951 resultados para Cognitive dysfunction syndrome
Resumo:
Williams syndrome (WS) is a rare genetic disorder with a unique cognitive profile in which verbal abilities are markedly stronger than visuospatial abilities. This study investigated the claim that orientation coding is a specific deficit within the visuospatial domain in WS. Experiment I employed a simplified version of the Benton Judgement of Line Orientation task and a control, length-matching task. Results demonstrated comparable levels of orientation matching performance in the group with WS and a group of typically developing (TD) controls matched by nonverbal ability, although it is possible that floor effects masked group differences. A group difference was observed in the length-matching task due to stronger performance from the control group. Experiment 2 employed an orientation-discrimination task and a length-discrimination task. Contrary to previous reports, the results showed that individuals with WS were able to code by orientation to a comparable level as that of their matched controls. This demonstrates that, although some impairment is apparent, orientation coding does not represent a specific deficit in WS. Comparison between Experiments I and 2 suggests that orientation coding is vulnerable to task complexity. However, once again, this vulnerability does not appear to be specific to the population with WS, as it was also apparent in the TD controls.
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Williams syndrome (WS) is a rare genetic disorder. At a cognitive level, this population display poor visuo-spatial cognition when compared to verbal ability. Within the visuo-spatial domain, it is now accepted that individuals with WS are able to perceive both local and global aspects of an image, albeit at a low level. The present study examines the manner in which local elements are grouped into a global whole in WS. Fifteen individuals with WS and 15 typically developing controls, matched for non-verbal ability, were presented with a matrix of local elements and asked whether these elements were perceptually grouped horizontally or vertically. The WS group was at the same level as the control group when grouping by luminance, closure, and alignment. However, their ability to group by shape, orientation and proximity was significantly poorer than controls. This unusual profile of grouping abilities in WS suggests that these individuals do not form a global percept in a typical manner. (c) 2004 Published by Elsevier Ltd.
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It is now well established that the prevalence of mental health difficulties in individuals with autism spectrum disorders (ASD) is considerably higher than in the general population. With recent estimates of the prevalence of autism spectrum disorders being as high as one percent, increasing numbers of children and young people are presenting to local and specialist services with mental health problems in addition to a diagnosis of ASD. Many families report that the impact of the mental health problems can be as or more impairing than the autism spectrum difficulties themselves. Clinical services are frequently called upon to treat these difficulties; however, there is limited evidence for the effectiveness of treatments in this population. This paper reports a case series of children and adolescents with ASD and an anxiety disorder who were treated with a standard cognitive behaviour therapy (CBT) rationale adapted to take account of the neuropsychological features of ASD. Common features of the presentation of the disorders and also treatment processes are discussed.
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The goal of this research was to investigate the changes in neural processing in mild cognitive impairment. We measured phase synchrony, amplitudes, and event-related potentials in veridical and false memory to determine whether these differed in participants with mild cognitive impairment compared with typical, age-matched controls. Empirical mode decomposition phase locking analysis was used to assess synchrony, which is the first time this analysis technique has been applied in a complex cognitive task such as memory processing. The technique allowed assessment of changes in frontal and parietal cortex connectivity over time during a memory task, without a priori selection of frequency ranges, which has been shown previously to influence synchrony detection. Phase synchrony differed significantly in its timing and degree between participant groups in the theta and alpha frequency ranges. Timing differences suggested greater dependence on gist memory in the presence of mild cognitive impairment. The group with mild cognitive impairment had significantly more frontal theta phase locking than the controls in the absence of a significant behavioural difference in the task, providing new evidence for compensatory processing in the former group. Both groups showed greater frontal phase locking during false than true memory, suggesting increased searching when no actual memory trace was found. Significant inter-group differences in frontal alpha phase locking provided support for a role for lower and upper alpha oscillations in memory processing. Finally, fronto-parietal interaction was significantly reduced in the group with mild cognitive impairment, supporting the notion that mild cognitive impairment could represent an early stage in Alzheimer’s disease, which has been described as a ‘disconnection syndrome’.
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The present research aimed to comprehensively explore psychopathology in Williams syndrome (WS) across the lifespan and evaluate the relationship between psychopathology and age category (child or adult), gender and cognitive ability. The parents of 50 participants with WS, aged 6-50 years, were interviewed using the Schedule for Affective Disorders and Schizophrenia for School-Age Children (K-SADS-PL). The prevalence of a wide range of Axis I DSM-IV disorders was assessed. In addition to high rates of anxiety and Attention Deficit Hyperactivity Disorder (ADHD) (38% and 20% respectively), 14% of our sample met criteria for a depressive disorder and 42% of participants were not experiencing any significant psychopathological difficulties. There was some evidence for different patterns of psychopathology between children and adults with WS and between males and females. These relationships were largely in keeping with those found in the typically developing population, thus supporting the validity of applying theory and treatment approaches for psychopathology in the typically developing population to WS.
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There is increasing evidence that Williams syndrome (WS) is associated with elevated anxiety that is non-social in nature, including generalised anxiety and fears. To date very little research has examined the cognitive processes associated with this anxiety. In the present research, attentional bias for non-social threatening images in WS was examined using a dot-probe paradigm. Participants were 16 individuals with WS aged between 13 and 34 years and two groups of typically developing controls matched to the WS group on chronological age and attentional control ability respectively. The WS group exhibited a significant attention bias towards threatening images. In contrast, no bias was found for group matched on attentional control and a slight bias away from threat was found in the chronological age matched group. The results are contrasted with recent findings suggesting that individuals with WS do not show an attention bias for threatening faces and discussed in relation to neuroimaging research showing elevated amygdala activation in response to threatening non-social scenes in WS.
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Introduction: Observations of behaviour and research using eye-tracking technology have shown that individuals with Williams syndrome (WS) pay an unusual amount of attention to other people’s faces. The present research examines whether this attention to faces is moderated by the valence of emotional expression. Method: Sixteen participants with WS aged between 13 and 29 years (Mean=19 years 9 months) completed a dot-probe task in which pairs of faces displaying happy, angry and neutral expressions were presented. The performance of the WS group was compared to two groups of typically developing control participants, individually matched to the participants in the WS group on either chronological age or mental age. General mental age was assessed in the WS group using the Woodcock Johnson Test of Cognitive Ability Revised (WJ-COG-R; Woodcock & Johnson, 1989; 1990). Results: Compared to both control groups, the WS group exhibited a greater attention bias for happy faces. In contrast, no between-group differences in bias for angry faces were obtained. Conclusions: The results are discussed in relation to recent neuroimaging findings and the hypersocial behaviour that is characteristic of the WS population.
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The recent identification of multiple dominant mutations in the gene encoding β-catenin in both humans and mice has enabled exploration of the molecular and cellular basis of β-catenin function in cognitive impairment. In humans, β-catenin mutations that cause a spectrum of neurodevelopmental disorders have been identified. We identified de novo β-catenin mutations in patients with intellectual disability, carefully characterized their phenotypes, and were able to define a recognizable intellectual disability syndrome. In parallel, characterization of a chemically mutagenized mouse line that displays features similar to those of human patients with β-catenin mutations enabled us to investigate the consequences of β-catenin dysfunction through development and into adulthood. The mouse mutant, designated batface (Bfc), carries a Thr653Lys substitution in the C-terminal armadillo repeat of β-catenin and displayed a reduced affinity for membrane-associated cadherins. In association with this decreased cadherin interaction, we found that the mutation results in decreased intrahemispheric connections, with deficits in dendritic branching, long-term potentiation, and cognitive function. Our study provides in vivo evidence that dominant mutations in β-catenin underlie losses in its adhesion-related functions, which leads to severe consequences, including intellectual disability, childhood hypotonia, progressive spasticity of lower limbs, and abnormal craniofacial features in adults
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Our results suggest that central serotonin activity influences the appraisal of close intimate partnerships, raising the possibility that serotonergic dysfunction contributes to altered cognitions about relationships in psychiatric illnesses.
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Autism Spectrum Disorder (ASD) is diagnosed on the basis of behavioral symptoms, but cognitive abilities may also be useful in characterizing individuals with ASD. One hundred seventy-eight high-functioning male adults, half with ASD and half without, completed tasks assessing IQ, a broad range of cognitive skills, and autistic and comorbid symptomatology. The aims of the study were, first, to determine whether significant differences existed between cases and controls on cognitive tasks, and whether cognitive profiles, derived using a multivariate classification method with data from multiple cognitive tasks, could distinguish between the two groups. Second, to establish whether cognitive skill level was correlated with degree of autistic symptom severity, and third, whether cognitive skill level was correlated with degree of comorbid psychopathology. Fourth, cognitive characteristics of individuals with Asperger Syndrome (AS) and high-functioning autism (HFA) were compared. After controlling for IQ, ASD and control groups scored significantly differently on tasks of social cognition, motor performance, and executive function (P's < 0.05). To investigate cognitive profiles, 12 variables were entered into a support vector machine (SVM), which achieved good classification accuracy (81%) at a level significantly better than chance (P < 0.0001). After correcting for multiple correlations, there were no significant associations between cognitive performance and severity of either autistic or comorbid symptomatology. There were no significant differences between AS and HFA groups on the cognitive tasks. Cognitive classification models could be a useful aid to the diagnostic process when used in conjunction with other data sources-including clinical history.
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BACKGROUND: Autism Spectrum Conditions (ASC) are a group of developmental conditions which affect communication, social interactions and behaviour. Mitochondrial oxidative dysfunction has been suggested as a mechanism of autism based on the results of multiple genetic association and expression studies. SLC25A12 is a gene encoding a calcium-binding carrier protein that localizes to the mitochondria and is involved in the exchange of aspartate for glutamate in the inner membrane of the mitochondria regulating the cytosolic redox state. rs2056202 SNP in this gene has previously been associated with ASC. SNPs rs6716901 and rs3765166 analysed in this study have not been previously explored in association with AS. METHODS: We genotyped three SNPs (rs2056202, rs3765166, and rs6716901) in SLC25A12 in n?=?117 individuals with Asperger syndrome (AS) and n?=?426 controls, all of Caucasian ancestry. RESULTS: rs6716901 showed significant association with AS (P?=?0.008) after correcting for multiple testing. We did not replicate the previously identified association between rs2056202 and AS in our sample. Similarly, rs3765166 (P?=?0.11) showed no significant association with AS. CONCLUSION: The present study, in combination with previous studies, provides evidence for SLC25A12 as involved in the etiology of AS. Further cellular and molecular studies are required to elucidate the role of this gene in ASC.
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Mankind is facing an unprecedented health challenge in the current pandemic of obesity and diabetes. We propose that this is the inevitable (and predictable) consequence of the evolution of intelligence, which itself could be an expression of life being an information system driven by entropy. Because of its ability to make life more adaptable and robust, intelligence evolved as an efficient adaptive response to the stresses arising from an ever-changing environment. These adaptive responses are encapsulated by the epiphenomena of “hormesis”, a phenomenon we believe to be central to the evolution of intelligence and essential for the maintenance of optimal physiological function and health. Thus, as intelligence evolved, it would eventually reach a cognitive level with the ability to control its environment through technology and have the ability remove all stressors. In effect, it would act to remove the very hormetic factors that had driven its evolution. Mankind may have reached this point, creating an environmental utopia that has reduced the very stimuli necessary for optimal health and the evolution of intelligence – “the intelligence paradox”. One of the hallmarks of this paradox is of course the rising incidence in obesity, diabetes and the metabolic syndrome. This leads to the conclusion that wherever life evolves, here on earth or in another part of the galaxy, the “intelligence paradox’” would be the inevitable side-effect of the evolution of intelligence. ET may not need to just “phone home” but may also need to “phone the local gym”. This suggests another possible reason to explain Fermi’s paradox; Enrico Fermi, the famous physicist, suggested in the 1950s that if extra-terrestrial intelligence was so prevalent, which was a common belief at the time, then where was it? Our suggestion is that if advanced life has got going elsewhere in our galaxy, it can’t afford to explore the galaxy because it has to pay its healthcare costs.
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In recent years, research into the impact of genetic abnormalities on cognitive development, including language, has become recognized for its potential to make valuable contributions to our understanding of the brain–behaviour relationships underlying language acquisition as well as to understanding the cognitive architecture of the human mind. The publication of Fodor’s ( 1983 ) book The Modularity of Mind has had a profound impact on the study of language and the cognitive architecture of the human mind. Its central claim is that many of the processes involved in comprehension are undertaken by special brain systems termed ‘modules’. This domain specificity of language or modularity has become a fundamental feature that differentiates competing theories and accounts of language acquisition (Fodor 1983 , 1985 ; Levy 1994 ; Karmiloff-Smith 1998 ). However, although the fact that the adult brain is modularized is hardly disputed, there are different views of how brain regions become specialized for specific functions. A question of some interest to theorists is whether the human brain is modularized from the outset (nativist view) or whether these distinct brain regions develop as a result of biological maturation and environmental input (neuroconstructivist view). One source of insight into these issues has been the study of developmental disorders, and in particular genetic syndromes, such as Williams syndrome (WS) and Down syndrome (DS). Because of their uneven profiles characterized by dissociations of different cognitive skills, these syndromes can help us address theoretically significant questions. Investigations into the linguistic and cognitive profiles of individuals with these genetic abnormalities have been used as evidence to advance theoretical views about innate modularity and the cognitive architecture of the human mind. The present chapter will be organized as follows. To begin, two different theoretical proposals in the modularity debate will be presented. Then studies of linguistic abilities in WS and in DS will be reviewed. Here, the emphasis will be mainly on WS due to the fact that theoretical debates have focused primarily on WS, there is a larger body of literature on WS, and DS subjects have typically been used for the purposes of comparison. Finally, the modularity debate will be revisited in light of the literature review of both WS and DS. Conclusions will be drawn regarding the contribution of these two genetic syndromes to the issue of cognitive modularity, and in particular innate modularity.
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Background Autism Spectrum Conditions (ASC) are a group of neurodevelopmental conditions characterized by impairments in communication and social interaction, alongside unusually repetitive behaviors and narrow interests. ASC are highly heritable and have complex patterns of inheritance where multiple genes are involved, alongside environmental and epigenetic factors. Asperger Syndrome (AS) is a subgroup of these conditions, where there is no history of language or cognitive delay. Animal models suggest a role for oxytocin (OXT) and oxytocin receptor (OXTR) genes in social-emotional behaviors, and several studies indicate that the oxytocin/oxytocin receptor system is altered in individuals with ASC. Previous studies have reported associations between genetic variations in the OXTR gene and ASC. Methods The present study tested for an association between nine single nucleotide polymorphisms (SNPs) in the OXTR gene and AS in 530 individuals of Caucasian origin, using SNP association test and haplotype analysis. Results There was a significant association between rs2268493 in OXTR and AS. Multiple haplotypes that include this SNP (rs2268493-rs2254298, rs2268490-rs2268493-rs2254298, rs2268493-rs2254298-rs53576, rs237885-rs2268490-rs2268493-rs2254298, rs2268490-rs2268493-rs2254298-rs53576) were also associated with AS. rs2268493 has been previously associated with ASC and putatively alters several transcription factor-binding sites and regulates chromatin states, either directly or through other variants in linkage disequilibrium (LD). Conclusions This study reports a significant association of the sequence variant rs2268493 in the OXTR gene and associated haplotypes with AS.