301 research outputs found

    Effects of Age of Onset of Tonic-Clonic Seizures on Neuropsychological Performance in Children

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    Forty-eight children (aged 9 to 15 years) with tonic-clonic seizures were administered a neuropsychological test battery. The children with seizures of early onset (before age 5) were significantly impaired relative to the children with later onset on 8 of the 14 measures in the battery. The deficits were seen on tasks whose requirements included the repetition of a simple motor act, attention and concentration, memory, and complex problem solving. These findings emphasize the need for further research to determine the causal factors of the greater dysfunction seen in the early onset group. RÉSUMÉ Quarante huit enfants ÁgÉs de 9 À 15 ans souffrant de crises Épileptiques tonico-cloniques ont ÉtÉÉtudiÉs avec une batterie de tests neuropsychologiques. Pour huit des quatorze mesures de cette batterie de tests les enfants dont les cirses avaient dÉbutÉ prÉcocÉment (avant cinq ans) se sont avÉrÉs Étre signiflcativement dÉtÉriorÉs par rapport À ceux dont les crises avaient dÉbutÉ plus tardivement. Les dÉficits se sont manifestÉs pour des tÁches nÉcessitant la rÉpÉtition d'un acte moteur simple, attention et concentration, mÉmoire et capacitÉÀ rÉsoudre des problÈmes complexes. Ces rÉsultats mettent l'accent sur la nÉcessitÉ de poursuivre les recherches afin de dÉterminer les facteurs responsables de la plus grande dysfonction observÉe chez les enfants dont l'Épilepsie a dÉbutÉ tÔt dans la vie. RESUMEN Se ha aplicado una bateria de tests neuro-psicolÓgicos a 48 niÑos de 9 a 15 aÑos de edad que padecÍan ataques tonico-clÓnicos. Los niÑos con ataques de comienzo precoz (antes de los 5 aÑos) mostraron incapacidades significativas compareÁndolos con niÑos con comienzos mÁs tardios en 8 de los 14 tests de la bateria. Los defectos fueron detectados en las pruebas cuyos requisitos incluÍan la repeticiÓn de un acto motor simple, atenciÓn y concentraciÓn, memoria y resoluciÓn de problemas complejos. Estos hallazgos indican la necesidad de continuar la inves-tigaciÓn para determinar los factores causales de la mayor disfunciÓn observada en el grupo de comienzo precoz. ZUSAMMENFASSUNG 48 Kinder (9 bis 15 Jahre alt) mit tonisch-klonischen KrÄmpfen wurden mit einer neuropsychologischen Testbatterie untersucht. Die Kinder mit einem FrÜhbeginn der AnfÄlle (vor dem Alter von 5 Jahren) zeigten sich bei 8 von 14 Tests der Serie deutlich beeintrÄchtigt im VerhÄltnis zu Kindern mit spÄterem Anfallsbeginn. Die Defekte traten bei Aufgaben auf, die folgende AnsprÜche stellten: Wiederholung einer einfachen motorischen Handlung, Aufmerksamkeit und Konzentration, GedÄchtnis und komplexes ProblemlÖsen. Diese Befunde deuten auf die Notwendigkeit weiterer Untersuchungen, um die ursÄchlichen Faktoren der grÖßeren Funktionseinbuße zu bestimmen, die bei Patienten mit frÜhem Anfallsbeginn beobachtet wird.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65238/1/j.1528-1157.1981.tb04102.x.pd

    Genetic influences in different aspects of language development: The etiology of language skills in 4.5 year-old twins

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    The genetic and environmental etiologies of diverse aspects of language ability and disability, including articulation, phonology, grammar, vocabulary, and verbal memory, were investigated in a U.K. sample of 787 pairs of 4.5-year-old same-sex and opposite-sex twins. Moderate genetic influence was found for all aspects of language in the normal range. A similar pattern was found at the low end of the distribution with the exception of two receptive measures. Environmental influence was mainly due to nonshared factors, unique to the individual, with little influence from shared environment for most measures. Genetic and environmental influences on language ability and disability are quantitatively and qualitatively similar for males and females

    Parental phonological memory contributes to prediction of outcome of late talkers from 20 months to 4 years: a longitudinal study of precursors of specific language impairment

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    Background Many children who are late talkers go on to develop normal language, but others go on to have longer-term language difficulties. In this study, we considered which factors were predictive of persistent problems in late talkers. Methods Parental report of expressive vocabulary at 18 months of age was used to select 26 late talkers and 70 average talkers, who were assessed for language and cognitive ability at 20 months of age. Follow-up at 4 years of age was carried out for 24 late and 58 average talkers. A psychometric test battery was used to categorize children in terms of language status (unimpaired or impaired) and nonverbal ability (normal range or more than 1 SD below average). The vocabulary and non-word repetition skills of the accompanying parent were also assessed. Results Among the late talkers, seven (29%) met our criteria for specific language impairment (SLI) at 4 years of age, and a further two (8%) had low nonverbal ability. In the group of average talkers, eight (14%) met the criteria for SLI at 4 years, and five other children (8%) had low nonverbal ability. Family history of language problems was slightly better than late-talker status as a predictor of SLI.. The best predictors of SLI at 20 months of age were score on the receptive language scale of the Mullen Scales of Early Learning and the parent's performance on a non-word repetition task. Maternal education was not a significant predictor of outcome. Conclusions In this study, around three-quarters of late talkers did not have any language difficulties at 4 years of age, provided there was no family history of language impairment. A family history of language-literacy problems was found to be a significant predictor for persisting problems. Nevertheless, there are children with SLI for whom prediction is difficult because they did not have early language delay

    Vowel reduction in word-final position by early and late Spanish-English bilinguals

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    Vowel reduction is a prominent feature of American English, as well as other stress-timed languages. As a phonological process, vowel reduction neutralizes multiple vowel quality contrasts in unstressed syllables. For bilinguals whose native language is not characterized by large spectral and durational differences between tonic and atonic vowels, systematically reducing unstressed vowels to the central vowel space can be problematic. Failure to maintain this pattern of stressed-unstressed syllables in American English is one key element that contributes to a ?foreign accent? in second language speakers. Reduced vowels, or ?schwas,? have also been identified as particularly vulnerable to the co-articulatory effects of adjacent consonants. The current study examined the effects of adjacent sounds on the spectral and temporal qualities of schwa in word-final position. Three groups of English-speaking adults were tested: Miami-based monolingual English speakers, early Spanish-English bilinguals, and late Spanish-English bilinguals. Subjects performed a reading task to examine their schwa productions in fluent speech when schwas were preceded by consonants from various points of articulation. Results indicated that monolingual English and late Spanish-English bilingual groups produced targeted vowel qualities for schwa, whereas early Spanish-English bilinguals lacked homogeneity in their vowel productions. This extends prior claims that schwa is targetless for F2 position for native speakers to highly-proficient bilingual speakers. Though spectral qualities lacked homogeneity for early Spanish-English bilinguals, early bilinguals produced schwas with near native-like vowel duration. In contrast, late bilinguals produced schwas with significantly longer durations than English monolinguals or early Spanish-English bilinguals. Our results suggest that the temporal properties of a language are better integrated into second language phonologies than spectral qualities. Finally, we examined the role of nonstructural variables (e.g. linguistic history measures) in predicting native-like vowel duration. These factors included: Age of L2 learning, amount of L1 use, and self-reported bilingual dominance. Our results suggested that different sociolinguistic factors predicted native-like reduced vowel duration than predicted native-like vowel qualities across multiple phonetic environments

    Structural MRI studies of language function in the undamaged brain

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    In recent years, the demonstration that structural changes can occur in the human brain beyond those associated with development, ageing and neuropathology has revealed a new approach to studying the neural basis of behaviour. In this review paper, we focus on structural imaging studies of language that have utilised behavioural measures in order to investigate the neural correlates of language skills in the undamaged brain. We report studies that have used two different techniques: voxel-based morphometry of whole brain grey or white matter images and diffusion tensor imaging. At present, there are relatively few structural imaging studies of language. We group them into those that investigated (1) the perception of novel speech sounds, (2) the links between speech sounds and their meaning, (3) speech production, and (4) reading. We highlight the validity of the findings by comparing the results to those from functional imaging studies. Finally, we conclude by summarising the novel contribution of these studies to date and potential directions for future research

    Theorising terminology development: Frames from language acquisition and the philosophy of science

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    The manner in which our conceptualisation and practice of terminology development can be informed by processes of knowledge change in child language development and a paradigm shift in disciplines, has been relatively underexplored. As a result, insights into what appears to be fundamental processes of knowledge change have not been employed to reflect on terminology development, its dynamics, requirements and relationship to related fields. In this article, frames of knowledge change in child language development and the philosophy of science are used to examine terminology development as knowledge growth that is signalled lexico-semantically through a range of transformations: addition, deletion, redefinition and reorganisation. The analysis is shown to have implications for work procedures, expertise types, critique, and for the relationships between terminology development and translating

    Behavioural plasticity in Argyrodes antipodiana.

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    In this thesis I look at the behavioural plasticity of A.antipodiana while foraging and interacting with conspecifics. The aim is to see how an animal, with apparently limited intelligence is able to deal with environmental variability. I conclude that A.antipodiana appears to have been able to overcome these limitations very effectively by using four methods, of which the first two effectively reduce the amount of learning necessary. Firstly, A.antipodiana simplifies the situation as much as possible by ignoring some of the variability. For example, in social situations, A.antipodiana appears to recognize only a few categories of conspecifics, rather than recognize conspecifics as individuals. Consequently, the social groups of A.antipodiana are not characterized by complicating factors such as aggressive orders or dominance hierarchies. Secondly, A.antipodiana largely ignores current situations and instead bases much of its behavioural decisions on its internal conditions. For example, in male-male conflicts, males respond to their opponents largely according to their own size, level of hunger, the number of contests in which they have participated, or their past experience of winning or losing; rather than to the characteristics of their opponents. Likewise in social interactions A.antipodiana is more inclined to be aggressive towards conspecifics if it itself is foraging, and less inclined if it is feeding with the host. When the situation cannot be simplified, A.antipodiana adopts a third response which is to use the simplest method possible for adjusting its behaviour. For example, A.antipodiana's ability to develop araneophagic skills appears to be governed by a critical period. Thus rather than developing araneophagic skills through trial and error with practise, the ability appears to be simply 'switched on' if required. The fourth means by which A.antipodiana compensates for limited intelligence is to be very selective in the areas in which it does use learning. For example, A.antipodiana seems to use problem solving when foraging, but only when it is actually trying to reach the food bundle upon which the host is feeding. A.antipodiana also seems to learn to move more stealthfully on the host's web. There is even evidence that A.antipodiana may behave with intent when males are competing for opportunities to copulate. Thus the intelligence of A.antipodiana appears to be severely limited. However, despite these limitations, by reducing the amount of learning necessary, and then channelling what learning it has to very restricted, but very poignant areas of its behaviour, A.antipodiana, is able to respond very effectively to its variable environment
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