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This study was conducted to explore the neuropsychological abilities of premature Chilean children. Two groups (Premature and Control, 10 children each, age ranging from 5 to 7.11) were established based on weeks of gestation and/or weight at birth. Relevant variables such as age, gender, schooling, and socioeconomic level were matched considering Chile's particular demographic context. Children were assessed by means of the Evaluación Neuropsicológica Infantil (ENI-2) battery, measuring nine cognitive domains encompassing 23 subscales. In turn, subscales are grouped in two scales: Cognitive Functions and Executive Functions. Since the ENI-2 battery provides norms for Spanish-speaking children, obtained data were inspected both for possible between-group differences and either adjustment or deviance from average range. Results show that premature children perform within typical ranges in all subscales except for Visual attention and Graphic fluency. When comparing both groups, some differences emerged. These differences are most prominent in subscales related to visuoperceptual skills. Interestingly, between-group linguistic performance is very similar. The point is made that early linguistic interventions conducted on premature children seem to positively impact on oral language expression and comprehension. On the contrary, early interventions focused on visuospatial abilities did not seem to attain the same impact. This may be a consequence of visual-information processing problems derived from cortical dorsal stream's vulnerability, which literature correlates with prematurity.

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Hemispheric specialization of cognitive functions is a developmental process that shapes the brain from the gestational stage to adulthood. Functional connectivity of the resting brain has been largely used to infer the hemispheric organization of the spontaneous brain activity. In particular, two main properties have been largely explored throughout development: hemispheric asymmetry of functional connectivity and homotopic functional connectivity. However, their relation with specific cognitive processes typically associated with hemispheric specialization, such as visuospatial abilities, remains largely unexplored. Such relationships could be particularly relevant for the quest of developmental cognitive biomarkers in childhood, a significant maturation period of visuospatial abilities. Moreover, the relation between asymmetry and homotopy of brain functional connectivity is not well understood. We have examined these two properties in a sample of 60 typically developing children between 6 and 10 years of age, and explored their relation with visuospatial abilities. First, we identified a strong negative relation between homotopy and asymmetry across the brain. In addition, these properties showed areas in the posterior portion of the brain, with significant correlation with performance in visual memory and visual attention tasks. These results highlight the relevance of the hemispheric organization of spontaneous brain activity for developmental cognition, particularly for visuospatial abilities.

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A new tablet device version (IOS platform) of the Spatial Delayed Recognition Span Task (SDRST) was developed with the aim of investigating visuospatial Working Memory (WM) abilities based on touchscreen technology. This new WM testing application will be available to download for free in Apple Store app ("SDRST app"). In order to verify the feasibility of this computer-based task, we conducted three experiments with different manipulations and groups of participants. We were interested in investigating if (1) the SDRST is sensitive enough to tap into cognitive differences brought by aging and dementia; (2) different experimental manipulations work successfully; (3) cortical brain activations seen in other WM tasks are also demonstrated here; and (4) non-human primates are able to answer the task. Performance (scores and response time) was better for young than older adults and higher for the latter when compared to Alzheimer's disease (AD) patients. All groups performed better with facial stimuli than with images of scenes and with emotional than with neutral stimuli. Electrophysiology data showed activation on prefrontal and frontal areas of scalp, theta band activity on the midline area, and gamma activity in left temporal area. There are all scalp regions known to be related to attention and WM. Besides those data, our sample of adult captive capuchin monkeys (Sapajus libidinosus) answered the task above chance level. Taken together, these results corroborate the reliability of this new computer-based SDRST as a measure of visuospatial WM in clinical and non-clinical populations as well as in non-human primates. Its tablet app allows the task to be administered in a wide range of settings, including hospitals, homes, schools, laboratories, universities, and research institutions.

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A great amount of research has been developed around the early cognitive impairments that best predict the onset of Alzheimer's disease (AD). Given that mild cognitive impairment (MCI) is no longer considered to be an intermediate state between normal aging and AD, new paths have been traced to acquire further knowledge about this condition and its subtypes, and to determine which of them have a higher risk of conversion to AD. It is now known that other deficits besides episodic and semantic memory impairments may be present in the early stages of AD, such as visuospatial and executive function deficits. Furthermore, recent investigations have proven that the hippocampus and the medial temporal lobe structures are not only involved in memory functioning, but also in visual processes. These early changes in memory, visual, and executive processes may also be detected with the study of eye movement patterns in pathological conditions like MCI and AD. In the present review, we attempt to explore the existing literature concerning these patterns of oculomotor changes and how these changes are related to the early signs of AD. In particular, we argue that deficits in visual short-term memory, specifically in iconic memory, attention processes, and inhibitory control, may be found through the analysis of eye movement patterns, and we discuss how they might help to predict the progression from MCI to AD. We add that the study of eye movement patterns in these conditions, in combination with neuroimaging techniques and appropriate neuropsychological tasks based on rigorous concepts derived from cognitive psychology, may highlight the early presence of cognitive impairments in the course of the disease.

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The Clock Drawing Test (CDT) is a cognitive screening tool used in clinical and research settings. Despite its role on the assessment of global cognitive functioning, the specific cognitive components required for test performance are still unclear. We aim to assess the role of executive functioning, global cognitive status, visuospatial abilities, and semantic knowledge on Shulman’s CDT performance. Fifty-three mild cognitive impairment, 60 Alzheimer’s dementia, and 57 normal elderly controls performed the CDT, the Frontal Assessment Battery, the Mini-Mental State Examination, the Stick Design Test, and a naming test (TN-LIN). An ordinal regression assessed specific neuropsychological influences on CDT performance. All the cognitive variables were related to the CDT, accounting for 53% of variance. The strongest association was between the CDT and executive functions, followed by global cognitive status, visuospatial processing, and semantic knowledge. Our result confirms the multidimensional nature of the test and the major role of executive functions on performance.

O Teste do Desenho do Relógio (TDR) é um instrumento de rastreio cognitivo amplamente usado em contextos clínicos e de pesquisa. Embora seu papel na avaliação do funcionamento cognitivo global seja reconhecido, os componentes específicos necessários à sua realização não são claros. Objetivo: avaliar a influência das funções executivas, estado cognitivo global, processamento visioespacial e conhecimento semântico no TDR. Realizaram o TDR, a Bateria de Avaliação Frontal, o Mini-Exame do Estado Mental, a Construção com Palitos, e um teste de nomeação (TN-LIN) 53 pacientes com comprometimento cognitivo leve, 60 com Alzheimer e 57 idosos normais.. A influência de variáveis neuropsicológicas específicas no TDR foi avaliada através de regressão ordinal. Todas as variáveis se relacionaram com o teste, respondendo por aproximadamente 53% da variância. A associação mais forte foi entre o TDR e as funções executivas, seguidas pela cognição geral, processamento visioespacial e conhecimento semântico. Nossos resultados confirmam a natureza multidimensional da tarefa e o papel das funções executivas em sua realização.

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O progresso tecnológico e econômico de um país associa-se a melhorias na qualidade de vida à custa de uma demanda crescente do desempenho cognitivo e acadêmico da população. As dificuldades de aprendizagem da matemática (DAM) representam um risco, diminuindo potencialmente o capital cognitivo de uma sociedade. Os diagnósticos e intervenções neuropsicológicos melhoram potencialmente o funcionamento cognitivo e o bem-estar dos indivíduos. Pesquisas são necessárias para um planejamento efetivo e equitativo de políticas públicas. Os critérios diagnósticos atuais das dificuldades de aprendizagem são estatísticos e arbitrários, resultando em uma heterogeneidade clínica e em um alto índice de comorbidades. Neste artigo, foram analisados, através de uma revisão de literatura, os possíveis mecanismos cognitivos envolvidos nas DAM e em outros distúrbios relacionados. Conclui-se que o processamento fonológico, a memória de trabalho, o processamento visoespacial e o senso numérico são domínios potencialmente subjacentes às DAM. Mais estudos longitudinais e integrativos que avaliem simultaneamente a contribuição destes fatores são necessários.

Technological and economic progress is associated to higher living standards at the expense of growing demands on cognitive/academic performance. Mathematical learning difficulties (MLD) represent a risk factor, potentially diminishing a society's cognitive capital. Neuropsychological diagnosis and interventions potentially improve cognitive functioning and well-being. Research data are required to plan effective and equitable public policies. Current diagnostic criteria for learning difficulties are statistical and arbitrary, resulting in clinical heterogeneity and high comorbidity rates. In this paper, we discuss possible cognitive mechanisms involved in MLD and their relationship to other disorders through a literature review. It is concluded that phonological processing, working memory, visuospatial processing and number sense are domains potentially underlying MLD. More longitudinal and integrative studies, simultaneously assessing the contribution of these several factors are required.

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BACKGROUND: Few studies have assessed whether emotional content affects processes supporting working memory in Alzheimer disease (AD) patients. METHODS: We assessed 22 AD patients and 40 elderly controls (EC) with a delayed matching and non-matching to sample task (DMST/DNMST), and a spatial-delayed recognition span task (SRST; unique/varied) using emotional stimuli. RESULTS: AD patients showed decreased performance on both tasks compared with EC. With regard to the valence of the stimuli, we did not observe significant performance differences between groups in the DMST/DNMST. However, both groups remembered a larger number of negative than positive or neutral pictures on unique SRST. CONCLUSION: The results suggest that AD patients show a relative preservation of working memory for emotional information, particularly for negative stimuli.