WAIS-III WMS-III Discrepancy Analysis

Education-Stratified Base-Rate Information on Discrepancy Scores Within and Between the Wechsler Adult Intelligence Scale-Third Edition and the Wechsler Memory Scale-Third Edition.

“…The present investigation expands on the recent work by Tulsky et al (2000), Hawkins and Tulsky (2001, 2003), and the discrepancy data presented by The Psychological Corporation (1997, 2002). Specifically, we present educationally stratified, directional prevalence rates of discrepancy scores between the major index scores for the WAIS-III and the WMS-III and between the WAIS-III and WMS-III that can be directly used by clinicians to facilitate clinical decision making at the level of the individual.…”

“…In calculating the ORs, the WAIS-III Verbal Comprehension Index (VCI) was used as the reference score with which to contrast Immediate Memory (IM), General Memory (GM), and Processing Speed Index (PSI) scores. Because verbal abilities are often thought to remain relatively intact even with cognitive decline in neurologic conditions (see Hawkins & Tulsky, 2003; Matarazzo, 1972), the other variables were always subtracted from VCI. The IM, GM, and PSI indexes were selected as potential markers of compromised functioning because both AD and HD are clinically differentiated by their variable associations with memory impairment and slowed processing speed (Fields, 1998).…”

“…Early on, clinicians looked to the original Wechsler-Bellevue Scale (Wechsler, 1939; see Matarazzo, 1972, for review) to test the idea that certain intellectual abilities hold up with age whereas others do not (i.e., “hold-don't hold” deterioration ratio). Contemporary research continues to explore the clinical use of discrepancy scores to identify patients at risk for neurological conditions such as Alzheimer's disease (e.g., Hawkins & Tulsky, 2001, 2003; Jacobson, Delis, Bondi, & Salmon, 2002). Discrepancy analysis is particularly useful in contrasting factors of intelligence to memory given the expected cognitive discrepancies associated with neurologic damage.…”

“…Hawkins and Tulsky (2001) found that large discrepancies between IQ and WMS-III General Memory were more frequent among individuals with above average IQ scores but less frequent among individuals with below average IQ. They argued that use of simple difference discrepancy tables that are not stratified by ability level could lead to erroneous conclusions (Hawkins & Tulsky, 2001, 2003). Although the original WAIS-III—WMS-III Technical Manual (The Psychological Corporation, 1997) did not provide any base-rate information on discrepancy scores that was stratified by ability level, the WAIS-III—WMS-III Technical Manual Update (The Psychological Corporation, 2002) now provides tables on intratest WAIS-III discrepancies stratified by Full Scale IQ (cf.…”

Using Profile Analysis via Multidimensional Scaling (PAMS) to identify core profiles from the WMS-III.

“…If a clinical group displays more frequent instances of a particular profile, this does not permit clinicians to infer that a particular profile is evidence of a particular clinical condition. The following observations from Hawkins and Tulsky (2003) illustrate this point: Differences between the auditory and visual indexes may indicate lifelong strengths and weaknesses or acquired deficits in new learning and memory processes when information is presented in different modalities… . Along with the possibility of a differential sensitivity to diffuse compromise, an obvious question regarding the WMS–III indexes pertains to sensitivity to lateral insult.…”