Reliability of tests and measures used in the neuropsychological assessment of children

The Wechsler Adult Intelligence Scale-IV Cognitive Proficiency Index: alternate form reliability of the nine possible subtest tetrads

The Wechsler Adult Intelligence Scale (WAIS-IV) added a new interpretative level by assigning the ten standard subtests into one of two constructs, the General Ability Index or the Cognitive Proficiency Index (CPI). The CPI, inferred to be a non-intellective measure of information processing efficiency, is composed of the two Working Memory Index and the two Processing Speed Index subtests (DS, AR, CD, SS). However, each index has one supplemental subtest that can be used in place of a standard one, thereby creating nine possible CPI tetrads, except for senior adults 70-90. Measuring the equivalence reliability of the nine alternate CPI tetrads was the aim of this study. Using the WAIS-IV standardization data, it was shown that all nine CPI tetrads have exceptionally high subtest equivalence reliability (.90+). For neuropsychological research purposes, all nine CPI constructions can be considered interchangeable, alternate-form measures of composite information processing efficiency. However, more research is needed to establish their accuracy for individual assessment, as well as to measure the other important reliability and predictive construct validity characteristics of the nine CPI tetrads.

Longitudinal Evaluation of Working Memory in Duchenne Muscular Dystrophy

Objective: The developmental maturation of forward and backward digit spans—indices of working memory—in boys with nonsense (nm) Duchenne muscular dystrophy (DMD) (nmDMD) was assessed using prospective, longitudinal data. Methods: Fifty-five boys of the 57 subjects with genetically confirmed nmDMD—who were from the placebo arm of a 48-week-long phase 2b clinical trial—were evaluated. Forward and backward digit spans were obtained every 12 weeks for a total of five assessments in all study subjects. Changes in forward and backward digit spans were evaluated based on age, corticosteroid treatment, and DMD mutation location. Results: Boys with nmDMD had lower mean scores on normalized forward digit span. Normalized forward digit spans were comparable between subjects stratified by age and between corticosteroid-naïve and corticosteroid-treated subjects. When stratified by DMD mutation location, normalized forward digit spans were lower in nmDMD subjects with mutations downstream of DMD exon 30, exon 45, and exon 63, both at baseline evaluation and at follow-up evaluation at 48 weeks. On average, normalized backward digit span scores were stable over 48 weeks in these subjects. Developmental growth modeling showed that subjects with nmDMD mutations upstream of DMD exon 30, upstream of DMD exon 45, and upstream of DMD exon 63 appeared to make better gains in working memory than subjects with mutations downstream of DMD exon 30, downstream of DMD exon 45, and downstream of DMD exon 63. Conclusion: Performance in working memory shows deficits in nmDMD and differed based on nmDMD location. Maturation in cognition was seen over a 48-week period. The developmental trajectory of working memory in this cohort was influenced by DMD mutation location.

WAIS—R Validation of the Thurstone Test of Mental Alertness

This preliminary study evaluated the concurrent validity of the Thurstone Test of Mental Alertness as a brief intelligence test using the Wechsler Adult Intelligence Scale—Revised as the criterion of adult intellectual achievement. Analyses indicated that the Total score on Thurstone's test was significantly correlated with the standard summary scores as well as with the WAIS—R factor scores. On the Thurstone Test of Mental Alertness scores could accurately predict WAIS—R intelligence for this nonclinical sample of 32 undergraduates. The concurrent validity of the test as a brief intelligence test was inferred and the results were consistent with the range of correlations expected among all measures of global intellectual achievement. Reading comprehension was suggested as a principal factor attenuating the correlation between the two tests.

Neuropsychology in the Schools: Does It belong?

Many neuropsychological paradigms were initially based on adults with documented brain damage. In the past two decades, interest in pediatric neuropsychology has increased. This has been motivated by the belief that more comprehensive evaluation and subsequent differential diagnosis would lead to better treatment and educational programs for children. There continues to be conflicting views in school psychology regarding the appropriateness and usefulness of neuropsychological assessment in conjunction with the traditional psychoeducational battery used in the schools. Issues relating to this controversy, including validity and reliability of neuropsychological measures, information gained from neuropsychological assessment, and the relevancy of this information to specific populations, are discussed. Implications for future research related to the limits of neuropsychological assessment in the schools are highlighted.

The role of working memory and divided attention in metaphor interpretation

Although several types of figurative language exist, neuropsychological tests of non-literal language have focused on proverbs. Metaphors in the form X is (a) Y (e.g., The body's immunological response is a battle against disease.) place a lower demand on language skills and are more easily manipulated for novelty than proverbs. Forty healthy participants completed the Metaphor Interpretation Test (developed by the authors). The task includes 20 items chosen from a list of metaphors that were rated on several scales (e.g. imagery, aptness) in a study by Katz et al. (Metaphor Symb Act 3(4):191-214, 1988). Participants were asked to rate the familiarity and provide an explanation of each metaphor. A scoring system was developed to categorize answers into: abstract complete (AC), abstract partial (AP), concrete (CT), and other/unrelated (OT) types. Participants also completed short-term memory and divided attention tests. Overall, participants produced 56 % AC, 25.38 % AP, 7.88 % CT, and 10.88 % OT responses. It was found that a measure of verbal short-term memory span was the best predictor of performance on this task (adjusted R(2) = .369). It appears that short-term memory span, not working memory or divided attention, contributes most to providing abstract responses in explaining metaphors. This is in line with the idea that when one accesses the semantic network associated with a novel metaphor, one must hold this information in mind long enough to search for and link similar cognitive networks.

Intellectual Decline in Schizophrenia: Evidence from a Prospective Birth Cohort 28 Year Follow-up Study

It is well established that IQ is lower among persons with schizophrenia than in the general population. However, it remains unclear if there is deterioration beyond a premorbid deficit. In order to assess the question of IQ deterioration, we assessed persons pre- and-post psychosis, comparing those who developed schizophrenia with those who did not. Twenty six patients with schizophrenia and 59 normal controls, evaluated at age 7 in the prospective, longitudinal, National Collaborative Perinatal Project (NCPP), were re-tested approximately 28 years later. We assessed change in an estimate of IQ based on the Vocabulary and Block Design tests from the Wechsler intelligence scales. Persons who later developed schizophrenia were significantly impaired on IQ compared to controls at age 7, especially on measures of attention. At age 35, persons with schizophrenia demonstrated significant impairment and deterioration on both IQ sub-tests compared to controls. Because impairment occurs by early childhood and subsequent deterioration occurs at an unknown period, designs with more frequent assessment of IQ through the premorbid, prodromal and early phases of illness are required to identify the key period of decline. Future research on this sample will evaluate the prospective roles of family history and perinatal complications on cognition, and assess the specificity of these findings.

Empirically derived ability-achievement subtypes in a clinical sample

The purpose of the present study was to identify reliable and clinically meaningful patterns of ability and achievement using the WISC-III and WIAT. Cluster analysis was used to group the 182 WISC-III and WIAT profiles (10 WISC-III subtests and 4 WIAT subtests) of children between the ages of 9 and 14 years. Theoretical and empirical considerations were used to identify a cluster solution, which involved comparison of several five-, six- and eight-cluster solutions. A five-cluster solution was selected as being representative of the data, which was well replicated across three hierarchical clustering methods (i.e., complete linkage, average linkage-within groups, and average linkage-between groups (UPGMA)). The clusters were labeled based on their most salient characteristics, which included a group of predominantly low ability and achievement, a group demonstrating a pattern of verbal processing deficits, a group demonstrating a pattern of visual spatial/processing speed deficits, a group with low ability and achievement with average processing speed, and a group with deficits consistent with an ACID pattern. The external validity of the five subtypes was assessed through an evaluation of the relationship between cluster membership and neuropsychological test data. Most predictions regarding neuropsychological performance were supported by the data, providing further evidence of the validity of the five-cluster solution. Clinical implications of the ability-achievement typology and suggestions for future research are discussed.

Internal consistency of three tests from the Halstead-Reitan neuropsychological battery for older children

The internal consistency of three neuropsychological tests was examined in a sample of 334 referred children (9-14 years of age). Coefficient alpha was calculated to estimate reliability on the Seashore Rhythm Test (SRT), two forms of the Speech Sounds Perception Test (SSPT), and the Aphasia Screening Test (AST). The standard SSPT appears to have relatively good internal consistency with an average coefficient of.81. The average coefficient for the abbreviated form of the SSPT was considerably lower (i.e.,.73), highlighting the superiority of the standard form in clinical practice. Internal consistency of the SRT was relatively low (i.e.,. 67). This level of reliability may be acceptable in group research and for component tests, but is marginal for independent clinical use. Coefficient alpha for the AST was moderate (i.e.,.77), suggesting adequate reliability for a screening test. These reliability estimates are compared to those obtained in previous studies using these tests in adult samples and with other tests commonly used with children.

Assessment of cognitive deterioration in individual patients following cardiac surgery: correcting for measurement error and practice effects

Assessment of cognitive change in individual patients may be confounded by unreliability of test scores and effects of repeated testing. An index correcting for both problems is proposed and compared with change indices that do not or do not adequately deal with measurement error and practice effects. These indices were used to examine cognitive deterioration in a sample of 63 patients undergoing cardiac surgery. It was demonstrated that for test measures with a low reliability, failure to correct for measurement error resulted in overestimation of deterioration rates. For test measures with a high reliability, but showing substantial practice effects, failure to correct for practice effects resulted in underestimation of deterioration rates. With the proposed index, cognitive deterioration shortly after cardiac surgery was most frequently observed for attention and psychomotor speed, less frequently for verbal fluency, and only occasionally for learning and memory.

Use of a brief assessment examination in a study of subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis is a degenerative disease affecting children and young adults that remains a distinct and relatively frequent problem in developing countries worldwide. Recent advances in treatment prompted a study at King Faisal Specialist Hospital, Riyadh, Saudi Arabia, using oral isoprinosine and intraventricular alpha-interferon. Initially, the Neurological Disability Assessment and Index was used for tracking patient progress. However, an additional means of assessment was deemed necessary and the Brief Assessment Examination was devised. Largely cognitive based, the Brief Assessment Examination appeared to be more sensitive to mental status changes than the Neurological Disability Assessment and Index, though it correlated modestly with the Neurologic Disability Assessment and Index and more strongly with staging. In addition, the Brief Assessment Examination can be administered by technician-level staff with a minimum of training. Though more study is needed, preliminary findings suggest that the Brief Assessment Examination should be a useful tracking tool for subacute sclerosing panencephalitis, particularly in the developing world.

Temporal consistency and stability of three scales for measuring stress in adults

We investigated the 30-min. temporal consistency and temporal stability of three focal scales for measuring stress: the Cognitive Anxiety Scale-State, the Focusing Inventory Scale-State, and the Somatic Symptom Scale-State. These scales are applicable for individually measured reduction in stress in research on outcome with older adolescents and adults. All possess excellent internal consistency. All manifested significant temporal consistency and good to excellent temporal stability over 30 min. in a nonclinical sample of 60 undergraduates. Small significant differences in means on the Cognitive Anxiety Scale-State and the Somatic Symptom Scale-State were noted. The phenomenological states associated with stress were stable and consistent over 30 min., the optimal time interval used in research on stress.

Retrospective self-reported symptoms of attention-deficit hyperactivity disorder: reliability of the Wender Utah Rating Scale

We measured the internal consistency and four-week temporal consistency and temporal stability of the Wender Utah Rating Scale and its 25-item short form. The Wender scale is a rationally constructed retrospective self-report rating scale for symptoms of Attention-deficit Hyperactivity Disorder. Both scales manifested excellent internal consistency. Over one month, both versions manifested significant temporal consistency and good temporal stability in the nonclinical sample of 83 successful young adults most likely to be referred for an evaluation of suspected Attention-deficit Hyperactivity Disorder. The collegiate group had a considerably higher Wender score than the original normative group, calling into question the adequacy of the limited normative data. However, both forms of the scale are reliable and comprehensive validation research is advocated.

Issues associated with repeated neuropsychological assessments

Distinguishing practice effects from other factors in repeated neuropsychological assessments are discussed in the context of research studies and clinical/forensic assessments. Potential methodological procedures for reducing the impact of practice effects in research settings are outlined. In contrast, the potential clinical utility and interpretation of practice effects in clinical assessments and forensic evaluations are highlighted.

Neuropsychological practice effects x age: a brief note

This is a brief review of some literature on practice effects and age on neuropsychological testing. Research suggests that younger subjects show greater improvement when retested on intelligence tests than older persons. The implication is that the effects of neuropsychological practice may vary with the age of the person assessed. Suggestions for further research are discussed.

A five-factor model for motor, psychomotor, and visual-spatial tests used in the neuropsychological assessment of children

Previous confirmatory factor analysis has supported a distinction between simple and complex motor skill tests in a modified and expanded Halstead Reitan test battery (HRB). The present study used a sample of 722 right-handed boys and girls, aged 9 through 12, and expanded the sample of motor, psychomotor, and visual-spatial tests to further clarify this distinction. Restricted maximum-likelihood factor analysis resulted in correlated factors of Simple Motor Skill, Complex Visual-Spatial Relations, Simple Spatial Motor Operations, Motor Steadiness, and Speeded Motor Sequencing. These results provide additional evidence for the discriminant validity of this particular battery of tests, and explicate further the skills and abilities measured in neuropsychological assessments of children referred for evaluation.

Neuropsychological functioning of hydrocephalic children

A group of 30 five- to eight-year-old hydrocephalic children was administered a comprehensive battery of neuropsychological tests. As a group, they displayed a pattern of lower PIQ than VIQ. Their performance was within the average range of many neuropsychological tests, but they performed poorly on some measures of complex visuospatial functioning. It is concluded that hydrocephalic children at this early age exhibit relatively reduced efficiency in processing complex or novel nonverbal stimuli. The possibility of dysfunction in the posterior regions of the right cerebral hemisphere is discussed.