IQ: R.I.P

Examination of five- and four-subtest short form IQ estimations for the Wechsler Intelligence Scale for Children-Fifth edition (WISC-V) in a mixed clinical sample

Evaluating general cognitive ability (i.e., intelligence) is common in neuropsychological practice, and identifying abbreviated assessments of intelligence is often advantageous. Despite the Wechsler Intelligence Scale for Children, Fifth Edition's (WISC-V) widespread contemporary use, limited research has identified clinically useful short form (SF) full scale IQ (FSIQ) estimations in clinical samples. This study sought to address this gap in the literature. Two hundred sixty-eight pediatric participants (M age = 9.79; 69% male; 88% Caucasian/White) who underwent psychological/neuropsychological evaluation were included. Mean scores for WISC-V scores fell in the low average-to-average ranges, consistent with the clinical nature of this sample (e.g., M FSIQ = 85.3). Ten unique SF combinations with five (pentad) and four (tetrad) subtests, each intentionally selected to represent a breadth of domains subsumed by WISC-V FSIQ, were described by summing subtest age-corrected scaled scores. Regression-based and prorated FSIQ estimates were calculated, and mean differences suggested some prorated estimates should be arithmetically adjusted. Both regression-based and prorated/adjusted methods provided FSIQ estimates that were accurate within five Standard Score points of true FSIQ for approximately 81-92% (pentad) and 65-76% (tetrads) of participants. Prorated/adjusted estimates appeared to provide somewhat better accuracy than regression-based estimates. Relationships between SFs and true FSIQ did not appear to be moderated by participant age, gender, nor how many WISC-V subtests were administered to participants within this archival sample (i.e., 7 vs. 10). Implications of these findings, including benefits, detriments, and other considerations of each SF combination, in addition to limitations of this study, are discussed in detail.

Changes in neurocognitive function and central nervous system structure in childhood acute lymphoblastic leukaemia survivors after treatment: a meta-analysis

Acute lymphoblastic leukaemia (ALL) is the most common malignancy in children. Although the survival rate has increased dramatically over the last decades, patients struggle with the adverse side effects of treatment. Treatment for ALL includes chemotherapy and irradiation - both of which are linked to cognitive impairments and alterations in central nervous system (CNS) structure and function detected by neuroimaging and in neurocognitive studies. The present article is a meta-analysis of the existing evidence for the mechanisms underlying changes in the CNS and neurocognitive function in ALL survivors after treatment. We found that compared with controls, ALL survivors develop: (i) cognitive sequelae in intelligence, academics, attention, memory, processing speed and executive function domains; (ii) decreased grey and white matter volume in cortical and several subcortical brain regions, with functional changes particularly in frontal regions and the hippocampus; (iii) neurocognitive impairments related to CNS changes; and (iv) reduction, but not resolution, of late neurocognitive sequelae in patients in whom prophylactic irradiation was replaced by systemic/intrathecal chemotherapy. Continued work with advanced functional magnetic resonance imaging techniques will hopefully allow the detection of early CNS changes as biomarkers to help guide early diagnosis and intervention for neurocognitive defects in patients with childhood ALL.

Examination of Wechsler adult Intelligence Scale-Fourth Edition short-form IQ estimations in an outpatient psychoeducational sample

OBJECTIVE

The Wechsler Adult Intelligence Scale, 4th edition (WAIS-IV) is a commonly utilized cognitive battery across many clinical settings. However, due to various patient variables, an abbreviated assessment of intellectual abilities, may be clinically advantageous to allow for a more thorough assessment of other cognitive domains. The current study represents an attempt to propose additional short-form IQ estimations in an outpatient clinical sample.

METHODS

We examined archival data from 318 concurrent psychological/psychoeducational evaluations performed within a university clinic (M_age = 28.67; 53.8% women). Thirty-six unique 4-subtest short-form IQ combinations were created to ensure that each WAIS-IV index score was represented by a single subtest.

RESULTS

Complete data for the ten core subtests and FSIQ were available for 192 cases. Stepwise regression analyses revealed three short-form combinations that significantly accounted for unique variance in true FSIQ scores in the final model (R² = .981, F[3, 188] = 3257.597, p < .001). Regression-based and prorated FSIQ estimates were calculated, and both methods revealed that approximately 70-75% of participants' FSIQ estimates fell within five Standard Score points of true FSIQ.

CONCLUSION

Results suggest the utility of three derived 4-subtest short-form IQ estimations for use within a clinical sample.

Evolution of clinical neuropsychology: Four challenges

Quantitative and evidence-based approaches fail to capture "the whole person," neglect the important contributions of nonquantitative variables to understanding behavior, and have limitations when assessing individuals who fall outside traditional normative groups. The emphasis on quantitative and evidence-based practices is one challenge facing the profession. The lack of consensual definitions for various domains of interest is a second challenge, because it hinders research, poses communication challenges, and impedes the accumulation of knowledge about human behavior. A third challenge the profession faces is an overemphasis on the biological basis of behavior. Finally, the forth challenge is the impact of technology on practice. Since the 1970s, there has been a rapid advance in our ability to investigate the brain, resulting in a significant increase of information about brain functioning, making it difficult for clinicians to stay abreast of changes in the field. Advances in technology have resulted in "assessments" being completed by nonpsychologists. To place these and related challenges in context, a brief review of the history of assessment and efforts to investigate brain functioning will be presented. It is suggested that failure to meet these challenges will contribute to the demise of the profession. Suggestions for meeting these challenges are offered.

Searching for a neurologic injury's Wechsler Adult Intelligence Scale-Third Edition profile

This study aimed to investigate the presence of a Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) cognitive profile in a Portuguese neurologic injured sample. The Portuguese WAIS-III was administered to 81 mixed neurologic patients and 81 healthy matched controls selected from the Portuguese standardization sample. Although the mixed neurologic injury group performed significantly lower than the healthy controls for the majority of the WAIS-III scores (i.e., composite measures, discrepancies, and subtests), the mean scores were within the normal range and, therefore, at risk of being unobserved in a clinical evaluation. ROC curves analysis showed poor to acceptable diagnostic accuracy for the WAIS-III composite measures and subtests (Working Memory Index and Digit Span revealed the highest accuracy for discriminating between participants, respectively). Multiple regression analysis showed that both literacy and the presence of brain injury were significant predictors for all of the composite measures. In addition, multiple regression analysis also showed that literacy, age of injury onset, and years of survival predicted all seven composite measures for the mixed neurologic injured group. Despite the failure to find a WAIS-III cognitive profile for mixed neurologic patients, the results showed a significant influence of brain lesion and literacy in the performance of the WAIS-III.

The use of neuropsychological tests to assess intelligence

OBJECTIVE

We sought to derive a 'neuropsychological intelligence quotient' (NIQ) to replace IQ testing in some routine assessments.

METHOD

We administered neuropsychological testing and a seven-subtest short form of the Wechsler Adult Intelligence Scale to a community sample of 394 adults aged 18-96 years. We regressed Wechsler Full Scale IQs (W-FSIQ) on 23 neuropsychological scores and derived an NIQ from 9 measures that explained significant variance in W-FSIQ. We then compared subgroups of 284 healthy and 108 unhealthy participants in NIQ and W-FSIQ to assess criterion validity, correlated NIQ and W-FSIQ scores with education level and independence for activities of daily living to assess convergent validity, and compared validity coefficients for the NIQ with those of 'hold' and 'no-hold' indices.

RESULTS

By design, NIQ and W-FSIQ scores correlated highly (r = .84), and both were higher in healthy participants. The difference was larger for NIQ, which accounted for more variability in activities of daily living. The NIQ and 'no-hold' index were better predicted by health status and less predicted by educational status than the 'hold' index.

CONCLUSIONS

We constructed an NIQ that correlates highly with Wechsler FSIQ. Tests required to obtain NIQ are commonly used and can be administered in about 45 min. Validity properties of NIQ and W-FSIQ are similar. The NIQ bore greater resemblance to a 'no-hold' than 'hold' index. One can obtain a reasonably accurate estimate of current Full Scale IQ without formal intelligence testing from a brief neuropsychological battery.

Working Memory: A Selective Review

The purpose of this paper is to provide a selective overview of the evolution of the concept and assessment of working memory, and how its assessment has been confused with the assessment of some components of attention. A literature search using PsychNet Gold was conducted using the terms working memory. In addition, the writer reviewed recommendations from a sampling of recent neuropsychology texts in regard to the assessment of attention and working memory, as well as the two most recent editions of the Wechsler Memory Scale. It is argued that many clinicians have an incomplete understanding of the relationship between attention and working memory, and often conflate the two in assessment and treatment. Suggestions were made for assessing these abilities.

Wechsler's Intelligence Scales: Theoretical and Practical Considerations

The utility of Wechsler's intelligence scales, along with some important limitations, is deeply rooted in some basic theoretical notions about the tests. The present article traces the theoretical basis for the Wechsler scales and examines empirical evidence for and against the theory. Consistent with Wechsler's theoretical notions, construct and predictive validity of the Wechsler Scales are greatest at the more global IQ level and weakest at the level of profile analysis and individual subtest interpretation. Implications for clinical practice are discussed.

Enhancing the Clinical Utility of the Wasi: Reliabilities of Discrepancy Scores and Supplemental Tables for Profile Analysis

Internal consistency reliabilities for the Wechsler Abbreviated Scale of Intelligence (WASI; Wechsler, 1999) Verbal Scale IQ (VIQ)-Performance Scale IQ (PIQ) and subtest discrepancy scores are presented separately for the child and adult standardization samples. The reliabilities of the VIQ-PIQ discrepancy scores range from .78 to .87 for children and .81 to .91 for adults. The subtest discrepancy scores range from .59 to .81 for children and .67 to .85 for adults. Also provided are tables to (a) determine the significance between pairs of WASI subtest Tscores and (b) assist practitioners with ipsative strength and weakness determinations. Formulas are provided for practitioners who wish to generate additional tables when the situation requires a more precise analysis of a WASI profile.

Chemotherapy-only treatment effects on long-term neurocognitive functioning in childhood ALL survivors: a review and meta-analysis

Children treated for ALL without cranial radiation display significant IQ deficits of 6 to 8 points compared with healthy controls. Moderate deficits occur in other neurocognitive domains including working memory, information processing speed, and fine motor functioning.

Cognitive functions in myoclonic epilepsy with ragged red fibres – a case report

Introduction. Myoclonic epilepsy with ragged red fibers (MERRF) is a rare, progressive mitochondrial disease affecting multiple systems, including the central nervous system. Typical MERRF symptoms include: myoclonus, epileptic seizures, ataxia and cognitive decline. In mitochondrial diseases selective cognitive impairment or generalized decline, called mitochondrial dementia, is usually diagnosed.

Description of case. We present the case of an 18-year-old patient with progressive neurological symptoms such as multifocal myoclonus, cerebellar syndrome (gait impairment, intention tremor, ataxia and dysmetria). The diagnosis of MERRF was confirmed at the age of 16. Neuropsychological examination showed slowing of verbal learning and deficient spontaneous recall with improvement on recognition as well as low verbal fluency.

Discussion. The authors discuss differential diagnosis of mitochondrial diseases (MIDs) in respect to cognitive function impairment and, in particular, to dementia: MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes), KSS (Kearns-Sayre syndrome), NARP syndrome (neuropathy, ataxia, and retinitis pigmentosa and ptosis). The authors emphasize importance of comprehensive neuropsychological assessment in differential diagnosis of MIDs.

Conclusion. Mild and selective cognitive impairment was identified. The type and degree of cognitive function impairment is not sufficient to diagnose dementia in this particular case of MERRF. Comprehensive neuropsychological assessment is crucial in MID in order to provide the patient with useful recommendations for education planning.

Technical and Practical Issues in the Structure and Clinical Invariance of the Wechsler Scales

This discussion article addresses issues related to expansion of the Wechsler model from four to five factors; multiple broad CHC abilities measured by the Arithmetic subtest; advantages and disadvantages of including complex tasks requiring integration of multiple broad abilities when measuring intelligence; limitations of factor analysis, which constrain test developers to creating specific broad and narrow abilities as opposed to integrative tasks; implications from brain imaging research showing the critical role of neurological pathways that integrate brain regions; close relationship of the fluid reasoning factor to g, and the inadequacies of factor analytically driven statistical definitions of g in the development of improved models of intelligence. In this rejoinder to the commentaries in this special issue on structural models of the WAIS-IV and WISC-IV, the advantages and disadvantages of Schmid–Leiman’s transformation, which removes the effects of g on the broad abilities, and the use of nested or bifactor models in evaluating models of intelligence are also discussed.

The Evolution of the Wechsler Memory Scale: A Selective Review

In clinical use since 1940, the Wechsler Memory Scale was formally introduced to the psychological community in 1945 . By 1946, it ranked 90th out of the 100 most frequently used psychological tests. By 1969, it was the 19th most used psychological test and the 2nd most used test of memory. By 1982, it was the 12th most used test and the most used memory test-a popularity it continues to enjoy. The present article will briefly trace the origin of the Wechsler Memory Scale and examine its evolution across the revisions that appeared in 1987 , 1997 , and 2009 . Issues with norming and standardization, as well as reliability and validity, will be summarized. It is argued that the test continues to have several serious shortcomings, including a lack of anchoring in an explicit neuroanatomical theory of memory and an underlying factor structure that appears to have changed little despite changes in the manifest structure and content of the test.

Higher-order factor structures for the WISC-IV: implications for neuropsychological test interpretation

Factor-analytic studies support a hierarchical four-factor model for the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) with a prominent general, third-order factor. However, there is substantial disagreement on which type of higher-order model best fits the data and how different models should guide test interpretation in clinical practice, with many studies concluding interpretation should primarily be focused on general indicators of intelligence. We performed a series of confirmatory factor analyses with the WISC-IV standardization sample (N = 2,200, ages 6-16 years) to examine model fit and reexamined models used to support test interpretation at the general level. Consistent with previous research, bifactor models were difficult to identify; however, compared with bifactor and hierarchical models, the correlated factors model with no general higher-order factor provided the best fit to the data. Results from this study support the basic four-factor model specified in the WISC-IV technical manual, with test interpretation primarily focused at the factor level, rather than the general level suggested in previous studies.

Epilepsy-related long-term amnesia: anatomical perspectives

There are few clues as to the neural basis of selective long-term amnesia. We report group and single-case data to shed light on this issue. In a group study of patients with transient epileptic amnesia, there were no significant correlations between volumetric measures of the hippocampus and indices of accelerated long-term forgetting or longer-term autobiographical memory loss. Post-mortem investigations in a patient with temporal lobe epilepsy who showed accelerated long-term forgetting, together with a degree of autobiographical memory loss, yielded evidence of neuronal loss and gliosis in regions of both the right and the left hippocampus. Neuronal loss and gliosis were more evident in anterior than posterior hippocampus. These results indicate that the unusual forms of long-term forgetting seen in some patients with temporal lobe epilepsy have no gross anatomical correlate. The findings leave open the possibilities that subtle structural damage or subtle functional disturbance, perhaps in the form of subclinical epileptiform activity, underly epilepsy-related long-term amnesia.

Some Thoughts About Reasoning in Clinical Neuropsychology

The present paper argues that discussion of the role of reasoning in clinical neuropsychology has been largely restricted to a debate over the reliability and validity of end-stage decision-making. This has sometimes led to heated debate, but has not resulted in any careful consideration of either the process of clinical reasoning or the cognition of the clinician. There is already a wealth of theory and research on the kinds of errors typical of human judgement and decision-making. Moreover, much of this work is particularly relevant for neuropsychology, being frequently based on research on medical diagnosis. This literature is briefly reviewed, with examples that demonstrate the relevance of research in this area for clinical neuropsychology. Then, a step-by-step approach is taken to examining the process of clinical neuropsychological assessment, with consideration at each step of some of the issues that arise demanding clinical reasoning. Finally, the article is briefly summarised and some implications for clinical training are advanced.

Factor structure of paediatric timed motor examination and its relationship with IQ

Brain systems supporting higher cognitive and motor control develop in a parallel manner, dependent on functional integrity and maturation of related regions, suggesting neighbouring neural circuitry. Concurrent examination of motor and cognitive control can provide a window into neurological development. However, identification of performance-based measures that do not correlate with IQ has been a challenge. Method Timed motor performance from the Physical and Neurological Examination of Subtle Signs and IQ were analysed in 136 children aged 6 to 16 (mean age 10y 2.6mo, SD 2y 6.4mo; 98 female, 38 male) attending an outpatient neuropsychology clinic and 136 right-handed comparison individuals aged 6 to 16 (mean age 10y 3.1mo, SD 2y 6.1mo; 98 female, 38 male). Timed activities--three repetitive movements (toe tapping, hand patting, finger tapping) and three sequenced movements (heel-toe tap, hand pronate/supinate, finger sequencing) each performed on the right and left--were included in exploratory factor analyses. Results Among comparison individuals, factor analysis yielded two factors--repetitive and sequenced movements--with the sequenced factor significantly predictive of Verbal IQ (VIQ) (DeltaR(2)=0.018, p=0.019), but not the repetitive factor (DeltaR(2)=0.004, p=0.39). Factor analysis within the clinical group yielded two similar factors (repetitive and sequenced), both significantly predictive of VIQ, (DeltaR(2)=0.028, p=0.015; DeltaR(2)=0.046, p=0.002 respectively). Interpretation Among typical children, repetitive timed tasks may be independent of IQ; however, sequenced tasks share more variance, implying shared neural substrates. Among neurologically vulnerable populations, however, both sequenced and repetitive movements covary with IQ, suggesting that repetitive speed is more indicative of underlying neurological integrity.

Cognitive reserve and neuropsychological functioning in patients infected with hepatitis C

This study evaluated the influence of cognitive reserve on neuropsychological test performance in 198 patients infected with the hepatitis C virus. IQ scores, educational level, and occupational rating were combined to calculate a Cognitive Reserve Score (CRS) for each patient. Similar to studies of infection with the human immunodeficiency virus, there was a significantly increased risk of impairment in neuropsychological test performance in individuals with lower CRSs. It is important to account for CRS when assessing cognitive findings in large-scale clinical trials.

The Flynn effect and its relevance to neuropsychology

Evidence from several nations indicates that performance on mental ability tests is rising from one generation to the next, and that this "Flynn effect" has been operative for more than a century. No satisfactory explanation has been found. Nevertheless, the phenomenon has important implications for clinical utilization of IQ tests. This article summarizes the empirical basis of the Flynn effect, arguments about the nature of the skill that is increasing, and proposed explanations for the cause of the increase. Ramifications for clinical neuropsychology are discussed, and some of the broader implications for psychology and society are noted.

Prenatal methylmercury exposure and developmental outcomes: review of the evidence and discussion of future directions

I conducted a review of the published literature to assess the strength of the evidence for an association between prenatal exposure to methylmercury (MeHg) and subsequent child development. I identified 12 studies on this subject published since 1980. Of these, 3 were longitudinal studies--2 conducted in the Seychelle Islands, and 1 in the Faroe Islands. Nine were cross-sectional studies conducted in different countries where seafood, a source of MeHg, constituted a major part of the diet. The ages of the children studied ranged from 2 weeks to 12 years. The results of the longitudinal studies were contradictory. Researchers in the Faroe Islands identified an association between MeHg exposure and developmental effects, whereas those in the Seychelle Islands identified no such association. This inconsistency was mirrored in the results of the cross-sectional studies where there were some positive and some negative findings. It was concluded that it was not possible from currently available data to determine whether there is an association between prenatal MeHg exposure and adverse developmental effects in children. In advance of future research, consideration should be given to resolving the uncertainties surrounding exposure assessment and outcome measurement, as both elements varied between studies. It was suggested that questions of exposure assessment would benefit from the application of an expert review process. Outcome assessment would benefit from the development of theoretically based measures of specific aspects of cognitive functioning to replace the relatively crude measures of attainment and IQ currently employed in most studies. This would assist in the development of classic longitudinal studies by allowing repeated assessment over the full age range and providing data that are more readily interpretable and comparable between studies.

Ethical considerations in writing psychological assessment reports

In this article, the author addresses the ethical questions and decision evaluators associated with the writing of psychological assessment reports. Issues related to confidentiality, clinical judgment, harm, labeling, release of test data, and computer usage are addressed. Specific suggestions on how to deal with ethical concerns when writing reports are discussed, as well as areas in need of further research.

Measurement error: Implications for diagnosis and discrepancy models of developmental dyslexia

The diagnosis of developmental dyslexia (DD) is reliant on a discrepancy between intellectual functioning and reading achievement. Discrepancy-based formulae have frequently been employed to establish the significance of the difference between 'intelligence' and 'actual' reading achievement. These formulae, however, often fail to take into consideration test reliability and the error associated with a single test score. This paper provides an illustration of the potential effects that test reliability and measurement error can have on the diagnosis of dyslexia, with particular reference to discrepancy models. The roles of reliability and standard error of measurement (SEM) in classic test theory are also briefly reviewed. This is followed by illustrations of how SEM and test reliability can aid with the interpretation of a simple discrepancy-based formula of DD. It is proposed that a lack of consideration of test theory in the use of discrepancy-based models of DD can lead to misdiagnosis (both false positives and false negatives). Further, misdiagnosis in research samples affects reproducibility and generalizability of findings. This in turn, may explain current inconsistencies in research on the perceptual, sensory, and motor correlates of dyslexia.

Digit Span as a measure of everyday attention: a study of ecological validity

This study investigated the effectiveness of the WAIS-III Digit Span subtest to predict the everyday attention of 75 participants with heterogeneous neurological conditions who were administered the Digit Span subtest as well as the ecologically valid Test of Everyday Attention. In addition, the more visually oriented Picture Completion subtest along with the verbally loaded National Adult Reading Test were administered. Analysis indicated that, although Digit Span was a weak but statistically significant predictor of attentional ability (accounting for 12.7% of the unique variance). Picture Completion was a somewhat stronger predictor (accounting for 19% of the unique variance). The weak association of Digit Span and the Test of Everyday Attention, along with the finding that Picture Completion was a better predictor of performance on the Test of Everyday Attention, question the clinical utility of using Digit Span as a measure of everyday attention.

Block design as a measure of everyday spatial ability: a study of ecological validity

This study investigated the effectiveness of the WAIS-R Block Design subtest to predict everyday spatial ability for 65 university undergraduates (15 men, 50 women) who were administered Block Design, the Standardized Road Map Test of Direction Sense, and the Everyday Spatial Activities Test. In addition, the verbally loaded National Adult Reading Test was administered to assess whether the more visuospatial Block Design subtest was a better predictor of spatial ability. Moderate support was found. When age and sex were accounted for, Block Design accounted for 36% of the variance in performance (r = -.62) on the Road Map Test and 19% of the variance on the performance of the Everyday Spatial Activities Test (r = .42). In contrast, the scores on the National Adult Reading Test did not predict performance on the Road Map Test or Everyday Spatial Abilities Test. This suggests that, with appropriate caution, Block Design could be used as a measure of everyday spatial abilities.

Neuropsychological Toxicology

Humans exposed to neurotoxins may exhibit alterations in cognitive and affective functioning and report a wide range of subjective symptoms. The multidisciplinary field of “neuropsychological toxicology” provides a framework for the systematic assessment and interpretation of adverse effects. Neuropsychological assessment is of interest not only to clinicians, but also to regulatory and legislative authorities. The importance of neuropsychological toxicology in the area of occupational risk research is increasingly being recognized. Possible fields of application include behavioral monitoring for preventive purposes, expert assessment in the context of compensation cases, and treatment in rehabilitation programs. This article reviews common research approaches, selected findings, and methodological problems of this emerging discipline and summarizes the implications for related fields of psychological research.

Neuropsychological consequences of traumatic brain injury in children and adolescents

The study of the relationship between neuroscientific information and cognitive function and dysfunction is clearly a widely expanding field. In particular, there has been a growing body of research on traumatic brain injury (TBI) in children and adolescents. This article conveys recent findings concerning cognitive outcomes, with a particular focus on age differences with TBI, suggests a relationship between specific learning disorders and brain dysfunction, addresses differential hemisphere functioning with TBI, and alludes to recent developments in assessment of TBI.

Static and dynamic assessment practices after head injury

Many individuals suffer acquired brain injury (ABI) each year. This impacts on the need for rehabilitation supports and services that facilitate the achievement of personal goals. The role of assessment in the rehabilitation of people with ABI is examined. The extent to which assessment practices match (in any way) notions of achieving 'satisfying life' is canvassed, and functions of static and dynamic assessment conveyed. Evaluation of the functions of static and dynamic assessment in facilitating community re-entry is undertaken. The response of 18 subjects with ABI (XCA, 27.5 years, X period since trauma 6.0 years) to static and dynamic assessment processes are compared. The paper concludes by reasoning that community re-entry is the main goal of people with ABI, and that dynamic assessment processes contribute to the achievement of this.

Interpretation and Misinterpretation of the South African Wechsler-Bellevue Adult Intelligence Scale: A History and a Prospectus

The South African Wechsler is based on the 1939 Wechsler-Bellevue Adult Intelligence Scale. However, the name under which it was published by the National Institute of Personnel Research in 1969, the ‘South African Wechsler Adult Intelligence Scale’, has led a generation of South African psychologists to believe that this instrument is a local verson of the 1955 WAIS, a fundamentally revised and renormed Wechsler-Bellevue. It is argued that the continued use of the South African Wechsler-Bellevue, with its outdated norms and unknown statistical properties, is not in the public interest, and that diagnostic conclusions based on this instrument may be misleading. It is then argued that if a new adult intelligence scale is to be developed, this should be based on the 1981 revision of the Wechsler (WAIS-R), rather than the local scale now under development by the Human Sciences Research Council; and finally, that in psychology, South Africa is not a beggar at the world's door, and that the capability exists for the development of an innovative and culturally appropriate ability assessment device. One such possibility is described.

Reciprocal neurological developments of twins discordant for hydrocephalus

Studies of 10 sets of twins discordant for hydrocephalus in early life revealed striking differences in degree and nature of development of verbal vs. non-verbal cognitive functions, birth order, and hand and eye preference. Despite similar (four dizygotic pairs) or identical (six monozygotic pairs) genetic endowment and grossly similar intra- and extra-uterine environmental and socio-economic influences, the consistency of the differences between the hydrocephalic children and their seemingly normal twins indicate systematic differences in pre-, peri- and/or early postnatal organization and development of hemispheric function. Follow-up studies also documented development of above-average intelligence, despite drastically reduced cerebral mantle size in hydrocephalus of early onset. The atypical patterns of development of the non-hydrocephalic twins also confirm previously described qualifications reported in studies of the significance of genetic vs. environmental factors in twins.

Conventional intelligence measurements and neuropsychological concepts of adaptive abilities

The concept of intelligence and its representation by the Intelligence Quotient have been difficult to define and the subject of criticism for various reasons. Matarazzo and Kaufman have reviewed intelligence measurements and brain functions, but a biologically based explication of intelligence has not been explicitly proposed since the theories presented more than 40 years ago by Halstead and Hebb. The present study explored the overlap and differential sensitivity of intelligence measures (VIQ, PIQ, and FSIQ) and neuropsychological measures (Impairment Index and Category Test) to cerebral damage and educational attainment. The results indicated that neuropsychological measures may serve to broaden the concept of intelligence and that a brain-related criterion may contribute to a fuller understanding of its nature.

Neuropsychological assessment and brain imaging technologies in evaluation of the sequelae of blunt head injury

A 43 year old man with a traumatic amnesic syndrome experienced only a brief, if any, loss of consciousness following an injury to the head. Four years after this injury, his results on standard psychometric assessment were normal. Long-latency evoked response potentials results were normal, and the neurological examination and computed tomography scans were unhelpful in explaining his amnesic symptoms. He had no history of alcohol abuse, yet his neuropsychological profile was that of a Korsakoff-like amnesia with frontal lobe features. Magnetic-resonance images demonstrated evidence of extensive frontal lobe damage, while cerebral blood flow studies provided additional evidence of bilateral frontal lobe dysfunction. The case highlights the need for those giving opinions in medico-legal head trauma cases to go beyond a reliance on routine indicators, such as duration of coma, results of standard psychometric assessment and computed tomography scans, to more specialised neuropsychological evaluations and magnetic-resonance imaging scans.