A Model-Based Approach to Understanding Apraxia in Corticobasal Syndrome

Limb apraxia is a neurological disorder of higher cognitive function characterized by an inability to perform purposeful skilled movements and not attributable to an elementary sensorimotor dysfunction or comprehension difficulty. Corticobasal Syndrome (CBS) is an akinetic rigid syndrome with asymmetric onset and progression with at least one basal ganglia feature (rigidity, limb dystonia or myoclonus) and one cortical feature (limb apraxia, alien hand syndrome or cortical sensory loss). Even though limb apraxia is highly prevalent in CBS (70–80%), very few studies have examined the performance of CBS patients on praxis measures in detail. This review aims to (1) briefly summarize the clinical, neuroanatomical and pathological findings in CBS, (2) briefly outline what limb apraxia is and how it is assessed, (3) to comprehensively review the literature on limb apraxia in CBS to date and (4) to briefly summarize the literature on other forms of apraxia, such as limb-kinetic apraxia and buccofacial apraxia. Overall, the goal of the review is to bring a model-based perspective to the findings available in the literature to date on limb apraxia in CBS.     

压力和认知方式对基于事件错误记忆的影响

运用合作者误导信息干扰范式,通过3个实验探讨了不同压力（引导压力、警告压力和反馈压力）对不同认知方式个体的错误记忆的影响。结果表明：（1）正确引导减少了错误记忆,对改善错误记忆具有积极的作用,而错误引导则增加了错误记忆;（2）在引导压力条件下,社会警告可减少错误记忆,减少误导信息的效应;（3）肯定反馈可减少错误记忆,而否定反馈则明显增加了错误记忆;（4）不同认知方式个体在不同压力下的错误记忆方面存在差异,场依存个体受各种压力影响较大,场独立个体受影响较小。     

Effects of visual roll on steering control and gaze behavior in a motorcycle simulator

The goal of this study was to examine the effects of visual roll tilt on gaze and riding behavior when negotiating a bend using a motorcycle simulator. To this end, experienced motorcyclists rode along a track with a series of right and left turns whilst the degree of visual roll tilt was manipulated in three different conditions. Gaze behavior was analyzed by using the tangent point as a dynamic spatial reference; the deviation of gaze to this particular point was computed in both the horizontal and vertical directions. Steering control was assessed in terms of the lateral positioning, steering stability and number of lane departures. In the no-roll condition, the motorcyclists tracked a steering point on the road ahead, which was compatible with the hypothesis of “steer where you look” behavior. In the roll condition, our results revealed that the horizontal distribution of gaze points relative to the tangent point was preserved. However, significantly more fixations were made further ahead of the tangent point in the vertical direction. This modification of visual behavior was coupled with a degradation in steering stability and an offset in lateral positioning, which sometimes led to lane departures. These results are discussed with regard to models of visual control of steering for bend negotiation.     

Functions and Health at the Interface of Biology and Technology

Synthetic biology promises to eliminate the distinction between biology and engineering by delivering a philosophically interesting new kind of entity: a biological organism that is wholly designed and constructed by humans. The possibility of such organisms raises interesting questions in three domains: the analysis of (1) biological functions, (2) engineering functions, and (3) health and disease. This paper identifies and systematically answers these questions. This does not only establish how we should think about functions and health and disease in synthetic biological organisms, but it also reveals insights that are of broader relevance: (1) aetiological accounts of biological function need to omit or reinterpret reference to natural selection. This results in complete continuity between aetiological analyses of function in engineering and philosophy; (2) considering synthetic biology prompts interesting further questions about heritability, ancestry, and biological individuals; and (3) accounts of disease as biological dysfunction do not straightforwardly map onto our intuitive health and disease judgments regarding non-human animals. In response to the latter point I examine three possible avenues, and tentatively defend one on behalf of the ‘disease as dysfunction’ theorist.     

Critical thinking in North America: A new theory of knowledge,learning, and literacy

The pace of change in the world is accelerating, yet educational institutions have not kept pace. Indeed, schools have historically been the most static of social institutions, uncritically passing down from generation to generation outmoded didactic, lecture-and-drill-based, models of instruction. Predictable results follow. Students, on the whole, do not learn how to work by, or think for, themselves. They do not learn how to gather, analyze, synthesize and assess information. They do not learn how to analyze the diverse logic of the questions and problems they face and hence how to adjust their thinking to those problems. They do not learn how to enter sympathetically into the thinking of others, nor how to deal rationally with conflicting points of view. They do not learn to become critical readers, writers, speakers and listeners. They do not learn how to use their native languages clearly, precisely, or persuasively. They do not, therefore, become literate, in the proper sense of the word. Neither do they gain much in the way of genuine knowledge since, for the most part, they could not explain the basis for what they believe. They would be hard pressed to explain, for example, which of their beliefs were based on rational assent and which on simple conformity to what they have been told. They have little sense as to how they might critically analyze their own experience, or identify national or group bias in their own thinking. They are much more apt to learn on the basis of irrational than rational modes of thought. They lack the traits of mind of a genuinely educated person: intellectual humility, courage, integrity, perseverance, and faith in reason.Happily, there is a movement in education today striving to address these problems in a global way, with strategies and materials for the modification of instruction at all levels of education. At its foundation is an emerging new theory of knowledge, learning, and literacy, one which recognizes the centrality of independent critical thinking to all substantial learning, one which recognizes that higher-order, multilogical thinking is as important to childhood as to adult learning, and as important to foundational learning in monological as in multilogical disciplines. This educational reform movement is not proposing an educational miracle cure, for its leading proponents recognize that many social and historical forces must come together before the ideals of the critical thinking movement will become a full academic reality. Schools do not exist in a social vacuum. To the extent that the broader society is uncritical so, on the whole, will be society's schools. Nevertheless, the social conditions necessary for fundamental changes in schooling are increasingly apparent. The pressure for fundamental change is growing. Whether and to what extent these needed basic changes will be delayed or side-tracked, thus requiring new periodic resurgences of this movement, with new, more elaborate articulations of its ideals, goals, and methods — only time will tell.     

Dealing with time pressure

A sample of 250 people completed a questionnaire where they rated 30 statements describing their behavior and experiences during a recent time pressure situation. A factor analysis resulted in three factors: Personal Burden, Work Problems and Difficulties, and Challenge Orientation. People high on this last factor liked the excitement of being under pressure, were very absorbed in the task, and showed signs of being effective in dealing with the situation. Such individuals were having what has been identified as a flow experience often observed in sports and the arts. The results of this study suggest that effective coping with time pressure is related to taking a task-oriented attitude, avoiding self-preoccupation, and using time management skills to focus on successful achievement.     

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.     

公务员正常高值血压的流行现状及危险因素分析

对吉林省516名公务员的血压及心血管疾病危险因素进行描述性分析,用二分类Logistic回归法筛选危险因素。公务员正常高值血压现患率为34．9％。正常高值血压人群体重指数、腰围、空腹血糖、总胆固醇、低密度脂蛋白胆固醇、甘油三酯、血清肌酐、血尿酸、心一踝血管指数水平以及代谢综合征患病率均高于正常血压组低于高血压组,高密度...