Williams syndrome is a rare neurodevelopmental disorder caused by deletion of approximately 25 genes on chromosome 7q11.23. Children with the syndrome evidence large individual differences in both broad language and reading abilities. Nevertheless, as a group, children with this syndrome show a consistent pattern characterized by relative…

The age of female puberty appears to have decreased in the United States and western countries as child health and nutrition have improved and obesity has become more prevalent. Also, environmental contaminants, particularly endocrine disruptors, may also play a role in lowering the age of puberty. Puberty at an early age increases the risk of…

Previous research has shown that Lewis rats make more impulsive choices than Fischer 344 rats. Such strain-related differences in choice are important as they may provide an avenue for exploring genetic and neurochemical contributions to impulsive choice. The present systematic replication was designed to determine if these findings could be…

Although research has focused primarily on the wide range of variability in the cognitive phenotype between individuals with velo-cardio-facial syndrome (VCFS), we know relatively little about the extent to which within-individual expressions of the cognitive phenotype remain stable throughout development. General cognitive functioning in the low…

Giving students the opportunity to extract, manipulate and visualise DNA molecules enhances a constructivist approach to learning about modern techniques in biology and biotechnology Visualisation usually requires agarose gel electrophoresis and staining. In this article, we report on an alternative DNA stain, Nile Blue A, that may be used in the…

Elucidating the genetic and environmental aetiology of effortful control (mother and father reports at two time points), attentional control (observer reports), and their associations with internalizing and externalizing symptoms (mother and father reports) is the central focus of this paper. With a sample of twins in middle childhood…

Knowledge is essential for the functioning of every social system, especially for professionals in knowledge-intensive organisations. Since individuals do not possess all the work-related knowledge that they require, they turn to others in search for that knowledge. While prior research has mainly focused on antecedents and consequences of…

The prion protein Met129Val polymorphism has recently been related to human long-term memory with carriers of either the 129[superscript MM] or the 129[superscript MV] genotype recalling 17% more words than 129[superscript VV] carriers at 24 h following learning. Here, we sampled genotype differences in retrieval-related brain activity at 30 min…

Recent psychological and neuropsychological research suggests that executive functions--the cognitive control processes that regulate thought and action--are multifaceted and that different types of executive functions are correlated but separable. The present multivariate twin study of 3 executive functions (inhibiting dominant responses,…

Evidence suggests that visual processing is divided into the dorsal ("how") and ventral ("what") streams. We examined the normal development of these streams and their breakdown under neurological deficit by comparing performance of normally developing children and Williams syndrome individuals on two tasks: a visually guided action ("how") task,…

Williams syndrome (WS) is a genetic disorder associated with severe visuocognitive impairment. Individuals with WS also report difficulties with everyday wayfinding. To study the development of body-, environment-, and object-based spatial frames of reference in WS, we tested 45 children and adults with WS on a search task in which the participant…

The following is a historically informed review of Puerto Rican phenotype. Geared toward educating psychologists, this review discusses how various psychological issues associated with phenotype may have arisen as a result of historical legacies and policies associated with race and racial mixing. It discusses how these policies used various…

This article reviews research on speech and language abilities in people with cri du chat syndrome (CCS). CCS is a rare genetic disorder, with an estimated incidence between 1 in 15,000 and 1 in 50,000 births, resulting from a deletion on the short arm of chromosome 5. In general, individuals have delayed speech and language development, and some…

Although known for its distinctive food-related behaviors, Prader-Willi syndrome is a multisystem disorder with genetic, developmental, and behavioral features. Two separate and distinct eating disorders are noted: initial feeding difficulties and failure to thrive, and later overeating. Additional outcomes observed with this disorder include…

Memory and attentional control impairments are the two most common forms of dysfunction following mild traumatic brain injury (TBI) and lead to significant morbidity in patients, yet these functions are thought to be supported by different brain networks. This 3 T magnetic resonance diffusion tensor imaging (DTI) study investigates whether…