The utility of the A1 and A2 criteria in the diagnosis of PTSD

In the field of posttraumatic stress disorder (PTSD), the revisions to the DSM-IV definition of a potentially traumatic event are contentious. Proponents praise the subjective emphasis, while others contend that the changes to the criterion broadened the conceptualization of PTSD. This study examined the predictive utility of Criterion A events, examining the stressor (A1) and subjective emotional response (A2) components of the definition of a traumatic event. Rates of Criterion A events and PTSD were calculated for three diverse samples, and predictive power, sensitivity, specificity, and ROC curves were computed to determine the predictive utility of Criterion A requirements for PTSD symptom, duration, and functional impairment diagnostic criteria. Across all samples, the current Criterion A requirements did not predict much better than chance. Specifically, A2 reports added little to the predictive ability of an A1 stressor, though the absence of A2 predicted the absence of PTSD-related symptoms, their duration, and impairment. Notably, the combination of three A1 and A2 criteria showed the best prediction. Confronted events also showed less predictive ability than experienced events, with more variable performance across samples. These results raise fundamental questions about the threshold or "gate" that Criterion A ought to play in our current nosology.     

Bayes factors: Prior sensitivity and model generalizability

Model selection is a central issue in mathematical psychology. One useful criterion for model selection is generalizability; that is, the chosen model should yield the best predictions for future data. Some researchers in psychology have proposed that the Bayes factor can be used for assessing model generalizability. An alternative method, known as the generalization criterion, has also been proposed for the same purpose. We argue that these two methods address different levels of model generalizability (local and global), and will often produce divergent conclusions. We illustrate this divergence by applying the Bayes factor and the generalization criterion to a comparison of retention functions. The application of alternative model selection criteria will also be demonstrated within the framework of model generalizability.     

药品临床试验的伦理规范与医学科技进步--对非洲等地开展HIV药品临床试验的思考

目前,在非洲等地进行的HIV药品临床试验已成为国际上最有争议的话题之一.药品临床试验促进了医学科技的进步和发展,但同时带来了一些突出而复杂的伦理问题.面对这一难题,我们应正确看待医学科技进步与伦理之间的关系,以"尊重、公正、不伤害、受益"这一伦理基本原则指导HIV药品临床试验,促进医学和伦理道德的共同进步、协调发展.     

一个新的测量过程框架——对引入认知加工模型的再思考

从认知任务分析出发的测验设计,核心在于从认知加工的角度对项目底层作答机制作出解释。其中,能够刻画任务难度的模型最有可能与心理计量模型相结合。因而,具备成熟难度法则的各种小型理论或通用理论可以进入测量过程,实现从纯粹误差结构控制的测量到内容导引的测量的转变。在这样一个框架之下,理论对任务上作答过程的理解是否恰当,刺激特性变量与任务难度关系的揭示(即难度法则)是否准确,可以在测量的过程中进行证伪。项目反应理论还未及很好回答的效度问题,可望在这一拓展的框架中获得圆满解决。本文为新的测量过程框架提供了一个示意图。     

Subsumption and Relative Identity

This paper is a modification of Nicola Guarino and Christopher Welty's conception of the subsumption relation. Guarino and Welty require that that whether one property may subsume the other should depend on the modal metaproperties of those properties. I argue that the part of their account that concerns the metaproperty carrying a criterion of identity is essentially flawed. Subsequently, I propose to constrain the subsumption relation not, as Guarino and Welty require, by means of incompatible criteria of absolute identity but by means of incompatible criteria of relative identity. After discussing the benefits of applying relative identity in ontological investigations I provide a formal framework in which to prove a counterpart of the identity criteria constraint.This revised version was published online in October 2005 with corrections to the Cover Date.     

中国情境下家长式领导与员工绩效关系的元分析

本研究采用元分析技术和效标剖面元分析技术探讨中国情境下家长式领导与员工绩效之间的关系。通过文献收集与筛选, 共纳入139项研究400个效应值(N = 44605)。元分析结果发现：(1)仁慈领导、德行领导与任务绩效和组织公民绩效有较强的正相关关系, 与反生产绩效有较强的负相关关系。与之相反, 威权领导与任务绩效和组织公民绩效之间有显著的负相关关系, 与反生产绩效显著正相关。(2)低威权领导剖面(仁慈领导和德行领导水平高)对任务绩效和组织公民绩效的预测力最强, 高威权领导剖面(仁慈领导和德行领导水平低)对反生产绩效的预测力最强。(3)年龄能够调节家长式领导部分维度和绩效之间的关系强度, 性别对家长式领导分维度和绩效关系的调节效应不显著。研究结果进一步揭示了中国情境下家长式领导与个体绩效之间关系的“真相”。     

Cross-task and cross-manipulation stability in shifting the decision criterion

In recognition memory experiments participants must discriminate between old and new items, a judgment influenced by response bias. Research has shown substantial individual differences in the extent to which people will strategically adjust their response bias to diagnostic cues such as the prior probability of an old item. Despite this significant between subject variability, shifts in bias have been found to be relatively predictive within individuals across memory tests. Experiment 1 sought to determine whether this predictability extends beyond memory. Results revealed that the amount a subject shifted response bias in a recognition memory task was significantly predictive of shifting in a visual perception task, suggesting that shifting can generalise outside of a specific testing domain. Experiment 2 sought to determine how predictive shifting would be across two manipulations well known to induce shifts in bias: a probability manipulation and a response payoff manipulation. A modest positive relationship between these two methods was observed, suggesting that shifting behaviour is relatively predictive across different manipulations of shifting. Overall, results from both experiments suggest that response bias shifting, like response bias setting, is a relatively stable behaviour within individuals despite changes in test domain and test manipulation.     

The decision tree polytope and its application to sequential decision problems

This paper describes a new mathematical programming approach to sequential decision problems that have an underlying decision tree structure. The approach, based upon a characterization of strategies as extreme points of a 0–1 polytope called the ‘decision tree polytope’, is particularly suited to the direct examination of risk-return and other tradeoffs amongst strategies. However, it can also be used for conventional utility maximization if a utility function is available. Further, the approach requires no algorithmic development—it can be implemented using commercially available algebraic modeling software and can solve large problems. A related, and already known, approach can be used for some more general Markov decision problems. © 1998 John Wiley & Sons, Ltd.     

Insight in frontotemporal dementia: conceptual analysis and empirical evaluation of the consensus criterion "loss of insight" in frontotemporal dementia

The objective of this study was to suggest a new formulation of the core research diagnostic consensus criterion "loss of insight" in frontotemporal dementia (FTD). Eight patients with FTD (diagnoses made by interviews, medical and neuropsychological examination, CT scan, and regional cerebral glucose metabolism measured by positron emission tomography (PET) participated in the study). The results indicated that insight was present in three out of eight patients, and that insight appears to be a heterogeneous concept. Two types of insight emerged: Emotional insight associated with frontotemporal functions, and cognitive insight, related to posterior cognitive functions. These results suggest that loss of insight should not serve as a core criterion on FTD, but serves well as a supportive criterion of the disease.     

A Stimulus-Oriented Approach to Memory

ABSTRACT— Our understanding of short-term recognition memory can be enhanced by careful choice and control of test materials. Theory-driven manipulation of memory test stimuli, including visual textures, human faces, and complex sounds, minimize individual differences and make it possible to predict recognition performance for specific combinations of stimulus items. This stimulus-oriented approach to memory reveals that stimulus similarity plays two different important roles in recognition memory. By exploiting tools used in psychophysics, it is possible to generate mnemometric functions—detailed "snapshots" that capture key features of subjects' memory strength.