Background: Tourette's syndrome (TS) is a neurodevelopmental disorder associated with fronto-striatal dysfunction. There is debate as to the extent to which TS is associated with cognitive impairment. Some authors argue that any impairments seen are attributable to comorbid psychiatric symptomatology, whilst others have suggested that…

Background: Knowledge of genetic influences, on developmental disorders such as autism spectrum, attention deficit/hyperactivity disorder and learning disabilities, has increased the opportunities for understanding the influences of the early environment. Methods: This paper provides a selective, narrative review for clinicians of the effects of…

Background: Fragile X syndrome is one of the world's leading hereditary causes of developmental delay in males. The past decade has witnessed an explosion of research that has begun to unravel the condition at its various levels: from the genetic and brain levels to the cognitive level, and then to the environmental and behavioural levels. Our aim…

The dramatic increase in our understanding of the brain's development throughout childhood has increased our knowledge of the significance of micronutrients, such as iron and vitamin B-12, for this development. Deficiencies of these micronutrients have been shown to have an impact on students' cognitive development. Regardless of this knowledge,…

Disorders of white matter are some of the most commonly encountered conditions in the practice of child neurology. For a child presenting with evidence of neurological impairment, a magnetic resonance imaging (MRI) of the brain is usually performed and often proves informative in suggesting the diagnosis. Traditionally, primary white matter…

We review research on the neuropsychological effects that central nervous system (CNS) cancer treatments have on the cognitive abilities of children and adolescents. The authors focus on the two most common malignancies of childhood: leukemias and brain tumors. The literature review is structured so as to separate out earlier studies, generally…

The most devastating complication of sickle cell anemia is cerebral infarction, affecting [approximately]30% of all individuals with sickle cell anemia. Despite being one of the most common causes of stroke in infants and children, the mechanism of cerebral infarction in this population has not been extensively studied and is poorly understood.…

Epileptic encephalopathies are progressive clinical and electroencephalographic syndromes where deterioration is thought to be caused by frequent seizures and abundant EEG epileptiform activity. Seizures occur in approximately 10-15% of children with pervasive developmental disorders (PDD) and 8-10% have epileptiform EEG abnormalities without…

The potential role of environmental factors in autism spectrum disorders (ASD) is an area of emerging interest within the public and scientific communities. The high degree of heritability of ASD suggests that environmental influences are likely to operate through their interaction with genetic susceptibility during vulnerable periods of…

"Drosophila melanogaster" is emerging as a valuable genetic model system for the study of mental retardation (MR). MR genes are remarkably similar between humans and fruit flies. Cognitive behavioral assays can detect reductions in learning and memory in flies with mutations in MR genes. Neuroanatomical methods, including some at single-neuron…

An emerging body of literature points to the prominent role of the frontal lobes in the retrieval of verbs, whereas production of common and proper nouns arguably is mediated primarily by posterior and anterior temporal regions, respectively. Although the majority of studies examining the neuroanatomic distinctions between verb and noun retrieval…

Two findings serve as the hallmark for hemispheric specialization during lateralized lexical decision. First is an overall word advantage, with words being recognized more quickly and accurately than non-words (the effect being stronger in response latency). Second, a right visual field advantage is observed for words, with little or no…

Background: People with autism or Asperger Syndrome (AS) show altered patterns of brain activity during visual search and emotion recognition tasks. Autism and AS are genetic conditions and parents may show the "broader autism phenotype." Aims: (1) To test if parents of children with AS show atypical brain activity during a visual search…

Semantic priming refers to a reduction in the reaction time to identify or make a judgment about a stimulus that has been immediately preceded by a semantically related word or picture and is thought to result from a partial overlap in the semantic associates of the two words. A semantic priming lexical decision task using spoken words was…

Using 12 participants we conducted an fMRI study involving two tasks, word reversal and rhyme judgment, based on pairs of natural speech stimuli, to study the neural correlates of manipulating auditory imagery under taxing conditions. Both tasks engaged the left anterior superior temporal gyrus, reflecting previously established perceptual…