Wechsler Memory Scales (WMS)

Wechsler Memory Scales (WMS)

• Individually administered composite tests designed to assess a patient's memory components.
• It is now in its fourth edition (WMS-IV) and conforms to the WAIS-IV (Wechsler Adult Intelligence Scale–Fourth Edition).
• Provides a full range of memory functioning assessment that aligns with current memory theories.
• A core component of cognitive assessments, ranked ninth among tests used by clinical psychologists and third by neuropsychologists.

Memory Complaints

• Prevalent in client populations and link to anxiety, schizophrenia, depression, head injuries, stroke, learning disabilities, and neurotoxic exposure.
• Evaluating the effect of alcohol and drugs on memory is essential.
• Occupational exposure to industrial agents (lead, mercury, organic solvents) may impair memory.
• The need to distinguish between normal aging and dementia early expression will grow alongside the aging population.
• An important differential diagnosis separates pseudodementia from depression and Alzheimer's.
• Monitoring client progress with drugs for cognitive issues is important, specifically memory functions.
• Children's complaints are typically from learning disabilities; adults from neurotoxic exposure or head injuries; older adults from dementing conditions.
• Early conceptualizations saw memory as unitary.
• Later views consider memory to have short-term/long-term, working memory, declarative/procedural, and sensory components.
• Effective storage requires active engagement and working memory has an executive component that oversees information.
• Working memory has an attentional component with limited capacity.
• Verbal reports reflect conscious memory; unconscious memory measures by performance changes.
• Memory uses visual and auditory modes.

History and Development

• Wechsler memory scales mirrored the growth of memory knowledge.
• Each edition integrated new insights into memory.
• The first Wechsler Memory Scale (WMS; 1945) reflected earlier general concepts of memory, covering number sequences, story recall, visual designs, and paired words.
• Procedures were divided into visuospatial and auditory tasks, with an overall Memory Quotient like IQ scores (mean of 100, standard deviation of 15).
• It was valuable to check the IQ and Memory Quotient discrepancy, and the WMS was brief (15 minutes). Parallel forms added benefit by addressing practice effects.
• The WMS was limited by simple scoring methods, basic Memory Quotient algorithms, norms from a small sample (200 patients, 25–50 years), extrapolated scores for other ages, unused alternate form, and neglect of advancements in memory.
• Russell's adaptation (1975, 1988) corrected WMS flaws by using Logical Memory and Visual Reproduction subtests immediately combined with a 30-minute delay.
• This helped compare short-term to long-term memory.
• Research supported left-hemisphere (auditory deficit) and right-hemisphere (visual deficit) lesions.
• Poor psychometrics and standardization created confusion, as the full revision also titled "Wechsler Memory Scale-Revised (WMS-R)".
• The 1987 revision (WMS-R) had improved age-related norms (16-17 to 70-74 age groups) and a sample that mirrored 1980 census data.
• Five composite scores came from 12 subtests: General Memory, Attention-Concentration, Verbal Memory, Visual Memory, and Delayed Recall.
• Index scores had mean of 100 and standard deviation of 15.
• Scores divided by dividing into short-term/long-term memory (Delayed Recall) and verbal/auditory or visual (Verbal Memory and Visual Memory).
• WMS-R had low to adequate reliability (internal consistency .44 to .88, test-retest .51 to .60).
• Validity was good to adequate.
• Factor-analytic studies backed two- or three-factor solutions.
• The WMS-R could distinguish between normal/clinical groups, severity of deficits, everyday memory levels, and brain atrophy.
• The Attention-Concentration Index was sensitive in detecting cognitive issues.
• Research on visual/verbal memory related to brain laterality was inconsistent.
• The WMS-R surpassed WMS with better standards, population scope, studies, and index breakdown for aspect measurements.
• Limitations led to quick revision from low subtest/index reliabilities reducing the measurements, and indexes possibly not pinpoint specific components, theories left unused.
• The Memory Scale-III, released ten years after the WMS-R, intended to address "brain/behavior relationships involved in learning and memory."
• Subtests, improved scoring, new materials, and index configurations were developed for 6 primary/5 optional subtests to create index scores.
• Manual states 6 primary subtests completed in 30–35 minutes, with research indicating 42 minutes for 11 primary subtests.
• The shortened version was published in 2002 completed in 15–20 minutes (Wechsler Memory Scale-III Abbreviated).
• The WMS-III developed with the WAIS-III simultaneously for subtest sharing and conorming. Had a normative sample of 1,250 adults between 16 and 89, divided into 13 groups (100 subjects versus 50 in WMS-R).
• The WMS-III extended age range appropriate for older clients.
• The test-retest and internal consistency reliability for primary subtest scores was from .74 and .93 and .82 and higher for primary indexes.
• Interscorer reliabilities were above .90, even for tests requiring judgment (Logical Memory, Family Pictures, Visual Reproduction).
• In 1997, factor analyses reported a three-factor model.
• The 2002 Technical Manual presented five-factor model fitting age groups from 30–64 and 65–89; change consistent with memory components dissociating with old age.
• The index scores were meaningful with older people; a correlation of .98 existed between Immediate/General Memory. These can be redundant.
• Research found four-factor model (Auditory, Visual, Working Memory, Learning) and two-factor model.
• The WMS-III clinically differentiated clinical and normal groups; ex: patients with Alzheimer's, Huntington's, and Parkinson's diseases; multiple sclerosis; chronic alcohol abuse; temporal lobe epilepsy; schizophrenia showing consistently lower scores than the standardization sample.
• Findings: Korsakoff's patients attention/working memory normal with all other index scores impaired; patients with mild Alzheimer's scored between 60 and 71 except 80 in Working Memory; patients with brain injuries scored low; clinician ratings were reflected on WMS-III scores.
• Despite successes, the WMS-III posed limitations such as equivocal factor structure, longer testing, subtest overlap, and poor subtests, Faces, Family Pictures, Verbal Paired Associates.
• The scale was refined into the WMS-IV which improved the factor structure, reduced time, and eliminated the subtests
• It deleted the Digit Span and Letter-Number Sequencing, and the subtests specific to the WMS-III (Faces, Family Pictures, Spatial Span, Word Lists), and focused on items in visual working memory, added Spatial Addition, clarified procedures, and modified the Logical Memory, Verbal Paired Associates, Symbol Span, Designs.
• These modifications led to six subtests including an optional cognitive screen.
• Subtests had consistent readministration 20–30 minutes later; factor analyses showed five indexes.
• Significant change: a battery for adults 16–69 and modified battery for adults 65–90. This battery is short and has four indexes.
• To aid with interpretation, difference was included to aid interpretations or differences. An example; visual Memory higher than auditory.

WMS-IV Subtests

• Brief Cognitive Status (Optional): Basic tasks (orientation, counting backward, clock drawing, recall, inhibition, production) and total score to assess cognitive impairment (gross cognitive impairment*).
• Logical Memory (Ages 16-90):
  • I*: Repeating short stories, Adults (65–90) presented with one story (short-term auditory-verbal memory).
  • II: Recall story details (long term auditory-verbal recall) and answer yes/no questions (long-term auditory-verbal recognition).
• Verbal Paired Associates (Ages 16-90):
  • I: Pairs of words (dark light). Remembering second word (dark . . .?") (short-term auditory learning).
  • II: First word is read and paired word remembered (light . . .?”) (long-term auditory memory), word pairs with conditional pairs (long-term auditory recognition), recall word pairs (long-term auditory recall).
• Designs (Ages 16–69):
  • I: A series of designs on a grid (10 seconds). Identifying origination (short-term spatial memory).
• Visual Reproduction (Ages 16-90): II: Reproducing the original grid (long-term visuospatial memory) with visual on grids (long-term visual memory).
  • I: Design shown for 10 seconds. Draw them (short-term visual memory).
  • II: Requested to draw designs (free recall task) (long-term visual memory). Next, identify which of six designs on a page is the same as the design shown in condition I (long-term visual recall). Finally, (optional task), examinees are shown the original designs and requested to draw them (copy phase; visuospatial construction).
• Spatial Addition (Ages 16-90): Seeing grids and guided by the set of instructions (visual-spatial working memory).
• Symbol Span (Ages 16-90): Display symbols and instructed to identify in correct order (visual-sequencing working memory).

Standardization for WMS-IV

• Included the 2005 U.S. census (ages 16 and 90) and included 1,400 examinees (100 in 14 age bands) and exclusion criteria to eliminate inappropriate participants ( dementia, psychosis, medication.)
• Comparisons were appropriate due to WAIS-IV conformed it.

WMS-IV Reliability

• The test's subtest and index had appropriate test reliability. For example for test: Visual Reproduction II (.97) and Verbal Paired Associates (.94) to a lowest for Visual Reproduction (.74)
• Stronger test-retest would be stronger.

WMS-IV Validity

• Was presented in Pearson(2009A), and by correlations, interviews with participants, and more memory was reviewed and created.
• The sub tests will have a high score when comparable and low.
• Verbal Subtext score increased when compared to other tasks. They examined temporal.
• This states it’s a strong message.

Use with Diverse Groups

• Many WAIS considerations apply but differs from general ability which measure cognitive functions, WMS determines level of impairment
• WMS-IV measures a wide range of functions as a result the information can be complex.
• Index include a mean, standard deviation calculated the index itself (1-19
• In terms of relations with age related peers the contrast scores

Additional Considerations

• Malingering Is linked to gains from injury and surveys show they are high to the injury.
• The wais shows people’s complaints and the effort is “suboptimal.”

Final thoughts they will provide strategies for calculating whether an actual change occurred.