Neurocognitive correlates of type 1 diabetes mellitus in childhood.

Type 1 Diabetes Mellitus (T1DM) is one of the most prevalent chronic health conditions in children under the age of 18 years. Complications of the disease include hypo- and hyperglycemia, which can have an impact on children's performance in assessment situations, in the clinic, and in school. Because there is no cure for this disease, there is a need to understand the cognitive deficits associated with some of its complications, as this knowledge will impact on the choice of treatment regimens as well as educational interventions. This paper provides a comprehensive review of the relevant literature on the neurocognitive outcome of T1DM. In particular, disease- and treatment-related variables that are associated with poor performance on cognitive domains will be reviewed. Specifically, age of onset, duration, pubertal effects, and presence of hypoglycemia or hyperglycemia will be examined. These findings are not without controversy, and limitations to conclusions will also be presented. Where relevant, recommendations for future research directions will be provided.     

Hemispheric lateralization in 47,XXY Klinefelter's syndrome boys

Thirty-two boys with a 47,XXY karyotype were compared with chromosomally normal male controls in their performance on six tasks of hemispheric specialization. The results revealed that the 47,XXY subjects had smaller asymmetries on left hemisphere tasks and larger asymmetries on right hemisphere tasks than controls. Analyses of individual right and left side scores revealed that the atypical lateral asymmetries of the 47,XXYs were due to a shift toward greater right hemisphere involvement on four of the six measures. It was postulated that the slower fetal growth rates of the extra X chromosome group might contribute to their atypical hemispheric specialization and the failure of their left hemisphere to gain dominance over their right in language processing.     

A parametric measure of reflection-impulsivity

A modification of the Matching Familiar Figures Test containing items of varying numbers of response alternatives was given to seventeen impulsive and seventeen reflective first and second grade children who were ascertained by conventional methods. The slopes of the linear functions relating errors and latencies to alternative number significantly differentiated between impulsive and reflective groups. Significant correlations were also observed between latency and error slopes and an impulsivity score computed independently from group data. Since the differences were larger for the latency data, it was proposed that the slope of the relationship between response latencies and alternative set size can be used as a parametric index of reflection-impulsivity.     

Turner syndrome: a review of genetic and hormonal influences on neuropsychological functioning.

Turner syndrome (TS) is a genetic disorder affecting mainly females that arises from a loss of X chromosome material, most usually one of the two X chromosomes. TS is associated with a number of characteristic physical features such as short stature and absent ovaries as well as a set of common neuropsychological deficits and social and behavioral features. This paper will serve to review the cognitive, social, and psychoeducational abilities of individuals with TS as well as neuroimaging findings. Several putative genetic mechanisms contributing to their particular neurocognitive deficits will also be described including candidate genes. In addition, the available evidence on how hormones affect specific abilities in TS will be reviewed. It will be concluded that the TS neurobehavioral profile arises from an atypical cerebral organization caused by the complex interplay of insufficient expression of certain (unknown) genes on the X chromosome and by abnormal hormonal levels; however, it is still not clear exactly how the specific genes affect broader cognitive abilities. Future research needs to identify the elemental processes that are disturbed in TS and map these both to events in early brain development and subsequent brain function and to specific gene and hormonal contributions.     

Turner Syndrome: A Review of Genetic and Hormonal Influences on Neuropsychological Functioning

Turner syndrome (TS) is a genetic disorder in females that arises from the loss of X chromosome material. Affected individuals demonstrate a characteristic neuropsychological profile of strengths in verbal processing and weaknesses in visuospatial processing, consistent with the Nonverbal Learning Disabilities syndrome. Previous research has described a wide range of visuospatial deficits in TS; however, their verbal abilities are less extensively studied. The present paper describes the processing difficulties of a 9-year-old girl with TS who demonstrated problems in integrating details of a complex visual display and using organizational terms to describe visual scenes or events. Her specific cognitive disabilities were thought to underlie some of the social and behavioral problems she was currently experiencing. Her pattern of results is consonant with the neuropsychological pattern that others have attributed to right hemisphere dysfunction and/or white matter abnormality.     

Congenital Hypothyroidism: An Analysis of Persisting Deficits and Associated Factors

Congenital hypothyroidism (CH) is a neonatal disorder that is caused by a prolonged loss of thyroid hormone, which is essential for early brain development. While CH was once the leading cause of mental retardation, newborn screening for CH now allows for early identification and treatment. As a result, affected children now show normal physical and psychological development. Nevertheless, because they still undergo a brief but circumscribed period of thyroid hormone insufficiency, they are at risk for subtle selective impairments. This paper examines several of the persisting deficits observed in children with CH that was identified early in life by newborn screening as well as the relevant disease- and treatment-related factors contributing to such deficits. Highlighted will be (a) a weakness in visuospatial processing, which is associated with prenatal thyroid hormone insufficiency, (b) selective memory deficits associated with postnatal thyroid hormone insufficiencies, (c) a weakness in sensorimotor abilities also reflecting postnatal thyroid hormone insufficiencies, and (d) attention deficits, which are due to abnormal thyroid hormone levels at time of testing. Because these four disabilities implicate different neural substrates, the findings described presently will provide insights as to the specific time windows when different brain structures in the human critically need thyroid hormone.     

Improving executive functioning in children with fetal alcohol spectrum disorders

An extensive body of literature has documented executive function (EF) impairments in children with fetal alcohol spectrum disorders (FASD); however, few studies have aimed specifically at improving EF. One treatment program that shows promise for children with FASD is the Alert Program for Self-Regulation®, which is a 12-week treatment specifically designed to target self-regulation, a component of EF. The present study sought to examine if Alert would produce improvements in self-regulation that would generalize to other aspects of EF, behavior, and social skills in children with FASD. Twenty-five children aged 8–12 years diagnosed with an FASD were assigned in alternating sequence to either an immediate treatment (TXT) or a delayed treatment control (DTC) group. Both groups received a comprehensive evaluation of EF at baseline and upon completing therapy (TXT), or after a 12- to 14-week interval from baseline (DTC). Parents also completed questionnaires assessing EF and behavior at both time points. For the TXT group only, parent questionnaires were readministered at 6-month follow-up. At the 12-week follow-up, the TXT group displayed significant improvements in inhibitory control and social cognition. Parents of children in the TXT group reported improved behavioral and emotional regulation, as well as reduced externalizing behavior problems. These behavioral improvements along with further improved parent-rated inhibitory control was maintained at the 6-month follow-up. The EF disabilities in children with FASD can be remediated through a targeted treatment approach aimed at facilitating self-regulation skills.     

Visual search for features and conjunctions in development.

Visual search performance was examined in three groups of children 7 to 12 years of age and in young adults. Colour and orientation feature searches and a conjunction search were conducted. Reaction time (RT) showed expected improvements in processing speed with age. Comparisons of RT's on target-present and target-absent trials were consistent with parallel search on the two feature conditions and with serial search in the conjunction condition. The RT results indicated searches for feature and conjunctions were treated similarly for children and adults. However, the youngest children missed more targets at the largest array sizes, most strikingly in conjunction search. Based on an analysis of speed/accuracy trade-offs, we suggest that low target-distractor discriminability leads to an undersampling of array elements, and is responsible for the high number of misses in the youngest children.     

Dorsal and ventral visual streams: Typical and atypical development

The literature on visuospatial processing describes two distinct pathways within the brain: a dorsal route extending from the visual cortex into the parietal lobes that is critical for spatial processing and a ventral route extending from the visual cortex into the temporal lobes that is critical for form perception. These visual streams appear to differ in their developmental trajectories and their vulnerabilities to diverse neurodevelopmental conditions. The present work aims to investigate development and vulnerability in two aspects of dorsal and ventral visual-stream function, namely attention to location and attention to identity. In Study 1, we compare typically-developing (TD) youth aged 9 to 16 years with young adults aged 18 to 22 years on computerized location and identity tasks. In Study 2, we compare children and adolescents who have congenital hypothyroidism (CH), a pediatric endocrine disorder, with age-matched TD controls on the same tasks. The results from Study 1 show that the youths were less accurate than the adults at judging identity, whereas both groups were equally accurate at judging location. The results from Study 2 show that the youths with CH were slower but not less accurate than the TD youths in making both identity and location judgments. The results are interpreted as signifying later development of ventral (identity) stream functions compared to dorsal (location) but equal vulnerability of both functions in CH.     

Psychological skills and mindfulness training effects on the psychological wellbeing of undergraduate music students: An exploratory study

This study explored the efficacy of psychological skills and mindfulness training intervention on the psychological wellbeing of undergraduate music students. Participants were undergraduate music students (n = 36) from the Department of Music at a South African university, 21 of whom were elected to take the psychological skills and mindfulness training intervention. Data on their self-reported psychological wellbeing, psychological skills, mindfulness and performance anxiety levels were collected pre-and post-intervention. The analysis applied non-parametric procedures to determine changes in students’ psychological wellbeing after the seven-week intervention programme. Findings suggest improvements in psychological wellbeing, psychological skills, mindfulness and performance anxiety with training. Psychological skills and mindfulness training may have benefits to the psychological wellbeing of music students.