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To evaluate whether attention deficit hyperactivity disorder (ADHD) symptoms differ across cerebral palsy (CP) and the relationship of these symptoms to CP disease data. Each of the three groups (CP, ADHD, and control) included 22 volunteers, aged 6-18. The CP group was divided into two groups, with and without ADHD (CP + ADHD and CP-ADHD). The groups were compared in terms of clinical data, ADHD symptoms, and intelligence levels. ADHD was reported in 36.4% of the CP group and 9.1% of the control group (p = 0.031). The rate of moderate/severe motor disability was higher (p = 0.052), and the Wechsler Intelligence Scale for Children-Revised (WISC-R) (total, performance, verbal) scores were lower in the CP + ADHD group compared to the CP-ADHD group (p = 0.005, p = 0.005, p = 0.002). Cognitive problems/inattention scores were higher in the CP group compared to the control group (p = 0.015). WISC-R (total, performance, verbal) scores were lower in the CP group compared to the ADHD group (p = 0.008, p = 0.001, p = 0.047) and the control group (p < 0.001, p < 0.001, p = 0.001)., Conclusion: ADHD is more common in CP and may be seen in a predominantly inattentive presentation. It is related to a worse motor disability and intelligence level in CP., What Is Known: • Compared to the general population, ADHD is reported to be more common in children with CP., What Is New: • ADHD may be seen in a predominantly inattentive presentation rather than the other presentations in children with CP. • ADHD is related to a worse motor disability and intelligence level in CP., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Intelligence assessment in children with autism spectrum disorders (ASD) often sparks debates about sex/gender differences. Specifically, the question arises whether girls exhibit lower performance on intelligence scales compared to boys. This meta-analysis examines nine studies (N=1105; 809 boys and 296 girls) to quantify sex/gender differences on the Wechsler Intelligence Scale for Children (WISC) in children with ASD, comparing their results to typically developing children., Method and Procedures: Random-effects meta-analyses on WISC indices and subtests were conducted to address the heterogeneity across effect sizes. Results for children with ASD were compared to those of typically developing children., Outcomes and Results: Findings revealed no significant differences in general intellectual functioning (full-scale IQ), verbal comprehension, working memory, or processing speed between boys and girls in children with ASD. Boys showed an advantage only in the perceptual reasoning index. At the subtest level, boys outperformed on certain tasks, while girls excelled in others., Conclusions and Implications: The observed pattern of differences in the ASD population aligns quantitatively with those in typically developing populations. Differences, if present, are specific to certain indices rather than general intelligence. These insights contribute to a nuanced understanding of gender-related cognitive variations in the context of ASD., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Almajiri is a word that describes a child sent far away from his parents to study the Quran under the tutelage and care of a Muslim scholar, also known as a Mallam. In recent times, the capacity of the Mallam to cater for these children has declined, leading them to beg on the streets for sustenance. Cognitive capacity has rarely been studied amongst this population. This study was designed to compare the intelligence quotients of Almajirai attending Quranic Schools and that of pupils attending public primary school in Zaria, Northwest Nigeria., Methods: A comparative cross-sectional study design was employed to compare the intelligence quotients of 401 participants (200 Almajirai and 201 public primary school pupils). All participants were administered a socio-demographic questionnaire and the Wechsler Intelligence Scale for Children Fourth Version (WISC-IV)., Results: Public primary school pupils performed significantly better than Almajirai on all administered subtests of the WISC-IV except arithmetic. The mean Full-Scale IQ score of Almajirai was significantly lower than that of public primary school pupils (60.30±11.49 vs. 70.12 ± 11.9, p< 0.001, 95% CI= -12.12-7.52). The intelligence quotient of Almajirai was associated with the age of the child and the father's level of education while that of public primary school pupils was associated with their current class in school., Conclusion: Public primary school pupils performed better than Almajirai on intelligence tests indicating a need to reform Almajiri Education. It is recommended that the system be strengthened and its curriculum expanded to include other modules rather than its current restriction to religious education., Competing Interests: The Authors declare that no competing interest exists, (Copyright © 2024 by West African Journal of Medicine.)

Introduction: This study aims to use diffusion tensor imaging (DTI) in conjunction with brain graph techniques to define brain structural connectivity and investigate its association with personal income (PI) in individuals of various ages and intelligence quotients (IQ). Methods: MRI examinations were performed on 55 male subjects (mean age: 40.1 ± 9.4 years). Graph data and metrics were generated, and DTI images were analyzed using tract-based spatial statistics (TBSS). All subjects underwent the Wechsler Adult Intelligence Scale for a reliable estimation of the full-scale IQ (FSIQ), which includes verbal comprehension index, perceptual reasoning index, working memory index, and processing speed index. The performance score was defined as the monthly PI normalized by the age of the subject. Results: The analysis of global graph metrics showed that modularity correlated positively with performance score ( p = 0.003) and negatively with FSIQ ( p = 0.04) and processing speed index ( p = 0.005). No significant correlations were found between IQ indices and performance scores. Regional analysis of graph metrics showed modularity differences between right and left networks in sub-cortical ( p = 0.001) and frontal ( p = 0.044) networks. TBSS analysis showed greater axial and mean diffusivities in the high-performance group in correlation with their modular brain organization. Conclusion: This study showed that PI performance is strongly correlated with a modular organization of brain structural connectivity, which implies short and rapid networks, providing automatic and unconscious brain processing. Additionally, the lack of correlation between performance and IQ suggests a reduced role of academic reasoning skills in performance to the advantage of high uncertainty decision-making networks.

Background: Organophosphates and pyrethroids are two major groups of insecticides used for crop protection worldwide. They are neurotoxicants and exposure during vulnerable windows of brain development may have long-term impact on human neurodevelopment. Only few longitudinal studies have investigated associations between prenatal exposure to these substances and intelligence quotient (IQ) at school age in populations with low, mainly dietary, exposure., Objective: To investigate associations between maternal urinary concentrations of insecticide metabolites at gestational week 28 and IQ in offspring at 7-years of age., Materials and Methods: Data was derived from the Odense Child Cohort (OCC). Metabolites of chlorpyrifos (TCPy) and pyrethroids (3-PBA, cis- and trans-DCCA, 4-F-3PBA, cis-DBCA) were measured in maternal urine collected at gestational week (GW) 28. An abbreviated version of the Danish Wechsler Intelligence Scale for Children fifth edition (WISC-V) consisting of four subtests to estimate full scale IQ (FSIQ) was administered by trained psychologists. Data were analyzed by use of multiple linear regression and adjusted for confounders., Results: 812 mother/child-pairs were included. Median concentrations were 0.21 μg/L for 3-PBA, 1.67 μg/L for TCPy and the mean IQ for children were 99.4. Null association between maternal 3-PBA and child IQ at 7 years was seen, but with trends suggesting an inverse association. There was a significant association for maternal TCPy and child IQ at mid-level exposure. Trans-DCCA above the level of detection (LOD) was also associated with slightly lower child IQ, but the association was also not statistically significant., Conclusions: We found no significant associations between maternal 3-PBA metabolites and child IQ at 7 years, but with trends suggesting an inverse association. A non-significant trend between maternal TCPy exposure and child IQ in 7-year-children was seen even in this low exposed population. Given the widespread exposure and increasing use of insecticides, this should be elaborated in future studies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: The 10 core subtests of the Wechsler Adult Intelligence Scale-IV (WAIS-IV) suffice to produce the 4 index scores for clinical assessments. Factor analytic studies with the full complement of 15 subtests reveal a 5-factor structure that aligns with Cattell-Horn-Carroll taxonomy of cognitive abilities. The current study investigates the validity of 5-factor structure in a clinical setting with reduced number of 10 subtests., Method: Confirmatory factor analytic models were fitted to a clinical neurosciences archival data set (n&#95;Male = 166, n&#95;Female = 155) and to 9 age-group samples of the WAIS-IV standardization data (n = 200 for each group). The clinical and the standardization samples differed as (a) the former comprised scores from patients, aged 16 to 91, with disparate neurological diagnosis whereas the latter was demographically stratified, (b) only the 10 core subtests in the former but all 15 subtests in the latter were administered, and (c) the former had missing data, but the latter was complete., Result: Despite empirical constraints to eliciting 5 factors with only 10 indicators, the well-fitting, 5-factor (acquired knowledge, fluid intelligence, short-term memory, visual processing, and processing speed) measurement model evinced metric invariance between the clinical and standardization samples., Conclusion: The same cognitive constructs are measured on the same metrics in every sample examined and provide no reason to reject the assumption that the 5 underlying latent abilities of the 15 subtest version in the standardization samples can also be inferred from the 10 subtest version in clinical populations., (© The Author(s) 2023. Published by Oxford University Press.)

We investigate the notion that basic visual information is acting as a building block for more complex cognitive processes in humans. Specifically, we measured individual visual orientation discrimination thresholds to report significant correlations against the total standardised intelligence quotient (IQ), verbal-IQ and non-verbal IQ scores evaluated using the Wechsler Abbreviated Scale of Intelligence Second Edition (WASI-II) test battery comprising Verbal Reasoning, Block Design, Similarities and Matrix Reasoning subtests (N = 92). A multiple linear regression analysis showed that participants' performance in our visual discrimination task, could be explained only by individual scores in Verbal Reasoning which quantifies the ability to comprehend and describe words and Matrix Reasoning, which evaluates general visual processing skills including abstract and spatial perception. Our results demonstrate that low-level visual abilities and high-level cognitive processes are more tightly interwoven together than previously thought and this result could pave the way for further research on how cognition can be defined by basic sensory processes., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Mikellidou et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Intelligence tests are amongst the most used psychological assessments, both in research and clinical settings. To avoid missing data points, for participants who cannot complete Intelligence tests normed for their age, ratio IQ scores (RIQ) are routinely computed and used as a proxy of IQ. Here, we use the case of autism to examine the validity of this widely used, yet never scientifically validated, practice. We examine the differences between standard full-scale IQ (FSIQ) and RIQ. Data was extracted from four databases in which age, FSIQ scores and subtests raw scores (from which RIQ scores could be calculated) were available for 16,751 autistic participants between 2 and 18 years old. The Intelligence tests included were the MSEL (N = 12,033), DAS-II early years (N = 1270), DAS-II school age (N = 2848), WISC-IV (N = 471) and WISC-V (N = 129). RIQs were computed for each participant as well as the discrepancy (DSC) between RIQ and FSIQ. We performed a multiple linear regression model to assess the effects of age and FSIQ on DSC for each IQ test. Participants at the extremes of the FSIQ distribution tended to have a greater DSC than participants with average FSIQ. Furthermore, age significantly predicted the DSC, with RIQ superior to FSIQ for younger participants while the opposite was found for older participants. Similar results were found in secondary analyses including typically developing children. These results question the validity of the RIQ as an alternative scoring method, especially for individuals at the extremes of the normal distribution, for whom RIQs are most often employed., Competing Interests: Declaration of competing interest The authors declare that there were no conflicts of interest with respect to the authorship or the publication of this article., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Children's language background relates to their neurocognitive development. Knowledge of this relationship is important as bilingualism is common. However, research regarding language background in relation to performance on cognitive tests such as the WPPSI-IV and NEPSY-II is scarce. The present study compared WPPSI-IV and NEPSY-II performances between 5- and 6-year-old Swedish-speaking monolingual (n = 45) and Swedish-Finnish-speaking simultaneous bilingual (n = 34) children in Finland. The participants were gathered by stratified sampling and were assessed with the Swedish versions of the tests. In profile analyses, a significant monolingual advantage was found in some WPPSI-IV subtests and indexes requiring expressive vocabulary (Vocabulary, Similarities, Picture Naming, and Vocabulary Acquisition Index) and visuospatial skills (Object Assembly and Visual Spatial Index). No group differences were found between mono- and bilingual children in receptive language, visual memory, or fluid intelligence. Additionally, no differences were found on the Full Scale IQ. The performance on the WPPSI-IV Similarities subtest improved in a subgroup of bilinguals when answers in both Swedish and Finnish were accounted for, instead of accepting only answers in Swedish. No significant differences were found between mono- and bilinguals on the language and memory tasks of NEPSY-II. These findings highlight the importance of considering the child's language background when assessing expressive language in young children, as well as the benefits of assessing bilinguals in both of their languages., (© 2023 The Authors. Scandinavian Journal of Psychology published by Scandinavian Psychological Associations and John Wiley & Sons Ltd.)

Background: There is little systematic information about intelligence and academic achievement among sheltered homeless adults. This study adds descriptive data on intelligence and academic achievement, examines discrepancies across these concepts, and explores the associations among demographic and psychosocial characteristics in the context of intelligence categories and discrepancies., Methods: We studied intelligence, academic achievement, and discrepancies between IQ and academic achievement among 188 individuals experiencing homelessness who were systematically recruited from a large, urban, 24-hour homeless recovery center. Participants completed structured interviews, urine drug testing, the Wechsler Abbreviated Scale of Intelligence, and the Wide Range Achievement Test, 4th edition., Results: Average full-scale intelligence was low average (90) but higher than scores obtained in other studies of homeless populations. Academic achievement was lower than average (82 to 88). Performance/math deficits in the higher intelligence group indicate functional difficulties that could have contributed to homeless risk., Conclusions: The low-normal intelligence and below-average achievement scores are not extreme enough to warrant immediate attention and intervention for most individuals. Systematic screening during entry into homeless services might identify learning strengths and weaknesses, presenting modifiable factors that could be addressed in focused educational/vocational interventions.

ABSTRACT In this study, we validate an earlier proposal for an abridged 17-item National Adult Reading Test (NART) by comparing its performance in estimating full-scale IQ against both the full test and the Spot-the-Word 2 (STW-2) test in a new cohort. We also compare the performance of the 17-item NART to two previous attempts to shorten this test, the Mini-NART and the Short NART. Findings include that NART 17 is numerically stronger and statistically equivalent to the other short variants, the full 50-word NART, and STW-2. Unlike the Short NART, the 17-item NART is usable for participants of all ability levels rather than only those with low reading ability, while offering equally precise premorbid estimates. We also compute that two-thirds of STW-2 is ostensibly redundant for full-scale IQ estimation and we, therefore, propose that, subject to additional verification in an independent sample, an abridged version of this test may also benefit clinical practice.

Background: Docosahexaenoic acid (DHA) is a component of neural tissue. Because its accretion into the brain is greatest during the final trimester of pregnancy, infants born before 29 weeks' gestation do not receive the normal supply of DHA. The effect of this deficiency on subsequent cognitive development is not well understood., Methods: We assessed general intelligence at 5 years in children who had been enrolled in a trial of neonatal DHA supplementation to prevent bronchopulmonary dysplasia. In the previous trial, infants born before 29 weeks' gestation had been randomly assigned in a 1:1 ratio to receive an enteral emulsion that provided 60 mg of DHA per kilogram of body weight per day or a control emulsion from the first 3 days of enteral feeds until 36 weeks of postmenstrual age or discharge home, whichever occurred first. Children from 5 of the 13 centers in the original trial were invited to undergo assessment with the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) at 5 years of corrected age. The primary outcome was the full-scale intelligence quotient (FSIQ) score. Secondary outcomes included the components of WPPSI., Results: A total of 1273 infants underwent randomization in the original trial; of the 656 surviving children who had undergone randomization at the centers included in this follow-up study, 480 (73%) had an FSIQ score available - 241 in the DHA group and 239 in the control group. After imputation of missing data, the mean (±SD) FSIQ scores were 95.4±17.3 in the DHA group and 91.9±19.1 in the control group (adjusted difference, 3.45; 95% confidence interval, 0.38 to 6.53; P = 0.03). The results for secondary outcomes generally did not support that obtained for the primary outcome. Adverse events were similar in the two groups., Conclusions: In infants born before 29 weeks' gestation who had been enrolled in a trial to assess the effect of DHA supplementation on bronchopulmonary dysplasia, the use of an enteral DHA emulsion until 36 weeks of postmenstrual age was associated with modestly higher FSIQ scores at 5 years of age than control feeding. (Funded by the Australian National Health and Medical Research Council and Nu-Mega Ingredients; N3RO Australian New Zealand Clinical Trials Registry number, ACTRN12612000503820.)., (Copyright © 2022 Massachusetts Medical Society.)

This study investigated the factor structure of the French Wechsler Intelligence Scale for Children-Fifth Edition with five standardization sample age groups (6-7, 8-9, 10-11, 12-13, 14-16 years) using hierarchical exploratory factor analysis followed by Schmid-Leiman procedure. The primary research questions included (a) how many French Wechsler Intelligence Scale for Children-Fifth Edition factors should be extracted and retained in each age subgroup, (b) how are subtests associated with the latent factors, (c) was there evidence for the publisher's claim of five first-order factors and separate Visual Spatial and Fluid Reasoning factors, (d) what proportion of variance was due to general intelligence versus the first-order group ability factors following a Schmid-Leiman procedure, and (e) do results support the age differentiation hypothesis? Results suggested that four factors might be sufficient for all five age groups and results did not support the distinction between Visual Spatial and Fluid Reasoning factors. While the general factor accounted for the largest portions of variance, the four first-order factors accounted for small unique portions of variance. Results did not support the age differentiation hypothesis because the number of factors remained the same across age groups, and there was no change in the percentage of variance accounted for by the general factor across age groups.

Accurate prediction of premorbid functioning is important in neuropsychological assessment. We aimed to investigate the predictive accuracy of the TOPF and examine this word list at an item level against WASI-II scores, using Australian pronunciations. The sample of 219 healthy Australians were aged 18-82 years. Multiple regression analyses were used to replicate the TOPF and simple demographic models based on the US TOPF standardization. Rasch analyses provided a comparison of Australian, US and UK word order from the proportion of words pronounced correctly. The variance explained in WASI-II index scores ranged from R 2 =.12 (PRI) to .33 (FSIQ-2), which was approximately half that reported in the US standardization study. The accuracy of predicted WASI-II scores was also slightly less in our sample. Thirty-two words were out of place by five places or more compared with the US word order and 30 compared with the UK. These results add to concerns about the application the TOPF with norms developed in the US and UK in the Australian context. Clinicians are advised not to apply the five error discontinue rule when using the TOPF in the local context. Development of a more accurate word reading task for use in Australia is warranted.

Aim: Assessment of intelligence and executive function in 9-10-year-old preterm children as compared to a full-term comparison group and to reveal the background of the individual differences in the outcomes by analyzing the effects of perinatal and social-economic factors., Method: Seventy-two preterm children (divided into two groups: 32 extremely low birth weight, 40 very low birth weight) and a matched group of 33 healthy full-term children, aged 9-10 years, were tested using the Wechsler Intelligence Scales for Children (WISC-IV) and digital versions of tasks measuring executive function. As background information perinatal variables and maternal education were entered in the analysis., Results: In the WISC-IV all three groups performed in the normal range. The preterm children, particularly the ELBW subgroup, scored significantly lower than the full-term comparison group in several outcome measures. Behind the group means there were massive scatters of the individual scores. Lower maternal education, male gender, and bronchopulmonary dysplasia (BPD) increased the risk for performance deficits., Conclusion: Low-to-moderate risk preterm children as groups are disadvantaged in the development of intelligence and executive function as compared to healthy full-term children even until school-age. However, with appropriate protective factors they may have chances to develop comparably with their full-term, non-risk counterparts.

Background & Aim: Establishing a premorbid level of intellectual functioning is crucial for determining the severity level of impairment and prognosis for patients in clinical setting. Therefore, the study aimed to develop a method to estimate premorbid IQ of Hindi speaking Indian population., Methods and Materials: A Hindi vocabulary test was developed (N = 60) and standardized (N = 100). The regression algorithm has been developed using VAIS, WAPIS, RPMT, and a newly developed Vocabulary test, and validated on 100 normal individuals and on 39 brain injury patients., Results: The estimated premorbid Verbal IQ and performance IQ equation was developed by using demographic variables combine with Hindi vocabulary scores and Matrix Reasoning raw scores respectively. Both the estimated premorbid verbal and performance IQ were found to be significant and valid in estimating verbal and performance IQ in normal and brain injury population., Conclusion: These equations for estimating verbal and performance IQ were found significantly accurate in predicting verbal and performance IQ., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The relationship between intelligence and brain electrical activity has long aroused the interest of many researchers. Quantified EEG and event-related potentials have contributed significantly to the development of this topic. Conversely, movement-related potentials have contributed little for both adults and children. This study analyses possible relationships between intelligence and movement-related potentials. One hundred and ten normally developing boys performed a skilled performance task (SPT) that required adaptive programming, learning proper timing and performance improvement by providing real time knowledge of results and feedback. The EEG was recorded with Ag/AgCl electrodes over Fpz, Cz, Pz, right and left precentral (RPC, LPC), P3 and P4. Intelligence was tested using the Wechsler Intelligence Scale for Children-Revised (WISC-III-R). Linear and multiple linear regressions were used to test the association between intelligence quotients (IQ) and readiness potential or Bereitschaftspotential (BP) and skilled performance positivity (SPP). BP onset was significantly and positively related to verbal IQ, and BP amplitude was significantly related to all three IQs (verbal, performance and full) in all cerebral areas. Children with higher IQ had a greater BP amplitude. SPP latency was significantly and negatively related to age but not to IQ, while SPP amplitude was significantly and negatively related to all three IQs and smaller in children with higher IQ. BP and SPP amplitudes seem to reflect the efficiency of cognitive processes associated with the task., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: Current knowledge regarding differences in verbal intelligence scores (VIQ) and performance intelligence scores (PIQ) in preterm born children is limited. As early motor performance may be essential for developing later visual-perceptual and visual-motor skills, early motor performance may be associated with PIQ., Aims: To evaluate whether in preterm born children motor performance at two years was associated with PIQ at eight years., Methods: Single-centre cohort study including 88 children born <30 weeks' gestation between 2007 and 2011, who completed the Bayley Scales of Infant and Toddler Development-III (BSID-III) at two years and the Wechsler Intelligence Scale for Children-III-NL (WISC-III-NL) at eight years. Outcome measurements (mean (SD)) were gross and fine motor performance based on the BSID-III, and PIQ and VIQ based on the WISC-III-NL. Linear regression analysis was performed to evaluate the association between motor performance at two years and PIQ at eight years., Results: At two years, mean BSID-III gross motor scaled score was 9.0 (SD 3.0) and fine motor score was 11.5 (SD 2.3). At eight years, mean PIQ was 94.9 (SD 13.5) and mean VIQ 101.8 (SD 13.7). A one-point increase in fine motor scaled score was associated with 1.7 points (95% CI 0.5-2.8) increase in PIQ. Gross motor scaled score was not associated with PIQ., Conclusions: Fine motor performance in toddlerhood was related to PIQ at school age, with lower scores indicating a lower PIQ. Early assessment of fine motor performance may be beneficial in identifying children at risk for lower performance intelligence., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Objective: To examine whether Test of Premorbid Functioning (TOPF) and Wide Range Achievement Test-Word Reading subtest (WRAT WR) are interchangeable measures, and the relationship between these measures and intelligence, among patients with schizophrenia., Method: In this archival study, the authors examined neuropsychology referrals of an inpatient forensic state hospital. Patients with a schizophrenia spectrum disorder (SSD) who received the Wechsler Adult Intelligence Scale-Fourth Edition or the Wechsler Abbreviated Scale of Intelligence-Second Edition and either TOPF or WRAT WR were considered for inclusion. The final sample consisted of 119 individuals (73.1% male)., Results: Although there was a linear relationship between most TOPF variables and WRAT WR, their concordance was weak (concordance correlation coefficients [CCC] < 0.90). Poor concordance was also observed between current FSIQ and all standard scores (SS) derived from word reading measures. FSIQ-word reading measure discrepancy scores differed significantly from a hypothesized mean of 0 (mean discrepancy range = -7.42 to -16.60). Discrepancies greater than one standard deviation (>1 SD) were highest among demographics-based SS (i.e. TOPF Predicted and Simple without TOPF). Performance-based SS, particularly TOPF Actual and WRAT4 WR, had the fewest discrepancy scores >1 SD fromFSIQ., Conclusions: TOPF and WRAT WR should not be used interchangeably among institutionalized patients with SSDs. TOPF and WRAT WR were discrepant from FSIQ, with demographic variables producing higher SS relative to performance-based variables. Future research is needed to determine which of these measures more accurately estimates intelligence among inpatients withSSDs., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The fifth version of Wechsler Intelligence Scale for Children is designed to measure five distinct aspects of intelligence, incorporating a new fluid reasoning index to the four indexes of the previous fourth version. Several factor analyses, however, have failed to support the fifth factor. The Scandinavian version is the only national version not showing clear superiority for the five-factor solution in the Manual. In the present study, we analyze WISC-V protocols from a clinical sample of 237 children tested with the new Scandinavian version. We perform six confirmatory factor analyses (CFA) testing three hierarchical-, two bifactor-, and one correlated candidate factor models. The study shows that the three-factor model does not fit the data, and that all four- and five-factor models showed good fit. The four-factor bifactor model was somewhat better than the five-bifactor and hierarchical models, but the correlated five-factor model was the superior model. Finding support for five-factors in a clinical sample representative of those most probable to be tested with the test, strengthen the claim that also the Scandinavian version measure a distinct fluid factor as intended by the test owners, and thus that clinicians may use the index scores as their main level of analysis. Review of previous CFAs show that the choice of statistical methods for CFA, bifactor or hierarchical/correlated, influence whether second order factor models are better than g-factor models., (© 2021 The Authors. Scandinavian Journal of Psychology published by Scandinavian Psychological Associations and John Wiley & Sons Ltd.)

Introduction: Raven's Advanced Progressive Matrices (APM) are frequently utilized in clinical and experimental settings to index intellectual capacity. As the APM is a relatively long assessment, abridged versions of the test have been proposed. The psychometric properties of an untimed 12-item APM have received some consideration in the literature, but validity explorations have been limited. Moreover, both reliability and validity of a timed 12-item APM have not previously been examined., Method: We considered the psychometric properties of untimed (Study 1; N = 608; M age  = 27.89, SD  = 11.68) and timed (Study 2; N = 479; M age  = 20.93, SD  = 3.12) versions of a brief online 12-item form of the APM., Results: Confirmatory factor analyses established both versions of the tests are unidimensional. Item response theory analyses revealed that, in each case, the 12 items are characterized by distinct differences in difficulty, discrimination, and guessing. Differential item functioning showed few male/female or native English/non-native English performance differences. Test-retest reliability was .65 (Study 1) to .69 (Study 2). Both tests had medium-to-large correlations with the Wechsler Abbreviated Scale of Intelligence (2nd ed.) Perceptual Reasoning Index ( r = .50, Study 1; r = .56, Study 2) and Full-Scale IQ ( r = .34, Study 1; r = .41, Study 2)., Conclusion: In sum, results suggest both untimed and timed online versions of the brief APM are psychometrically sound. As test duration was found to be highly variable for the untimed version, the timed form might be a more suitable choice when it is likely to form part of a longer battery of tests. Nonetheless, classical test and item response theory analyses, plus validity considerations, suggest the untimed version might be the superior abridged form.

Background/aims: There is a consistent body of evidence on the association between single nutrients and cognition, but the role of a healthful dietary pattern on cognition in children has been seldomly studied. This study aims to assess the association between dietary patterns at 4 years (y) and cognitive abilities at 10-13y and examine whether adiposity mediated these associations., Methods: This study used data from a sub-sample of the population-based birth cohort Generation XXI, with complete information on diet and cognition (n = 3575). At 4y, data on dietary intake was collected by a validated food frequency questionnaire and dietary patterns were derived by latent class analysis, namely Energy-dense food (EDF) pattern, Snacking pattern and Healthier pattern (Reference). At 10-13y, the Portuguese Version of the Wechsler Intelligence Scale for Children®-Third Edition was administered by trained psychologists and age-adjusted composite scores were computed: a Full-Scale Intelligence Quotient (IQ), plus a Verbal IQ, Performance IQ and Processing Speed IQ. Age- and sex-specific body mass index (BMI) z-scores, body fat percentage from bioimpedance, and waist-to-weight ratio and waist-to-hip ratio were used as measures of adiposity. Regression coefficients and 95% confidence intervals (CI) were computed using linear regression models (adjusted for maternal age and education, pre-pregnancy BMI, smoking and alcohol intake during pregnancy, child's sex, birthweight, exclusive breastfeeding duration and having siblings at 4y). Mediation analysis was conducted using path analysis., Results: After adjustment, children classified in the EDF or a Snacking patterns at 4y were more likely to have lower scores on total IQ (β = -0.116; 95%CI:-0.192,-0.039 and β = -0.148; 95%CI -0.252,-0.044, respectively), Verbal IQ (β = -0.104; 95%CI -0.177, -0.031 and β = -0.163; 95%CI -0.262,-0.064, respectively) and Performance IQ (β = -0.116 95%CI -0.193,-0.040 and β = -0.147; 95%CI -0.250,-0.042, respectively) at 10-13y, when compared to those classified in the Healthier pattern. None of the adiposity measures seemed to explain the associations between dietary patterns and IQ., Conclusion: This study supports that early unhealthy dietary patterns were associated with lower child's cognitive ability, but this effect did not seem to be mediated by adiposity., Competing Interests: Conflict of interest None., (Copyright © 2021 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)

This study investigated the systematic rise in cognitive ability scores over generations, known as the Flynn Effect, across middle childhood and early adolescence (7-15 years; 291 monozygotic pairs, 298 dizygotic pairs; 89% White). Leveraging the unique structure of the Louisville Twin Study (longitudinal data collected continuously from 1957 to 1999 using the Wechsler Intelligence Scale for Children [WISC], WISC-R, and WISC-III ed.), multilevel analyses revealed between-subjects Flynn Effects-as both decrease in mean scores upon test re-standardization and increase in mean scores across cohorts-as well as within-child Flynn Effects on cognitive growth across age. Overall gains equaled approximately three IQ points per decade. Novel genetically informed analyses suggested that individual sensitivity to the Flynn Effect was moderated by an interplay of genetic and environmental factors., (© 2021 The Authors. Child Development © 2021 Society for Research in Child Development.)

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.

Purpose: Although the Wechsler Abbreviated Scale of Intelligence, Second Edition is commonly used by neuropsychologists in the assessment of intellectual functioning, there is a paucity of published literature examining its utility in detecting neurological disease/injury. This study constitutes an attempt to validate the four-subtest WASI-II (4-FSIQ) for use with patients with neurological disease/injury., Method: Participants were 59 patients referred for outpatient neuropsychological evaluation. Thirty-two individuals with diagnoses of dementia, stroke, traumatic brain injury, and other neurological disorders constituted the neurological group. A control group was comprised of 27 individuals with diagnoses of psychiatric disorders or age-related cognitive decline., Results: The WASI-II subtest and composite scores of the neurological group were all significantly ( ps < .0001) lower than those of the control sample, but pattern differences between the groups were absent. When premorbid IQs and WASI-II IQs were compared, neurological patients with neurological disease/injury displayed evidence of intellectual deterioration; whereas, control participants did not., Conclusions: Findings suggest that the 4-WASI-II is sensitive to the biological condition of the brain and provide preliminary validation for its use in the neuropsychological assessment of a diagnostically heterogeneous sample of patients with neurological disorders.

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 ( R 2 = .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.

Background: Children born preterm (<37 weeks' gestation) have an increased risk of poor neurodevelopment, including lower intelligence quotient (IQ) scores compared with their term-born counterparts., Objective: To explore the differences in psychometric scores for cognition and motor skills when they are age-standardized according to chronological age instead of corrected age for children born preterm., Methods: We assessed = 554 children born <33 weeks' gestation with the Bayley Scales of Infant Development, 2nd edition (mental and motor scores) at 18 months and the Weschler Abbreviated Scale of Intelligence (IQ score) at seven years of age. Scores were standardized according to chronological age and corrected age and differences between mean chronological and corrected scores were compared, along with the proportion of children whose scores could be classified as impaired., Results: When scores were standardized according to chronological age instead of corrected age there was a large significant difference of 17.3 points on the mental scale (79.5 vs. 96.8, respectively) and 11.8 points on the motor scale (84.8 vs. 96.6, respectively) at 18 months. By seven years, the difference in IQ scores remained, although of a smaller magnitude at 1.9 points between mean chronological and corrected age scoring (97.2 vs. 99.1, respectively)., Conclusion: Consistent with previous literature, outcome assessments for preterm infants consistently differed according to use of chronological or corrected age to standardized scores. Cognitive scores were impacted more severely than motor scores, and differences were more substantial in early childhood than later in childhood. For clinical purposes, correction for preterm birth is only likely to have an impact during early childhood, however assessments for research purposes should continue to correct into childhood to account for the persistent bias due to preterm birth., Competing Interests: Professor Makrides reports serving on board for Trajan Nutrition until Nov 2020. No other authors reported any financial disclosures.

Knowledge of intelligence is essential for interpreting cognitive performance following traumatic brain injury (TBI). The Test of Premorbid Functioning (ToPF), a word reading test co-normed with the Wechsler Adult Intelligence Scale 4 th Edition (WAIS-IV), was examined as a tool for estimating premorbid intelligence in persons with a history of TBI. Fifty-two participants with mild, moderate, or severe TBI were administered the ToPF and WAIS-IV between two weeks and 19 months post-injury. The independent ability of the ToPF/demographic score and the Verbal Comprehension Index (VCI) to predict WAIS-IV Full Scale IQ (FSIQ) was examined, as were discrepancies between ToPF and WAIS-IV scores within and between participants. The ToPF/demographic predicted FSIQ accounted for a significant proportion of variability in actual FSIQ, above and beyond that accounted for by education or time since injury. ToPF and WAIS-IV scores did not differ by injury severity. In our sample, the ToPF/demographic predicted FSIQ underestimated intelligence in a substantial portion of our participants (31%), particularly in those with high average to superior intelligence. Finally, VCI scores were more predictive of actual FSIQ than the ToPF/demographic predicted FSIQ. The ToPF frequently underestimated post-injury intelligence and is therefore not accurately measuring premorbid intelligence in our sample, particularly in those with above average to superior intelligence. Clinicians are encouraged to administer the entire WAIS-IV, or at minimum the VCI subtests, for a more accurate measure of intelligence in those with above average intelligence and history of TBI.

Researchers continue to debate the constructs measured by commercial ability tests. Factor analytic investigations of these measures have been used to develop and refine widely adopted psychometric theories of intelligence particularly the Cattell-Horn-Carroll (CHC) model. Even so, this linkage may be problematic as many of these investigations examine a particular instrument in isolation and CHC model specification across tests and research teams has not been consistent. To address these concerns, the present study used Monte Carlo resampling to investigate the latent structure of four of the most widely used intelligence tests for children and adolescents. The results located the approximate existence of the publisher posited CHC theoretical group factors in the Differential Abilities Scales-Second edition and the Kaufman Assessment Battery for Children-Second edition but not in the Wechsler Intelligence Scale for Children-Fifth edition or the Woodcock-Johnson IV Tests of Cognitive Abilities. Instead, the results supported alternative conceptualizations from independent factor analytic research. Additionally, whereas a bifactor model produced superior fit indices in two instruments (Wechsler Intelligence Scale for Children-Fifth edition and Woodcock-Johnson IV Tests of Cognitive Abilities), a higher order structure was found to be superior in the Kaufman Assessment Battery for Children-Second edition and the Differential Abilities Scales-Second edition. Regardless of the model employed, the general factor captured a significant portion of each instrument's variance. Implications for IQ test assessment, interpretation, and theory are discussed.

Background: The embodied cognition hypothesis implies a close connection between motor and cognitive development. Evidence for these associations is accumulating, with some studies indicating stronger relations in clinical than typically developing samples., Aims: The present study extends previous research and investigates relations between fine motor skills and intelligence in typically developing children (n = 139, 7-13 years) and same-aged children with attention deficit hyperactivity disorder (ADHD, n = 46). In line with previous findings, we hypothesized stronger relations in children with ADHD than in typically developing children., Methods and Procedure: Fine motor skills were assessed using the standardized Movement Assessment Battery for Children. Intelligence was measured with the standardized Wechsler Intelligence Scale for Children., Outcomes and Results: Regression analyses indicated significant relations between fine motor skills and full-scale IQ, perceptual reasoning, working memory, and processing speed. Moderation analyses identified stronger relations between fine motor skills and full-scale IQ, perceptual reasoning, and verbal comprehension in children with ADHD compared to typically developing children., Conclusions and Implications: Results suggest a close relation between fine motor skills and intelligence in children with and without ADHD, with children diagnosed with ADHD showing stronger relations. Findings support combined motor-cognitive interventions in treating children with ADHD., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The latent factor structure of the German Wechsler Intelligence Scale for Children-Fifth edition (German WISC-V) was examined using complementary hierarchical exploratory factor analyses (EFAs) with Schmid and Leiman transformation and confirmatory factor analyses (CFAs) for all reported models from the German WISC-V Technical Manual and rival bifactor models using the standardization sample ( N = 1,087) correlation matrix of the 15 primary and secondary subtests. EFA results did not support a fifth factor (Fluid Reasoning). A four-factor model with the dominant general intelligence ( g ) factor resembling the WISC-IV was supported by EFA. CFA results indicated the best representation was a bifactor model with four group factors, complementing EFA results. Present EFA and CFA results replicated other independent assessments of standardization and clinical samples of the United States and international versions of the WISC-V and indicated primary, if not exclusive, interpretation of the Full Scale IQ as an estimate of g .

Reduced global hippocampus volumes have been demonstrated in premature-born individuals, from newborns to adults; however, it is unknown whether hippocampus subfield (HCSF) volumes are differentially affected by premature birth and how relevant they are for cognitive performance. To address these questions, we investigated magnetic resonance imaging (MRI)-derived HCSF volumes in very premature-born adults, and related them with general cognitive performance in adulthood. We assessed 103 very premature-born (gestational age [GA] <32 weeks and/or birth weight <1,500 g) and 109 term-born individuals with cognitive testing and structural MRI at 26 years of age. HCSFs were automatically segmented based on three-dimensional T1- and T2-weighted sequences and studied both individually and grouped into three functional units, namely hippocampus proper (HP), subicular complex (SC), and dentate gyrus (DG). Cognitive performance was measured using the Wechsler-Adult-Intelligence-Scale (full-scale intelligence quotient [FS-IQ]) at 26 years. We observed bilateral volume reductions for almost all HCSF volumes in premature-born adults and associations with GA and neonatal treatment intensity but not birth weight. Left-sided HP, SC, and DG volumes were associated with adult FS-IQ. Furthermore, left DG volume was a mediator of the association between GA and adult FS-IQ in premature-born individuals. Results demonstrate nonspecifically reduced HCSF volumes in premature-born adults; but specific associations with cognitive outcome highlight the importance of the left DG. Data suggest that specific interventions toward hippocampus function might be promising to lower adverse cognitive effects of prematurity., (© 2020 The Authors. Human Brain Mapping published by Wiley Periodicals LLC.)

The present study investigated measurement invariance across gender on the German Wechsler Intelligence Scale for Children-Fifth Edition (WISC-V). The higher order model that was preferred by the test publishers was tested on a population-representative German sample of 1,411 children and adolescents aged between 6 and 16 years. Confirmatory factor analyses were conducted to test for measurement invariance. As soon as partial scalar invariance could be established by freeing nonequivalent subtest intercepts, results demonstrated that 11 out of 15 subtest scores have the same meaning for male and female children. These findings support interpretable comparisons of the WISC-V test scores between males and females but only in due consideration of partial scalar invariance and with respect to the underlying factor structure. Despite this, however, results did not support the overall structural validity of the higher order model. Thus, replacing the former Perceptual Reasoning factor by Fluid Reasoning and Visual Spatial may be considered inappropriate due to the redundancy of the FRI as a separate factor. Results also indicated that the WISC-V provides stronger measurement of general intelligence ( Full Scale IQ ) than measurements of cognitive subdomains (WISC-V indexes). Interpretative emphasis should thus be placed on the Full Scale IQ rather than the WISC-V indexes.

The factor structure of the intelligence and scholastic skills domains of the Intelligence and Development Scales-2 was examined using exploratory factor analyses with the standardization and validation sample ( N = 2,030, aged 5 to 20 years). Results partly supported the seven proposed intelligence group factors. However, the theoretical factors Visual Processing and Abstract Reasoning as well as Verbal Reasoning and Long-Term Memory collapsed, resulting in a five-factor structure for intelligence. Adding the three scholastic skills subtests resulted in an additional factor Reading/Writing and in Logical-Mathematical Reasoning showing a loading on abstract Visual Reasoning and the highest general factor loading. A data-driven separation of intelligence and scholastic skills is not evident. Omega reliability estimates based on Schmid-Leiman transformations revealed a strong general factor that accounted for most of the true score variance both overall and at the group factor level. The possible usefulness of factor scores is discussed.

Aim: To determine IQ at 26 to 30 years in very-low-birthweight (VLBW) adults compared with term-born controls; and to examine the stability of IQ in VLBW individuals between 7 to 8 years and 26 to 30 years, identify perinatal and social predictors of IQ, and assess the contribution of brain volume to IQ., Method: At 26 to 30 years, 229 VLBW adults (71% survivors of prospectively enrolled national cohort) and 100 term-born controls were tested on the Wechsler Abbreviated Scale of Intelligence. For VLBW, IQ at 7 to 8 years, perinatal and social data were extracted from the data set, and 150 adults underwent volumetric cranial magnetic resonance imaging (MRI)., Results: At 26 to 30 years, the mean adjusted difference between VLBW and controls for total IQ was 9.4 (95% CI 6.5-12.4) points. In VLBW individuals the correlation between IQ scores at 7 to 8 years and 26 to 30 years was 0.78. On multiple regression analysis, parental education was the strongest predictor of verbal and total IQ at both ages. Birthweight was a strong predictor of perceptual and total IQ. In VLBW individuals with MRI scans, the addition of brain volume as a variable increased the variance explained for perceptual and total IQ., Interpretation: VLBW adults have mean IQ scores 9 to 11 points below controls. Parental education and birthweight are the strongest predictors of IQ., (© 2020 Mac Keith Press.)

The neural substrate of high intelligence performances remains not well understood. Based on diffusion tensor imaging (DTI) which provides microstructural information of white matter fibers, we proposed in this work to investigate the relationship between structural brain connectivity and intelligence quotient (IQ) scores. Fifty-seven children (8-12 y.o.) underwent a MRI examination, including conventional T1-weighted and DTI sequences, and neuropsychological testing using the fourth edition of Wechsler Intelligence Scale for Children (WISC-IV), providing an estimation of the Full-Scale Intelligence Quotient (FSIQ) based on four subscales: verbal comprehension index (VCI), perceptual reasoning index (PRI), working memory index (WMI), and processing speed index (PSI). Correlations between the IQ scores and both graphs and diffusivity metrics were explored. First, we found significant correlations between the increased integrity of WM fiber-bundles and high intelligence scores. Second, the graph theory analysis showed that integration and segregation graph metrics were positively and negatively correlated with WISC-IV scores, respectively. These results were mainly driven by significant correlations between FSIQ, VCI, and PRI and graph metrics in the temporal and parietal lobes. In conclusion, these findings demonstrated that intelligence performances are related to the integrity of WM fiber-bundles as well as the density and homogeneity of WM brain networks.

Objective: The literature lacks independent investigations of the influence of tablet administration of cognitive assessments in applied clinical settings. The present study examined the influence of iPad administration on (Wechsler Adult Intelligence Scale-Fourth Edition) WAIS-IV core subtest scores in a university-based clinic., Method: Record review was conducted for a convenience sample (N = 66) of university students who were administered the WAIS-IV via iPad or traditional format. Bayesian difference testing was used to evaluate the strength of the evidence for subtest score equivalence across groups., Results: Evidence supported score equivalency for the 10 core subtests across administration groups (BF > 3). The one exception was digit span-forward condition, for which equivalence was supported (BF = 2.44), but did not meet cut-off criteria., Conclusions: iPad administration of WAIS-IV is unlikely to influence subtest scores in routine clinical practice with healthy young adults. Further independent research in diverse clinical populations is recommended., (© The Author(s) 2020. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.)

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.

Introduction: There is debate about the optimal approach to diagnose neurocognitive impairment in people with HIV disease. The current "gold-standard" uses normative data to determine whether performance is below that of demographically comparable peers. This study investigated the utility of a discrepancy analysis approach, which compares normative neurocognitive performance directly to estimated premorbid intellectual functioning. Method: A total of 570 adults with and without HIV disease completed a comprehensive neurocognitive battery and the Wechsler Test of Adult Reading (WTAR), an oral word reading measure that was used to estimate premorbid verbal IQ. Normative scores for six neurocognitive domains were subtracted from the WTAR standardized score to calculate discrepancy scores where higher scores indicated greater discrepancies. Results: In models adjusting for relevant confounds, an interaction between HIV serostatus and domain discrepancy scores emerged such that persons with HIV had significantly higher discrepancy scores than seronegative participants, specifically in the domains of attention and episodic memory. Of clinical relevance, persons with HIV were two to three times more likely than their seronegative counterparts to have clinically discordant performance relative to premorbid verbal IQ in these domains. Additionally, the standard normative approach and discrepancy analysis method had fair to moderate agreement for classifying attention and episodic memory impairment in the participants with HIV disease. Conclusions: HIV disease is associated with discrepancies between premorbid IQ estimates and the domains of attention and memory, consideration of which may be a clinically useful complement to standard normative approaches to diagnosing HIV-associated neurocognitive disorders.

Background: Children born very preterm are at higher risk of adverse neurocognitive and educational outcomes. However, how low intelligence (IQ) and low executive function may each contribute to poorer academic outcomes at school age requires clarification., Aim: To examine the associations between intelligence, executive function and academic achievement in children born very preterm., Design/methods: This cohort study assessed children born <30 weeks' gestation or <1500 g at age 7 years using the Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV) for IQ, and the Test of Everyday Attention for Children (TEA-Ch) and Behavior Rating Inventory of Executive Function (BRIEF) for executive function. Academic achievement was rated by teachers against curriculum standards., Results: Of the 76 children (35 girls, 41 boys, mean age = 7.2 year), 22 (28%) were rated below expected level for reading, 32 (42%) for writing and 38 (50%) for mathematics. After adjustment for sex and socioeconomic status, low IQ (OR's 9.0-12.3) and most low executive function measures (OR's 4.1-9.3) were associated with below-expected achievement. After further adjustment for IQ, low cognitive flexibility (OR = 9.3, 95% CI = 1.2-71.5) and teacher ratings of executive function (OR = 5.3, 95% CI = 1.4-20.2) were associated with below-expected achievement. Mediation analysis showed IQ had indirect effects on writing (b = 1.5, 95% CI = 0.6-3.1) via attentional control; and on reading (b = 1.0, 95% CI = 0.2-3.2) and writing (b = 0.8, 95% CI = 0.1-2.5) via cognitive flexibility., Conclusions: Both low IQ and low executive function are associated with below-expected teacher-rated academic achievement in children born very preterm. IQ may influence academic achievement in part through executive function., Competing Interests: Declaration of competing interest None., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: Research on the health effects of chemical mixtures has focused mainly on early life rather than adolescence, a potentially important developmental life stage., Objectives: We examined associations of a metal mixture with general cognition in a cross-sectional study of adolescents residing near ferromanganese industry, a source of airborne metals emissions., Methods: We measured manganese (Mn), lead (Pb), copper (Cu), and chromium (Cr) in hair, blood, urine, nails, and saliva from 635 Italian adolescents 10-14 years of age. Full-scale, verbal, and performance intelligence quotient (FSIQ, VIQ, PIQ) scores were assessed using the Wechsler Intelligence Scale for Children-III. Multivariable linear regression and Bayesian kernel machine regression (BKMR) were used to estimate associations of the metal mixture with IQ. In secondary analyses, we used BKMR's hierarchical variable selection option to inform biomarker selection for Mn, Cu, and Cr., Results: Median metal concentrations were as follows: hair Mn, 0.08 μ g / g ; hair Cu, 9.6 μ g / g ; hair Cr, 0.05 μ g / g ; and blood Pb, 1.3 μ g / dL . Adjusted models revealed an inverted U-shaped association between hair Cu and VIQ, consistent with Cu as an essential nutrient that is neurotoxic in excess. At low levels of hair Cu (10th percentile, 5.4 μ g / g ), higher concentrations (90th percentiles) of the mixture of Mn, Pb, and Cr ( 0.3 μ g / g , 2.6 μ g / dL , and 0.1 μ g / g , respectively) were associated with a 2.9 (95% CI: - 5.2 , - 0.5 )-point decrease in VIQ score, compared with median concentrations of the mixture. There was suggestive evidence of interaction between Mn and Cu. In secondary analyses, saliva Mn, hair Cu, and saliva Cr were selected as the biomarkers most strongly associated with VIQ score., Discussion: Higher adolescent levels of Mn, Pb, and Cr were associated with lower IQ scores, especially at low Cu levels. Findings also support further investigation into Cu as both beneficial and toxic for neurobehavioral outcomes. https://doi.org/10.1289/EHP6803.

To examine whether neurodevelopment at preschool age predicts IQ levels and needs for special education services in school-age children with single ventricle (SV) physiology. Thirty-five patients with SV physiology were assessed using the Bayley Scale of Infant and Toddler Development (BSID) II or III at 3 years and the Wechsler Intelligence Scale for Children-Fourth Edition (WISC) at 8 years. Whether the children were receiving special education services was also determined. Factors associated with the mental developmental index (MDI) of the BSID, the full-scale IQ (FSIQ) of the WISC, and special education services were also analyzed. The MDI and FSIQ of children with SV physiology were significantly lower than the values in healthy children (P < 0.01). The MDI at 3 years was moderately correlated with FSIQ at 8 years (P < 0.01, R 2  = 0.41). Ten patients (28.6%) received special education services in their school. Children with MDI <85 were more likely than those with MDI ≥85 to require special education services at school age (53% and 10%, respectively, P < 0.01). Weight at birth and stage II were correlated with the MDI, extracorporeal circulation time at stage II was correlated with FSIQ, and age at Fontan operation was correlated with FSIQ and special education services. The toddler neurodevelopment index may predict not only IQ levels but also the need for special education services in school-age children. Children with low neurodevelopmental scores need to be followed closely for a long time., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objective: Schizophrenia has recently been associated with widespread white matter microstructural abnormalities, but the functional effects of these abnormalities remain unclear. Widespread heterogeneity of results from studies published to date preclude any definitive characterization of the relationship between white matter and cognitive performance in schizophrenia. Given the relevance of deficits in cognitive function to predicting social and functional outcomes in schizophrenia, the authors carried out a meta-analysis of available data through the ENIGMA Consortium, using a common analysis pipeline, to elucidate the relationship between white matter microstructure and a measure of general cognitive performance, IQ, in patients with schizophrenia and healthy participants., Methods: The meta-analysis included 760 patients with schizophrenia and 957 healthy participants from 11 participating ENIGMA Consortium sites. For each site, principal component analysis was used to calculate both a global fractional anisotropy component (gFA) and a fractional anisotropy component for six long association tracts (LA-gFA) previously associated with cognition., Results: Meta-analyses of regression results indicated that gFA accounted for a significant amount of variation in cognition in the full sample (effect size [Hedges' g]=0.27, CI=0.17-0.36), with similar effects sizes observed for both the patient (effect size=0.20, CI=0.05-0.35) and healthy participant groups (effect size=0.32, CI=0.18-0.45). Comparable patterns of association were also observed between LA-gFA and cognition for the full sample (effect size=0.28, CI=0.18-0.37), the patient group (effect size=0.23, CI=0.09-0.38), and the healthy participant group (effect size=0.31, CI=0.18-0.44)., Conclusions: This study provides robust evidence that cognitive ability is associated with global structural connectivity, with higher fractional anisotropy associated with higher IQ. This association was independent of diagnosis; while schizophrenia patients tended to have lower fractional anisotropy and lower IQ than healthy participants, the comparable size of effect in each group suggested a more general, rather than disease-specific, pattern of association.

Language abilities in early childhood show stability over time and play an important role in the development of other cognitive processes. Identifying modifiable environmental risk factors is important to informing prevention and early intervention efforts. Maternal verbal ability has been previously linked to child verbal ability. The current study examined whether maternal and child verbal abilities were linked indirectly through early childhood maternal responsiveness. Data come from a longitudinal birth cohort study. Participants included 133 mothers and their children recruited from maternity wards shortly after birth. Maternal verbal ability was measured using the Vocabulary subtest from the Wechsler Abbreviated Scale of Intelligence, Second Edition (child age 8 months). Child verbal ability was assessed using the Peabody Picture Vocabulary Test (36 months). A latent maternal responsiveness variable was estimated using three developmentally sensitive indicators; one during infancy (child age 8 months) and two when children were 36 months. Results of a structural equation model indicated a significant indirect effect from maternal verbal abilities to child verbal abilities through maternal responsiveness. This indirect path was significant even after inclusion of another indirect path from maternal executive functioning to child verbal ability through maternal responsiveness (which was not significant). Future studies will benefit from experimental, genetically sensitive and/or cross-lagged designs to allow for conclusions related to directionality and causality. This body of research has implications for the study of the intergenerational transmission of verbal abilities and associated skills, behaviours and adaptive outcomes., (© 2019 John Wiley & Sons Ltd.)

Opioid maintenance therapy (OMT) is generally recommended for pregnant opioid-dependent women. However, much is still unknown about the potential long-term effects of prenatal methadone and buprenorphine exposure. This study explored the long-term effects of prenatal methadone and buprenorphine exposure in a cohort (n = 41) of children, aged 9-11 years, using the Wechsler Abbreviated Scale of Intelligence (WASI) to measure cognitive development and salivary cortisol samples to measure HPA-axis activity. Prenatally exposed children scored significantly lower on all four subtests of WASI (vocabulary, similarities, block design, and matrix reasoning), compared to a comparison group (all p < .05). No group differences were found for salivary cortisol levels or cortisol reactivity levels (all p > .05). Cortisol levels significantly predicted matrix reasoning scores for the OMT group, β = -65.58, t(20) = 15.70, p = .02. Findings suggest that prenatal exposure to methadone or buprenorphine does not have long-term effects on children's HPA-axis functioning. However, since children of women in OMT scored significantly lower on tasks of cognitive function, careful follow-up throughout the school years and across adolescence is recommended., (© 2019 Wiley Periodicals, Inc.)

Associations between cognitive and motor timing performance are documented in hundreds of studies. A core finding is a correlation of about - 0.3 to - 0.5 between psychometric intelligence and time interval production variability and reaction time, but the nature of the relationship remains unclear. Here, we investigated whether this relation is subject to near and far transfer across a battery of cognitive and timing tasks. These tasks were administered pre- and post-five daily 30 min sessions of sensorimotor synchronization training with feedback for every interval. The training group exhibited increased sustained attention performance in Conners' Continuous Performance Test II, but no change in the block design and figure weights subtests from the WAIS-IV. A passive control group exhibited no change in performance on any of the timing or cognitive tests. These findings provide evidence for a direct involvement of sustained attention in motor timing as well as near transfer from synchronization to unpaced serial interval production. Implications for the timing-cognition relationship are discussed in light of various putative timing mechanisms.

Substantial overlap between executive functions (EFs) and intelligence has been reported. Yet further research is required with respect to how the specific components of the two constructs are interrelated. The present study was aimed at exploring the relationship between EFs and intelligence by examining the latent structure of the Wechsler Adult Intelligence Scale (WAIS-IV) and the Executive Functions Module from the Neuropsychological Assessment Battery (NAB). The aim was also to test the correspondence of the two measures to the Cattell-Horn-Carroll (CHC) theory. 205 healthy participants, aged 18-89 years, were administered the NAB and WAIS-IV. Confirmatory factor analysis (CFA) was employed to explore the latent constructs underlying the two test batteries. Models based on the current WAIS-IV index structure showed worse model fit than models based on the CHC theory. In particular, factors representing broad CHC abilities comprehension knowledge (Gc), fluid reasoning (Gf), visual processing (Gv), processing speed (Gs), and working memory capacity (Gwm) proved model fit improvement. The best model fit, however, provided a five-factor model combining the Gf and Gwm abilities into one factor and additionally including a retrieval fluency (Gr) factor. The results demonstrate strong relationships between the WAIS-IV and the NAB Executive Functions Module and suggest substantial overlap between EFs and intelligence within the CHC framework. Nevertheless, according to the recent update of the CHC theory, the NAB fluency tasks may represent a distinct EF factor comprising Gr abilities independent from the WAIS-IV.

Fetal and infant exposures to β-hexachlorocyclohexane (β-HCH) occur through placental and breastmilk transfers. No studies have examined the relationship between β-HCH and child intelligence quotient (IQ). This study examined associations between in utero β-HCH exposure and cognitive development in 7-year-old children. Data from women and children (n = 256) participating in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) birth cohort study were evaluated. We assessed exposure to β-HCH by measuring maternal serum concentration during pregnancy. We administered the Wechsler Intelligence Scale for Children (WISC), Fourth Edition, to children at age 7. Analyses were adjusted for maternal age, country of birth, work status, parity, and other pesticide exposures, language used for child cognitive assessment, and duration of breastfeeding. Higher serum β-HCH concentrations were associated with higher cognitive scores across all unadjusted models for the full-scale and sub-scale cognitive tests. In the adjusted models, a 10-fold increase in serum β-HCH concentration was associated with a 4.5-point increase in Working Memory IQ score (95% CI, 0.6 to 8.3; p = 0.02). We observed no significant interaction by length of breastfeeding or sex on associations. Our findings suggest that prenatal exposure to β-HCH is not adversely related to IQ at age 7 in a cohort of Mexican American children with fairly high exposure in utero as measured by maternal serum levels. Future research must replicate these findings in other study cohorts of women and children.

Premature birth bears an increased risk for aberrant brain development concerning its structure and function. Cortical complexity (CC) expresses the fractal dimension of the brain surface and changes during neurodevelopment. We hypothesized that CC is altered after premature birth and associated with long-term cognitive development. One-hundred-and-one very premature-born adults (gestational age <32 weeks and/or birth weight <1500 ​g) and 111 term-born adults were assessed by structural MRI and cognitive testing at 26 years of age. CC was measured based on MRI by vertex-wise estimation of fractal dimension. Cognitive performance was measured based on Griffiths-Mental-Development-Scale (at 20 months) and Wechsler-Adult-Intelligence-Scales (at 26 years). In premature-born adults, CC was decreased bilaterally in large lateral temporal and medial parietal clusters. Decreased CC was associated with lower gestational age and birth weight. Furthermore, decreased CC in the medial parietal cortices was linked with reduced full-scale IQ of premature-born adults and mediated the association between cognitive development at 20 months and IQ in adulthood. Results demonstrate that CC is reduced in very premature-born adults in temporoparietal cortices, mediating the impact of prematurity on impaired cognitive development. These data indicate functionally relevant long-term alterations in the brain's basic geometry of cortical organization in prematurity., Competing Interests: Declaration of competing interest None., (Copyright © 2019. Published by Elsevier Inc.)

Background: Studies on early predictors of intelligence often focus on single or few predictors and often on childhood intelligence. This study compared the contributions of a broad selection of potential early predictors of intelligence at different adult ages., Methods: Information on predictors was recorded prospectively in the Copenhagen Perinatal Cohort during pregnancy, at delivery, and at 1- and 3-year examinations for children born between 1959-61. Adult intelligence was assessed at three independent follow-ups using three different tests of intelligence: Børge Priens Prøve, Wechsler Adult Intelligence Scale, and Intelligenz-Struktur-Test 2000R. From a total of 4697 cohort members, three non-overlapping samples were derived., Results: The included predictors explained between 22.2-24.3% of the variance in adult IQ, with parental socioeconomic status and sex explaining 16.2-17.0%. Other consistent predictors were head circumference at birth, increase in head circumference head during the first three years, and 3-year milestones. Head circumference was the most important anthropometric measure compared to measures of weight and length., Conclusion: Besides social status and sex, the strongest and most consistent early predictors of adult intelligence were physical or behavioural characteristics that to some extent reflect brain-and cognitive development., Competing Interests: The authors have declared that no competing interests exist.