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111.
Investigations using invertebrate species have led to a considerable progress in our understanding of the mechanisms underlying learning and memory. In this review we describe the main behavioral and neuronal findings obtained by studying the habituation of the escape response to a visual danger stimulus in the crab Chasmagnathus granulatus. Massed training with brief intertrial intervals lead to a rapid reduction of the escape response that recovers after a short term. Conversely, few trials of spaced training renders a slower escape reduction that endures for many days. As predicted by Wagner’s associative theory of habituation, long-term habituation in the crab proved to be determined by an association between the contextual environment of the training and the unconditioned stimulus. By performing intracellular recordings in the brain of the intact animal at the same time it was learning, we identified a group of neurons that remarkably reflects the short- and long-term behavioral changes. Thus, the visual memory abilities of crabs, their relatively simple and accessible nervous system, and the recording stability that can be achieved with their neurons provide an opportunity for uncovering neurophysiological and molecular events that occur in identifiable neurons during learning.  相似文献   
112.
Disruptions to hypothalamic-pituitary-adrenal (HPA) axis function have been associated with varying forms of psychopathology in children. Studies suggesting children with ADHD have blunted HPA function have been complicated by the prevalence of comorbid diagnoses and heterogeneity of ADHD. The goals of this research were to assess the relations between waking and stress–response salivary cortisol levels and comorbid disruptive behavior (DBD) and anxiety (AnxD) disorders and problems in boys with ADHD, and to examine whether cortisol levels varied across ADHD subtypes. One hundred seventy elementary school-age boys with ADHD provided salivary cortisol at waking and in reaction to venipuncture. Parent reports were used to assess boys’ psychiatric diagnoses and severity of behavioral problems. Boys’ comorbid AnxD and anxiety problems were associated with greater cortisol reactivity, whereas boys’ comorbid DBD and oppositional problems predicted diminished adrenocortical activity. Reactive cortisol increases were greatest in boys with ADHD and comorbid AnxD, but without DBD. ADHD subtypes were not differentially associated with waking, pre-stress baseline, or reactive cortisol levels. However, comorbid DBD predicted decreased cortisol reactivity in boys with inattentive and hyperactive subtypes of ADHD, but not in boys with combined subtype of ADHD. The results clarify previous patterns of distinct and divergent dysregulations of HPA function associated with boys’ varying kinds of psychopathology.
Paul D. HastingsEmail:
  相似文献   
113.
This paper discusses two forms of separability of item and person parameters in the context of response time (RT) models. The first is separate sufficiency: the existence of sufficient statistics for the item (person) parameters that do not depend on the person (item) parameters. The second is ranking independence: the likelihood of the item (person) ranking with respect to RTs does not depend on the person (item) parameters. For each form a theorem stating sufficient conditions, is proved. The two forms of separability are shown to include several (special cases of) models from psychometric and biometric literature. Ranking independence imposes no restrictions on the general distribution form, but on its parametrization. An estimation procedure based upon ranks and pseudolikelihood theory is discussed, as well as the relation of ranking independence to the concept of double monotonicity.I am indebted to Wim van der Linden for bringing Thissen's (1983) paper to my notice, and to Martijn Berger, Frans Tan, and the anonymous reviewers for their constructive comments on earlier drafts of this paper.  相似文献   
114.
该研究对拓广等级展开模型(GGUM)进行了拓展,取消GGUM中关于主观反应类别阈限对称的假设,并将拓展之后的新模型和GGUM同时用于生活取向测验修订版(LOT-R)的被试反应数据分析,采用新编的单项目、两项目对和三项目组χ2/df计算程序计算和比较新模型和GGUM在该测验数据上的拟合差异。结果显示,新编程序与Stark等人开发的MODFIT程序具有同样的有效性,新模型在这些指标上的值显著小于GGUM,并且均小于3,表明新模型较GGUM更适合于分析LOT-R的反应数据,说明新模型更适用于分析具有多个评定等级的人格测验数据。根据以上结果,该研究认为,未来人格测验的数据分析应该使用没有对主观反应类别阈限进行对称限定的新拓展的模型更合理。  相似文献   
115.
Adaptive learning games should provide opportunities for the student to learn as well as motivate playing until goals have been reached. In this paper, we give a mathematically rigorous treatment of the problem in the framework of Bayesian decision theory. To quantify the opportunities for learning, we assume that the learning tasks that yield the most information about the current skills of the student, while being desirable for measurement in their own right, would also be among those that are efficient for learning. Indeed, optimization of the expected information gain appears to naturally avoid tasks that are exceedingly demanding or exceedingly easy as their results are predictable and thus uninformative. Still, tasks that are efficient for learning may be experienced as too challenging, and the resulting failures can lower motivation. Therefore, in addition to quantifying the expected informational benefit for learning of any prospective task to be presented next, we also model the expected motivational cost of its presentation, measured simply as the estimated probability of failure in our example model. We propose a “learner-friendly” adaptation algorithm that chooses the learning tasks by optimizing the expected benefit divided by the expected cost. We apply this algorithm to a Rasch-like student model implemented within a real-world application and present initial results of a pilot experiment.  相似文献   
116.
There is increasing focus on the neurophysiological underpinnings of brain activations, giving birth to an emerging branch of neuroscience – neuroenergetics. However, no common definition of “brain activation” exists thus far. In this article, we define brain activation as the information-driven reorganization of energy flows in a population of neuroglial units that leads to an overall increase in energy utilization in this population. On the basis of this definition, the key aspects of modern biochemical and biophysical approaches to neuroenergetics are considered from the perspective of the links between these approaches within the context of the free energy minimization principle and the neurophysiological conception of deviance detection. In this light, we consider brain basal activity as subserving internal representations of the environment (predictive coding), and brain activation as reflecting the level of deviance from predictive coding.  相似文献   
117.
Ellis的ABC理论和Schachter的情绪认知理论及试验说明,个体的认知信念影响情绪和行为反应.也就是说,患者对疾病事件的认知评价直接影响着情绪和行为表现.因此,在认知心理学相关理论指导下,医师对患者履行告知义务时必须遵循准确性原则、个性化原则及艺术性原则等,让患者对疾病事件有充分的知情与信息掌握,帮助患者改变观察问题的角度,正确认知与评价疾病事件,进而以积极、健康的情绪和行为表现来配合医务人员的诊治.  相似文献   
118.
本文首先分析了经典测验理论存在的局限,然后在潜在特质理论和项目特征曲线两大概念基础上阐述了项目反应理论及其基础模型的测量学原理,介绍了多个项目反应理论基础模型.最后简要介绍了七项当前应用项目反应理论指导大型题库建设和指导编制各种新型测验的热点内容.  相似文献   
119.
期望反应模式是认知诊断分类的类中心,确定了诊断范围中属性及其层级关系后,类中心的数目由测验Q矩阵决定.类中心应该是完备的,即理论上有多少个知识状态就应该有多少个类中心,这涉及评分方式、Q矩阵设计、Q矩阵评价与修改、认知诊断测验如何实施等问题的讨论.重点给出多级评分认知诊断测验不同属性层级对应的完备Q矩阵设计的例子和罗列了Wang等人(2013)的Q矩阵修改的方法.  相似文献   
120.

This article focuses on emergency medical care in black urban populations, suggesting that the classification of a “community” within clinical trial language is problematic. The article references a cultural history of black Americans with pre-hospital emergency medical treatment as relevant to contemporary emergency medicine paradigms. Part I explores a relationship between “autonomy” and “community.” The idea of community emerges as a displacement for the ethical principle of autonomy precisely at the moment that institutionalized medicine focuses on diversity. Part II examines a clinical trial for the blood substitute PolyHeme® (Northfield Laboratories, Inc., Evanston, IL). It illustrates the ways in which bias in research paradigms and Institutional Review Board decisions attach to the notion and utility of the language of “community.” The conclusion's contemporary anecdote makes apparent the vitality of the issues of prehospital emergency medical care and the ways in which decisions and practices fall too easily into a narrative of culturally biased treatment.  相似文献   
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