门静脉血流改变对晚期高位胆管癌的诊断价值

通过探讨正常人与高位胆管癌病人之间的门静脉血流改变,发现两者之间有明显的不同。所以门静脉血流改变在诊断高位胆管癌方面具有重要意义。     

Associations of transcranial doppler velocity,age, and gender with cognitive function in children with sickle cell anemia in Nigeria

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 (M_age = 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.     

Locus of control and the flow experience: An experimental analysis

The present research addresses the notion that the compatibility of skills and task demands involved in a given activity elicits a flow experience that renders the respective activity rewarding. The study employed an experimental paradigm to document the causal impact of skills–demands compatibility on the emergence of flow and revealed that participants characterized by a strong internal locus of control (LOC) were most sensitive to the manipulation of skills–demands compatibility and experienced flow under conditions of a fit of skills and task demands, whereas individuals with a weak internal LOC did not enter the state of flow. In line with previous findings, this suggests that distinct personality attributes are of critical relevance for the experience of flow to emerge. Copyright © 2008 John Wiley & Sons, Ltd.     

教学设计中的成绩表现和心流体验:基于认知负荷视角

教学设计是为优化教学效果而形成的教学实施方案。为提高学习表现,认知负荷理论认为在组织教学设计时需考虑内、外认知负荷两大因素,但少有研究关注学生在学习过程中的体验。本研究通过单词复合性操纵内在负荷,通过呈现方式操纵外在负荷,探究两类负荷对心流体验及表现的影响。结果发现,内在负荷对心流及表现均有影响,外在负荷仅在低水平组表现出对心流及表现的影响,另外内外负荷在低水平组的表现上存在交互作用。结果表明,教学设计中的内在负荷是影响心流及表现的稳定因素,外在负荷不仅受知识水平影响,其对表现的有效性还受内在负荷的调节。     

Hypertension and cognitive function

Previous research indicates that blood pressure may impact a variety of cognitive functions, including short-term memory, abstract reasoning, visual-spatial abilities, and attention (Boller, Vrtunski, Mack, & Kim, 1977; Elias, Robbins, Schultz, & Pierce, 1990; Franceschi, Tancredi, Smirne, Mercinelli, & Canal, 1982; Mazzucchiet al., 1986). However, studies which have assessed the cognitive functioning of hypertensive adults have offered conflicting results, particularly when hypertension levels were in the mild range (e.g., Bolleret al., 1977; Eliaset al., 1990; Elias, Wolf, D'Agostino, Cobb, & White, 1993; Farmeret al., 1987, 1990; Franceschiet al., 1982; Pérez-Stable, Coates, Halliday, Gardiner, & Hauck, 1992; Schmidtet al., 1991; Waldstein, Ryan, Manuck, Parkinson, & Bromet, 1991). A number of factors may contribute to the inconsistent findings in this area. Researchers have employed a wide range of neuropsychological instruments to assess varying domains of cognitive function. Sample sizes in some studies have been too small to ensure sufficient power. Finally, studies have employed varying methodological control over potential confounding factors such as concurrent medical conditions, alcohol abuse, psychiatric disorders, or antihypertensive medication. This study compared male veterans with blood pressures in the mildly hypertensive range (n=166) to normotensive veterans (n=176) on neuropsychological measures of verbal fluency, visual-spatial ability, verbal and visual memory, dexterity, attention, and executive functions. Results revealed that, after controlling for differences in education and income, there was no relationship between mild hypertension and combined measures of cognitive performance. The present findings suggest that mild hypertension alone has little effect on cognitive function in adults.     

描述性规范提升义务献血的意愿而非行为

描述性规范指大多数人的做法对他人态度和行为的影响。本研究试图利用描述性规范改变公众的义务献血意愿和行为。研究由两个相似实验组成。实验1发现描述性规范促进了被试义务献血的意愿, 但并没有影响实际献血行为; 实验2在实验1的基础上试图通过增加短信提醒来促进义务献血行为, 但是结果同样显示描述性规范促进了被试的献血意愿而非行为。本文对此原因进行了讨论。     

动机过程对青少年网络游戏行为意向的影响模型

从行为动机的角度探讨影响青少年网络游戏玩家游戏意向的主要因素。通过对北京市中学生进行抽样调查并采用结构方程模型的方法对模型进行检验。结果显示,青少年网络游戏玩家的游戏意向受多种内在动机和外在动机共同影响。青少年玩网络游戏的基本内在动机（如,社会交际、超越现实、自我效能和享受乐趣）促进沉浸动机的形成。同时,沉浸是提高游戏意向的内在动机,主观规范和游戏涉入度是分别降低和提高游戏意向的外在动机。此外,内部动机和外部动机对游戏意向的影响存在交互作用