Parsimonious prediction of Wechsler Memory Scale--III memory indices

Equations for prorating the Wechsler Memory Scale--III (WMS-III) Index scores were derived and validated on a sample of 252 mixed clinical cases. Regression equations were performed using age-scaled scores as predictors and the sum of age-scaled scores for Immediate Memory (IM) and General Memory (GM) as the criteria. Including Logical Memory and Verbal Paired Associates with either Faces or Family Pictures resulted in estimated scores that accounted for 95% to 97% of the variance for IM and GM. Over 80% of these cases had estimated sum of scaled scores that fell within 3 points of actual sum of scaled scores, within 1 standard error of measurement. When only Logical Memory and Verbal Paired Associates were included, estimations accounted for only 87% of the variance, and only 60% of the estimated scores fell within 3 points of actual sum of scaled scores. The regression equations are presented, as are the confidence intervals derived from a bootstrapping procedure that created 15,000 different samples.     

Construct and concurrent validity of the Cambridge neuropsychological automated tests in Portuguese older adults without neuropsychiatric diagnoses and with Alzheimer’s disease dementia

We aimed to analyze the construct and concurrent validity of the Rapid Visual Information Processing (RVP), Paired Associates Learning (PAL), Reaction Time (RTI), and Spatial Working Memory (SWM) tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB®). Inclusion criteria were checked in a first session. The CANTAB and additional pencil-and-paper tests were administered within 1 week. The participants (aged 69–96 years) were 137 Portuguese adults without neuropsychiatric diagnoses and 37 adults with mild-to-moderate Alzheimer’s disease dementia. Comparisons were made between the CANTAB tests and between these tests and the Rey Complex Figure Test (RCFT), Verbal Fluency (VF) test, and some Wechsler Memory Scale-III and Wechsler Adult Intelligence Scale-III subtests. Most intra-test correlations were stronger than the CANTAB inter-test correlations. The RVP correlated more with VF animals (.44), the PAL with RCFT immediate recall (–.52), the RTI with RVP mean latency (.42), and the SWM with Spatial Span backward (–.39).     

Measurement of individual differences: lessons from memory assessment in research and clinical practice

An examination of test manuals and published research indicates that widely used memory tests (e.g., Verbal Paired Associates and Word List tests of the Wechsler Memory Scale, Rey Auditory Verbal Learning Test, and California Verbal Learning Test) are afflicted by severe ceiling effects. In the present study, the true extent of memory ability in healthy young adults was tested by giving 208 college undergraduates verbal paired-associate and verbal learning tests of various lengths; the findings demonstrate that healthy adults can remember much more than is suggested by the normative data for the memory tests just mentioned. The findings highlight the adverse effects of low ceilings in memory assessment and underscore the severe consequences of ceiling effects on score distributions, means, standard deviations, and all variability-dependent indices, such as reliability, validity, and correlations with other tests. The article discusses the optimal test lengths for verbal paired-associate and verbal list-learning tests, shows how to identify ceiling-afflicted data in published research, and explains how proper attention to this phenomenon can improve future research and clinical practice.     

Defects of immediate memory related to the cerebral blood flow distribution

Different forms of memory defects were studied in 16 patients with organic dementia. The test performance was related to the regional cerebral blood flow (rCBF) in the left (dominant) hemisphere. Verbal memory (Paired Associates) correlated to the blood flow in temporal and parietal regions. Spatial recognition (Memory for Objects, Memory for Geometrical Design) correlated to the temporal and lower frontal regions. One spatial memory test (Visual Retention test) correlated to the temporal region only. Another spatial memory test (Memory for Design) did not show correlations to any regions of the dominant hemisphere. Finally it was found that the hemisphere mean flow values did not correlate to performance. This emphasizes the main finding—the regional correlations. It is concluded that memory performance involves various extratemporal regions depending upon the specific quality of the memory task to be performed.     

Episodic future thinking: Linking neuropsychological performance with episodic detail in young and old adults

Episodic future thinking (EFT) has been linked with our ability to remember past events. However, its specific neurocognitive subprocesses have remained elusive. In Experiment 1, a study of healthy older adults was conducted to investigate the candidate subprocesses of EFT. Participants completed a standard EFT cue word task, two memory measures (Verbal Paired Associates I, Source Memory), and two measures of executive function (Trail Making Test, Tower Test). In Experiment 2, healthy young adults also completed an EFT task and neuropsychological measures. The link between neurocognitive measures and five characteristics of EFT was investigated. Specifically, it was found that Source Memory and Trail Making Test performance predicted the episodic specificity of future events in older but not younger adults. Replicating previous findings, older adults produced future events with greater semantic but fewer episodic details than did young adults. These results extend the data and emphasize the importance of the multiple subprocesses underlying EFT.     

WAIS-IV subtest covariance structure: conceptual and statistical considerations

D. Wechsler (2008b) reported confirmatory factor analyses (CFAs) with standardization data (ages 16-69 years) for 10 core and 5 supplemental subtests from the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV). Analyses of the 15 subtests supported 4 hypothesized oblique factors (Verbal Comprehension, Working Memory, Perceptual Reasoning, and Processing Speed) but also revealed unexplained covariance between Block Design and Visual Puzzles (Perceptual Reasoning subtests). That covariance was not included in the final models. Instead, a path was added from Working Memory to Figure Weights (Perceptual Reasoning subtest) to improve fit and achieve a desired factor pattern. The present research with the same data (N = 1,800) showed that the path from Working Memory to Figure Weights increases the association between Working Memory and Matrix Reasoning. Specifying both paths improves model fit and largely eliminates unexplained covariance between Block Design and Visual Puzzles but with the undesirable consequence that Figure Weights and Matrix Reasoning are equally determined by Perceptual Reasoning and Working Memory. An alternative 4-factor model was proposed that explained theory-implied covariance between Block Design and Visual Puzzles and between Arithmetic and Figure Weights while maintaining compatibility with WAIS-IV Index structure. The proposed model compared favorably with a 5-factor model based on Cattell-Horn-Carroll theory. The present findings emphasize that covariance model comparisons should involve considerations of conceptual coherence and theoretical adherence in addition to statistical fit.     

Age-related Changes in Memory and Fluid Reasoning in a Sample of Healthy Old People

ABSTRACT

Participants in the Healthy Old People in Edinburgh (HOPE) study (N = 398) were assessed on Raven's Progressive Matrices and Logical Memory on up to three occasions. Covariates included education, social class, disease and medication status, blood pressure and study outcome. Raven's score declined linearly with age, whereas decline in Logical Memory was accelerating. There was significant variation in individuals' rates of decline for Ravens but not Logical Memory. Slope–intercept covariances were not significant. Those who later developed dementia already exhibited lower scores, more so for Logical Memory than Raven's. Death and study attrition were related to performance, again greater for Logical Memory. Conclusions: The HOPE approach of progressive screening is a feasible and practical method for studying healthy cognitive ageing. As predicted for an initially healthy sample, rates of decline were relatively homogeneous. The hypothesis of differential decline was not supported, nor was a strict interpretation of the hypothesis that cognitive ageing is entirely pathology driven.     

The WISC-V in children and adolescents with epilepsy

Despite its popularity in the neuropsychological evaluation of children, the utility of the Wechsler Intelligence Scale for Children – Fifth Edition (WISC-V) has not yet been investigated in children with epilepsy. Eighty clinically referred children and adolescents with epilepsy were administered the WISC-V as part of a comprehensive assessment and scores were compared to matched controls from the WISC-V standardization sample. T tests compared WISC-V indices and subtests between patients and controls and Chi-square analyses compared the rates of low scores. Correlational analyses assessed the relationships between epilepsy severity variables (e.g., age of onset, duration of epilepsy, number of antiepileptic drugs, seizure frequency). All WISC-V composites and subtests were significantly lower in patients versus controls and the rate of low scores was higher in patients than controls for all composites and subtests with the exception of Figure Weights. The Working Memory Index and Processing Speed Index were most sensitive to impairment, while the Verbal Comprehension Index and Fluid Reasoning Index were least sensitive. Of the epilepsy severity variables, age of seizure onset and number of antiepileptic drugs were strong predictors of deficits, whereas seizure frequency was the weakest predictor. Importantly, no significant differences were seen in children with right hemisphere epilepsy versus left on the five WISC-V composites, though a trend was seen towards a lower Visual-Spatial Index in those with right-sided focal seizures.     

A confirmatory factor analysis of the California Verbal Learning Test--Second Edition (CVLT-II) in the standardization sample

The purpose of this study is to determine the latent structure of the California Verbal Learning Test-Second Edition (CVLT-II; Delis, Kramer, Kaplan, & Ober, 2000) at three different age levels, using the standardization sample. Maximum likelihood confirmatory factor analyses are performed to test four competing hypothetical models for fit and parsimony. A four-factor model consisting of Attention Span, Learning Efficiency, Delayed Memory, and Inaccurate Memory provides the best fit to the data at two age levels (16-30 years and 31-60 years, respectively) but the factor structure is somewhat less robust in the oldest age group (>60 years). The results clarify the latent structure of the CVLT-II and suggest that a multifactorial interpretation of quantitative and qualitative indexes from this instrument is appropriate for clinical practice with most adults, although findings may need to be interpreted more cautiously among older persons.     

Replication of the factor structure of the Wechsler Adult Intelligence Scale--Third Edition with a Canadian sample

Exploratory and confirmatory factor analyses of the subtests of the Wechsler Adult Intelligence Scale--Third Edition (WAIS-III; D. Wechsler, 1997b) were conducted on a stratified sample of Canadian adults (n = 718). As was previously demonstrated for the children's version of this scale, the factor model of the American standardization sample was replicated across this Canadian national sample. Results of the factor analyses confirmed the presence of the 4 WAIS-III factors: Verbal Comprehension, Perceptual Organization, Working Memory, and Processing Speed.     

Confirmatory factor analysis of the WAIS-IV/WMS-IV

The Wechsler Adult Intelligence Scale-fourth edition (WAIS-IV) and the Wechsler Memory Scale-fourth edition (WMS-IV) were co-developed to be used individually or as a combined battery of tests. The independent factor structure of each of the tests has been identified; however, the combined factor structure has yet to be determined. Confirmatory factor analysis was applied to the WAIS-IV/WMS-IV Adult battery (i.e., age 16-69 years) co-norming sample (n = 900) to test 13 measurement models. The results indicated that two models fit the data equally well. One model is a seven-factor solution without a hierarchical general ability factor: Verbal Comprehension, Perceptual Reasoning, Processing Speed, Auditory Working Memory, Visual Working Memory, Auditory Memory, and Visual Memory. The second model is a five-factor model composed of Verbal Comprehension, Perceptual Reasoning, Processing Speed, Working Memory, and Memory with a hierarchical general ability factor. Interpretative implications for each model are discussed.     

Psychometric properties and reference data for Danish versions of Free and Cued Selective Reminding Test,Category Cued Memory Test and Logical Memory

Memory assessment is a key element in neuropsychological testing. Gold standard evaluation is based on updated normative data, but in many small countries (e.g. in Scandinavia) such data are sparse. In Denmark, reference data exist for non‐verbal memory tests and list‐learning tests but there is no normative data for memory tests which capture narrative recall and cued recall. In a nation‐wide study, Free and Cued Selective Reminding Test (FCSRT ), WMS ‐III Logical Memory (LM ) and a newly developed test Category Cued Memory Test (CCMT ‐48) were applied in 131 cognitively intact persons (aged 60–96 years). Regression‐based reference data for Danish versions of FCSRT , CCMT ‐48 and LM adjusted for age, education and gender are provided. Gender and age‐group had a significant impact on the expected scores, whereas the effect of education had a limited effect on expected scores. Test performances were significantly correlated in the range 0.21–0.51. Based on these findings and previous results it may be relevant to assess both free recall, cued recall and recognition to tap the earliest changes associated with neurodegeneration, and this study therefore provides an important supplement to existing Danish normative data. Future studies should investigate the discriminative validity of the tests and the clinical utility of the presented reference data.     

Two- and three-factor solutions of the WAIS-III

The third edition of the Wechsler Adult Intelligence Scale manual reports four-factor solutions for the WAIS-III, and subsequent research has validated four-factor solutions for a variety of samples. These four factors consistently correspond to the four Factor Indexes that are yielded by the WAIS-III. However, the WAIS-III still provides Verbal and Performance IQs, in addition to the Indexes, making it desirable to examine two-factor solutions as well. In addition, because the Wechsler literature includes much interpretation of three-factor solutions, these solutions were likewise examined. Principal factor analysis followed by Varimax and Oblimin rotations of two and three factors were performed on data for the total WAIS-III sample ages 16 to 89 years (N=2,450). The two-factor solutions were viewed as a construct validation of Wechsler's two separate IQs, although the Working Memory subtests tended to load higher on the Performance scale than on their intended scale (Verbal); three-factor solutions were interpreted within the context of Horn's expanded fluid-crystallized theory and research on working memory. Both the two- and three-factor Varimax-rotated solutions were related to similar factor analyses conducted previously for the Wechsler Adult Intelligence Scale-Revised and the Wechsler Intelligence Scale for Children-III. Coefficients of congruence between like-named factors consistently exceeded .90, and usually .98, across different Wechsler batteries.     

Learning Chinese characters may improve visual recall.

From elementary through high school, Japanese children are required to memorize a large number of distinct visual forms, i.e., roughly 2,000 Chinese characters, and tremendous effort is expended in learning to read and write them. We hypothesized that early training in memorizing Chinese characters and the use of these characters in daily life shapes brain development and facilitates recall of visual forms in general, including geometrical figures in visual recall tests. To demonstrate whether the learning of Chinese character is correlated with specific aspects of memory, we administered the Wechsler Memory Scale-Revised (WMS-R) to a representative sample of the normal Japanese population (316 persons, 100% Japanese) and compared their scores with data previously obtained from a representative sample of the normal U.S. population (316 persons, 82.5% Caucasian). The WMS-R has 12 memory subtests, each measuring a different aspect of memory and includes two visual recall subtests (Visual Reproduction I and II). Compared to the Americans, the Japanese group obtained significantly higher scores on these two visual recall subtests in each of the six age groups tested (16 to 74 years old). Further, the scores of Japanese on the two visual recall subtests did not decline across age groups as much as scores for the U.S. group. Japanese also scored significantly higher on the Visual Memory Span subtest in three age groups.     

Differential Memory Test Sensitivity for Diagnosing Amnestic Mild Cognitive Impairment and Predicting Conversion to Alzheimer's Disease

ABSTRACT

Episodic memory is the first and most severely affected cognitive domain in Alzheimer's disease (AD), and it is also the key early marker in prodromal stages including amnestic mild cognitive impairment (MCI). The relative ability of memory tests to discriminate between MCI and normal aging has not been well characterized. We compared the classification value of widely used verbal memory tests in distinguishing healthy older adults (n = 51) from those with MCI (n = 38). Univariate logistic regression indicated that the total learning score from the California Verbal Learning Test-II (CVLT-II) ranked highest in terms of distinguishing MCI from normal aging (sensitivity = 90.2; specificity = 84.2). Inclusion of the delayed recall condition of a story memory task (i.e., WMS-III Logical Memory, Story A) enhanced the overall accuracy of classification (sensitivity = 92.2; specificity = 94.7). Combining Logical Memory recognition and CVLT-II long delay best predicted progression from MCI to AD over a 4-year period (accurate classification = 87.5%). Learning across multiple trials may provide the most sensitive index for initial diagnosis of MCI, but inclusion of additional variables may enhance overall accuracy and may represent the optimal strategy for identifying individuals most likely to progress to dementia.     

Demographic and intellectual correlates of the Short-term Memory Test.

This study examined the effect of demographic variables and intellectual factors on the Short-term Memory Test. Subjects were 20 patients neurologically diagnosed as brain-damaged. There was only one significant correlation between Verbal IQ and the Short-term Memory Test. Demographic variables of age, education, and sex did not correlate significantly with scores of the Short-term Memory Test.     

Neuropsychological correlates of psychopathology in an unselected cohort of young adolescents

Members of a birth cohort were assessed for psychopathology and neuropsychological dysfunction at age 13. Ss who met DSM-III criteria for a single disorder, multiple disorders, and no disorder were compared on 5 composite neuropsychological measures. The multiple disorders group performed significantly worse than did the nondisordered group on the Verbal, Visuospatial, Verbal Memory, and Visual-Motor Integration factors. They also showed the highest rate of neuropsychological impairment. The attention-deficit disorder group performed significantly worse than did the nondisordered group on the Verbal Memory and Visual-Motor Integration factors, and the anxiety disorder group performed significantly worse than did the nondisordered group on the Visual-Motor Integration factor. Results suggest that neuropsychological dysfunction is more often associated with multiple rather than single, psychiatric disorders in adolescents. The problem of comorbidity in studies of neuropsychological function in childhood and adolescent psychopathology is highlighted.     

A latent growth curve analysis of late-life sensory and cognitive function over 8 years: evidence for specific and common factors underlying change

Correlations among rates of change in sensory and cognitive functioning in adulthood were evaluated. Measures of Vision, Hearing, Memory, Speed and Verbal ability were obtained in 1992, 1994, and 2000 in the Australian Longitudinal Study of Aging (N = 2,087 at baseline). Data from 1,823 participants who undertook at least 1 clinical assessment were analyzed using latent growth curve models. A significant moderate-sized association between rates of change in Memory and Vision was found. This remained after statistically controlling for the effects of age, gender, education, self-rated health, medical conditions, and depressive symptoms. Rate of change in Hearing was weakly associated with rate of change in Memory. The results support a theory incorporating a major role for unique factors in addition to common factors underlying sensory and cognitive change in old age.     

Apolipoprotein e gene variability and cognitive functions at age 79: a follow-up of the Scottish mental survey of 1932

Apolipoprotein E (APOE) genotype is a possible influence on nonpathological cognitive aging. The authors studied 462 community-dwelling, 79-year-old people born in 1921, whose childhood IQ had been assessed in the Scottish Mental Survey of 1932 (Scottish Council for Research in Education, 1933). Adjusting for sex, childhood IQ, and self-reported illnesses, the authors found that those with an APOE e4 allele had significantly lower Wechsler Logical Memory (D. Wechsler, 1987) scores than those without an e4 allele. Those people with APOE s2/e3 genotypes had significantly higher Wechsler Logical Memory scores than e3/s3, who were significantly higher than e3/e4. Neither nonverbal reasoning nor verbal fluency were affected. In this sample, APOE genotype contributed to verbal memory in old age.