Confirmatory factor analysis of combined Wechsler Adult Intelligence Scale—Revised and Wechsler Memory Scale—Revised scores in a healthy community sample.

Abstract

This study examined the joint factor structure of the Wechsler Adult Intelligence Scale-Revised (D. Wechsler, 1981) and Wechsler Memory Scale-Revised (D. Wechsler, 1987) in a sample of 399 healthy young adults (206 women and 193 men) recruited for a normative study in Sydney, Australia: the Macquarie University Neuropsychological Normative Study. Using confirmatory factor analysis, the authors contrasted alternative models of ability in the respective Wechsler scales, focusing in particular on hypotheses relating to memory function. The best-fitting solution comprised a model representing Verbal Comprehension, Perceptual Organization, Attention-Concentration, Verbal Memory and Visual Memory. The results are discussed in terms of the incremental validity of ability assessment, potential for improvement in model-fit, and implications for professional practice.Psychologists often administer and interpret jointly the scores derived from the Wechsler Adult Intelligence and Memory Scales (Flanagan, Genshaft, & Harrison, 1997;Kaufman, 1990). Research with a variety of ability scales suggests that, like other ability batteries, the Wechsler Intelligence Scales sample important dimensions of cognition . As well, evaluation of long-term or anterograde-memory abilities adds to the explanatory power of models of cognition (Atkinson, 1991;Flanagan & McGrew, 1997).Factor analysis of versions of the Wechsler Intelligence scales has been reviewed often (e.g., Kaufman, 1990;Matarazzo, 1972), most recently in the WAIS-IIIAVMS-III manual (Psychological Corporation, 1997). Many studies suggest that a three-factor oblique solution comprising Verbal Comprehension, Perceptual Organization, and Freedom-From-Distractibility provides the best representation of the abilities measured by the 11 subtest scores. Most recently, with the addition of some new subtests, a fourfactor solution for the WAIS-III has been reported (Psychological Corporation, 1997), adding Processing Speed as a factor to the familiar three factors.

Measurement invariance of core cognitive abilities in heterogeneous neurological and community samples

“…As in previous studies, we modeled measurement commonality in WMS-R subtests (Psychological Corporation, 2002;Roth, Conboy, Reeder, & Boll, 1990). Testing of alternative intelligence and memory ability hypotheses followed the strategy outlined by Bowden et al (1999) in which competing oblique factor models of clinical memory function were contrasted with a simpler model that assumed only one general memory ability in addition to the three abilities measured by the WAIS-R (Jurden et al, 1996;Kaufman & Lichtenberger, 2002;Psychological Corporation, 2002;Woodard, 1993). The simplest model examined was a four-factor model distinguishing among Verbal Comprehension, Perceptual Organization, Working Memory, and anterograde memory ability (Model 4 in Table 3).…”

“…Material-specific memory disorders are forms of disability involving reduced long-term retrieval or anterograde memory function prominently affecting acquisition and retention of either auditory-verbal or visuospatial memory (Bell & Davies, 1998;Heilbronner, 1992;Lee et al, 1989). The results of factor analytic studies of the WMS-R and WMS-III have produced varied results, most studies reporting one of two alternate three-factor structures, either distinguishing revised versions (see Bowden et al, 1999;Psychological Corporation, 2002), particularly because we have access to a representative community sample of adults. Further, we wanted to evaluate the invariance of the measurement model across clinical and community samples.…”

Overview of the WAIS–IV/WMS–IV/ACS

“…Similar joint factor analytic studies have been published for the WAIS-R and WMS-R (Bowden, Carstairs, & Shores, 1999) and the WAISÀIII and WMSÀIII (Tulsky & Price, 2003). Tulsky and Price (2003) completed an extensive evaluation of the joint factor structure of the WAISÀIII and WMSÀIII.…”

Neuropsychological correlates of hippocampal and rhinal cortex volumes in patients with mesial temporal sclerosis

“…To measure verbal and nonverbal episodic memory, composite scores were calculated which combined immediate and delayed indices from the Wechsler Memory Scales (Wechsler, 1987(Wechsler, , 1997. These composite scores were derived from a previously validated latent-trait model of cognitive abilities reported by our group and based on large community control and clinical samples (Bowden et al, 1999(Bowden et al, , 2001). In addition, specific verbal and nonverbal memory tests were examined, namely the Logical Memory subtest from the Wechsler Memory Scales, and the Spatial Maze, which are amongst the most reliable and best-validated measures of auditory-verbal and visuospatial anterograde memory function, respectively (Wechsler, 1981;Bowden and Smith, 1994;Wechsler, 1997).…”

“…The Verbal Memory Index composite score was the sum of WMS-R immediate and delayed verbal subtest scores (Bowden et al, 1999(Bowden et al, , 2001 or the equivalent sum of WMS-III immediate and delayed verbal subtests. The WMS-III scores were rescaled to the same mean and standard deviation as the WMS-R scores, in a manner directly analogous to the computation of z-scores.…”