Wechsler Digit Span subtest: diagnostic usefulness with dyslexic children

The current study supports Levinson's contention (1988) that the diagnosis of dyslexia cannot be based solely on neurophysiological evidence but must be made in conjunction with reading and educational test scores. Contrary to much current research, in the present study specific WISC-R profiles are identified within a stringently defined subgroup of 57 9- to 12-yr-old dyslexic children. Well-defined subtest scatter can differentiate dyslexics from proficient readers. In particular, the Digit Span subtest, which is not routinely administered by psychologists or included in computing Verbal IQ, can be considered an important component of a diagnostic battery. Unexpectedly, Coding emerged with Digit Span as a third factor in a principal component analysis; statistically significant sex differences appeared on the Coding task. Findings appear to confirm the phonological encoding deficiencies displayed by dyslexics on the Digit Span subtest. This study strongly supports consideration of WISC-R subtest differences, along with correlated factors, neurophysiological and perceptual evidence, when diagnosing dyslexic children. Cross-validation is planned.     

On the use of the WISC-R supplementary subtests as alternates

If a regularly administered WISC-R subtest cannot be administered properly or is invalidated, the manual suggests that a supplementary subtest, either Digit Span or Mazes, can serve as a substitute, but perhaps prorating the sum of scaled scores on the remaining subtests would be better. Data from the WISC-R standardization sample were analyzed to investigate the psychometric properties of these two variants of the standard procedure. Proration consistently resulted in higher validities (i.e., correlations between scores on the variant Verbal, Performance, or Full Scale and scores on the corresponding original scale), whereas substitution almost as consistently resulted in higher reliabilities, but in both cases the differences were small. Examiners may decide for themselves whether or not to use the supplementary subtests as alternates.     

Psychometric validity of proration and Digit Span substitution for estimating WISC--R verbal and Full Scale IQs

This study investigated the merits of substituting the Digit Span subtest for an invalid Verbal Scale subtest versus a proration method in calculating WISC--R Verbal and Full Scale IQ. Subjects were 93 child and adolescent psychiatric patients (67 boys and 26 girls) who ranged in age from 8 to 16 yr. Analysis indicated that the use of Digit Span as a substitute for the regularly administered Verbal subtests was inferior to the use of the comparable proration method. Although relatively few cases of misclassification occurred for either method in relation to Full Scale IQ, the rate of Verbal IQ misclassification by the Digit Span substitution method was significantly greater than with use of its proration. When faced with a choice, clinicians should attach greater validity to prorated estimates of a child's WISC--R Verbal IQ.     

The backward span of the Corsi Block-Tapping Task and its association with the WAIS-III Digit Span

The Corsi Block-Tapping Task measures visuospatial short-term and working memory, but a standardized backward condition is lacking. The authors present a standardized backward procedure that was examined in 246 healthy older adults (ages 50 to 92), comparing the results with the Digit Span subtest of the Wechsler Adult Intelligence Scale--Third Edition. Principal component analysis resulted in a two-factor model, dissociating a verbal and a spatial working-memory factor. Also the Corsi backward is not more difficult than the Corsi forward, in contrast to the Digit Span backward that is more difficult than the Digit Span forward. This may suggest that the Corsi Block-Tapping Task backward task relies on processing within working-memory's slave systems, whereas the Digit Span backward also relies on the central executive component of working memory. Finally, regression-based normative data and cutoff scores for older adults are presented for use in clinical practice.     

Three-year stability of WISC-R factor scores for black and white, female and male children classified as learning-disabled

Wechsler Intelligence Scale for Children-Revised (WISC-R) test and retest scores for a homogeneous sample (N=322) of approximately equal numbers of black and white, female and male learning-disabled children were compared over 3 years for factor structure and factor structure stability. These analyses were also conducted with a subsample (N=229) of the total sample for whom Digit Span scores were available. The socioeconomic status of children in the sample was determined by parents' occupation. The results suggested that WISC-R factor structure was stable over 3 years. Two-and three-factor solutions were found for the total group; three factors were found when Digit Span was included in the analysis. Coefficients of congruence indicated factorial similarity between groups of black and white, female and male children classified as learning-disabled.     

WISC-R subtest but no overall VIQ-PIQ difference in Dutch children with PDD-NOS

VIQ-PIQ differences have been studied in children with autism and Asperger syndrome but have not been studied in a separate group of children with PDD-NO, although, PDD-NOS has a much higher prevalence rate than autism and deficits in communication and social interaction are severe. The Wechsler Intelligence Scale for Children-Revised (WISC-R) was administered to 100 children, aged 6-12 years, with PDD-NOS (n = 76), autism (n = 13), and Asperger syndrome (n = 11). PDD-NOS was diagnosed using explicit research criteria. No overall differences between VIQ and PIQ were found in PDD-NOS and autism. Peaks in the subtest scores on Information, Similarities, Picture Arrangement, and Mazes, and troughs in the subtest scores on Comprehension, Digit Span, and Coding were demonstrated in children with PDD-NOS. Their score on the Freedom from Distractibility factor was lower than the scores on the Verbal Comprehension factor and the Perceptual Organization factor. Children with PDD-NOS seemed to have a similar VIQ-PIQ profile as children with autism, and on the subtest level children with PDD-NOS showed some similarities to children with Asperger syndrome or autism. It was not possible to distinguish PDD-NOS from autism or Asperger syndrome by using IQ scores.     

WISC-R Subtest But No Overall VIQ–PIQ Difference in Dutch Children with PDD-NOS

VIQ–PIQ differences have been studied in children with autism and Asperger syndrome but have not been studied in a separate group of children with PDD-NO, although, PDD-NOS has a much higher prevalence rate than autism and deficits in communication and social interaction are severe. The Wechsler Intelligence Scale for Children-Revised (WISC-R) was administered to 100 children, aged 6–12 years, with PDD-NOS (n = 76), autism (n = 13), and Asperger syndrome (n = 11). PDD-NOS was diagnosed using explicit research criteria. No overall differences between VIQ and PIQ were found in PDD-NOS and autism. Peaks in the subtest scores on Information, Similarities, Picture Arrangement, and Mazes, and troughs in the subtest scores on Comprehension, Digit Span, and Coding were demonstrated in children with PDD-NOS. Their score on the Freedom from Distractibility factor was lower than the scores on the Verbal Comprehension factor and the Perceptual Organization factor. Children with PDD-NOS seemed to have a similar VIQ–PIQ profile as children with autism, and on the subtest level children with PDD-NOS showed some similarities to children with Asperger syndrome or autism. It was not possible to distinguish PDD-NOS from autism or Asperger syndrome by using IQ scores.     

Correlation between gray/white matter volume and cognition in healthy elderly people

This study applied volumetric analysis and voxel-based morphometry (VBM) of brain magnetic resonance (MR) images to assess whether correlations exist between global and regional gray/white matter volume and the cognitive functions of semantic memory and short-term memory, which are relatively well preserved with aging, using MR image data from 109 community-dwelling healthy elderly individuals. We used the Information and Digit Span subtests of the Wechsler Adult Intelligent Scale-Revised as measures of semantic memory and short-term memory, respectively. We found significant positive correlations between the gray matter ratio, the percentage of gray matter volume in the intracranial volume, and performance on the Digit Span subtest, and between the regional gray matter volumes of the bilateral anterior temporal lobes and performance on the Information subtest. No significant correlations between performance on the cognitive tests and white matter volume were found. Our results suggest that individual variability in specific cognitive functions that are relatively well preserved with aging is accounted for by the variability of gray matter volume in healthy elderly subjects.     

Multifactorial assessment of reading disability: identifying the best predictors

A multifactorial diagnostic assessment battery was evaluated using data obtained from 105 reading-disabled children and their matched controls (total N = 210). A stepwise discriminant function analysis selected five nonreading measures from among 16 as the best diagnostic predictors of reading disability. These measures included WISC-R Information and Digit Span, self-reported family histories of reading problems, and tests of symbol-processing speed and letter fluency.     

A multivariate comparison of the intellectual performance of black and white children matched on four demographic variables

This study investigated the performance of 285 matched pairs of Black and White children from the standardization sample on the 12 subtests and 3 IQ scales of the Wechsler Intelligence Scale for Children—Revised (WISC-R). The children were matched on four demographic variables found in a previous (Reynolds and Gutkin, 1979) study to be significantly related to WISC-R performance: sex, socioeconomic status as determined by the occupation of the head of household, region of residence in the U.S. and urban vs rural residence. Multivariate analysis of variance comparing performance across race on the 15 dependent variables revealed that Whites exceeded Blacks on all tasks except Digit Span—a test of rote memory. Results were also related to the evaluation of the Spearman hypothesis.     

The Relationship Between Performance on the Gordon Diagnostic System and Other Measures of Attention

Tests purporting to measure attention were administered to college students to examine their relationship to three relatively new tests of attention from the Gordon Diagnostic System (GDS). All subjects received the Standard Delay, Vigilance, and Distractibility Tests of the GDS. In addition, 69 of 136 subjects received the Digit Span, Arithmetic, and Digit Symbol subtests of the Wechsler Adult Intelligence Scale-Revised (WAIS-R), and Kagan's Matching Familiar Figures Test. After the GDS, the other 67 subjects received the Visual Span subtest of the Wechsler Memory Scale-Revised (WMS-R), and the Stroop. Replication (across two studies) and gender influences were not evident on GDS performance. Performance data on this test for these 136 college students, collapsed across replication and gender, are presented. Although within-test correlations were strong, correlations between tests were weak. A ceiling effect on the Vigilance task may have effected its correlations with other tests. Results suggest that the GDS tasks are not substitutes for commonly used tests of attention, but may be useful as an additional source of information in the assessment of attention.     

Reliable digit span is unaffected by laboratory-induced pain: implications for clinical use

Reliable Digit Span (RDS) is an indicator used to assess the validity of cognitive test performance. Scores of 7 or lower suggest poor effort or negative response bias. The possibility that RDS scores are also affected by pain has not been addressed thus potentially threatening RDS specificity. The current study used cold pressor-induced pain to investigate the effect of pain on RDS scores. Sixty undergraduate volunteers randomly assigned to one of three conditions (control, simulator, pain) completed the Digit Span subtest from the Wechsler Adult Intelligence Scale-III from which the RDS is derived. No differences in RDS scores were found between the control and pain groups, and neither group scored below 8. Sixty-five percent of the simulator group scored 7 or below. These results suggest that RDS is not affected by pain, and scores of 7 or less in persons with pain can be more confidently attributed to negative response bias.     

Reliability of the WAIS-III subtests, indexes, and IQs in individuals with substance abuse disorders

Reliability of the WAIS-III for 100 male patients with substance abuse disorders was determined. Means for age and education were 46.06 were (SD = 8.81 years) and 12.70 years (SD = 1.51 years). There were 63 Caucasians and 37 African Americans. Split-half coefficients for the 11 subtests (Digit Symbol-Coding, Symbol Search, and Object Assembly were omitted) ranged from .92 for Vocabulary and Digit Span to .77 for Picture Arrangement. The median subtest reliability coefficient was .86. Composite reliabilities were excellent for the Indexes (.94 to .95) and IQs (.94 to .97), with all coefficients > or = .94. Using the Fisher z test to compare correlation coefficients from independent samples, none of the reliability estimates differed significantly from those reported for the WAIS-III standardization sample. Similar findings emerged when reliabilities were determined separately for Caucasian and African American participants.     

White matter hyperintensities and working memory: an explorative study

White matter hyperintensities (WMH) are commonly observed in elderly people and may have the most profound effect on executive functions, including working memory. Surprisingly, the Digit Span backward, a frequently employed working memory task, reveals no association with WMH. In the present study, it was investigated whether more detailed analyses of WMH variables and study sample selection are important when establishing a possible relationship between the Digit Span backward and WMH. To accomplish this, the Digit Span backward and additional working memory tests, WMH subscores, and cardiovascular risk factors were examined. The results revealed that performance on the Digit Span backward test is unrelated to WMH, whereas a relationship between other working memory tests and WMH was confirmed. Furthermore, a division between several white matter regions seems important; hyperintensities in the frontal deep white matter regions were the strongest predictor of working memory performance.     

Construct validity of the Bender-Gestalt II: comparison with Wechsler Intelligence Scale for Children-III

This study investigated the relationships of visuomotor constructs as measured by the Bender-Gestalt II with the subtests of the WISC-III. A factor analysis included the standardized Copy and Recall scores of the Bender-Gestalt II and subtest scores of the WISC-III. The Copy score was predicted to load on measures of visual and spatial thinking and the Recall score on a short-term memory factor. The results of a principal components analysis suggest a four-factor solution with the Bender-Gestalt II Copy score loading on a visual and spatial thinking factor primarily with WISC-III Perceptual Organization subtests. The Recall score loaded on a visual and spatial thinking factor as well as a short-term memory factor with the WISC-III Digit Span subtest. The results suggest the Bender-Gestalt II Copy subtest shared commonality with the visual and spatial tasks given the similarity in the visuomotor demands of each test and was less influenced by processing speed or cultural knowledge than other tests on the visual and spatial thinking factor. Also, results suggest Bender-Gestalt II Recall measures elements of both visual and spatial thinking as well as aspects of short-term memory and memory retrieval. Clinical guidelines for co-administration and underlying processing demands are discussed.     

White Matter Hyperintensities and Working Memory: An Explorative Study

ABSTRACT

White matter hyperintensities (WMH) are commonly observed in elderly people and may have the most profound effect on executive functions, including working memory. Surprisingly, the Digit Span backward, a frequently employed working memory task, reveals no association with WMH. In the present study, it was investigated whether more detailed analyses of WMH variables and study sample selection are important when establishing a possible relationship between the Digit Span backward and WMH. To accomplish this, the Digit Span backward and additional working memory tests, WMH subscores, and cardiovascular risk factors were examined. The results revealed that performance on the Digit Span backward test is unrelated to WMH, whereas a relationship between other working memory tests and WMH was confirmed. Furthermore, a division between several white matter regions seems important; hyperintensities in the frontal deep white matter regions were the strongest predictor of working memory performance.     

Learning style and intelligence of reading disabled students

This study examined the relationship between elements of the Learning Style Inventory and various scales of the WISC-R for reading disabled students. Previous research generally suggests that reading disabled students have preferences that tap the visual-spatial domain and have higher WISC-R Performance Scale and subtest scores than Verbal Scale and subtest scores. Subjects with IQs of 90 or better on either the Verbal or Performance Scales of the WISC-R and a consistency score of 75 or better on the inventory were selected. Contrary to what might be expected, data generally showed a nonmeaningful pattern of correlations between scales of the Learning Style Inventory and WISC-R Performance-type functioning. However, as an important part of the validation of the inventory, lack of association between the two can be interpreted as support for its construct validity.     

The effect of a commercial game on children's block design scores on the WISC-R IQ test

Two experiments investigated the extent to which 10-year old children's scores on the WISC-R Block Design subtest were affected by prior experience with a specific commercial game that involved blocks and matching patterns. Experiment 1 found that 12 10-year old children who happened to have experience with the particular commercial game scored approximately three scaled score points higher on the WISC-R Block Design subtest than 24 matched children without game experience. In Experiment 2, 24 children who did not have prior experience with this particular commercial game were randomly assigned either to a Game condition (involving two 15-minute sessions with the game) or to a No-Game condition (which involved no further game experience). Children in the Game condition subsequently increased their WISC-R Block Design scores more than children in the No-Game condition. Taken together, the experiments indicate that relatively brief interactions with a commercial game can cause a significant improvement in children's performance on an IQ subtest.     

WAIS digit span-based indicators of malingered neurocognitive dysfunction: classification accuracy in traumatic brain injury

The present study determined specificity and sensitivity to malingered neurocognitive dysfunction (MND) in traumatic brain injury (TBI) for several Wechsler Adult Intelligence Scale (WAIS) Digit Span scores. TBI patients (n = 344) were categorized into one of five groups: no incentive, incentive only, suspect, probable MND, and definite MND. Performance of 1,063 nonincentive patients (e.g., cerebrovascular accident, memory disorder) was also examined. Digit Span scores included reliable digit span, maximum span forward both trials correct, maximum span forward, combined maximum forward and backward span, Digit Span scaled score, maximum span backward both trials correct, and maximum span backward. In TBI, sensitivity to MND ranged from 15% to greater than 30% at specificities of 92% to 98%. Patient groups with documented brain pathology had higher false-positive error rates. These results replicate previous known-groups malingering studies and provide valuable data supporting the WAIS Digit Span scores in detection and diagnosis of malingering.     

Conceptual tempo as a moderator variable in predicting first grade achievement test scores

This study examined the utility of a set of tests for predicting the academic achievement of separate samples of impulsive and reflective first graders. The predictor tests were the Peabody Picture Vocabulary Test, the Columbia Mental Maturity Scale, Wepman's Auditory Discrimination Test, the ITPA Sound Blending Subtest, the WISC Digit Span Subtest, and Kaufman's WISC-R Verbal Comprehension Factor (Comprehension, Information, Similarities, and Vocabulary). The criterion measures were drawn from the Stanford Achievement Test and included scores for Total Auditory, Total Mathematics, Total Reading, Vocabulary and Listening Comprehension. Multiple regression analyses revealed that (a) for three of the five criterion variables, the optimal equations for predicting the achievement test scores differed for impulsives and reflectives, and (b) given the same predictor scores, the predicted achievement of impulsive and reflective children different considerably. It was concluded that conceptual tempo is an important moderator variable in predicting academic performance.