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51.
The effects of lexical context on phonological processing are pervasive and there have been indications that such effects may be modulated by attention. However, attentional modulation in speech processing is neither well documented nor well understood. Experiment 1 demonstrated attentional modulation of lexical facilitation of speech sound recognition when task and critical stimuli were identical across attention conditions. We propose modulation of lexical activation as a neurophysiologically plausible computational mechanism that can account for this type of modulation. Contrary to the claims of critics, this mechanism can account for attentional modulation without violating the principle of interactive processing. Simulations of the interactive TRACE model extended to include two different ways of modulating lexical activation showed that each can account for attentional modulation of lexical feedback effects. Experiment 2 tested conflicting predictions from the two implementations and provided evidence that is consistent with bias input as the mechanism of attentional control of lexical activation. 相似文献
52.
Hanson SS 《Theoretical medicine and bioethics》2006,27(3):215-226
It is commonly assumed that persons who hold abortions to be generally impermissible must, for the same reasons, be opposed to embryonic stem cell research [ESR]. Yet a settled position against abortion does not necessarily direct one to reject that research. The difference in potentiality between the embryos used in ESR and embryos discussed in the abortion debate can make ESR acceptable even if one holds that abortion is impermissible. With regard to their potentiality, in vitro embryos are here argued to be more morally similar to clonable somatic cells than they are to in vivo embryos. This creates an important moral distinction between embryos in vivo and in vitro. Attempts to refute this moral distinction, raised in the recent debate in this journal between Alfonso Gómez-Lobo and Mary Mahowald, are also addressed. 相似文献
53.
到底路有多长--对干细胞移植治疗研究的一点思考 总被引:1,自引:0,他引:1
目前干细胞研究的争论主要集中于干细胞研究的过程和方式,诸如干细胞来源以及被提取干细胞的胚胎的权利与地位等伦理问题是争论的焦点所在,而对于研究的最终目的是治病而非克隆人则少有争议.然而在伦理问题等争论相对较小的干细胞应用研究领域,就应用于人的技术层面而言还有很多问题有待解决.安全性(safety)和有效性(efficacy)原则是目前公认的干细胞临床应用研究的基准.干细胞移植治疗最终应用于临床可能还有相当一段路程要走,无论是研究者还是伦理学家以及社会舆论和普通百姓在其中都应当并可以发挥积极的作用. 相似文献
54.
The Wernicke-Lichtheim-Geschwind (WLG) theory of the neurobiological basis of language is of great historical importance, and it continues to exert a substantial influence on most contemporary theories of language in spite of its widely recognized limitations. Here, we suggest that neurobiologically grounded computational models based on the WLG theory can provide a deeper understanding of which of its features are plausible and where the theory fails. As a first step in this direction, we created a model of the interconnected left and right neocortical areas that are most relevant to the WLG theory, and used it to study visual-confrontation naming, auditory repetition, and auditory comprehension performance. No specific functionality is assigned a priori to model cortical regions, other than that implicitly present due to their locations in the cortical network and a higher learning rate in left hemisphere regions. Following learning, the model successfully simulates confrontation naming and word repetition, and acquires a unique internal representation in parietal regions for each named object. Simulated lesions to the language-dominant cortical regions produce patterns of single word processing impairment reminiscent of those postulated historically in the classic aphasia syndromes. These results indicate that WLG theory, instantiated as a simple interconnected network of model neocortical regions familiar to any neuropsychologist/neurologist, captures several fundamental "low-level" aspects of neurobiological word processing and their impairment in aphasia. 相似文献
55.
Lamia P. Barakat Kim Smith-Whitley Kwaku Ohene-Frempong 《Journal of clinical psychology in medical settings》2002,9(3):201-209
To identify disease-related risk factors and psychosocial resistance factors that impact adherence to prescribed treatment in the context of admission to a Hematology Acute Care Unit (HACU) designed to provide acute care for children with sickle cell disease (SCD) presenting with pain or fever. A total of 73 primary caregivers and 24 children (if age 8 or older) completed standardized forms during the HACU admission. Treatment adherence variables (medical staff rating, SCD-related care activities, percentage of agreement between treatment recommendations made and care activities, and attendance at hematology clinic) indicated moderate-to-high adherence. Based on regression analyses, the risk variable of disease-related stress and the resistance variables of family flexibility and less reliance on passive coping accounted for significant portions of the variance in treatment adherence. Empirical evaluation of interventions designed to improve communication regarding expectations for the care of children with SCD and to support active family problem solving during times of SCD-related stress must be ongoing. 相似文献
56.
干细胞研究取得了里程碑式的进展,在临床疾病的预防和治疗中具有广阔的应用前景,这些研究成果凝聚了各国研究人员的集体智慧,多向立体思维方法得到了充分体现。 相似文献
57.
Kemar V. Prussien Auwal Salihu Shehu U. Abdullahi Najibah A. Galadanci Khadija Bulama Raymond O. Belonwu 《Child neuropsychology》2019,25(6):705-720
Children with sickle cell anemia (SCA) have elevated cerebral blood velocity relative to healthy peers. The primary aim of this study was to evaluate the association between cerebral blood velocity, measured by transcranial Doppler (TCD) ultrasound, age, and gender with cognitive function in children with SCA in Nigeria. Eighty-three children (Mage = 9.10, SD = 1.90 years; 55% female) with SCA in Nigeria completed cognitive assessments and a TCD ultrasound. The association between TCD velocity and measures of perceptual reasoning (Raven’s Progressive Matrices), working memory (WISC-IV Digit Span), and executive planning (Tower of London, TOL) were assessed. Results showed that elevated TCD velocity significantly predicted lower scores on TOL Time Violations and Total Problem-Solving Time when controlling for BMI, hemoglobin level, and parent education, suggesting that TCD velocity is related to the efficiency of executive function. Further, age was negatively related to children’s performance on the Ravens Matrices and TOL Total Correct, and boys showed greater deficits on the TOL Total Correct relative to girls. Moderation analyses for gender showed that there was a conditional negative association between TCD velocity and Digit Span for boys, but not for girls. Findings suggest that children with SCA in Nigeria with elevated TCD velocity are at risk for deficits in efficiency of executive planning, and boys with elevated TCD velocity are particularly at increased risk for deficits in auditory working memory. Implications of this study are important for interventions to reduce cerebral blood velocity and the use of TCD in this population. 相似文献
58.
胞外体是由多种细胞分泌的一种膜性小囊泡,参与多种生理及病理生理过程。近年研究发现,由抗原提呈细胞分泌的胞外体富集MHCI/II类分子、协同刺激分子、热休克蛋白70~90等多种生物活性分子于一身,在体内外免疫调节中起关键作用。就胞外体的基本特征及其作为一种新型的亚细胞疫苗在抗肿瘤和抗病毒免疫中的应用前景予以综述。 相似文献
59.
人类胚胎干细胞研究伦理问题的调查和讨论 总被引:3,自引:0,他引:3
此次对各级医生进行关于人类胚胎干细胞研究伦理认知的调查研究,其目的是为制订相关的伦理准则提供认知依据,调查是在我国东西部二个城市的8家三级医院进行,采用随机抽样、自愿无记名填写信息表方法调查.调查结果表明,50%以上医生认为早期胚胎不是道德意义的人,70%以上医生对胚胎干细胞的研究表示支持.海峡两岸的医生由于有相同的文化根源,在对待胚胎干细胞研究的伦理观点及态度上极其接近. 相似文献
60.
异基因造血干细胞移植(Allo-HSCT)是目前治疗恶性血液病及其它疾病的主要手段之一,它具有自然科学的一般规律,也有其独特性,其中闪烁着哲学智慧的光辉,用哲学的思想来指导工作的进行,能促进Allo-HSCT的不断发展和取得更好的疗效. 相似文献