Confirmatory analysis of the factor structure of the wechsler memory scale-revised

Abstract

Memory functions are known to be multifaceted. Models of the dimensionality of memory, as measured by the Wechsler Memory Scale-Revised (WMS-R), were investigated. Confirmatory factor analysis was used to explore one-, two-, and three-factor models for the first eight subtests of the WMS-R given to normal subjects in the standardization sample (N = 316) and a heterogeneous sample of clinical subjects (N = 343). The best fitting model was a two-factor model with general memory and attention/concentration dimensions.     

Interrater agreement on the wechsler memory scale-revised in a mixed clinical population

Logical Memory and Visual Reproduction subtests of the Wechsler Memory Scale-Revised (WMS-R) were administered as a part of a comprehensive neuropsychological test battery to 50 inpatient and outpatient male veterans (M = 52 years) with diagnoses of neurologic, alcoholic, and psychiatric conditions. Tests were scored blindly by two trained examiners and kappa values were reported for Logical Memory text, and individual scoring criteria for Visual Reproductions. Almost perfect interrater agreement beyond chance was generally observed, thus replicating excellent interrater reliability obtained from a healthy normative sample. Mild variability (moderate agreement) on individual items is discussed.     

Confirmatory factor analysis of the wechsler memory scale-revised in a sample of head-injured patients

Abstract

As part of a standard evaluation of neuropsychological sequelae, the Wechsler Memory Scale-Revised (WMS-R) was administered to 107 patients with a history of traumatic brain injury. Confirmatory factor analyses were conducted on the 12 subtests of the WMS-R to examine the fit of various hypothesized factor patterns, including patterns identified in previous exploratory factor analytic studies. Because part of the correlation between immediate and delayed recall trials of the same material is attributable to a common measurement procedure, this correlation due to measurement commonality was partialled out of the conceptual factor structure. The results suggested the presence of 3 distinct but highly correlated factors: attention/concentration, immediate memory, and delayed recall. Models that posited separate verbal and nonverbal memory processes failed to improve fit over more parsimonious models. Comparisons with previous factor analytic studies and implications for clinical assessment are discussed.     

Development of the wechsler memory scale-revised

Abstract

The 1945 Wechsler Memory Scale has been revised in terms of content, structure, scoring procedures, and norms. The changes and additions were guided in part by limitations of the original scale. This paper describes this process.     

Factor structure of the wechsler memory scale-revised

Abstract

The factor structure of the Wechsler Memory Scale-Revised (WMS-R) was examined in a large (N = 434) sample of patients referred to the neuropsychology laboratories of two large medical centers. The subtests of the WMS-R were subjected to principal-components factor analysis. Some analyses included only the immediate-recall subtests, while other analyses included both immediate-and delayed-recall subtests. Additional analyses included VIQ and PIQ from the WAIS-R. Initial analyses of immediate-recall subtests indicated a two-factor solution similar to that reported in the standardization sample. Inclusion of IQ scores also revealed a two-factor solution with IQ scores and most memory subtests loading on separate factors. Inclusion in the analysis of delayed-recall subtests revealed three-factor solution with factors interpreted as representing verbal memory, nonverbal memory, and attention/IQ. These results are discussed in terms of factor-analytic studies of the earlier Wechsler Memory Scale, and the implications of the current data for research and clinical practice.     

An elaborated administration of the wechsler memory scale-revised

Abstract

The Wechsler Memory Scale-Revised (Wechsler, 1987) was elaborated by adding 20 recognition items for Logical Memory (LM) and by adding recognition, matching, and copy trials for Visual Reproductions (VR). Reliability was very good for VR copy (α = .77, interrater agreement, 100% within 1 point). Reliability was modest for LM recognition (α = .42) and for VR recognition (α = .58), but reasonable given the small number of items on each measure. The reliability coefficient was very weak for VR matching (a = .10), limited considerably by the ease of the task for this healthy sample and by the small number of items. After statistically correcting for imperfect reliability, validity coefficients (correlations with similar tests that are well standardized) were good for all of the new trials (r = .60 to r = 1.00). Age- and education-appropriate reference data are provided using 81 healthy adults. Further validation using theoretically and clinically meaningful patient groups would be very valuable. In the meantime, the new trials should serve the clinician well as screening tools.     

A prorating system for the wechsler memory scale-revised

Various sensory and motor impairments may render a patient unable to complete certain subtests on the Wechsler Memory Scale-Revised (WMS-R). Consequently, when a subtest is missing from the battery, the clinician is unable to obtain one or more of the summary indices typically provided by the WMS-R. The present study used a mixed clinical sample (N = 300) to derive regression weights that may be used to predict a patient's performance on each of the WMS-R memory indices when a subtest is missing. The relative contributions of each subtest to the scale with which it is associated and the predictive accuracy of the regression equations are discussed.     

Factor analysis of the wechsler memory scale-revised and the halstead-reitan neuropsychological battery

A principal components factor analysis of the 12 subtests of the WMS-R, WAIS Verbal and Performance IQ scores, and measures of a modified Halstead-Reitan Neuropsychological Battery was performed on a sample of 135 patients. The Visual Reproduction subtests I and II factored with other spatial measures and Performance IQ while Logical Memory I and II and Verbal Paired Associates I and II emerged as separate verbal memory factors. Additionally, two attention/concentration factors were found, one primarily verbal and one primarily visual. Further study in the interpretation of the Verbal and Visual Memory Indexes was advised.     

Cross-validation of a method for predicting wechsler memory scale-revised index scores

Abstract

Equations for prorating Wechsler Memory Scale-Revised General Memory (GM) and Delayed Recall (DR) index scores (Woodward & Axelrod, 1995) were confirmed in clinical samples of patients who were seen for comprehensive neuropsychological testing with (1) moderate or severe closed-head injuries (n = 53); (2) mild head injury/concussion (n = 47); and (3) patients with intractible seizures who were seen for neuropsychological testing prior to neurosurgical resection (n = 24). Fifty-one of the closed-head injury (CHI) patients were involved in litigation related to their injury at the time of this evaluation. Predicted GM and DR index scores fell within 6 points of the obtained scores for 91% and 92%, respectively, of the CHI sample, and 100% of the seizure resection sample. This is well within the standard error of measurement of these index scores. There were no significant differences in accuracy of estimated index scores between litigants and non-litigants or between levels of head injury severity. These findings confirm the earlier cross-validation results reported by Axelrod et al. (1996) in a mixed sample of traumatic brain injury and other neurological insult.     

Residual neuropsychological deficits following head-injury on the wechsler memory scale-revised

Abstract

The Wechsler Memory Scale-Revised (WMS-R) was administered to 13 individuals with normal premorbid abilities who had experienced moderate to severe head injuries at least 1 year previously. Results were compared to performance on the Rey Auditory-Verbal Learning Test (RAVLT), the Rey-Osterrieth Complex Figure Test (ROCFT), and the Paced Auditory Serial-Addition Task (PASAT). The findings in the present sample of head-injured individuals indicated greater construct validity for the WMS-R Indexes of Verbal, Visual, and Delayed Memory than for the Attention Concentration Index. Further research is suggested to replicate and clarify these findings, and it is further recommended that additional measures of attention and concentration be used to supplement the WMS-R in clinical practice.     

Psychometric properties and factor structure of the wechsler memory scale-revised in a sample of persons with intractable epilepsy

Abstract

The Wechsler Memory Scale-Revised (WMS-R) is used routinely as a presurgical assessment of memory for clients considering elective resection of the temporal lobe and/or hippocampus for the relief of intractable temporal lobe epilepsy. This research investigated the psychometric properties of the WMS-R in a population of people with epilepsy. The sample consisted of 181 patients with a diagnosis of epilepsy who underwent a complete neuropsychological examination as a routine part of their investigation. The results confirm that the WMS-R has acceptable levels of reliability as measured by internal consistency. A factor analysis revealed a consistent three-factor structure: Visual Memory, Verbal Memory, and Attention/Concentration factors. Multiple regression analysis, however, indicated that the Visual Memory index was susceptible to a number of influences, throwing into question whether it is a pure measure of nonverbal memory functioning.     

The performance of patients with schizophrenia on the wechsler memory scale-revised

The performance of 45 patients with schizophrenia was examined on the Wechsler Memory Scale-Revised (WMS-R). The patients demonstrated a relatively flat performance profile across the five major WMS-R index scores suggesting similar levels of impairment in memory and attentional processes, in memory for visual and verbal materials, and in immediate and delayed recall. The General Memory Index (GMI) was lower than Full Scale IQ (FSIQ) scores in the majority of cases, and a large portion of the sample demonstrated fairly severe differential impairments of memory with FSIQ exceeding the GMI by 15 or more points. These results are consistent with prior findings of memory impairment in schizophrenia and support the validity of the WMS-R as a measure of memory deficits in schizophrenia.     

Factor structure of the wechsler memory scale-revised (WMS-R) in a clinical sample: A methodological reappraisal

Principal components and common factors of the Wechsler Memory Scale-Revised (WMS-R) were derived from a clinical sample (N = 168) of males referred for neuropsychological evaluation at a rural Veterans Administration Medical Center. One general memory component accounting for 54% of the variance was consistently identified, whether the analyses included the eight immediate subtests alone, all 12 immediate and delayed-recall subtests, or the WMS-R and VIQ/PIQ combined. Minimal support for a second factor which contributed 9.4% of the total variance was found only after Verbal and Performance IQ scores were included in the analysis. The failure of these data to support previous reports of multiple WMS-R components is attributed in part to different factor retention criteria. Principal-component loadings nominally exceeded those derived by common factor analysis. Clinical implications of these findings are discussed.     

Confirmatory factor analysis of the behavioral dyscontrol scale in a mixed clinical sample

The Behavioral Dyscontrol Scale (BDS) is a brief measure of executive functioning originally designed for use primarily with older adults. Previous research suggests that factors derived from exploratory factor analysis of the BDS have clinical utility and are theoretically meaningful; however, the factor structure has not been previously submitted to confirmatory analysis, and there are several potential methodological problems with the previous exploratory factor analysis. In this study, we conducted a confirmatory factor analysis of the BDS. Findings were largely consistent with the original exploratory analysis (Grigsby, Kaye, & Robbins, 1992) in suggesting a three-factor model, although the three-factor model was a better fit if factors were allowed to correlate with one another. The findings of this study lend support to the current practice of using factor scores in clinical and research applications.     

Estimating memory function: Disparity of wechsler memory scale-revised and California verbal learning test indices in clinical and normal samples

Although a high degree of convergence has been reported between the California Verbal Learning Test (CVLT) and the Wechsler Memory Scale-Revised (WMS-R), standard scores from these tests may not provide commensurate global estimations of memory function. Data were reviewed from 161 subjects who had taken both tests, including schizophrenic (n = 33) and temporal-lobe epilepsy (n = 31) patients and 97 normal volunteers. The patient group performed approximately one standard deviation below the normal mean on the WMS-R indexes, but three standard deviations below the normal mean on CVLT indices. The normal volunteers, who were well-educated as a group, performed approximately one standard deviation above the population-based mean on the WMS-R (commensurate with their IQ level), but at the mean of the CVLT reference sample. These findings suggest that the standardization samples for these two tests are not representative of the same population. The CVLT normative reference sample appears to have been higher functioning than the WMS-R sample, and may also have been characterized by a narrower range of memory function. The implications of these findings with respect to the clinical evaluation of memory are discussed.     

Confirmatory factor analysis of the Adult Asperger Assessment: the association of symptom domains within a clinical population

Autism Spectrum Disorder (ASD) is a behaviourally defined disorder characterised by impairments in three domains of social interaction, communication, and repetitive, stereotyped behaviours and activities. Proposed changes to diagnostic criteria suggest that the diagnostic triad may no longer fit as the best way to conceptualise ASD, and that social and communication impairments should be considered as a single domain. The aim of this study was to examine the structure of symptom domains within the Adult Asperger Assessment (AAA; Baron-Cohen, Wheelwright, Robinson, & Woodbury-Smith, 2005), a diagnostic tool for high functioning adults. As theoretical models already exist, confirmatory factor analysis was used to examine data from a clinical population of adults (n = 153) diagnosed with Asperger Syndrome (AS) and High Functioning Autism (HFA). Confirmatory factor analysis was used to fit different models based on the structure proposed by the authors of the AAA, the traditional triad and the newly proposed diagnostic dyad. Analysis suggested that none of the tested models were a good fit on the AAA dataset. However, it did highlight very high correlations between social and communication factors (r > 0.9) within unmodified models. The results of the analysis provide tentative support for the move towards considering ASD as a dyad of ‘social-communication’ impairments and repetitive/restricted interests behaviours and activities, rather than the traditional triad.     

An exploratory factor analysis of the children's depression rating scale-revised

An exploratory factor analysis was performed in a clinical sample of 314 children and adolescents to investigate the factor structure of the Children's Depression Rating Scale-Revised (CDRS-R; Poznanski et al. 1984). A maximum likelihood method followed by a Promax rotation yielded five factors: observed depressive mood, anhedonia, morbid thoughts, somatic symptoms and reported depressive mood. The age group and gender differences on the factors scores are evaluated. After controlling for gender, the adolescents had more severe depression in terms of observed depressive mood, anhedonia, and somatic symptoms. After controlling for age groups, girls had higher scores for reported depressive mood.     

Confirmatory factor analysis of the ADNI neuropsychological battery

The Alzheimer’s Disease Neuroimaging Initiative (ADNI) is a large multi-center study designed to develop optimized methods for acquiring longitudinal neuroimaging, cognitive, and biomarker measures of AD progression in a large cohort of patients with Alzheimer’s disease (AD), patients with Mild Cognitive Impairment, and healthy controls. Detailed neuropsychological testing was conducted on all participants. We examined the factor structure of the ADNI Neuropsychological Battery across older adults with differing levels of clinical AD severity based on the Clinical Dementia Rating Scale (CDR). Confirmatory factor analysis (CFA) of 23 variables from 10 neuropsychological tests resulted in five factors (memory, language, visuospatial functioning, attention, and executive function/processing speed) that were invariant across levels of cognitive impairment. Thus, these five factors can be used as indicators of cognitive function in older adults who are participants in ADNI.     

Attitudes towards mental health problems scale: Confirmatory factor analysis and validation in the Portuguese population

Several studies about stigmatization and shame toward mental health problems have contributed to minimizing the impact of these negative attitudes on people diagnosed with mental illnesses, on their families and on their communities. The Attitudes Towards Mental Health Problems Scale (ATMHP) is a self-report scale aimed at the assessment of attitudes toward mental health that involve several factors relating to attitudes and shame (internal, external, and reflected shame) when facing mental health problems. The goal of the current study was to translate, and to adapt this scale to the Portuguese population, and to study its psychometric properties in a sample of Azorean adults with and without psychiatric problems. The scale was administered to 411 participants with ages between 19 and 81 years. Confirmatory factor analysis was carried out on the initial model proposed by the authors of the ATMHP, and results showed a poor adjustment. An alternative model comprising an additional factor was tested and presented good model fit indices. Based on the alternative model, further analysis revealed that the scale has good psychometric properties.