Below-average IQ Research Articles

Warburg effect linked to cognitive-executive deficits in FMR1 premutation.

A 55-200 CGG repeat expansion in the 5'-UTR of the fragile X mental retardation 1 (FMR1) gene is known as a premutation. Some carriers are affected by the neurodegenerative disorder fragile X-associated tremor/ataxia syndrome (FXTAS), primary ovarian insufficiency, and neurobehavioral impairments. Based on the mitochondrial dysfunction observed in fibroblasts and brain samples from carriers, as well as in neurons and brains from a mouse model of the premutation, we evaluated the presence of the Warburg effect in peripheral blood mononuclear cells (PBMCs) from 30 premutation carriers with either a rebalance of the metabolism [increasing glycolysis while decreasing oxidative phosphorylation (oxphos)] or a metabolic amplification (increasing glycolysis while maintaining/increasing oxphos). Deficits in oxphos-more pronounced in FXTAS-affected subjects-were accompanied by a shift toward glycolysis, suggesting increased glycolysis despite aerobic conditions. Differential proteomics extended these findings, unveiling a decreased antioxidant response, translation, and disrupted extracellular matrix and cytoskeleton organization with activation of prosenescence pathways. Lower bioenergetics segregated with increased incidence of low executive function, tremors, below-average IQ, and FXTAS. The combination of functional and proteomic data unveiled new mechanisms related to energy production in the premutation, showing the potential of being applicable to other psychiatric disorders to identify endophenotype-specific responses relevant to neurobiology.-Napoli, E., Song, G., Schneider, A., Hagerman, R., Eldeeb, M. A. A. A., Azarang, A., Tassone, F., Giulivi, C. Warburg effect linked to cognitive-executive deficits in FMR1 premutation.

Numerical magnitude processing deficits in children with mathematical difficulties are independent of intelligence

Developmental dyscalculia (DD) is thought to arise from difficulties in the ability to process numerical magnitudes. Most research relied on IQ-discrepancy based definitions of DD and only included individuals with normal IQ, yet little is known about the role of intelligence in the association between numerical magnitude processing and mathematical difficulties (MD). The present study examined numerical magnitude processing in matched groups of 7- to 8-year-olds (n=42) who had either discrepant MD (poor math scores, average IQ), nondiscrepant MD (poor math scores, below-average IQ) or no MD. Both groups of children with MD showed similar impairments in numerical magnitudes processing compared to controls, suggesting that the association between numerical magnitude processing deficits and MD is independent of intelligence.

Is Scientifically Based Reading Instruction Effective for Students With Below-Average IQs?

This longitudinal randomized-control trial investigated the effectiveness of scientifically based reading instruction for students with IQs ranging from 40 to 80, including students with intellectual disability (ID). Students were randomly assigned into treatment ( n = 76) and contrast ( n = 65) groups. Students in the treatment group received intervention instruction daily in small groups of 1 to 4 for approximately 40 to 50 min for 1 to 4 academic years. On average, students in the treatment group made significantly greater progress than students in the contrast condition on nearly all language and literacy measures. Results demonstrate the ability of students with low IQs, including students with mild to moderate ID, to learn basic reading skills when provided appropriate, comprehensive reading instruction for an extended period of time.

Cognition, academic achievement, language, and psychopathology in pediatric chronic epilepsy: Short-term outcomes

Children with epilepsy and control children were followed over a 2-year interval. Comorbidities of epilepsy, often defined as problems related to IQ, academic achievement, language, and psychopathology, were evaluated prospectively. It was hypothesized that over time (1) the presence of comorbidities would predict worse outcomes, and (2) epilepsy variables would negatively impact comorbidities. The study included 39 children with complex partial seizures (CPS), 25 children with childhood absence epilepsy (CAE), and 27 healthy children, aged 7.6–16.1 years. The findings were notable for stability over the interval in all three groups. Additionally, baseline seizure variables and change over the interval appear to play a role in IQ and math achievement scores of children with epilepsy with average IQ and in the reading achievement scores of those with below-average IQ. However, seizure variables at baseline and follow-up were not predictors of DSM-IV diagnoses, depression, anxiety, or behavioral problems.

Foundations of phonological awareness in pre‐school children with cerebral palsy: the impact of intellectual disability

Children with cerebral palsy (CP) and accompanying disabilities are prone to reading difficulties. The aim of the present study was to examine the foundations of phonological awareness in pre-school children with CP in comparison with a normally developing control group. Rhyme perception was regarded as an early indicator of phonological awareness, whereas non-verbal reasoning, speech ability, auditory perception, auditory short-term memory and vocabulary were regarded as foundation measures. A number of tasks were administrated to examine group differences in rhyme perception and its foundation measures. Correlations between the tasks were analysed for both groups followed by multiple regression analyses wherein rhyme perception was predicted by its foundation measures. Children with CP scored below their normally developing peers on emergent phonological awareness and its foundation measures. Regarding the prediction of phonological awareness, non-verbal reasoning followed by pseudoword articulation, were found to predict phonological awareness, i.e. rhyme perception, in the group of children with CP. In the control group, auditory perception was a significant predictor of emergent phonological awareness. The CP group was further split up into two groups according to the children's non-verbal reasoning skills, i.e. general IQ. The below-average IQ group scored below the average IQ group on phonological awareness and on most foundation measures. In addition, the average IQ group of the children with CP scored lower than the control group. The results of this study indicate that general intelligence and speech ability (i.e. pseudoword articulation) can be seen as important facilitators of emergent phonological awareness in children with CP. These findings support the role of intelligence in the emergence of phonological awareness in children with CP. Children with CP with intellectual disabilities seem to have a disadvantage in acquiring phonological awareness, especially when their speech abilities are also impaired. However, general intelligence is not enough to predict phonological awareness as other foundation measures are also important for phonological awareness independent of general intelligence.

Stimulation of the Posterior Hypothalamus for Medically Intractable Impulsive and Violent Behavior

Objective: To describe the therapeutic effect of deep brain stimulation for the treatment of patients with below-average IQs who are affected by aggressive and disruptive behavior and who are resistant to any drug and/or conservative treatment (including occupational therapy). Patients and Methods: Two consecutive patients suffering from mental retardation with aggressive and disruptive behavior and resistant to any pharmacological treatment underwent deep brain stimulation electrode placement in the posteromedial hypothalamus for continuous chronic high-frequency stimulation (HFS). The stereotactic coordinates of the target were chosen according to the study by Sano et al., which involved hypothalamic stereotactic lesions. Results: HFS of the posteromedial hypothalamus demonstrated consistent improvement of disruptive behavior in both patients at the follow-up evaluation 1 year later. Conclusions: HFS of the posteromedial hypothalamus showed similar results to those obtained by Sano et al. in the 1960s with radiofrequency lesions of the same target volume. The reversibility of neurostimulation allows HFS to control disruptive behavior when conservative treatments are ineffective, and drug therapy is uneventful or causes severe side effects. In conclusion, this neuromodulation procedure improved the quality of life and the range of social relationships for both of the treated patients.

Assessment of Psycho-Educational Needs in a Clinical Sample of Children With Sickle Cell Disease

Sickle cell disease (SCD) is associated with impaired cognitive and academic functioning, yet prevalence rates of educational needs and accommodations are not known. The Hematology-Oncology Psycho-Educational Needs Assessment was administered to 72 parents of youth, ages 5 to 17, with SCD. Half of the parents identified concerns about their children's learning; however, only 36% had undergone testing for learning problems, and only 26% had individualized education plans. Many parents (33%) reported concerns about attention/memory, and 36% of youth had failed a grade. Of 33 participants referred for neuropsychological evaluation, only 13 completed testing, which revealed below-average IQ and achievement scores. Considerable morbidity was reported; one third of participants missed over 20 school days per year, and 42% reported disease-related difficulties participating in school. Many youth with SCD present cognitive, academic, and functional difficulties, for which universal screening may promote earlier detection and psycho-educational intervention.

Children Conceived Using Intracytoplasmic Sperm Injection Do Not Have an Increased Risk of Delayed Mental Development at 5 Years of Age

Since intracytoplasmic sperm injection (ICSI) was first used a decade ago, there has been concern about possible long-term adverse effects on health, psychosocial status, and developmental outcomes. The initial controlledstudy of ICSI children 1 year of age, using the Bayley Mental Development Index, found an increased risk of delayed mental development compared with children conceived naturally or using in vitro fertilization (IVF); the relative risk was 9.2. The present study reassessed development at age 5 years using a more accurate measure of cognitive ability, the Wechsler Preschool and Primary Scales of Intelligence-Revised (WPPSI-R). Mental development was assessed in 97 ICSI, 80 IVF, and 110 naturally conceived (NC) children. They included 213 of the original cohort of 253 children. The mean age at the time of assessment was 61 months. Mean values for the WPPSI-R were within the normal range in all 3 groups, and no between-group differences were apparent. Delayed full-scale IQ scores (IQ below 85) were recorded for 5.2% of ICSI, 2.5% of IVF, and 0.9% of NC children. Normal scores were obtained for 58.7%, 61.2%, and 56.4% of children, respectively. Accelerated scores (IQ above 115) were recorded for 36.1% of the ICSI group, 36.3% of IVF children, and 42.7%% of NC children. There were no significant between-group differences in any of these 3 categories. The likelihood of a delayed full-scale IQ score in the ICSI group was not significantly increased when compared with the other groups, individually or together. On multivariate analysis, the only significant and independent predictor of a below-average full-scale IQ score was a lower maternal educational level. Within the ICSI group, full-scale IQ was not related to the type of defect in paternal sperm. These findings should reassure parents of children conceived using ICSI that the procedure does not impair long-term cognitive function. The genetic influence of parental cognitive ability appears to be more important than the mode of conception.

Comparison of the Psychosocial Typology of Children With Below Average IQ to that of Children With Learning Disabilities

This study investigates the subtypal patterns of psychosocial functioning of children with below average IQ (BAIQ) using the application of both Q-factor analysis and profile-matching. The results suggest that the psychosocial dimensions of children with BAIQ are quite similar to those of children with LD in a general sense. Many of the same subtypes were derived, and the proportions of children displaying normal, mild, and severe levels of psychopathology were not significantly different from those of children with LD. There were some minor differences, however: For example, children with BAIQ exhibited a greater tendency to display psychopathology with internalizing features. Consistent with previous research involving children with LD, there were no changes in either type or severity of psychopathology with advancing years.

Regularities in Spearman's Law of Diminishing Returns

The lower average correlations among mental tests in groups of individuals of above-average IQ than is found in groups of individuals of below-average IQ implies a smaller general factor, or g, in the higher-IQ group, a phenomenon Spearman called the ‘Law of Diminishing Returns’. This phenomenon was confirmed in six independent data sets based on three different test batteries. It implies that psychometric g is less general in persons of high IQ and more general among those of low IQ. Two heretofore unknown effects were revealed consistently: (1) The g loadings of the various tests in a battery do not differ uniformly or randomly between high- and low-IQ groups; rather, the loadings are much more variable for higher-IQ samples than for lower-IQ samples; (2) Those tests in a battery that are less g-loaded (where g loadings are based on the general population) consistently show greater decrements in their g loadings between low- and high-IQ groups than do the more highly g-loaded tests, which show relatively little difference between low- and high-IQ groups.

Med Check

Med Check

Stability of WISC-R scores in children with learning difficulties

Student records of 130 children with learning difficulties who had been tested twice were examined to determine the stability of WISC-R scores over time. There were significant losses in Verbal IQ and Full Scale IQ. Subjects in the above-average IQ range had greater losses in Verbal IQ and Full Scale IQ and greater gains in Performance IQ than did those in the below-average IQ range. Children initially tested before age 8 had a significant IQ loss, but those tested after age 8 maintained a constant IQ. The WISC-R is most frequently administered to children with learning difficulties. Results presented here suggest that the IQs in this population are not as stable as was previously thought, and this may provide a rationale for the periodic readministration of the WISC-R.

Qualitative and quantitative differences among dyslexic, normal, and nondyslexic poor readers

This study tested the hypothesis that when a stringent criterion of normal IQ is applied in the selection of dyslexic readers, and when dyslexics, nondyslexic poor readers, and normal readers are matched on reading comprehension — rather than word reading — significant differences among these groups can be demonstrated. Two groups of poor readers from primary grades, one with normal IQ (dyslexics) and the other with below-average IQ (nonspecific reading disabled, NSRD) were matched for reading comprehension with a group of younger normal readers. The dyslexic group was found to be inferior to the other two groups in tests of decoding and spelling. The dyslexic readers were more context-dependent for word recognition than the other two groups. The NSRD group did not differ from the normal readers in these aspects but had the worst performance on a test of inferential comprehension. It was concluded that dyslexics differ from normal readers and low-IQ poor readers in word and nonword reading skills and context-dependency for reading. A group of six adult dyslexics were also found to be deficient in decoding skills. A lack of unanimity in the use of certain terminology, a substantial age difference between low-IQ poor readers and normals, and the difference in the criteria used for matching the different groups could be factors that can explain the disagreements seen between the findings of the present study and those reported by some other studies. Potential problems associated with reading-age matched experimental design are discussed.

Hallucinations in children with conduct and emotional disorders: I. The clinical phenomena.

In a retrospective study, children referred to the Maudsley Hospital with conduct or emotional disorders who also suffered from hallucinations were found to be older than other children seen with similar diagnoses, more of them had below-average IQs and they were more frequently admitted as in-patients. In most cases hallucinations were auditory. When compared with a group of 20 controls matched on these differentiating features, the 20 children with hallucinations had more precipitants of illness, a shorter duration of the disorder, symptoms of depression, and a family history of mood changes. They also had more symptoms suggestive of cognitive-perceptual dysfunction.

The regression equation method of determining academic discrepancy

This article discusses the regression equation approach to quantifying academic discrepancy, which is an aspect of most generally accepted learning disability definitions. The concept of regression toward the mean and its relevance to determining underachievement is presented. Variations of the expectancy formula and IQ-achievement difference approaches fail to fully consider regression effects and therefore will produce the serious identification errors of including too many children with above-average IQs and too few with below-average IQs. The parameter estimation variation of the regression equation approach is advocated as the best method for quantifying the academic discrepancy aspect of learning disabilities.

Clinical samples of children with below-average IQs are not "nonimpaired" and other troubles: Comment on Klesges and Sanchez.

Clinical samples of children with below-average IQs are not "nonimpaired" and other troubles: Comment on Klesges and Sanchez.

Clinical samples of children with below-average IQs are not "nonimpaired" and other troubles: comment on Klesges and Sanchez.

Clinical samples of children with below-average IQs are not "nonimpaired" and other troubles: comment on Klesges and Sanchez.