通道估计可靠性先验知识在早期的知觉加工阶段影响多感觉信息整合

统计最优化理论认为, 在多感觉信息整合的过程中, 大脑是以加权平均的方式将多个感觉通道的信息整合为统一的感觉信息, 通道信息的利用权重根据各通道信息的可靠性来确定。近期的几个行为研究结果则显示, 有关通道估计可靠性的先验知识同样能够影响通道信息在整合过程中的利用权重。然而, 这些研究结果不能确定先验知识对多感觉信息整合的影响是发生在认知加工的感知觉阶段还是决策阶段。当前研究致力于对此问题进行探讨。实验通过赋予两种颜色字母不同的视、听一致概率(高概率、低概率), 测量并分析被试在各概率水平下对视听一致刺激的反应时。实验数据显示不同的视听一致概率能够调制对视听一致刺激的反应时。该结果揭示通道估计可靠性先验知识在早期的知觉加工阶段影响多感觉信息整合。     

自闭症儿童能否痊愈?——来自谱系个体“最佳结果”及剩余缺陷研究的证据分析

自闭症谱系障碍预后效果不佳, 通常被认为是一种伴随终生的疾病。不过随着研究的拓展和深入, 部分早期被诊断为自闭症的儿童, 随着年龄增长和相关干预措施的介入, 其认知、适应性等方面均可达到正常发展水平, 并且不再符合自闭症的诊断标准, 即达到了“最佳结果”。但多数个体仍然存在不同程度的剩余缺陷。本文以自闭症预后结果评定和“最佳结果”定义演变为切入点, 分析“最佳结果”个体剩余缺陷的具体表现, 并梳理此类群体的个体特征与结果预测因素, 以期能为自闭症个体的系统干预提供有效依据。     

Fractal dynamics of heart beat interval fluctuations in corticotropin-releasing factor receptor subtype 2 deficient mice

Non-linear fractal analysis of cardiac interbeat time series was performed in corticotropin-releasing factor receptor subtype 2 (CRFR2) deficient mice. Heart rate dynamics in mice constitutes a self-similar, scale-invariant, random fractal process with persistent intrinsic long-range correlations and inverse power-law properties. We hypothesized that the sustained tachycardic response elicited by intraperitoneal (ip) injection of human/rat CRF (h/rCRF) is mediated by CRFR2. In wildtype control animals, heart rate was increased to about maximum levels (~ 750 bpm) while in CRFR2-deficient animals baseline values were retained (~ 580 bpm). The tachycardic response elicited by ip-application is mediated by CRFR2 and is interpreted to result from sympathetic stimulation. However, the functional integrity of CRFR2 would not present a prerequisite to maintaining the responsiveness and resiliency of cardiac control to external environmental perturbations experimentally induced by extrinsic ip-application of h/rCRF or under physiological conditions that may be associated with an increased peripheral release of CRF. Under stressful physiological conditions achieved by novelty exposure, CRFR2 is not involved in the cardiodynamic regulation to external short-term stress. While the hypothesis of involvement of CRFR2 in cardiac regulation upon pharmacological stimulation cannot be rejected, the present findings suggest that the mechanism of action is by sympathetic stimulation, but would not unambiguously allow to draw any conclusions as to the physiological role of CRFR2 in the control of cardiac dynamics.     

Prediction and classification in nonlinear data analysis: Something old,something new,something borrowed,something blue

Prediction and classification are two very active areas in modern data analysis. In this paper, prediction with nonlinear optimal scaling transformations of the variables is reviewed, and extended to the use of multiple additive components, much in the spirit of statistical learning techniques that are currently popular, among other areas, in data mining. Also, a classification/clustering method is described that is particularly suitable for analyzing attribute-value data from systems biology (genomics, proteomics, and metabolomics), and which is able to detect groups of objects that have similar values on small subsets of the attributes.This article is based on the Presidential Address Jacqueline Meulman gave on July 9, 2003 at the 68th Annual Meeting of the Psychometric Society held near Cagliari, Italy on the island of Sardinia.—Editor     

Several programming models with unascertained parameters and their applications

Several programming models are introduced with the consideration of available unascertained information. In this case, the so‐called unascertained information is some numerical values whose ranges are known but their exact values are not. These models resolve several vital weaknesses of the traditional programming methods to a certain degree. Our study includes considerations of linear and non‐linear programming models with grey parameters, grey 0–1 programming, and satisfactory and quasi‐optimal solutions of grey linear programmings. Finally, some practical applications are given in order to test the applicability of our theory. Copyright © 1999 John Wiley & Sons, Ltd.     

Optimal trade-offs of multiple factors in transfer pricing problems

Transfer pricing problems have been extensively researched by a number of scholars. It is well recognized that transfer pricing problems have a multiple-criteria (objectives) feature and can be formulated as a model of multiple-criteria linear programming. However, few methods have the capability of dealing with all possible optimal trade-offs of multiple criteria in optimal solutions of the models. In this paper a linear multiple-factor model is developed to provide managers with a more systematic and comprehensive scenario of all possible optimal transfer prices depending on both multiple criteria and multiple constraint levels. The trade-offs of all possible optimal transfer prices can be used as a basis for managers of a corporation to make a high-quality decision in selecting their transfer pricing systems for business competition. © 1998 John Wiley & Sons, Ltd.