Developmental Cognitive Disorders Research Articles

Developmental Disorders of Language, Learning and Cognition

Developmental Disorders of Language, Learning and Cognition

The clasp between NetrinG and NGL becomes crystal clear

The clasp between NetrinG and NGL becomes crystal clear

An Isoform-Specific SnoN1-FOXO1 Repressor Complex Controls Neuronal Morphogenesis and Positioning in the Mammalian Brain

Control of neuronal positioning is fundamental to normal brain development. However, the cell-intrinsic mechanisms that govern neuronal positioning remain to be elucidated. Here, we report that the spliced protein products of the transcriptional regulator SnoN, SnoN1 and SnoN2, harbor opposing functions in the coordinate regulation of neuronal branching and positioning. Knockdown of SnoN2 stimulates axon branching in primary neurons and impairs migration of granule neurons in the rat cerebellar cortex in vivo. By contrast, SnoN1 knockdown suppresses SnoN2 knockdown-induced neuronal branching and strikingly triggers excessive migration of granule neurons in the cerebellar cortex. We also find that SnoN1 forms a complex with the transcription factor FOXO1 that represses the X-linked lissencephaly gene encoding doublecortin (DCX). Accordingly, repression of DCX mediates the ability of SnoN1 to regulate branching in primary neurons and granule neuron migration in vivo. These data define an isoform-specific SnoN1-FOXO1 transcriptional complex that orchestrates neuronal branching and positioning in the brain with important implications for the study of developmental disorders of cognition and epilepsy.

EEG complexity as a biomarker for autism spectrum disorder risk

BackgroundComplex neurodevelopmental disorders may be characterized by subtle brain function signatures early in life before behavioral symptoms are apparent. Such endophenotypes may be measurable biomarkers for later cognitive impairments. The nonlinear complexity of electroencephalography (EEG) signals is believed to contain information about the architecture of the neural networks in the brain on many scales. Early detection of abnormalities in EEG signals may be an early biomarker for developmental cognitive disorders. The goal of this paper is to demonstrate that the modified multiscale entropy (mMSE) computed on the basis of resting state EEG data can be used as a biomarker of normal brain development and distinguish typically developing children from a group of infants at high risk for autism spectrum disorder (ASD), defined on the basis of an older sibling with ASD.MethodsUsing mMSE as a feature vector, a multiclass support vector machine algorithm was used to classify typically developing and high-risk groups. Classification was computed separately within each age group from 6 to 24 months.ResultsMultiscale entropy appears to go through a different developmental trajectory in infants at high risk for autism (HRA) than it does in typically developing controls. Differences appear to be greatest at ages 9 to 12 months. Using several machine learning algorithms with mMSE as a feature vector, infants were classified with over 80% accuracy into control and HRA groups at age 9 months. Classification accuracy for boys was close to 100% at age 9 months and remains high (70% to 90%) at ages 12 and 18 months. For girls, classification accuracy was highest at age 6 months, but declines thereafter.ConclusionsThis proof-of-principle study suggests that mMSE computed from resting state EEG signals may be a useful biomarker for early detection of risk for ASD and abnormalities in cognitive development in infants. To our knowledge, this is the first demonstration of an information theoretic analysis of EEG data for biomarkers in infants at risk for a complex neurodevelopmental disorder.

The influence of emotion on cognitive control: relevance for development and adolescent psychopathology.

The last decade has witnessed an explosion of research into the neural mechanisms underlying emotion processing on the one hand, and cognitive control and executive function on the other hand. More recently, studies have begun to directly examine how concurrent emotion processing influences cognitive control performance but many questions remain currently unresolved. Interestingly, parallel to investigations in healthy adults, research in developmental cognitive neuroscience and developmental affective disorders has provided some intriguing findings that complement the adult literature. This review provides an overview of current research on cognitive control and emotion interactions. It integrates parallel lines of research in adulthood and development and will draw on several lines of evidence ranging from behavioral, neurophysiological, and neuroimaging work in healthy adults and extend these to work in pediatric development and patients with affective disorders. Particular emphasis is given to studies that provide information on the neurobiological underpinnings of emotional and cognitive control processes using functional magnetic resonance imaging. The findings are then summarized and discussed in relation to neurochemical processes and the dopamine hypothesis of prefrontal cortical function. Finally, open areas of research for future study are identified and discussed within the context of cognitive control emotion interactions.

Developmental Disorders of Language Learning and Cognition

Charles Hulme and Margaret J. Snowling, (Chichester: Wiley, 2009), [Pp. 434.], ISBN 978-0-631-20612-5 ., £24.99 (pbk)The accurate identification and appropriate management of developmental disorder...

Genomic Copy Number Variation in Disorders of Cognitive Development

Genomic Copy Number Variation in Disorders of Cognitive Development

Developmental Disorders of Language, Learning and Cognition - By Charles Hulme, & Margaret J. Snowling

Developmental Disorders of Language, Learning and Cognition – By Charles Hulme, & Margaret J. Snowling Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Developmental Disorders of Language Learning and Cognition

Developmental Disorders of Language Learning and Cognition

Electroencephalogram Discharges in Atypical Cognitive Development

To investigate the significance of electroencephalogram (EEG) discharges and their treatment, we retrospectively reviewed the charts of 22 children with atypical cognitive development that did not respond to standard educational therapy and demonstrated discharges on EEG. Most children demonstrated no obvious symptoms of seizures, and developmental regression and/or fluctuations were uncommon. The majority of children demonstrated a language and attention disorder and autism symptomatology and had multifocal discharges on EEGs. Of the 20 patients treated with antiepileptic medications, 70% demonstrated definite improvement within 1 clinic visit. This study suggests that children with EEG discharges and developmental cognitive disorders demonstrate a unique pattern of symptomatology and discharges on EEG. This study suggests that children with developmental cognitive disorders that do not respond to standard therapy may benefit from screening with an EEG and a trial of antiepileptic mediation if discharges are detected.

Editorial: Beyond diagnosis - taking a ‘global’ view of research and practice

Editorial: Beyond diagnosis - taking a ‘global’ view of research and practice

Neurocognitive approaches to developmental disorders of numerical and mathematical cognition: The perils of neglecting the role of development

The present paper provides a critical overview of how adult neuropsychological models have been applied to the study of the atypical development of numerical cognition. Specifically, the following three assumptions are challenged: 1. Profiles of strength and weaknesses do not change over developmental time. 2. Similar neuronal structures are activated in children and adults, as well as the notion that 3. Similarities in behavioral performance imply equivalence in underlying neurocognitive mechanisms. Data from behavioral and neuroimaging studies with both typically and atypically developing children is reviewed to illustrate the pitfalls of these assumptions. The present review proposes that, instead of resting on adult neuropsychological models, the use of both cross-sectional and longitudinal methods is required to elucidate the age-related changes in brain and behavior that give rise to the breakdown of numeracy and mathematics. Empirical data derived from such studies will generate explanatory models of the development of atypical numerical cognition.

Harris Infant Neuromotor Test: Comparison of US and Canadian Normative Data and Examination of Concurrent Validity With the Ages and Stages Questionnaire

The Harris Infant Neuromotor Test (HINT) was developed as a screening tool for potential motor and cognitive developmental disorders in infants. Scoring on the HINT has been shown to be reliable, and several studies have supported the validity of the HINT. Normative values for the tool have been developed using Canadian infants. The aims of this study were (1) to further evaluate the validity of the HINT by comparing data obtained on US infants who were developing typically with data previously acquired on Canadian infants and (2) to determine the concurrent validity of the HINT with the Ages and Stages Questionnaire (ASQ). Secondary analyses of HINT scores for US white and nonwhite infants and for US infants who had parents with lower levels of education and US infants who had parents with higher levels of education (as a proxy for socioeconomic status [SES]) were conducted. Cross-sectional exploratory and quasi-experimental comparative research designs were used to evaluate the validity of the HINT. Sixty-seven infants from the United States who were developing typically and who were aged 2.5 to 12.5 months were recruited via convenience sampling. Sixty-four of these infants were compared with Canadian infants matched for age, sex, ethnicity or race, and parental education. The HINT was administered by raters who had been trained to attain acceptable levels of interrater reliability, and parents completed the ASQ. The HINT scores for US white versus nonwhite infants (n=46) and infants who had parents with lower SES versus a higher SES (n=52) were compared. There were no significant differences between HINT total scores for US and Canadian infants or for US racial or ethnic groups and SES groups. There were high correlations (r=-.82 to -.84) between HINT and ASQ scores. The study used a small US sample with limited geographical diversity. Small sample numbers also did not allow for comparisons of specific racial or ethnic groups. The SES groups were created primarily using parental education as a proxy for SES. The results suggest that HINT screening in the United States is supported on the basis of Canadian norms and the validity of the HINT in screening for motor and cognitive delays. Although there is preliminary support for the HINT as an appropriate screening tool for US infants who are nonwhite or who have parents with a lower SES, more research is warranted.

L’enfance du schizophrène

We are able to identify the different risk factors involved in the development of the disorder from a study of the childhood of a schizophrenic patient. More specifically, we will define the perinatal risk factors : season and place of birth, viral exposure during pregnancy and obstetric complications. Developmental factors will also be discussed. Socialisation, language, psychomotor and cognitive development disorders are all developmental difficulties seen during the childhood of the schizophrenic patient. Finally we will finish by discussing a few psychosocial risk factors.

Neuroimaging features in a case of developmental central auditory processing disorder

We describe a case of developmental central auditory processing disorder (CAPD) that was diagnosed with a multidisciplinary approach including structural and functional neuroimaging. A patient with developmental CAPD was investigated using diagnostic tools of MRI and 18F-FDG HRRT-PET as well as neuropsychology and electrophysiology. Besides impaired auditory processing, our patient also showed some impediments in supramodal, cognitive and linguistic processes. His MRI showed selective atrophy in the bilateral auditory cortices, and the PET images showed hypometabolism in the bilateral auditory cortices and the precuneus. Such a multidisciplinary diagnostic approach that includes neuroimaging methods will be helpful in differentiating developmental CAPD from other developmental cognitive disorders.

Foreword

Foreword

Fresh ideas for treating developmental cognitive disorders

Fresh ideas for treating developmental cognitive disorders

Epilepsy in Shunted Posthemorrhagic Infantile Hydrocephalus Owing to Pre- or Perinatal Intra- or Periventricular Hemorrhage

Epilepsy is relatively common in infants with hydrocephalus. Its mechanism is controversial; in fact, studies on etiologically heterogeneous series are not able to clarify the mechanism generating epilepsy or to suggest effective prevention and treatment strategies. Our study is aimed at assessing the onset and evolution of epilepsy, as well as concurrent cognitive development of a homogeneous series of shunted posthemorrhagic hydrocephalus owing to pre- or perinatal intra- or periventricular hemorrhage. Forty patients were enrolled in the study. Twenty-six were patients with grade II-III intraventricular hemorrhage, 16 of whom had associated ischemic lesions. In the remaining 14 patients, a grade IV intra-ventricular hemorrhage was found. Epilepsy was observed in 27 patients. Aside from 10 cases with nonsyndromic forms of epilepsy, it was possible to define at least three different age-dependent epileptic syndromes: symptomatic neonatal location-related epilepsy with transient West's syndrome in infancy in 5 patients; West's syndrome in 8 patients; and continuous spike-waves during sleep in 4 patients. Epilepsy was significantly correlated with ischemic lesions only. Early thalamic injuries frequently evolved toward continuous spike-waves during sleep, indicating that patients with thalamic injury must be monitored to detect continuous spike-waves during sleep early. Cerebellar atrophy, in addition to epilepsy and other brain injuries, accounted for disorders of cognitive development.

Distinguishing proximal from distal causes is useful and compatible with accounts of compensatory processing in developmental disorders of cognition

Models of the architecture of mature cognitive systems can inform the study of normal and disordered cognitive development, if one distinguishes between proximal and distal causes of performance. The assumption of residual normality need not be made in order to apply adult models to performance early in development, because these models can be modified to reflect the results of compensatory processing.

Raising the bar for connectionist modeling of cognitive developmental disorders

Cognitive developmental disorders cannot be properly understood without due attention to the developmental process, and we commend the authors’simulations in this regard. We note the contribution of these simulations to the nascent field of connectionist modeling of developmental disorders and outline a set of criteria for assessing individual models in the hope of furthering future modeling efforts.