79 resultados para Youth movements
Resumo:
Background Event-related desynchronization/synchronization (ERD/ERS) is a relative power decrease/increase of electroencephalogram (EEG) in a specific frequency band during physical motor execution and mental motor imagery, thus it is widely used for the brain-computer interface (BCI) purpose. However what the ERD really reflects and its frequency band specific role have not been agreed and are under investigation. Understanding the underlying mechanism which causes a significant ERD would be crucial to improve the reliability of the ERD-based BCI. We systematically investigated the relationship between conditions of actual repetitive hand movements and resulting ERD. Methods Eleven healthy young participants were asked to close/open their right hand repetitively at three different speeds (Hold, 1/3 Hz, and 1 Hz) and four distinct motor loads (0, 2, 10, and 15 kgf). In each condition, participants repeated 20 experimental trials, each of which consisted of rest (8–10 s), preparation (1 s) and task (6 s) periods. Under the Hold condition, participants were instructed to keep clenching their hand (i.e., isometric contraction) during the task period. Throughout the experiment, EEG signals were recorded from left and right motor areas for offline data analysis. We obtained time courses of EEG power spectrum to discuss the modulation of mu and beta-ERD/ERS due to the task conditions. Results We confirmed salient mu-ERD (8–13 Hz) and slightly weak beta-ERD (14–30 Hz) on both hemispheres during repetitive hand grasping movements. According to a 3 × 4 ANOVA (speed × motor load), both mu and beta-ERD during the task period were significantly weakened under the Hold condition, whereas no significant difference in the kinetics levels and interaction effect was observed. Conclusions This study investigates the effect of changes in kinematics and kinetics on resulting ERD during repetitive hand grasping movements. The experimental results suggest that the strength of ERD may reflect the time differentiation of hand postures in motor planning process or the variation of proprioception resulting from hand movements, rather than the motor command generated in the down stream, which recruits a group of motor neurons.
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This paper develops a framework of risk and protective factors to conceptualise the relationship between HIV-related stigma, asset inheritance and chronic poverty among widows and caregiving children and youth in eastern Africa. Analysis of two qualitative studies with 85 participants in rural and urban areas of Tanzania and Uganda reveals that gendered and generational inequalities and stigmatisation sometimes led to property grabbing and chronic poverty. Human and social capital and preventative measures however may help widows and caregiving young people in HIV-affected households to safeguard land and other assets, within a wider supportive environment that seeks to tackle structural inequalities.
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This paper focuses on the determinants of the labor market situation of young people in developed countries and the developing world, with a particular emphasis on the role of vocational training and education policies. We highlight the role of demographic factors, economic growth and labor market institutions in explaining young people's transition into work. Subsequently, we assess differences between the setup and functioning of the vocational education and training policies across major world regions as an important driver of differential labor market situation of youth. Based on our analysis, we argue in favor of vocational education and training systems combining work experience and general education and provide some policy recommendations regarding the implementation of education and training systems adapted to a country's economic and institutional context.
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This paper aims to consider whether there is a link between youth happiness levels and adult life satisfaction. Our results are unequivocal that such a link exists both because demographic and socio-economic conditions are persistent over a lifetime and also because there is a persistence in personality effects. To test this link, we estimate a model of happiness for a sample of young people. This model provides us with a range of variables measuring socio-economic effects and personality effects amongst young people. These variables are then included in the adult life satisfaction model. The model is estimated using data from the British Household Panel Survey for 1994–2008. In addition to childhood happiness levels influencing adult life satisfaction significantly, we also find that the youthful personality trait for happiness has a larger effect on adult life satisfaction than demographic and socio-economic conditions.
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A number of recent studies have investigated how syntactic and non-syntactic constraints combine to cue memory retrieval during anaphora resolution. In this paper we investigate how syntactic constraints and gender congruence interact to guide memory retrieval during the resolution of subject pronouns. Subject pronouns are always technically ambiguous, and the application of syntactic constraints on their interpretation depends on properties of the antecedent that is to be retrieved. While pronouns can freely corefer with non-quantified referential antecedents, linking a pronoun to a quantified antecedent is only possible in certain syntactic configurations via variable binding. We report the results from a judgment task and three online reading comprehension experiments investigating pronoun resolution with quantified and non-quantified antecedents. Results from both the judgment task and participants' eye movements during reading indicate that comprehenders freely allow pronouns to corefer with non-quantified antecedents, but that retrieval of quantified antecedents is restricted to specific syntactic environments. We interpret our findings as indicating that syntactic constraints constitute highly weighted cues to memory retrieval during anaphora resolution.
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This paper investigates whether bank integration measured by cross-border bank flows can capture the co-movements across housing markets in developed countries by using a spatial dynamic panel model. The transmission can occur through a global banking channel in which global banks intermediate wholesale funding to local banks. Changes in financial conditions are passed across borders through the banks’ balance-sheet exposure to credit, currency, maturity, and funding risks resulting in house price spillovers. While controlling for country-level and global factors, we find significant co-movement across housing markets of countries with proportionally high bank integration. Bank integration can better capture house price co-movements than other measures of economic integration. Once we account for bank exposure, other spatial linkages traditionally used to account for return co-movements across region – such as trade, foreign direct investment, portfolio investment, geographic proximity, etc. – become insignificant. Moreover, we find that the co-movement across housing markets decreases for countries with less developed mortgage markets characterized by fixed mortgage rate contracts, low limits of loan-to-value ratios and no mortgage equity withdrawal.
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We know that from mid-childhood onwards most new words are learned implicitly via reading; however, most word learning studies have taught novel items explicitly. We examined incidental word learning during reading by focusing on the well-documented finding that words which are acquired early in life are processed more quickly than those acquired later. Novel words were embedded in meaningful sentences and were presented to adult readers early (day 1) or later (day 2) during a five-day exposure phase. At test adults read the novel words in semantically neutral sentences. Participants’ eye movements were monitored throughout exposure and test. Adults also completed a surprise memory test in which they had to match each novel word with its definition. Results showed a decrease in reading times for all novel words over exposure, and significantly longer total reading times at test for early than late novel words. Early-presented novel words were also remembered better in the offline test. Our results show that order of presentation influences processing time early in the course of acquiring a new word, consistent with partial and incremental growth in knowledge occurring as a function of an individual’s experience with each word.
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While eye movements have been used widely to investigate how skilled adult readers process written language, relatively little research has used this methodology with children. This is unfortunate as, as we discuss here, eye-movement studies have significant potential to inform our understanding of children’s reading development. We consider some of the empirical and theoretical issues that arise when using this methodology with children, illustrating our points with data from an experiment examining word frequency effects in 8-year-old children’s sentence reading. Children showed significantly longer gaze durations to low than high-frequency words, demonstrating that linguistic characteristics of text drive children’s eye movements as they read. We discuss these findings within the broader context of how eye-movement studies can inform our understanding of children’s reading, and can assist with the development of appropriately targeted interventions to support children as they learn to read.
Resumo:
Children’s eye movements during reading. In this chapter, we evaluate the literature on children’s eye movements during reading to date. We describe the basic, developmental changes that occur in eye movement behaviour during reading, discuss age-related changes in the extent and time course of information extraction during fixations in reading, and compare the effects of visual and linguistic manipulations in the text on children’s eye movement behaviour in relation to skilled adult readers. We argue that future research will benefit from examining how eye movement behaviour during reading develops in relation to language and literacy skills, and use of computational modelling with children’s eye movement data may improve our understanding of the mechanisms that underlie the progression from beginning to skilled reader.
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The eye movements of 24 children and 24 adults were monitored to compare how they read sentences containing plausible, implausible, and anomalous thematic relations. In the implausible condition the incongruity occurred due to the incompatibility of two objects involved in the event denoted by the main verb. In the anomalous condition the direct object of the verb was not a possible verb argument. Adults exhibited immediate disruption with the anomalous sentences as compared to the implausible sentences as indexed by longer gaze durations on the target word. Children exhibited the same pattern of effects as adults as far as the anomalous sentences were concerned, but exhibited delayed effects of implausibility. These data indicate that while children and adults are alike in their basic thematic assignment processes during reading, children may be delayed in the efficiency with which they are able to integrate pragmatic and real world knowledge into their discourse representation.
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Recent evidence indicates that each eye does not always fixate the same letter during reading and there has been some suggestion that processing difficulty may influence binocular coordination. We recorded binocular eye movements from children and adults reading sentences containing a word frequency manipulation. We found disparities of significant magnitude between the two eyes for all participants, with greater disparity magnitudes in children than adults. All participants made fewer crossed than uncrossed fixations. However, children made a higher proportion of crossed fixations than adults. We found no influence of word frequency on children’s fixations and on binocular coordination in adults.
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Transforming the meaning of the term 'guerrilla' which had once meant feud or private warfare, and then irregular war conducted by special forces on behalf of a state or government, the Spanish Guerrilla (part of the Peninsular War) against Napoleon became the model to be emulated by insurgency movements across the world. Even though the term itself continued to be used, even in Spanish, for special operations, in henceforth became imbued with an ideological dimension, which is how it would be used especially in the 20th century.
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Background Serotonin is under-researched in attention deficit hyperactivity disorder (ADHD), despite accumulating evidence for its involvement in impulsiveness and the disorder. Serotonin further modulates temporal discounting (TD), which is typically abnormal in ADHD relative to healthy subjects, underpinned by reduced fronto-striato-limbic activation. This study tested whether a single acute dose of the selective serotonin reuptake inhibitor (SSRI) fluoxetine up-regulates and normalizes reduced fronto-striato-limbic neurofunctional activation in ADHD during TD. Method Twelve boys with ADHD were scanned twice in a placebo-controlled randomized design under either fluoxetine (between 8 and 15 mg, titrated to weight) or placebo while performing an individually adjusted functional magnetic resonance imaging TD task. Twenty healthy controls were scanned once. Brain activation was compared in patients under either drug condition and compared to controls to test for normalization effects. Results Repeated-measures whole-brain analysis in patients revealed significant up-regulation with fluoxetine in a large cluster comprising right inferior frontal cortex, insula, premotor cortex and basal ganglia, which further correlated trend-wise with TD performance, which was impaired relative to controls under placebo, but normalized under fluoxetine. Fluoxetine further down-regulated default mode areas of posterior cingulate and precuneus. Comparisons between controls and patients under either drug condition revealed normalization with fluoxetine in right premotor-insular-parietal activation, which was reduced in patients under placebo. Conclusions The findings show that a serotonin agonist up-regulates activation in typical ADHD dysfunctional areas in right inferior frontal cortex, insula and striatum as well as down-regulating default mode network regions in the context of impulsivity and TD.
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‘White Youth’ recovers and explains the relationship between far-right organisations and British youth culture in the period between 1977 and 1987. In particular, it concentrates on the cultural spaces opened up by punk and the attempts made by the National Front and British Movement to claim them as conduits for racist and/or ultra-nationalist politics. The article is built on an empirical basis, using archival material and a historical methodology chosen to develop a history ‘from below’ that takes due consideration of the socio-economic and political forces that inform its wider context. Its focus is designed to map shifting cultural and political influences across the far right, assessing the extent to which extremist organisations proved able to adopt or utilise youth cultural practice as a means of recruitment and communication. Today the British far right is in political and organisational disarray. Nonetheless, residues tied to the cultural initiatives devised in the 1970s–80s remain, be they stylistic, nostalgic or points of connection forged to connect a transnational music scene.