Book and test review

Archives of Clinical Neuropsychology 16 (2001) 193 ± 198

Book and test review Arthur MacNeill Horton, Jr., Associate Editor Psych Associates, Towson, MD, USA

Children's Memory Scale, by M. Cohen. San Antonio, TX: Psychological Corporation, 1997. Cohen's ``Children's Memory Scale'' (CMS; Cohen, 1997) provides a measure of learning and memory for children aged 5 to 16 years. Cohen states that the development of this instrument aims to improve upon existing children's memory tests by (a) better accounting for childhood developmental change, (b) allowing meaningful comparisons with commonly used children's intelligence tests, (c) allowing for comparison with the Wechsler Memory Scale-III (WMS-III; Wechsler, 1997), (d) providing a memory test which is academically and clinically germaine, and (e) keeping the subtests and administration ``child friendly.'' 1. Theoretical model The test was developed using the ``Milkjug of Memory'' model, based on current research in human memory theory. In brief, Cohen presents a sequential model in which directed attention promotes short-term immediate memory, which is divided into Auditory-Verbal and Visual-Nonverbal domains. Data from each domain is maintained in working memory, which leads to new learning. Information is then stored in long-term memory. Long-term memory is divided into two types, declarative and procedural memory. Declarative (explicit) memory is further divided into episodic memory (event specific memories from daily living) and semantic memory, which contains factual information. Procedural (implicit) memory is divided into skill learning (i.e., how to ride a bike) and classical conditioning. The retrieval of stored memory is understood as a function of either free recall or recognition recall, which returns data to working memory. For reasons of practicality, procedural memory is not measured by the CMS. 2. Factorial structure of the CMS Based on this model, and supported with a confirmatory factor analysis, the test is divided into three domains (factors). Auditory/Verbal (A/V), Visual/Nonverbal (V/N), and Attention/ 0887-6177/01/$ ± see front matter D 2001 National Academy of Neuropsychology. PII: S 0 8 8 7 - 6 1 7 7 ( 9 9 ) 0 0 0 6 4 - 5

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Book and test review / Archives of Clinical Neuropsychology 16 (2001) 193±198

Concentration (A/C). Each domain consists of two subtests, with a supplemental test available for each domain. Which of two record forms are used depends on the child's age (5±8 years or 9±16 years). Normative data is provided based on a sample of 1,000 children in 10 age groups (ages 13/14 and 15/16 are combined groups). Each age group was divided according to race/ethnicity, geographic region, and parents' education, with some case weighting to adjust proportions to match those in the 1995 U.S. Census report. There were an equal number of girls and boys in the sample. There are eight index scores: Visual Immediate, Visual Delayed, Verbal Immediate, Verbal Delayed, General Memory, Attention/Concentration, Learning, and Delayed Recognition. Standard scores, confidence intervals, and percentiles are computed for each index. Because the CMS was co-normed with the Wechsler Intelligence Scale for Children-III (WISC-III; Wechsler, 1991) and the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R; Wechsler, 1989), an ``ability-memory discrepancy analysis'' (Cohen, 1997b) can be computed to compare the differences between memory functioning and intellectual abilities. This statistical analysis helps the examiner identify subject weaknesses in comparison to same-aged peers. Use of the Wechsler Full Scale IQ (FSIQ) is recommended for determining predicted scores, although Verbal IQ (VIQ) or Performance IQ (PIQ) comparisons are possible. The record form also allows the examiner to compute the subject's learning curve for Dot Locations, Word Pairs, and Word Lists and compare this performance with the normative sample. When hand scoring, the examiner must weigh the importance of the added interpretive data against the additional scoring time. 2.1. Subtests There are six subtests in the core battery. Dot Locations is an easily administered visual learning task with three learning trials and a delay. Stories is a verbal memory task with two short stories for each of three age bands (5±8, 9±12, and 13±16). Like the WMS-III, responses are scored for both story units and thematic units recalled. A delayed free recall and delayed recognition trial are included. Faces provides an immediate and delayed measure of facial recognition. Faces subtest is a monotonous task that requires the subject to view 16 photographs (for the 9±16-year-olds) during the identification trials and 48 more photographs during the immediate recognition trials. Frequent prompting may be required to keep the child's interest and avoid random responding. Word Pairs has three learning trials of 14 word pairs, along with a long delay and recognition trials. The Numbers subtest is a measure of digit span, both forward and backward. Sequences is a timed measure of 12 different series, ranging from numbers to months of the year. Points are awarded for accuracy and speed. There are also three supplemental subtests. For the V/N domain, the Family Pictures subtest measures the subject's ability to recall details from four family scenes with both immediate and delayed trials. This test is problematic, as it requires substantial verbal encoding for success and it is more difficult to administer than the core subtests within this domain. As an option for the A/V domain, Word Lists is a selective reminding task with a delayed free recall and delayed recognition trials. Picture Locations is a test of A/C in which the subject must remember the locations of pictures dispersed within a rectangle.


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The CMS does a nice job of providing delayed measures on a majority of the tasks, with recognition trials on two of the core subtests. Once scored, the information on the summary sheet is comprehensive and useful. Comparisons of predicted and actual scores can be easily transformed into learning curves for three of the subtests. Computer software is available from the vender. The test is attractively detailed with colorful stimuli well suited to keep a child's interest. Instructions are clearly written in the stimulus booklets and easy to follow. The core subtests are relatively similar to existing child and/or adult neuropsychological instruments and require little practice time. However, learning to administer the supplemental tests (Family Pictures, Word lists, and Picture Locations) is more difficult. Hand scoring is somewhat complex and time consuming. The record forms would benefit from less print and a larger font. If the scoring instructions had been left in the manual, the record form would be easier to use and appear less cluttered. Identifying core and supplemental subtests as such in the record form would help avoid unnecessary confusion. Administration time tends to take considerably longer than the manual predicts. In practice, administration time for the core subtests was approximately 60 minutes, whereas the manual predicts 30 to 35 minutes. 2.2. Internal consistency Based on the information provided in the manual, the test's internal consistency was robust, with the General Memory Index correlation across age groups ranging from .88 to .93. Index reliability coefficients tended to be greater than individual subtest coefficients, as would be expected with a larger number of data points. Significant practice effects can be expected if the test is readministered within a 2-month period. Interrater reliability was high, with most subtest correlations at .98 or above. The lowest interrater correlation was found for the retroactive score on the Word List subtest (.88). Construct validity was determined by comparing within-subtest differences, differences between subtests within a given domain, and differences between indexes. Moderate-to-high correlations were reported between immediate and delayed trials within subtests. Correlations between subtests within domains were found to be low to moderate. Dot Locations and Faces subtests (V/N) had the lowest correlation (r = .06±.16). The General Memory Index exhibited a moderate-to-high correlation with all indexes. As anticipated, correlations within domains were higher than those comparisons between domains. The CMS General Memory Index has a moderate positive correlation with the FSIQ scores of the WISC-III and WPPSI-R (.58 and .56, respectively). CMS verbal indexes correlate moderately with VIQ scores in the expected direction. The CMS visual/nonverbal indexes had a weak positive correlation with PIQ scores, actually having a higher correlation with the WPPSI-R VIQ than the PIQ. The correlation was high (.73) between the WISC-III Freedom From Distractibility factor and the CMS Attention/Concentration Index. 2.3. CMS and other memory measures In comparison to the Wide Range Assessment of Memory and Learning (WRAML; Sheslow & Adams, 1990), there was a moderate positive correlation between the two General

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Memory Indexes (.64). The verbal indexes correlated moderately with their corresponding measures, while the Visual Memory Index on the WRAML correlated moderately with the CMS Visual Delayed Index, but only at .26 with the CMS Visual Immediate Index. Although the WRAML does not have an Attention/Concentration measure, the CMS Attention/ Concentration Index correlates highly with the WRAML Verbal Index. There was a moderate relationship between the Learning indexes on the two instruments. Cohen also compared the performances of 86 16-year-olds who were administered both the CMS and WMS-III. It should be remembered that with the exception of Dot Locations, the WMS-III shares variations of all the CMS core subtests. Variations of two supplemental subtests, Family Pictures and Word Lists, can also be found on the WMS-III. The correlation between General Memory Indexes on the two instruments was .67. Verbal index correlations were moderate to high, whereas visual memory indexes showed a positive moderate correlation. The WMS-III Working Memory Index was most highly correlated with the CMS Attention/Concentration Index (.68). Although the WMS-III does not have a learning index, it is noteworthy that the Immediate Memory Index correlated highest with the CMS Learning measure (.66). CMS Word Lists subtest had strong convergent validity with the California Verbal Learning Test-Children's Version (CVLT-C; Delis, Kramer, Kaplan, & Ober, 1994), as the CMS Learning score correlates at .70 with the CVLT-C Trial 1±5 score, and there was a .78 correlation between the CMS Word Lists Delayed and the CVLT-C Long Delay scores. 2.4. CMS and achievement Academic achievement scores on the Wechsler Individual Achievement Test (Wechsler, 1992) were shown to correlate at a moderate level overall, with the lowest correlation with the visual/nonverbal indexes. School grades appeared to have a weak relationship to CMS performance, with the visual/nonverbal indexes having the lowest correlation. In other comparisons, Reading, Math, and Language scores on five group-administered achievement tests had a low-to-moderate positive correlation with the Auditory/Verbal, General Memory, Attention/Concentration, and Learning indices, but these indexes had a weaker and less consistent relationship with Spelling, Science, and Social Studies skills. 2.5. CMS and neuropsychology Executive functioning, as measured by the Wisconsin Card Sorting Test (WCST; Heaton, 1981) and the Children's Category Test (CCT; Boll, 1993), was moderately correlated to the CMS General Memory Index on both instruments. Auditory/verbal indexes were more strongly correlated to WCST and CCT performance than were the visual/nonverbal indexes. The Attention/Concentration Index exhibited a low to moderate correlation with WCST scores. Language Processing, as measured by the Clinical Evaluation of Language Fundamentals3rd Edition (Semel, Wiig, & Secord, 1995), was found to be significantly correlated with A/C in both the expressive and receptive language indexes. Receptive language also was significantly correlated with the CMS General Memory Index, the Verbal Immediate Index, and the Learning Index.


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Preliminary studies indicate the CMS may be sensitive to the effects of several common neurological disorders. When 17 children with temporal lobe epilepsy were tested, nearly one third were within the impaired range (index standard score 69) on the General Memory, Verbal Delayed, and Delayed Recognition Indexes. Over one fourth of a traumatic brain injury group tested in the impaired range on the Verbal Immediate Index, whereas one fifth of the traumatic brain injury group scored in the impaired range on the General Memory and Verbal Delayed Indexes. In a small group of children with a known brain tumor, over half performed in the impaired range on the Delayed Recognition Index, whereas one in four were impaired in the Attention/Concentration Index. Children with learning disabilities in reading, writing, math, or in combination obtained impaired scores most often in the Attention/Concentration (23%), Delayed Recognition (20.3%), or the Verbal Immediate (17.4%) Indexes. Eighty-seven children with Attention Deficit Hyperactive Disorder (ADHD), either the predominantly Inattentive or Combined type, and all on stimulant therapy, demonstrated differentiating impairment across indexes. As a total group, the children performed poorest on the Attention/Concentration and Verbal Immediate Indexes. However, when divided into subtypes, 22% of the Inattentive group obtained impaired scores on the Learning Index, whereas only 7.3% were impaired in the Combined group. In the Combined group, the largest percentage (14.6) were impaired in the Attention/Concentration Index, whereas none of the Inattentive group fell within the impaired range on that index. Of the 30 children tested with Specific Language Impairment, the highest number (16.7%) were within the impaired range in the Delayed Recognition and Attention/ Concentration Indexes. In conclusion, the Children's Memory Scale provides a useful measure of children's learning and memory. It also appears to have achieved a majority of its stated goals. Because the test was co-normed with the WISC-III and WPPSI-R, memory functions can be critically compared to intellectual functioning. As the child ages, comparisons to WMS-III performance will exhibit a clear continuum of performance. The two tests share versions of the same subtests and are highly correlated. The CMS provides good normative data, with a relatively large sample broken up into age groups allowing sensitivity to developmental changes. Cohen's research has exhibited significant relationships between the CMS and measures of intelligence and academic achievement, and sensitivity to a number of neurologic and neurodevelopmental disorders. His differential findings between types of ADHD subjects is particularly noteworthy. It is encouraging that this new instrument was developed. A quick review of the literature demonstrates the need for more basic research in the development of children's memory abilities. The ability to compare predicted index scores based on IQ with actual scores, in addition to predicted learning curves, provides the examiner an effective means to identify subject strengths and weaknesses in comparison to same-aged peers. In its entirety, the test is highly comprehensive. However, due to the time required to complete all six core subtests, many clinicians may choose to administer only specific subtests as part of a flexible battery. The difficulty in measuring V/N memory as a distinct factor remains elusive. Although the CMS subtests (Faces and Dot Locations) within this domain may provide clinically useful information, their construct validity appears wanting as a measure of visual memory. Although the CMS does not provide the ideal measure of visual memory (also identified

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as a problem with the WMS III), the similarities between the two instruments do allow for great continuity across the life span. Mark C. Monahan, Ph.D. U.S. Naval Hospital San Diego, CA, USA Eileen B. Fennell, Ph.D. Department of Clinical and Health Psychology University of Florida Health Science Center, PO Box 100165 Gainesville, FL 32610-0165, USA References Boll, T. (1993). Children's Category Test. San Antonio, TX: Psychological Corporation. Cohen, M. J. (1997a). Children's Memory Scale. San Antonio, TX: Psychological Corporation. Cohen, M. J. (1997b). Manual for the Children's Memory Scale ( p. 84). San Antonio, TX: The Psychological Corporation. Delis, D., Kramer, J., Kaplan, E. & Ober, B. (1994). California Verbal Learning Test-Children's Version. San Antonio, TX: Psychological Corporation. Heaton, R. (1981). Wisconsin Card Sorting Test. Odessa, FL: Psychological Assessment Resources. Semel, E., Wiig, E., & Secord, W. (1995). Clinical Evaluation of Language Fundamentals (3rd ed.). San Antonio, TX: Psychological Corporation. Sheslow, D., & Adams, W. (1990). Wide Range Assessment of Memory and Learning. Wilmington, DE: Jastak Associates. Wechsler, D. (1989). Wechsler Preschool and Primary Scale of Intelligence (Revised). San Antonio, TX: Psychological Corporation. Wechsler, D. (1991). Wechsler Intelligence Scale for Children (3rd ed.). San Antonio, TX: Psychological Corporation. Wechsler, D. (1992). Wechsler Individual Achievement Test. San Antonio, TX: Psychological Corporation. Wechsler, D. (1997). Wechsler Memory Scale (3rd ed.). San Antonio, TX: Psychological Corporation.