The negative effects of very low birthweight on intellectual development have been well documented, and more recently this effect has been shown to generalize to birthweights within the normal range. In this study we investigate the etiology of this relationship by using a classical twin design to disentangle the contributions of genes and environment. A previous Dutch study (Boomsma et al., 20...

OBJECTIVES/HYPOTHESIS In this meta-analysis, we reviewed observational studies investigating differences in intelligence quotient (IQ) scores of children with unilateral hearing loss compared to children with normal hearing. DATA SOURCES PubMed Medline, Cumulative Index to Nursing and Allied Health Literature, Embase, PsycINFO. METHODS A query identified all English-language studies related...

Investment traits--the tendency to seek out and engage in cognitive activity--might affect intellectual growth across the life span, specifically the development from fluid to crystallized intelligence. Here we explore how childhood IQ at age 11 years, IQ at age 79, and the investment trait Typical Intellectual Engagement (TIE) at age 81 affect the mean level and change in verbal fluency scores...

The Duchenne muscular systrophy (DMD) is a muscular dystrophy with cognitive impairment present in 20-30% of the cases. In the present study, in order to study the relationship between the α-dystroglycan (α-DG) immunostaining in skeletal muscle and cognitive performance in DMD patients, 19 were assessed. Twelve patients performed the intelligence quotient (IQ) below the average. Among the 19 pa...

The Duchenne muscular dystrophy (DMD) is a muscular dystrophy with cognitive impairment present in 20-30% of the cases. In the present study, in order to study the relationship between the alpha-dystroglycan (alpha-DG) immunostaining in skeletal muscle and cognitive performance in DMD patients, 19 were assessed. Twelve patients performed the intelligence quotient (IQ) below the average. Among t...

In this study, some executive function measures (Wisconsin Card Sorting Test [WCST], verbal fluency, and Trial Making Test [TMT], Form A and Form B) were correlated with Wechsler Intelligence Scale for Children-Revised (WISC-R) scores. Fifty 13- to 16-year-old normal children were selected. It was found that verbal fluency tests correlated about 0.30 with Verbal Intelligence Quotient (IQ) and F...

This study examined children from an unselected birth cohort who had Wechsler Intelligence Scale for Children-Revised (WISC-R) verbal and performance IQ discrepancies that placed them beyond the 90th percentile. It was hypothesized that, relative to their cohort peers, these children would be characterized by greater frequency of perinatal difficulties, early childhood neurological abnormalitie...

BACKGROUND Impairments in executive functioning (EF) and intelligence quotient (IQ) are frequently observed in children with attention deficit hyperactivity disorder (ADHD). The aim of this paper was twofold: first, to examine whether both domains are viable endophenotypic candidates for ADHD and second to investigate whether deficits in both domains tend to co-segregate within families. METH...