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WAIS-IV. Advances in the Assessment of Intelligence
Abstract
The Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) is the latest revision of Wechsler's adult intelligence scales, the most widely used tests of intelligence for adults. It represents a continuing tradition of change and innovation that has been most evident in recent revisions of the scale. This chapter provides an overview of the scale's historical and contemporary foundations. The Wechsler Adult Intelligence Scale-Fourth Edition reflects the culmination of over 70 years of progressive revisions to the Wechsler line of adult intelligence measures. Wechsler's foresight in defining intelligence in practical terms has allowed the very flexibility needed for ongoing revisions to his intelligence scales in light of advances in theory, research, and the measurement of intelligence. The most recent editions of the Wechsler intelligence scales have involved dramatic changes based on burgeoning research advances in neuropsychology, cognitive neuroscience, and contemporary intelligence theory, as well as increasing sophistication in psychological measurement. Despite these substantial innovations, some critics perpetuate the myth that the Wechsler intelligence scales are outdated or atheoretical. This chapter elaborates on Wechsler's views about intelligence and the progressive adaptations to his intelligence scales in light of contemporary theory and research.
... Most of the working memory tests like auditory digit span would require the participant to recollect, mentally manipulate and verbally reproduce the series of auditory token presented. Coalson et al. [13], explained that auditory digit span measures involve auditory processing along with attention and mental manipulation. Hence inadequate audibility/auditory processing ability in children with APD would manifest deficits in the cognitive skills which may lead to misdiagnosis and erroneous rehabilitation strategies [14,15]. ...
... This is further backed by the lack of improvement in the auditory sequencing scores, which is again a task of auditory short term memory, reported in the present study. This is in concurrence with the explanation by Coalson et al. [13], that the auditory digit span measures involve attention, auditory processing and mental manipulation; hence the improvement in the auditory processing skills resulted in an improvement in the digit span measures as well. ...
Objectives
Speech perception in the presence of background noise is identified as one of the most affected auditory processes in children with auditory processing disorders (APD). Mechanism of speech-in-noise perception is extensively studied and is reported to involve different auditory and cognitive skills. However previous research has reported mixed results investigating the relationship between the cognitive skills and speech-in-noise perception in children with APD. The present study intended to study the correlation between the speech-in-noise perception and other auditory and cognitive skills, and also to find the efficacy of speech-in-noise training in other auditory and cognitive skills in children with APD.
Method
The study imparted words in noise training utilizing monosyllable and trisyllable words in the presence of speech shaped noise and 4-talker babble. Participants included 20 children with APD, 10 of them in the experimental group who underwent the training and the remaining 10 served as controls. Auditory outcome measures included five behavioural APD tests and four digit span tests to assess cognition.
Results
There was a significant improvement in the speech-in-noise perception measures, temporal processing measures (gap detection test and duration pattern test) and the backward, ascending and descending digit span measures after the training in participants in the experimental group. However, Spearman rank order correlation did not reveal a significant correlation between the speech-in-noise perception scores and any of the auditory or cognitive measures.
Conclusion
Even though there was no correlation within and between auditory and cognitive measures, speech-in-noise training improved the temporal processing skills as well as the working memory skills in children with APD supporting the relationship between the said processes. These relationships with evidence from further research could be utilized to design more effective treatment strategies for children with APD.
... All versions of the WAIS and WMS combine scores from multiple subtests into factors or indexes, with the goals of improving reliability and validity and of providing an interpretative framework for the observed measures. Although the WAIS and WMS have practical (but not atheoretical; see Coalson, Raiford, Saklofske, & Weiss, 2010;Kaufman, 2010) origins, their evolution has been influenced not only by factor analyses of previous versions, but also by current theories of intelligence, cognition, and neuropsychology. The WAIS-IV subtests are similar to those in the WAIS-III, with two core additions: visual puzzles (included in the perceptual reasoning index) and digit span sequencing (included in the working memory index; Wechsler, 2008). ...
... Finally, further theoretical and empirical work is needed on WAIS-IV and WMS-IV. On a theoretical level, although both the WAIS and WMS have evolved to better conform to current theories of intelligence, cognition, and neuropsychology (Coalson et al., 2010;Drozdick, Wahlstrom, Zhu, & Weiss, 2012;Kaufman, 2010), in particular the WAIS remains the focus of considerable controversy. For example, many researchers have argued that the WAIS is better described by the Cattell-Horn-Carroll theory than by the model outlined in the Wechsler manual (e.g., Benson et al., 2010;Ward, Bergman, & Hebert, 2012); for a review, see (McGrew, 2009), but there is still disagreement over this issue, and competing theories and measures of intelligence exist (e.g., Reynolds & Kamphaus, 2003). ...
New editions of the Wechsler Adult Intelligence and Memory scales are now available. Yet, given the significant changes in these new releases and the skepticism that has met them, independent evidence on their psychometric properties is much needed but currently lacking. We administered the WAIS-IV and the Older Adult version of the WMS-IV to 145 older adults. We examined how closely our data matched the normative sample by comparing our scaled scores with those of the publisher and by evaluating interrelations among sub-tests using confirmatory factor analysis. Not surprisingly, scaled scores from our sample were somewhat higher than those from the normative sample on some tests. Factor analysis on our sample provided support for a higher-order model of the WAIS-IV/WMS-IV Older Adults battery combined. In addition, allowing some sub-tests to load on more than one factor significantly improved model fit. The best fitting model for our sample was also the best for the normative sample. Overall, the data suggest that the factor analysis models generated from the normative samples for the new WAIS-IV and WMS-IV are reliable.
... Scale -Fourth Edition (WAIS-IV) Block Design subtests (Coalson et al., 2010;Nguyen-Louie et al., 2017); and Wechsler Intelligence Scale for Children -Third Edition (Wechsler, 1991) and WAIS-IV Digit Span subtests (Egeland, 2015;Nguyen-Louie et al., 2017). Adult versions of applicable tests were administered at timepoints in which participants were ≥18 years old. ...
The influence of alcohol use on later neurocognitive functioning is well researched, yet few studies have investigated whether neurocognition post‐drinking initiation in adolescence predicts changes in later alcohol use. The objective of this study was to investigate neurocognitive task performance during maximum alcohol use in late adolescence as predictors of drinking behaviors 3–7 years later. Analyses (n = 105) were conducted on a longitudinal data set involving adolescents (12–13 years old) who were followed for 16 years. Time 1 (T1) was defined as the individuals' maximum drinking year within the first 10 study years and Time 2 (T2) was the first available data entry 3–7 years after T1. Four hierarchical linear regression models predicting follow‐up alcohol use were estimated: drinking days, average drinks per drinking day, peak drinks, and binge episodes. All models included inhibition/cognitive flexibility, visuospatial ability, verbal memory, working memory, and their interactions with sex, while covarying for age at T1, follow‐up duration, and controlling for T1 drinking. Better visuospatial ability at T1 predicted decreases in later binge episodes at T2 (β = −0.19, p = 0.048, partial r² = 0.039). While better inhibition/cognitive flexibility at T1 predicted increases in follow‐up drinks per drinking day at T2 (β = 0.18, p = 0.016, partial r² = 0.057). Findings suggest specific neurocognitive abilities during maximum drinking in late adolescence are useful as predictors of change in later drinking quantity per occasion and could potentially inform intervention research targeting this age group.
... Letter-Number Sequencing (LNS) is a well-known purported measure of verbal working memory (Coalson et al., 2010;Haut et al., 2000;Ramos & Machado, 2021). In the LNS version included in the Wechsler scales, participants are verbally presented with an alternating list of numbers and letters (e.g., R 4 B 9 L 3) and are instructed to reproduce the numbers in ascending order followed by the letters in alphabetical order (e.g., 3 4 9 B L R). Haut et al. (2000) found that young individuals aged 23-26 (N = 8) activate brain areas involved in working memory (e.g., dorsolateral prefrontal and posterior parietal cortices) during completion of LNS. ...
Repeated neuropsychological assessments are often conducted in clinical and research settings to track cognitive changes over single or multiple intervals in patients with Parkinson's disease (PD). Yet few studies have documented test-retest reliability in PD. To address this gap, we used data from the Parkinson's Progression Markers Initiative (PPMI) to investigate the reliability of five well-known neuropsychological tests over a 3-year follow-up assessment in early-stage PD with either normal (PD-NC; N = 158) or abnormal (PD-AC; N = 39) cognitive screening, categorized based on recommended cutoffs for the Montreal Cognitive Assessment (MoCA), and healthy older adults (HOA; N = 102). All participants analyzed maintained the same cognitive status category across the assessment points. Intraclass correlation coefficients (ICCs) estimated reliability. The overall ICCs calculated across time points were as follows: Judgment of Line Orientation (PD-NC = .47, PD-AC = .50, HOA = .59); Letter-Number Sequencing (PD-NC = .64, PD-AC = .64, HOA = .65); Semantic Fluency (PD-NC = .69, PD-AC = .89, HOA = .77); Symbol Digit Modalities Test (PD-NC = .67, PD-AC = .83, HOA = .71). For the two primary components of the Hopkins Verbal Learning Test-Revised, we found the following ICCs: immediate recall (PD-NC = .46, PD-AC = .57, HOA = .58); delayed recall (PD-NC = .42, PD-AC = .57, HOA = .54). Findings from this study provide useful information for clinicians and researchers toward selecting suitable neuropsychological tests to monitor cognition at two or more time points among newly diagnosed individuals with PD and HOA.
... Participants reported their age, gender, and years of education. IQ scores were estimated with the matrix reasoning and the vocabulary sub-tasks of the Wechsler Adult Intelligence Scale (WAIS-IV, 25). Participants completed Beck's Depression Inventory (BDI-II, 26) and State-Trait Anxiety Inventory (STAI, 27) to assess depression and anxiety symptoms. ...
Background. Cannabis legislation and attitudes towards use are changing. Given that evidence from cultural neuroscience research suggests that culture influences the neurobiological mechanisms underlying behavior, it is of great importance to understand how cannabis legislation and attitudes might affect the brain processes underlying cannabis use disorder. Methods. Brain activity of 100 dependent cannabis users and 84 controls was recorded during an N-back working memory (WM) task in participants from the Netherlands (NL; users=60, controls=52) and Texas, US (TX; users=40, controls=32). Participants completed a cannabis culture questionnaire as a measure of perceived benefits (positive) and perceived harms (negative) of cannabis from their personal, friends-family’s, and country-state’s perspectives. Amount of cannabis use (grams/week), DSM-5 CUD symptoms, and cannabis-use-related problems were assessed. Results. Cannabis users self-reported more positive and less negative (personal and friends-family) cannabis attitudes than controls, with this effect being significantly larger in the TX cannabis users. No site difference in country-state attitudes were observed. TX cannabis users and those perceiving more positive country-state attitudes showed a more positive association between grams/week and WM-related activity in the superior parietal lobe. NL cannabis users and those with less positive personal attitudes showed a more positive association between grams/week and WM-load-related activity in the temporal pole. Conclusions. Both site and cultural attitudes moderated the association of quantity of cannabis use (but not severity and problems) with WM- and WM-load related activity. Importantly, differences in legislation did not align with perceived cannabis attitudes and appear to differentially affect brain activity associated with cannabis use.
... The FDS and BDS tests measures share cognitive processing in that the FDS reflects the passive updating processing, but the BDS requires beyond mere storage of representation (i.e., manipulation and processing) (Bopp & Verhaeghen, 2005). Specifically, the BDS is fundamentally a more attentionally demanding test than the FDS (Coalson et al., 2010;Wongupparaj et al., 2017). Therefore, a longer period of the intervention may accordingly benefit more complex cognitive functions (i.e., active updating of WM). ...
With the rapid growth of the older population globally, it is anticipated that age-related cognitive decline in the prodromal phase and more severe pathological decline will increase. Moreover, currently, no effective treatment options for the disease exist. Thus, early and timely prevention actions are promising and prior strategies to preserve cognitive functions by preventing symptomatology from increasing the age-related deterioration of the functions in healthy older adults. This study aims to develop the virtual reality-based cognitive intervention for enhancing executive functions (EFs) and examine the EFs after training with the virtual reality-based cognitive intervention in community-dwelling older adults. Following inclusion/exclusion criteria, 60 community-dwelling older adults aged 60–69 years were involved in the study and randomly divided into passive control and experimental groups. Eight 60 min virtual reality-based cognitive intervention sessions were held twice a week and lasted for 1 month. The EFs (i.e., inhibition, updating, and shifting) of the participants were assessed by using standardized computerized tasks, i.e., Go/NoGo, forward and backward digit span, and Berg’s card sorting tasks. Additionally, a repeated-measure ANCOVA and effect sizes were applied to investigate the effects of the developed intervention. The virtual reality-based intervention significantly improved the EFs of older adults in the experimental group. Specifically, the magnitudes of enhancement were observed for inhibitory as indexed by the response time, F(1) = 6.95, p < .05, ηp2 = .11, updating as represented by the memory span, F(1) = 12.09, p < .01, ηp2 = .18, and the response time, F(1) = 4.46, p = .04, ηp2 = .07, and shifting abilities as indexed by the percentage of correct responses, F(1) = 5.30, p = .03, ηp2 = .09, respectively. The results indicated that the simultaneous combined cognitive-motor control as embedded in the virtual-based intervention is safe and effective in enhancing EFs in older adults without cognitive impairment. Nevertheless, further studies are required to investigate the benefits of these enhancements to motor functions and emotional aspects relating to daily living and the well-being of older populations in communities.
... In addition, they contained a lot of pieces that could be damaged or lost or administered inconsistently. Furthermore, subtest Object Assembly was excluded to decrease dependence on time bonus points (Coalson, Raiford, Saklofske, & Weiss, 2010;Larrabee, 2004;Wechsler, 2008b). ...
Četvrta revizija Vekslerove skale za procenu inteligencije kod odraslih (WAIS-IV) je klinički instrument koji se zadaje individualno i koji je konstruisan za procenu intelektualnih sposobnosti adolescenata i odraslih. WAIS-IV se sastoji od 15 suptestova (10 sržnih i 5 dopunskih) koji procenjuju kognitivno funkcionisanje u četiri domena - verbalno razumevanje (eng. verbal comprehension - VCI), perceptivno rezonovanje (eng. perceptual reasoning - PRI), radna memorija (eng. working memory - WMI) i brzina procesiranja (eng. processing speed - PSI), kao i opštu intelektualnu sposobnost (eng. Full-Scale IQ - FSIQ). WAIS-IV je zadat uzorku od 262 ispitanika: 104 ispitanika iz uzorka koji je reprezentativan za širu oblast Beograda, 62 ispitanika sa dijagnozom shizofrenije, 63 sa dijagnozom depresije i 33 ispitanika sa intelektualnim teškoćama. Psihometrijske karakteristike WAIS-IV suptestova su analizirane u okvirima teorije stavskog odgovora (eng. IRT) i klasične testne teorije (eng. CTT). Rezultati su pokazali da se IRT pouzdanost kreće od .86 (Razumevanje i Dopune) do .95 (Precrtavanje), dok je IRT pouzdanost FSIQ bila .94. Sveukupno, svi suptestovi dobro diskriminišu ispitanike duž celog kontinuuma intelektualnih sposobnosti. WAIS-IV omogucava visoko pouzdanu procenu intelektualnih sposobnosti na srpskoj populaciji.
It is now well understood that HIV-positive individuals, even those under effective ART, tend to develop a spectrum of cognitive, motor, and/or mood conditions which are contemporarily referred to as HIV-associated neurocognitive disorder (HAND), and which is directly related to HIV-1 infection and HIV-1 replication in the central nervous system (CNS). As HAND is known to induce difficulties associated with attention, concentration, and memory, it is thus legitimate and pertinent to speculate upon the possibility that HIV infection may well influence human cognition and intelligence. We therefore propose herein to review the concept of intelligence, the concept of cells of intelligence, the influence of HIV on these particular cells, and the evidence pointing to differences in observed intelligence quotient (IQ) scores between HIV-positive and HIV-negative individuals. Additionally, cumulative research evidence continues to draw attention to the influence of the gut on human intelligence. Up to now, although it is known that HIV infection profoundly alters both the composition and diversity of the gut microbiota and the structural integrity of the gut, the influence of the gut on intelligence in the context of HIV infection remains poorly described. As such, we also provide herein a review of the different ways in which HIV may influence human intelligence via the gut-brain axis. Finally, we provide a discourse on perspectives related to HIV and human intelligence which may assist in generating more robust evidence with respect to this issue in future studies. Our aim is to provide insightful knowledge for the identification of novel areas of investigation, in order to reveal and explain some of the enigmas related to HIV infection.
Cannabis legislation and attitudes towards use are changing. Given that evidence from cultural neuroscience research suggests that culture influences the neurobiological mechanisms underlying behaviour, it is of great importance to understand how cannabis legislation and attitudes might affect the brain processes underlying cannabis use disorder. Brain activity of 100 dependent cannabis users and 84 controls was recorded during an N-back working memory (WM) task in participants from the Netherlands (NL; users = 60, controls = 52) and Texas, USA (TX; users = 40, controls = 32). Participants completed a cannabis culture questionnaire as a measure of perceived benefits (positive) and perceived harms (negative) of cannabis from their personal, friends-family's and country-state's perspectives. Amount of cannabis use (grams/week), DSM-5 CUD symptoms and cannabis use-related problems were assessed. Cannabis users self-reported more positive and less negative (personal and friends-family) cannabis attitudes than controls, with this effect being significantly larger in the TX cannabis users. No site difference in country-state attitudes was observed. TX cannabis users, compared with NL cannabis users, and those cannabis users perceiving more positive country-state attitudes showed a more positive association between grams/week and WM-related activity in the superior parietal lobe. NL cannabis users, compared with TX cannabis users, and those cannabis users with less positive personal attitudes showed a more positive association between grams/week and WM-load-related activity in the temporal pole. Both site and cultural attitudes moderated the association of quantity of cannabis use with WM-and WM-load-related activity. Importantly, differences in legislation did not align with perceived cannabis attitudes and appear to be differentially associated with cannabis use-related brain activity.
Objective:
In this study we aimed to investigate the screening and diagnostic properties of various self-report instruments to identify measures which most effectively detect ADHD in a correctional sample.
Method:
The sample consisted of 193 male high security prisoners in Sweden. We investigated if measures of ADHD symptoms, executive functioning, impulsivity, estimated IQ and working memory could differentiate participants with ADHD from those with ASPD or no diagnosis.
Results:
Participants with ADHD obtained significantly higher total scores on all included measures. Although we found that some of the measures were more efficient in differentiating ADHD, mean values were generally elevated in the sample.
Conclusion:
Results demonstrate the importance of investigating psychometric properties in relevant samples to assure a measurement's usefulness in different contexts, in this case a correctional setting, where the high influence of unspecific behavioral indicators in these measurements might negatively affect their validity.
Background:
Multiple sclerosis (MS) affects over 2.5 million individuals worldwide, yet much of the disease course is unknown. Hemispheric vulnerability in MS may elucidate part of this process but has not yet been studied. The current study assessed neuropsychological functioning as it relates to hemispheric vulnerability in MS.
Methods:
Verbal IQ, as measured by verbal comprehension index (VCI), nonverbal IQ, as measured by perceptual reasoning index (PRI) and memory acquisition were compared in right-handed (dextral) and non-right-handed (non-dextral) persons with MS (PwMS).
Results:
Linear mixed-effects modeling indicated a significant main effect of handedness, F(1, 195.35) = 3.95, p = .048, for a composite measure of VCI, PRI, and memory acquisition, with better performance for dextral PwMS. In examining differences for specific neuropsychological measures, the largest effect size between dextral and non-dextral participants was seen in PRI (d = 0.643), F(1,341) = 12.163, p = .001. No significant interaction effect between handedness and IQ was found, F(3, 525.60) = 0.75, p = .523.
Conclusions:
Dextral PwMS perform better than non-dextral PwMS when assessing neuropsychological performance for memory and IQ combined. Results are suggestive of increased vulnerability in the left brain to the pathological process of MS.
Alfred Binet has done an outstanding job in psychology, and among others laying the founding stone of intelligence, measurement can also be attributed to his name. He linked in his research with Theodore Simon the children’s performance closely to their age, creating this way the concept of mental age. Using this information, Based on these outcomes, William Stern created the concept of IQ as it is known today, which was further developed by Lewis Terman. The first IQ test measuring the adults’ IQ was done by David Wechsler, which was revised several times to our day. These gave rise to the concept of deviation IQ, which is measured by the intelligence tests used today.
Mild traumatic brain injury (mTBI) is usually caused by a bump, blow, or jolt to the head or penetrating head injury, and carries the risk of inducing cognitive disorders. However, identifying the biomarkers for the diagnosis of mTBI is challenging as evident abnormalities in brain anatomy are rarely found in patients with mTBI. In this study, we tested whether the alteration of functional network dynamics could be used as potential biomarkers to better diagnose mTBI. We propose a sparse dictionary learning framework to delineate spontaneous fluctuation of functional connectivity into the subject‐specific time‐varying evolution of a set of overlapping group‐level sparse connectivity components (SCCs) based on the resting‐state functional magnetic resonance imaging (fMRI) data from 31 mTBI patients in the early acute phase (<3 days postinjury) and 31 healthy controls (HCs). The identified SCCs were consistently distributed in the cohort of subjects without significant inter‐group differences in connectivity patterns. Nevertheless, subject‐specific temporal expression of these SCCs could be used to discriminate patients with mTBI from HCs with a classification accuracy of 74.2% (specificity 64.5% and sensitivity 83.9%) using leave‐one‐out cross‐validation. Taken together, our findings indicate neuroimaging biomarkers for mTBI individual diagnosis based on the temporal expression of SCCs underlying time‐resolved functional connectivity. We proposed a sparse dictionary learning framework to delineate spontaneous fluctuation of functional connectivity into the subject‐specific time‐varying evolvement of a set of overlapping group‐level sparse connectivity components (SCCs). The identified SCCs were consistently distributed in the cohort of subjects without significant inter‐group differences in connectivity patterns. Nevertheless, subject‐specific temporal expression of these SCCs could be used to effectively discriminate mTBI patients from healthy controls (HCs).
There is growing interest to use early cognitive ability to predict schooling and employment outcomes in low- and middle-income countries (LMICs). Rather than using educational attainment and school enrollment as predictors of future economic growth or of improving an individual’s earning potential, mounting evidence suggests that cognitive ability may be a better predictor. The relationship between cognitive ability, education, and employment are essential to predict future development in LMICs. We performed a systematic literature review and meta-analysis of the evidence regarding the relationship between cognitive ability and educational outcomes, and between cognitive ability and economic outcomes across LMICs. We searched peer-reviewed studies since 2000 that quantitatively measured these relationships. Based on an initial search of 3,766 records, we identified 14 studies, including 8 studies that examined the cognition-education link and 8 studies that assessed cognition-employment returns in LMICs. Identified studies showed that higher cognitive ability increased the probability of school enrollment, academic achievement, and educational attainment across LMICs. A meta-analysis of returns to wages from cognitive ability suggested that a standard deviation increase in cognitive test scores was associated with a 4.5% (95% CI 2.6%–9.6%) increase in wages. Investments into early cognitive development could play a critical role in improving educational and economic outcomes in LMICs. Further research should focus particularly in low-income countries with the least evidence, and examine the impact on education and economic outcomes by cognitive domains to provide more robust evidence for policy makers to take action.
Emotional intelligence (EI) is here analyzed as a construct referring to the individual differences in perceiving, regulating, managing, and exploiting emotions, assuming in particular a trait approach to the exploration of the phenomenon. Specifically, the role of trait EI in the definition of the possible in space and in time is addressed, analyzing how individual differences in the management and use of emotions can explain the emerging of different pasts, different futures, as well as different possible worlds. Moreover, the role of trait EI in the expression of the individual potential is explored, taking as example two research topics (i.e., prosocial behavior and creative performance) to understand how emotional intelligence can help in understanding the emerging of possible selves. Finally, future possible research scenarios are offered to explore the use of trait EI as a study variable in the investigation of the possible.
Background: Rapid eye movement sleep behavior disorder (RBD) is thought to be a prodromal symptom of Parkinson's disease (PD). RBD is also thought to be involved in cognitive decline and dementia in PD. In PD, although the relationship between RBD and cognitive dysfunctions was confirmed by considerable studies, whether RBD was associated with distinct types of cognitive defects is worth of study.
Objectives: This systematic review summarizes the evidence relating to cognitive dysfunction in PD patients with RBD (PD-RBD) and those without and explores their specificity to cognitive domains.
Methods: A meta-analysis using a random-effects model was performed for 16 different cognitive domains, including global cognitive function, memory (long-term verbal recall, long-term verbal recognition, long-term visual recall, short-term spatial recall, and short-term verbal recall), executive function (general, fluid reasoning, generativity, shifting, inhibition, and updating), language, processing speed/complex attention/working memory, visuospatial/constructional ability, and psychomotor ability. The cognitive difference between the groups of patients was measured as a standardized mean difference (SMD, Cohen's d). PD-RBD patients were classified into Confirmed-RBD (definite diagnosis with polysomnography, PSG) and Probable-RBD (without PSG re-confirmation). In some domains, RBD patients could not be analyzed separately due to the exiguity of primary studies; this analysis refers to such RBD patients as “Mixed-RBD.”
Results: Thirty-nine studies with 6,695 PD subjects were finally included. Confirmed-RBD patients showed worse performance than those without in global cognitive function, long-term verbal recall, long-term verbal recognition, generativity, inhibition, shifting, language, and visuospatial/constructional ability; Probable-RBD, in global cognitive function and shifting; and Mixed-RBD, in long-term visual recall, short-term spatial recall, general executive function, and processing speed/complex attention/working memory.
Conclusion: This meta-analysis strongly suggests a relationship between RBD, Confirmed-RBD in particular, and cognitive dysfunctions in PD patients. Early and routine screening by sensitive and targeted cognitive tasks is necessary for all PD-RBD patients because it may offer the therapeutic time window before they evolve to irreversible dementia.
Objective
A prerequisite of any psychological instrument used to compare individuals from different groups is measurement invariance (MI). It indicates that the test measures the same psychological constructs regardless of the particular grouping variable of the test-taker. Our purpose was to evaluate the MI across sex, age groups and educational levels in the recently adapted Estonian version of the Wechsler Adult Intelligence Scale – Third Edition (WAIS-III).
Method
We analysed the Estonian standardization sample of WAIS-III (N = 770) with confirmatory factor analysis (CFA) to establish the best baseline factor model for further analysis. Multi-group confirmatory factor analysis (MG-CFA) was applied to evaluate MI of the test and, granted this, mean differences across sex, age groups and educational levels.
Results
CFA supported the four-factor model. The test demonstrated partial MI across sexes; latent mean comparisons showed that men had a significantly higher mean score on the Perceptual Organization factor. Partial MI also held across age groups and, as expected, older groups had significantly lower means than younger age groups. The analyses across the educational levels failed to prove the MI as the metric invariance was not tenable.
Discussion
The results of this study provide evidence that the structural model underlying the Estonian adaption of WAIS-III is partially invariant across sex and age groups, hence the test functions same manner across these groups. Estonian WAIS-III was not invariant across the educational levels, which may indicate that the measure has a different structure or meaning to different educational groups.
Factor-based Wechsler Adult Intelligence Scale–Fourth Edition (WAIS-IV) tetrads were investigated using the Taiwan WAIS-IV standardization sample of 1,105 normal adults aged between 16 and 90 years. Various psychometric characteristics, time constraints, and qualities of estimation were compared among 90 tetrads using linear equation procedures. Among the tetrads, the Information–Visual Puzzle–Digit Span–Digit Symbol combination had higher performance than the other combinations with respect to overall estimation quality and time saved. Moreover, the Similarities–Visual Puzzle–Digit Span–Digit Symbol, Information–Matrix Reasoning–Digit Span–Digit Symbol, and Information–Visual Puzzle–Letter Number Sequencing–Digit Symbol combinations obtained the most efficient estimates. For clinicians who value the utility of Block Design, the Information–Block Design–Digit Span–Digit Symbol combination was found to provide high estimation quality. The findings also revealed that the previously recommended Wechsler Adult Intelligence Scale–Third Edition tetrads are no longer the best solutions for the WAIS-IV. Furthermore, even the selected WAIS-IV tetrads had substantial misclassification rates; the four-factor short forms tend to underestimate the full-scaled IQ for highly intelligent adults. Therefore, these short forms should be used cautiously and for screening purposes only.
The Wechsler Adult Intelligence Scale–Fourth Edition (WAIS-IV) is one of the most well-known tests in the field of adult intelligence assessment. This study explores the validity of the Egyptian adaptation for the subscales of the WAIS-IV. Confirmatory factor analysis (CFA) indicated that the first-order, second-order, and bifactor models of both the five-factor Cattel–Horn–Carroll (CHC) and the four-factor structures fitted with the WAIS-IV. When the Arithmetic subscale was pathed to Perceptual Reasoning and Working Memory, the modified four first-order factor showed a better fit than any other model. Estimates of internal consistency revealed that Cronbach’s alpha was very high (.91) for the WAIS-IV scale and for four-factor structures (ranging from .81 to .95), while ωh was low (0.61) for the WAIS-IV scale and for four-factor structures, ranging from 0.20 to 0.68. Overall, these findings provided adding evidence about the dimensionality of WAIS-IV with a new sample.
The WAIS-IV, WMS-IV WMS-IV Flexible Approach (WMS-IV Flex), and Advanced Clinical Solutions for the WAIS-IV/WMS-IV (ACS) are a comprehensive set of tests for evaluating cognitive functioning of adolescents and adults. The WAIS-IV measures multiple components of verbal, visual-perceptual, auditory working memory, and processing speed abilities. Theoretical and empirical support for the usefulness of measuring fluid reasoning with the WAIS-IV is discussed. The WMS-IV can be used to measure different aspects of declarative and episodic memory. Joint factor analysis of the WAIS-IV/WMS-IV supports a five- or seven-factor model for integrated interpretation of the batteries. New index scores based on the joint factor analysis and theoretical considerations are presented. The ACS provides clinicians with the ability to parse memory functioning into more refined analysis of errors and processes, evaluate social perception and executive functions, measure change in cognitive functioning from a premorbid level or across time, and evaluate the results for invalid performance. The co-development of the WAIS-IV/WMS-IV/ACS provides clinicians with a variety of clinical measures for evaluating the cognitive functioning of individuals with developmental, psychiatric, neurological, and medical disorders.
Background
The dramatic decrease in U.S. blood lead levels (BLLs) since the 1970s has been documented—however, the anticipated societal impact on intelligence quotient (IQ) has not. The objectives of this study were to determine whether mean IQs of American adults, adjusted for demographics, have increased in concert with society׳s decreasing BLL.
Methods
Mean IQs of eight normal adult cohorts (N=800), tested individually in 2007 by trained clinicians, were compared using ANCOVA and correlation analysis. Cohorts ranged in mean societal BLLs from 4 1/2 μg/dL (born 1985–1987) to 19 μg/dL (born 1963–1972). IQs were adjusted for confounders—education, gender, ethnicity, region, urban status. To control for age, we analyzed IQ data for a second adult sample (N=800), tested in 1995—all born when BLLs were high (1951–1975, BLL ≥15 μg/dL).
Results
When controlling for education, gender, ethnicity, and region, the regression of IQs on BLLs was significant (r=−0.84, p<0.01); the modeled change in BLLs from 20 to 4 μg/dL suggests predicted increases of 3.8 IQ points (95% CI, 1.4–6.2). Also controlling for urban status produced significance (r=−0.88, p<0.01) with predicted increases of 5.2 points (95% CI, 2.4–8.0). Control analyses ruled out aging as a confounder.
Conclusions
The dramatic societal decreases in BLLs in the U.S. since the 1970s were associated with a 4–5-point increase in the mean IQs of Americans. This effect is consistent with researchers’ predictions; however, other variables (e.g., medical advances) may have contributed to the IQ gains.
Sixty-five 5-year old children participated in 4 experimental tasks of word learning that varied systematically in the amounts of phonological and nonphonological learning required. Measures of the children’s performances on 2 measures of phonological memory (digit span and nonword repetition), vocabulary knowledge, and nonverbal ability were also obtained. Learning of the sound structures of new words was significantly, and to some degree independently, associated with aspects of both phonological memory skill and vocabulary knowledge. Learning of pairs of familiar words was linked with current vocabulary knowledge, although not with phonological memory scores. The findings suggest that both existing lexical knowledge and phonological short-term memory play significant roles in the long-term learning of the sounds of new words. The study also provides evidence of both shared and distinct processes contributing to nonword repetition and digit span tasks.
The goal of this article is to summarize current brain research on intelligence and creativity that may be relevant to education in the near future. Five issues are addressed: (a) Why is there a neuroscience interest in intelligence? (b) Can intelligence be located in the brain? (c) Why are some brains smarter than others? (d) What do we know about creativity and the brain? and (e) Can information about an individual's brain structure and function be useful to benefit his or her education? As we enter the 21st century, old controversies about measure- ment of intelligence are less relevant. Integrating neuroscience findings into education practices is a daunting challenge that will require educators to reexamine old ideas and acquire fundamental backgrounds in new areas.
5 oblique primary factors were found consistently in the age groups studied. Contrary to belief, children exhibit a lesser degree of generality of intellectual functioning than adults. Verbal and Full Scale IQs measure general intellectual ability. Interpretations based on single subtest scores are questionable. 27 refs. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Discusses various opinions on the nature and meaning of intelligence. It is argued that intelligence is a multifaceted entity, a product of many factors and subject to innumerable influences; if defined in terms of capability, it is not a single capacity but "a complex of many abilities." The psychological reference systems and the conditions and constraints that make possible a consistent definition of intelligence are discussed. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
There is no more central topic in psychology than intelligence and intelligence testing. With a history as long as psychology itself, intelligence is the most studied and likely the best understood construct in psychology, albeit still with many “unknowns.” The psychometric sophistication employed in creating intelligence tests is at the highest level. The authors provide an overview of the history, theory, and assessment of intelligence. Five questions are proposed and discussed that focus on key areas of confusion or misunderstanding associated with the measurement and assessment of intelligence. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Among the basic questions concerning memory is the problem of "how the human brain records, stores, and transmits information… . I believe that acquired engrams are laid down like genetic codes, are transmitted as genetic information and revived and assembled into memories by some matching method. The matching may be either chemical or electrical and at some levels of neural organization of the sort we identify with frequency radio tuning or electrical resonance… . [If] we conceive of learning as a linking of sequential responses or facts, it is not the facts but the links between them which are altered by the learning process." Brain function resembles genetic replication and resonance phenomena rather than devices currently employed in automata. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Deficits in attention are frequently reported following severe traumatic brain injury (TBI). However, methodological differences make it difficult to reconcile inconsistencies in the research findings in order to undertake an evidence-based assessment of attention. The current study therefore undertook a meta-analytic review of research examining attention following severe TBI. A search of the PsycINFO and PubMed databases spanning the years 1980 to 2005 was undertaken with 24 search terms. Detailed inclusion and exclusion criteria were used to screen all articles, leaving 41 studies that were included in the current meta-analysis. Weighted Cohen's d effect sizes, percentage overlap statistics, and confidence intervals were calculated for the different tests of attention. Fail-safe Ns were additionally calculated to address the bias introduced by the tendency to publish significant results. Large and significant deficits were found in specific measures of information-processing speed, attention span, focused/selective attention, sustained attention, and supervisory attentional control following severe TBI. Finally, age, education, and postinjury interval were not significantly related to these deficits in attention.
Based on the similarity of brain areas lesioned in neglect and those activated by spatial working memory (WM) tasks in normals, we hypothesized that neglect may involve spatial WM impairments. A left neglect patient with right inferior frontal and basal ganglia damage performed cancellation tasks, making either highly visible marks (to provide a reminder of visited items), or invisible marks (so only spatial WM could represent cancelled items). Invisible marks led to repeated cancellations for targets that differed only in location, but not for targets with memorable unique identities, suggesting a deficit of spatial WM, with non-spatial WM spared. Neglect was greater for cancellation with invisible marks, consistent with a role for deficient spatial WM in cancellation deficits, but contrary to account solely in terms of attention capture by salient visible marks made in ipsilesional space.
The Test of Everyday Attention (TEA) was designed to address some of the limitations of established measures of attention. However, very few studies have examined its clinical utility. A group of 35 patients who had sustained a severe TBI were compared with 35 age- and education-matched controls on the TEA, Stroop, SDMT, WMS-R Digit Span, Ruff 2s and 7s Selective Attention Test, and PASAT. Of the TEA subtests, only the Map and Telephone Search subtests of the TEA produced significant differences between the two groups, suggesting a deficit in visual selective attention following TBI. Principal components analysis revealed a four-component / factor structure of attention, largely consistent with previous studies. A logistic regression found that the TEA Map Search and Modified Colour-Word subtest of the Stroop were best able to discriminate between the TBI and control groups. When the TBI group was divided into Early ( < 1 year post injury) and Late ( > 2 years post injury) groups, there was an additional deficit on the Lottery (sustained attention) subtest in the Early TBI group, indicating that there is some recovery in attentional function beyond 1 year post injury.
The Wechsler Adult Intelligence Scale--Third Edition (WAIS-III; D. Wechsler, 1997) permits the calculation of both traditional IQ and index scores. However, if only the subtests constituting the index scores are administered, especially those yielding the Verbal Comprehension and Perceptual Organization Indexes, there is no equivalent measure of Full Scale IQ. Following the procedure for calculating a General Ability Index (GAI; A. Prifitera, L. G. Weiss, & D. H. Saklofske, 1998) for the Wechsler Intelligence Scale for Children--Third Edition (D. Wechsler, 1991), GAI normative tables for the WAIS-III standardization sample are reported here.
The WAIS standardization data for four age groups (18-19, 25-34, 45-54, and 60- over 75) were separately factor-analyzed using complete centroid extraction, blind oblique rotation to simple structure and a positive manifold, and a second-order analysis into a general factor and orthogonal primary-specifics." Among the conclusions were the following: "Three major correlated factors, Verbal Comprehension, Perceptual Organization, and Memory, are found with striking consistency over the age range studied. These are the same factors as have previously been reported for the Wechsler-Bellevue" and "only one exception to factorial invariance over age occurs. In the 60- over 75 group, the Memory factor undergoes a sharp increase in variance at the cost of the general factor. Thus, in aged subjects, intellectual performance, even on verbal tests, becomes dependent to a noteworthy degree on memory ability." 20 references.
A rationale for the subtests of the WAIS derived from factor analyses is presented. "Each subtest's measurement function, in terms of a dominant general factor (G), three major common factors (Verbal Comprehension, Perceptual Organization, Memory), and two minor factors was presented. The results in the three younger groups (18-19, 25-34, 45-54) were found to be quite similar, but some subtests undergo a change in measurement function in the oldest group (60- over 75)." Specificities were "not found high enough to warrant unique interpretations of the subtests," a finding similar to a previous report of this author (see ^W27:^n 4251).
Research has suggested that short-term memory and working memory (as measured by simple and complex span tasks, respectively) are separate constructs that are differentially related to higher order cognitive abilities. This claim is critically evaluated by reviewing research that has compared simple and complex span tasks in both experimental and correlational studies. In addition, a meta-analysis and re-analyses of key data sets were conducted. The review and analyses suggest that simple and complex span tasks largely measure the same basic subcomponent processes (e.g., rehearsal, maintenance, updating, controlled search) but differ in the extent to which these processes operate in a particular task. These differences largely depend on the extent to which phonological processes are maximized and variability from long list lengths is present. Potential methodological, psychometric, and assessment implications are discussed and a theoretical account of the data is proposed.
Nearly 1,000 adults performed a battery of cognitive tests and working memory tasks requiring simultaneous storage and processing of information. Because the amount of to-be-remembered information, or set size, varied randomly across trials, the relation between fluid intelligence and working memory could be examined across different levels of complexity and across successive trials in the working memory tasks. Strong influences of fluid intelligence were apparent in the simplest versions and on the initial trials in the working memory tasks, which suggests that the relation between working memory and fluid intelligence is not dependent on the amount of information that must be maintained, or on processes that occur over the course of performing the tasks.
For both experienced psychologists and graduate students, this book moves quickly through the essentials of WISC-IV interpretation and onto an insightful analysis of the major cognitive domains assessed by WISC-IV. It is the intention of the editors to raise the standard of practice from a simplistic 'test-label-place' model to a clinical model of assessing to understand and intervene. In the first chapter, the reader is presented with a comprehensive array of societal and home environment factors for which there is empirical evidence indicating their impact on the development of childrens cognitive abilities, and ultimately their scores on intelligence tests. Subsequent chapters address issues related to the assessment of cognitive abilities that compose 'g', with special emphasis on the clinical correlates of working memory and processing speed from both neuropsychological and cognitive information processing perspectives. Each new chapter builds on material presented in previous chapters and progresses the reader purposefully through deeper levels of understanding of WISC-IV and cognitive assessment in general. Two chapters explicate the processing approach to interpretation that is the corner stone of the WISC-IV Integrated. A further chapter addresses the interpretation of WISC-IV findings within the context of other instruments as part of a full psychological evaluation. The final chapter provides an extensive case example of how to write psychological evaluation reports from a child-centered rather than a score-centered perspective that can have transforming impact on parents and teachers approach to the child. Overall, these four editors are the architects of a masterful new book on advanced WISC-IV interpretation from a clinical perspective, Together with the complimentary book, WISC-IV Clinical Use and Interpretation this new book promises to also become the standard text for all psychologists who use the WISC-IV in clinical practice. * The Wechsler scale is the most widely used assessment of children's intelligence * Authored by Harcourt Assessment staff with exclusive data on the WISC-IV * Discusses interpretation of 4 subtest scores of WISC-IV * Suggests teaching strategies based on WISC-IV scores * Predicts scholastic achievement based on WISC-IV subtest scores * Discusses modification of score interpretation based on culture, SES, & other contextual factors.
The Wechsler Intelligence Scale for Children - Revised (WISC-R) was factor analyzed at ages 6.5 to 16.5 (n = 200 per age group). The factor structure was remarkably consistent across the age range, with 3 factors emerging for each group: Verbal Comprehension, Perceptual Organization, and Freedom from Distractibility. These factors resemble the factors identified for the 1949 WISC, although the WISC-R structure was more stable and in closer agreement with Wechsler's Verbal Performance dichotomy than was the structure of its predecessor. The results of the study are discussed in terms of their clinical applications, particularly interpretation of WISC-R profiles.
This chapter describes current theories and research that informs the psychologist who plays a central role in the initial diagnosis and subsequent assessments of children with attention deficit hyperactive disorder (ADHD). Knowing the overall cognitive ability of a child with ADHD is of relevance in planning behavioral and educational programming. Current theories described in this chapter have, for example, also implicated the significance of working memory impairments in ADHD. The Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) also has considerable clinical value for monitoring cognitive changes of paramount importance in determining the efficacy of medical, psychological, and educational programs. Intelligence testing plays an integral role in the assessment process. Intelligence tests like the Wechsler scales are not sufficiently sensitive to be used exclusively in making a diagnosis of ADHD or for discrimination among the various subtypes of ADHD. Clinical and educational needs may require a reexamination of a child's ability in a short span of time to confirm the first test results or to ensure an accurate diagnosis.
This chapter describes the Wechsler intelligence scale for children-third edition (WISC-III). It highlights the several critical elements that may be of advantage in the interpretation of the scale. The topics addressed are selectively based on the primary issues that are often not understood or neglected when using and interpreting the test. This chapter discusses the selected topics that help the practitioners while interpreting the results of the scale, and role in diagnosis as well as the approaches to subtest, and scale interpretation. The process approach to the investigation of WISC-–III scores and performance renders an analysis of the different component processes that contribute to performance on selected critical subtests. This approach allows the identification of profiles to recognize spared and impaired cognitive functions. Focusing on the particular bases of success and failure, this method lends itself directly to the development of individualized interventions.
Adult cognitive age differences in the Wechsler Adult Intelligence Scale-III Canadian normative data were curvilinear for most scales and for the Verbal Comprehension (VC), Perceptual Organization (PO), and Working Memory (WM) factors. These showed stable or increasing scores in early adulthood followed by decreasing scores, necessitating a nonlinear (continuous parameter estimation) approach to modeling adult age differences. Means were as high as or higher than the 18-year-olds until 60 years for PO and 70 years for WM and VC. As the means showed no interpretable differences across 20 to 30 years of adult cohorts, no one year can be identified as the highest scoring. "What If" analyses correcting for possible Flynn effects and for the hypothesis that changes in Processing Speed may underlie some of the age differences suggest that further testing of these two effects is a necessary prerequisite to advancing our understanding of adult age differences.
Random-array letter cancellation tasks are commonly used in the clinical assessment of visuospatial function. How stimulus properties and aging affect cancellation performance is not well understood. This study evaluated the effects of stimulus factors and age on 3 measures of cancellation performance. Thirty younger and 30 older adults each completed 12 cancellation forms that varied in paper size, stimulus density, and target-to-distractor (T/D) ratio. Interactions between stimulus factors were identified for a calculated composite measure of speed and accuracy (effectiveness), a standardized measure of the time required for completion of forms, and a standardized measure of the number of omission errors. The results showed complex interactions between stimulus factors that were different for each dependent variable. These interactions were generally similar for both age groups. The findings indicate that both stimulus properties and dependent variables must be carefully considered in the design and interpretation of cancellation paradigms.
The climate in psychology at the turn of the present century was right for the development of measures of intelligence. Many researchers were involved in efforts to find effective measures, most of which were based on empirical relationships rather than theories of human abilities. During the first quarter of the century, Terman's Stanford-Binet became the dominant instrument, but the debate over the nature of intelligence was carried out between Charles Spearman and E. L. Thorndike. There are clear antecedents of modern measurement methods and theories in the work of this period.
(from the cover) Psychologists and special educators are increasingly called upon to assess students newly immigrated from another country. The Wechsler tests are perhaps the most widely translated intelligence tests in the world and yet, little is known about the standardization efforts in different countries or how well the WISC-III travels across country, cultural and linguistic borders. This book informs professionals about these issues with respect to 16 different countries in which the WISC has been translated and validated for use. Sources for obtaining translated versions are provided so that psychologists can assess immigrant students with greater confidence in multiple languages, and the assistance of a bilingual examiner. Issues presented are history of the development of the Wechsler tests, use of the WISC-III in each country and its potential use with ethnic groups in multicultural societies, and intelligence and cognitive processes from cross-cultural and indigenous perspectives. Relationships between WISC-III scores and affluence and education are also discussed. The cross-cultural analysis of the data strongly indicates that the WISC-III is a remarkably robust measure of intelligence with cross-cultural relevance. (PsycINFO Database Record (c) 2010 APA, all rights reserved) (cover)
The objective of this paper, in line with the other papers of this special issue, is to show the potentialities of combining intelligence research and cognitive psychology. The development of intelligence is here addressed from two usually separate perspectives, a psychometric one, and a neo-Piagetian one. Two studies are presented. In Experiment 1, children aged 6, 7, 9, and 11 years (N = 100) were administered two working memory tasks and three Piagetian tasks. In Experiment 2, children aged 8–12 years (N = 207), young adults aged 20–35 (N = 160), and older adults aged 60–88 years (N = 135) were administered working memory and processing speed tasks, as well as the Raven Standard Matrices task. Regression and commonality analyses were run to analyse the age-related variance in the Piagetian tasks (Study 1), and in the Raven task (Study 2). In both experiments, working memory accounted for a large part of the age differences observed, but more so in Study 1 (Piagetian tasks) than in Study 2 (Raven task). It is concluded that working memory mediates the effect of age on fluid intelligence during childhood and during adulthood.
Presents a selective review of the WISC-R literature to relate research results to test interpretation. The interpretive topics covered are inferences drawn from factor-analytic findings, subtest specificity, the meaning of normal interscale and intrascale scatter, characteristic subtest profiles for some exceptional populations, assessment of minority group children, and WISC–WISC-R IQ differences. (2½ p ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
The concept of intelligence includes several factors. The cognitive ability such as abstract reasoning, verbal, spatial, numerical and other specific factors. The conative functions like drive, persistence, will, and/or some aspects of temperament. The non-intellective factors which include capacities and traits which are really factors of the personality per se. The discrepancy today lies in the fact that the clinical psychologist purports to measure mental abilities by psychometric tests; however, in his interpretation of the IQ or MA wide social, psychological and biological interpretations are made. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
review some of the special characteristics and concerns that may influence the assessment techniques and procedures a psychologist uses to assess depression and dementia in older clients in light of unique aspects of this population / [deals] with attributes of psychologists that may affect their interactions with an older client / [attributes] include cultural stereotypes of older adults as well as special issues of transference and countertransference / although the focus of the evaluation should be on the performer [the older person], as a responsible professional, the clinical psychologist must also reflect on how he or she consciously or unconsciously shapes the outcome (PsycINFO Database Record (c) 2012 APA, all rights reserved)
[This book] investigates the most recent methods being utilized in assessing children's knowledge and aptitude. Valuable case studies, anecdotes, and research reports . . . provide up-to-date information in the field of intelligence testing.
This lucid explanation of the principles of children's intelligence assessment and diagnostic practice offers in-depth coverage of a wide variety of tests. It explains step-by-step methods to be utilized when interpreting them. A uniform interpretative system that can be applied to all measures of intelligence is provided. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
This book is designed to help busy mental health practitioners quickly acquire the knowledge and skills they need to make optimal use of the Wechsler Adult Intelligence Scale—Third Edition (WAIS-III). The initial chapters of the book provide step-by-step guidance on test administration, scoring, and interpretation. In the chapters following, the authors provide their expert assessment of the test's relative strengths and weaknesses, valuable advice on its clinical applications, exciting new research data on aging and IQ, and several illuminating case reports. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
This study investigated the utility of considering Digits Forward (DF) and Digits Backward (DB) as separate components of the Wechsler Adult Intelligence Scale-Revised (WAIS-R). Protocols of WAIS-Rs, Peabody Picture Vocabulary Tests-Revised (PPVT-Rs), and Standard Progressive Matrices (SPMs) were examined (N = 50). Pearson correlations of Forward and Backward digit repetition and scores from PPVT-Rs and SPMs were calculated. Repetitions of DF were correlated significantly (p < .01) with SPM performance. Repetitions of DB were correlated significantly with performance on the PPVT-R (p < .02), although a stronger correlation was obtained between DB and SPM performance (p < .001). These findings indicate that although DF and DB tasks are related, the combination of these tasks into a single score might obscure important information.
The authors are indebted to Harry E. Anderson, Jr., for the major efforts required to obtain the sample and administer the tests of this experiment. In this regard, we express our gratitude to the school systems in Georgia for enabling us to use the extensive testing facilities of that state. Of course we are grateful to the children who contributed their time as subjects. We also thank Mark Foster for his considerable assistance in calculations. The work of this study was supported under a grant (to Horn) from the National Institute of Mental Health (Grant Number 1R01 MH 2845501).
The parieto-frontal integration theory (P-FIT) nominates several areas distributed throughout the brain as relevant for intelligence. This theory was derived from previously published studies using a variety of both imaging methods and tests of cognitive ability. Here we test this theory in a new sample of young healthy adults (N = 100) using a psychometric battery tapping fluid, crystallized, and spatial intelligence factors. High resolution structural MRI scans (3T) were obtained and analyzed with Voxel-based Morphometry (VBM). The main findings are consistent with the P-FIT, supporting the view that general intelligence (g) involves multiple cortical areas throughout the brain. Key regions include the dorsolateral prefrontal cortex, Broca's and Wernicke's areas, the somato-sensory association cortex, and the visual association cortex. Further, estimates of crystallized and spatial intelligence with g statistically removed, still share several brain areas with general intelligence, but also show some degree of uniqueness.
Heterogeneous results among neuro-imaging studies using psychometric intelligence measures may result from the variety of tests used. The g-factor may provide a common metric across studies. Here we derived a g-factor from a battery of eight cognitive tests completed by 6929 young adults, 40 of whom also completed structural MRI scans. Regional gray matter (GM) was determined using voxel-based-morphometry (VBM) and correlated to g-scores. Results showed correlations distributed throughout the brain, but there was limited overlap with brain areas identified in a similar study that used a different battery of tests to derive g-scores. Comparable spatial scores (with g variance removed) also were derived from both batteries, and there was considerable overlap in brain areas where GM was correlated to the respective spatial scores. The results indicate that g-scores derived from different test batteries do not necessarily have equivalent neuro-anatomical substrates, suggesting that identifying a “neuro-g” will be difficult. The neuro-anatomical substrate of a spatial factor, however, appears more consistent and implicates a distributed network of brain areas that may be involved with spatial ability. Future imaging studies directed at identifying the neural basis of intelligence may benefit from using a psychometric test battery chosen with specific criteria.
We assessed residual cognitive deficits in young people with idiopathic and cryptogenic epilepsy. In the setting of an ongoing prospective study, we invited participants initially diagnosed and enrolled in the cohort 8–9 years earlier to undergo standardized neuropsychological assessment. Sibling controls were invited when available. We analyzed 143 pairs in which cases had idiopathic or cryptogenic epilepsy and both case and control had normal intelligence. Compared with that for siblings, the Full Scale IQ for cases was 3.3 points lower (P = 0.01) mainly due to slower processing speed, which was 5.6 points lower (P = 0.0004). Word reading (P = 0.04) and spelling (P = 0.01), but not other scores, were also lower in cases. Remission status and drug use did not influence findings. In young people of normal intelligence with idiopathic or cryptogenic childhood-onset epilepsy, substantial residual effects of epilepsy appear to be confined largely to slower processing speed.
This study had two goals. One was to assess whether the WMS-III Spatial Span subtest operates as a visual analogue of Digit Span while the second was to determine whether backward span is a more sensitive measure of working memory than the forward span condition. Analyses based on the WAIS-III-WMS-III standardization and clinical group data revealed some important distinctions between Digit and Spatial Span. The two tasks exhibited differences in patterns of performance on the forward versus backward conditions, in their relationships with age, and in their methodology. Moreover, the backward conditions of both Digit and Spatial Span did not appear more affected by risk factors such as aging or pathology than the forward scores. This runs contrary to the widespread notion that backward span provides differential sensitivity regarding working memory processing.
The Wechsler Adult Intelligence Scale (WAIS) assesses a wide range of cognitive abilities and impairments. Factor analyses have documented four underlying indices that jointly comprise intelligence as assessed with the WAIS: verbal comprehension (VCI), perceptual organization (POI), working memory (WMI), and processing speed (PSI). We used nonparametric voxel-based lesion-symptom mapping in 241 patients with focal brain damage to investigate their neural underpinnings. Statistically significant lesion-deficit relationships were found in left inferior frontal cortex for VCI, in left frontal and parietal cortex for WMI, and in right parietal cortex for POI. There was no reliable single localization for PSI. Statistical power maps and cross-validation analyses quantified specificity and sensitivity of the index scores in predicting lesion locations. Our findings provide comprehensive lesion maps of intelligence factors, and make specific recommendations for interpretation and application of the WAIS to the study of intelligence in health and disease.
When attempting to determine the middle of a line, patients with neglect deviate from true center. Deviation may be induced by perceptual-attentional bias, premotor-intentional bias, or both. Using a video-based apparatus, we decoupled perceptual from premotor influences on line bisection performance in patients with hemispatial neglect to examine (a) the relationship between primary and secondary bias and (b) the relationship of bias type to lesion location. The same video-based procedure was applied to target cancellation to determine if neglect type varied as a function of task. Primary attentional-perceptual bias was found using line bisection in 14/26 subjects, most of whom had lesions involving the posterior hemisphere. Primary premotor-intentional bias on line bisection was more often associated with lesions of frontal-subcortical structures. The neglect type determined by the bisection task agreed with the results of target cancellation in most cases. Secondary bias was determined based upon whether decoupling decreased the magnitude of bisection error (concordant), increased error (discordant), or produced no significant change. Most patients showed a secondary bias, with 12/26 in the discordant group and 11/26 in the concordant group. Discordant secondary bias was more common in premotor-intentional neglect (10/12) than in perceptual-attentional neglect (2/14), whereas concordant bias was more common in the latter group (10/14) compared to the former (1/12). The nonrandom relationship between primary and secondary bias may provide a more detailed description of ways in which anatomically separate components of a cortical network contribute to spatial processing under conditions of perceptuomotor incongruity.
Many variables have been assumed to reflect speed of processing, and most are strongly related to age in the period of adulthood. One of the primary theoretical questions with respect to aging and speed concerns the relative roles of specific and general age-related effects on particular speed variables. Distinguishing between specific (or unique) and general (or shared) age-related influences on measures of speed has been complicated, in part because the issues are sometimes framed in terms of extreme all-or-none positions, and because few researchers have employed analytical procedures suitable for estimating the relative contributions of each type of influence. However, recent methods focusing on partitioning age-related variance have indicated that large proportions of the age-related effects on individual speed variables are shared with age-related effects on other variables. Although these theoretical ideas and analytical procedures are fairly new, they may be relevant to a variety of psychophysiological or neurobiological variables.
The practice of combining forward and backward memory span, as represented so prominently on the various Wechsler Scales, to arrive at a composite score for clinical interpretation is examined historically and actuarially using a large (N = 1,342) nationally stratified random sample of children from ages 5 years through 19 years. Past literature does not support the additive nature of forward and backward memory span as elements of a common process. Factor analyses of forward and backward recall using both digits and letters indicate that the two memory processes are distinct as well and should not be combined for clinical interpretation.
This study investigates the extent to which working memory, motor speed and perceptual processing speed influence Wechsler Adult Intelligence Scale-III (WAIS-III) Processing Speed Index (PSI) scores. Sixty-eight adult outpatients with Traumatic Brain Injury (TBI) of varying severity and complete data on all outcome measures were identified. Two cases with outlying values on one outcome measure were omitted from the final sample. Working memory was measured by the Working Memory Index score from the WAIS-III. Motor speed was measured as score on the Halstead-Reitan Finger Oscillation Test (finger tapping) and perceptual processing as score on the Trail Making Test--Part B. In hierarchical multiple regression analyses, working memory accounted for 10% of the variance in PSI scores, whereas motor speed only accounted for 3%. An independent measure of perceptual processing, Trail Making Test--B, accounted for 26% of the variance in WAIS-III PSI scores. The total variance accounted for by the three factors was 56%. Findings confirm that the WAIS-III PSI scores of individuals who have received a TBI reflect perceptual processing speed, with an additional component attributable to working memory. Motor speed made only a small contribution to WAIS-III PSI scores in the present sample.
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