Binary Choice Reaction Time as a Function of the Relationship between Durations and Forms of Responses

In a choice between responding with the left or right hand, some kinds of differences between the movements increase RT (Reaction Time) while others do not. Of the first kind are differences in form, while differences in the finger used are of the latter kind. In previous experiments differences in form were confounded with differences in duration. Since there is some indication that a difference in duration is sufficient to lengthen RT, both characteristics were varied separately. It turned out that a difference in form (duration being constant) has essentially the same effects as a difference in duration (form being constant): Mean RT is longer, variability of RT and MT (movement time) is larger, and frequency of choice errors is smaller than in choice between identical movements. These effects, which seem to be associated with choice between movements of different temporal patterns, are interpreted in terms of advance specification of movement parameters. Additional results on the relationship between response duration and RT suggest that RT does not depend on duration (or velocity) per se, but on how much the duration deviates from quickest performance.     

Constraint Respecters, Constraint Challengers, and Crisis Decision Making in Democracies: A Case Study Analysis of Kennedy versus Reagan

Models linking domestic political constraints (audience costs, pressures for the diversionary use of force, democratic norms and institutions) to foreign policy behavior generally assume that leaders simply recognize and submit to constraints in their domestic environments—a strong structural argument. In contrast, research on political leadership and decision making suggests that leaders vary systematically in their orientations toward constraints: "constraint respecters" tend to internalize potential constraints, while "constraint challengers" are more likely to view them as obstacles to be overcome. This article develops an integrative theoretical framework that explicitly incorporates these insights and applies them to the domain of crisis decision making. After identifying leaders' expected orientations toward constraints via at-a-distance methods, the plausibility of hypotheses derived from this framework is examined through case studies that explore the decision-making processes employed by President Kennedy (a "constraint respecter") and President Reagan (a "constraint challenger") during international crises. The results suggest that there is important variation in how leaders perceive and respond to domestic constraints, and that leadership style is one—though not the only—important source of this variation.     

Deductive databases for computing certain and consistent answers from mediated data integration systems

We address the problem of retrieving certain and consistent answers to queries posed to a mediated data integration system under the local-as-view paradigm with open sources and conjunctive and disjunctive view definitions. For obtaining certain answers a query program is run under the cautious stable model semantics on top of a normal deductive database with choice operator that specifies the class of minimal legal instances of the integration system. This methodology works for all monotone Datalog queries. To compute answers to queries that are consistent with respect to given global integrity constraints, the specification of minimal legal instances is combined with another disjunctive deductive database that specifies the repairs of those legal instances. This allows to retrieve the answers to any Datalog^¬ query that are consistent with respect to global universal and referential integrity constraints.     

Non-Compliance Shouldn't Be Better

Agent-relative consequentialism is thought attractive because it can secure agent-centred constraints while retaining consequentialism's compelling idea—the idea that it is always permissible to bring about the best available outcome. We argue, however, that the commitments of agent-relative consequentialism lead it to run afoul of a plausibility requirement on moral theories. A moral theory must not be such that, in any possible circumstance, were every agent to act impermissibly, each would have more reason (by the lights of the very same theory) to prefer the world thereby actualized over the world that would have been actualized if every agent had instead acted permissibly.     

Regularized Partial and/or Constrained Redundancy Analysis

Methods of incorporating a ridge type of regularization into partial redundancy analysis (PRA), constrained redundancy analysis (CRA), and partial and constrained redundancy analysis (PCRA) were discussed. The usefulness of ridge estimation in reducing mean square error (MSE) has been recognized in multiple regression analysis for some time, especially when predictor variables are nearly collinear, and the ordinary least squares estimator is poorly determined. The ridge estimation method was extended to PRA, CRA, and PCRA, where the reduced rank ridge estimates of regression coefficients were obtained by minimizing the ridge least squares criterion. It was shown that in all cases they could be obtained in closed form for a fixed value of ridge parameter. An optimal value of the ridge parameter is found by G-fold cross validation. Illustrative examples were given to demonstrate the usefulness of the method in practical data analysis situations. We thank Jim Ramsay for his insightful comments on an earlier draft of this paper. The work reported in this paper is supported by Grants 10630 from the Natural Sciences and Engineering Research Council of Canada to the first author.     

Perception—Action Coupling during Bimanual Coordination: The Role of Visual Perception in the Coalition of Constraints That Govern Bimanual Action

Constraints pertaining to interlimb coordination have been studied extensively in the past decades. In this debate, F. Mechsner (2004) has taken a provocative position by putting primary emphasis on perceptual principles that mediate coordinative stability. Whereas the present authors agree that the role of perceptual principles is of critical importance during coordination, they take issue with Mechsner's extreme position and with the evidence forwarded to support a purely perceptual-cognitive approach to bimanual coordination. More specifically, the authors emphasize that current knowledge about brain function argues against a dualism between perception and action, criticize the presented evidence that posture manipulations during coordination provide decisive evidence against motoric and muscular constraints, and report on potential pitfalls associated with the use of visual transformation procedures to support complex coordination patterns.     

Effects of decision-phase time constraints on emotion-based learning in the Iowa Gambling Task

Research employing the Iowa Gambling Task (IGT) has frequently shown that learning is impaired in various clinical populations. However, precisely what constitutes "unimpaired" control group learning remains unclear. In order to understand some of the possible factors underlying variability in control group IGT performance, the present study sought to manipulate features of the task to intentionally disrupt learning. Specifically, the present study investigated the effects of time constraints on emotion-based learning during automated administration of the IGT. For two groups of participants, a time-constraint of either 2-s or 4-s was implemented during the critical decision making period, while a control group received no time constraint. We also evaluated participants' subjective experience after every block of 20 trials. Results demonstrated that the 2-s group differed significantly from the control group. Subjective experience measures revealed rapid development of awareness of the advantageous and disadvantageous decks among all three groups. Overall, our findings demonstrate, for the first time, the effects of decision-phase time constraints on emotion-based learning and indicate that the IGT reward/punishment schedules are to some extent cognitively penetrable.     

预测视角下双因子模型与高阶因子模型的一般性模拟比较

高阶因子模型本质上是一种特殊的双因子模型, 应用中却常被当做双因子模型的竞争模型。已有研究以满足比例约束的双因子模型(此时等价于一个高阶因子模型)为真实测量模型产生模拟数据, 比较了用双因子模型和高阶因子模型作为测量模型的预测效果。本文使用不满足比例约束的双因子模型(此时不与任何高阶因子模型等价)为真实测量模型产生模拟数据进行比较, 所得结果与满足比例约束的双因子模型的结果有很大差别, 双因子模型结构系数的相对偏差较小、检验力较高, 但第Ⅰ类错误率略高。结论是, 在比例约束条件成立时可以使用高阶因子模型, 否则, 从统计角度看, 一般情况下使用双因子模型进行预测比较好。     

Parameterizing inequality constraints on unique variances in linear structural models

Current computer programs for analyzing linear structural models will apparently handle only two types of constraints: fixed parameters, and equality of parameters. An important constraint not handled is inequality; this is particularly crucial for preventing negative variance estimates. In this paper, a method is described for imposing several kinds of inequality constraints in models, without the necessity for having computer programs which explicitly allow such constraints. The examples discussed include the prevention of Heywood cases, extension to inequalities of parameters to be greater than a specified value, and imposing ordered inequalities. Work on this project was aided by the City University of New York—Professional Staff Congress Research Award Program Grant Number 13631.