ and 11 Control participants matched for age and education. Neuropsychological evaluation demonstrated that the HIV+ group had mild impairment in memory retrieval and motor functioning, but was not demented. Morphometric measurements suggested no atrophy in basal ganglia regions. The results of the fMRI analysis revealed hypoactivation of the left caudate, left dorsolateral prefrontal cortex, and bilateral ventral prefrontal cortex in the HIV+ group. Functional connectivity analysis demonstrated less functional connectivity between the caudate and prefrontal cortex and basal ganglia regions in the HIV+ group. In contrast, the HIV+ group demonstrated increased activation of right postcentral/supramarginal gyrus, and greater connectivity between the caudate and this same anterior parietal region. The results of this study extend previous investigations by demonstrating compromised function of the caudate and connected prefrontal regions in HIV during cognition. This disruption of fronto-striatal circuitry likely precedes the development of cognitive impairment in HIV.

Metric and structural equivalence of core cognitive abilities measured with the Wechsler Adult Intelligence Scale-III in the United States and Australia

Equivalence of the psychological model underlying Wechsler Adult Intelligence Scale–Third Edition (WAIS-III) scores obtained in the United States and Australia was examined in this study. Examination of metric invariance involves testing the hypothesis that all components of the measurement model relating observed scores to latent variables are numerically equal in different samples. The assumption of metric invariance is necessary for interpretation of scores derived from research studies that seek to generalize patterns of convergent and divergent validity and patterns of deficit or disability. An Australian community volunteer sample was compared to the US standardization data. A pattern of strict metric invariance was observed across samples. In addition, when the effects of different demographic characteristics of the US and Australian samples were included, structural parameters reflecting values of the latent cognitive variables were found not to differ. These results provide important evidence for the equivalence of measurement of core cognitive abilities with the WAIS-III and suggest that latent cognitive abilities in the US and Australia do not differ.

Changes in Cognitive Function During Substance Use Disorder Treatment

This study investigated the pattern of acute cognitive function of an ecologically valid sample of 58 consecutively admitted adults completing a 24 day residential/day substance use disorder treatment program at a Veterans Affairs Medical Center and its change over the 24 days of monitored abstinence. Participants were assessed at entry with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Form A and at treatment conclusion with the RBANS Form B and with the Similarities subtest of the Wechsler Adult Intelligence Scale-III (WAIS-III) and the Trail Making A and B tests at both time points. There were significant (p < 0.002) improvements in the RBANS Immediate Memory, Attention, and Total Index scores over the course of treatment and on the Similarities subtest and the Trail Making A and B tests with effect sizes ranging between 0.37 and 0.56. There was greater cognitive performance increase for participants in the lower versus upper quantiles at treatment entry on all cognitive measures.