An empirical comparison between some models for multidimensional scaling

Abstract.— The results of three methods for multidimensional scaling—Torgerson's metric analysis, a non-metric method (TORSCA), and a method dealing with individual differences in multidimensional scaling (INDSCAL)—were compared in experiments on rhythm experience and on perception of sound quality. The INDSCAL analysis seemed to be the most adequate method for treating the data in these experiments.     

On some connections between logic and category theory

Categories may be viewed as deductive systems or as algebraic theories. We are primarily interested in the interplay between these two views and trace it through a number of structured categories and their internal languages, bearing in mind their relevance to the foundations of mathematics. We see this as a common thread running through the six contributions to this issue of Studia Logica.     

On the size of refutation Kripke models for some linear modal and tense logics

LetL be any modal or tense logic with the finite model property. For eachm, definer _L (m) to be the smallest numberr such that for any formulaA withm modal operators,A is provable inL if and only ifA is valid in everyL-model with at mostr worlds. Thus, the functionr _L determines the size of refutation Kripke models forL. In this paper, we will give an estimation ofr _L (m) for some linear modal and tense logicsL.     

On the relationship between negative affective priming and prefrontal cognitive control mechanisms

Although several studies have examined inhibition of affective stimuli, valence-dependent cognitive control effects remain poorly understood. Behavioural and functional imaging (functional magnetic resonance imaging) data were collected from 17 healthy participants to examine neural correlates of the Negative Affective Priming (NAP) task. We created relative ratio scores considering the reaction times of prime trials in order to assess the amount of interference after the presentation of negative and positive distracter words. Behavioural results showed an attenuated NAP effect for negative distracters compared to neutral stimuli. Furthermore, priming negative distracters generated more interference by reacting to the probe target than positive distracters. Neuroimaging data revealed a stronger prefrontal activation during negative NAP trials compared to positive NAP and neutral control trials, which was reflected in a heightened activation of superior and middle frontal gyrus as well as parietal cortex. The findings show the impact of negative distracters on prefrontal response, contributing to the understanding of NAP effects in healthy subjects.     

On choosing between deterministic and indeterministic models: underdetermination and indirect evidence

There are results which show that measure-theoretic deterministic models and stochastic models are observationally equivalent. Thus there is a choice between a deterministic and an indeterministic model and the question arises: Which model is preferable relative to evidence? If the evidence equally supports both models, there is underdetermination. This paper first distinguishes between different kinds of choice and clarifies the possible resulting types of underdetermination. Then a new answer is presented: the focus is on the choice between a Newtonian deterministic model supported by indirect evidence from other Newtonian models which invoke similar additional assumptions about the physical systems and a stochastic model that is not supported by indirect evidence. It is argued that the deterministic model is preferable. The argument against underdetermination is then generalised to a broader class of cases. Finally, the paper criticises the extant philosophical answers in relation to the preferable model. Winnie’s (1998) argument for the deterministic model is shown to deliver the correct conclusion relative to observations which are possible in principle and where there are no limits, in principle, on observational accuracy (the type of choice Winnie was concerned with). However, in practice the argument fails. A further point made is that Hoefer’s (2008) argument for the deterministic model is untenable.     

The asymptotic standard errors of some estimates of uncertainty in the two-way contingency table

Estimates of conditional uncertainty, contingent uncertainty, and normed modifications of contingent uncertainty have been proposed for the two-way contingency table. The asymptotic standard errors of the estimates are derived.This research was supported by NIH Special Research Resources Grant RR-3.     

Relations between mechanisms of CNS arousal and mechanisms of stress

In the centennial year of the birth of Hans Selye, this review compares his classical concepts of stress with a modern approach to mechanisms of CNS arousal. Relations between the two concepts are described. Neuroanatomical, neurophysiological, and functional genomic mechanisms underlying CNS arousal are briefly reviewed. Controls over stress responses and arousal are compared to particular concepts of control system engineering. Understanding these two systems is of crucial importance because their dysregulation is associated with large numbers of disease states.     

On the equivalence between elimination-by-aspects and generalised extreme value models of choice behaviour

Elimination-by-aspects and generalised extreme value offer competing paradigms for the representation of a common behaviour, that of individual discrete choice. Observing certain consistencies in their mathematical structure, several eminent authors have commented on the degree of equivalence between the two paradigms. Most contributions to this debate have, however, been less than definitive. More fundamentally, the contributions lack consensus. We advance the debate by establishing formal mathematical conditions under which three-alternative tree models from the two paradigms are exactly equivalent. We then extend our analysis to consider more general models, showing that equivalence can be established for general tree models, but not for cross-nested models.     

Family factors and adolescent substance use: models and mechanisms

This article considers the relation of family factors to adolescent substance use, with a focus on the specific pathways by which family factors have their effects. We review findings on four types of variables (family substance use, parental support and monitoring, parent-child conflict, and family life events) and discuss theoretical models of how family risk and protective factors are related to adolescents' outcomes. The evidence favors a transactional model in which family factors have largely mediated effects on adolescent substance use through relations to adolescents' self-control, life events, and peer affiliations; interactions between variables are also prominent. We discuss the implications of mediated effects for theoretical models of human development and consider how the transactional approach opens avenues for preventive intervention.     

On the relations between random walk models for two-choice response times

We state a condition on the moment-generating functions of the random walk model derived by Link and Heath (1975), which is necessary and sufficient to yield the sequential probability ratio test of Wald (1947) and the reaction-time model proposed by Stone (1960). A restricted form of this condition can also be obtained by imposing the types of symmetries on the moment-generating functions considered by Link and Health (1975) and Thomas (1975). The various conditions are contrasted and their implications for empirical investigation are discussed.     

条件化恐惧复发的动物模型及相关神经机制

创伤后应激障碍(PTSD)受到国内外普遍关注, 临床上常用的暴露疗法就是基于消退原理, 但经过治疗的患者复发率仍然很高, 这提示抑制复发可能是治疗创伤后应激障碍的关键问题。条件性恐惧复发的动物模型主要包括重建、续新和自发恢复, 但是对续新的研究最多。前人的研究结果表明, 恐惧复发具有异质性, 但海马、前额叶与杏仁核三大脑区或许构成了共同的神经基础。文章从脑区机制及药理干预方面进行了综述, 以期对基础研究和临床诊治提供参考。     

An efficient one- and two-way avoidance apparatus capable of producing identical one- and two-way avoidance performance

A platformed one- and two-way avoidance apparatus is described in which the need for handling the subjects in the one-way task is eliminated and the two-way task is very quickly learned. The acquisition curves obtained for these two tasks are indistinguishable.     

MCMC estimation and some model-fit analysis of multidimensional IRT models

A Bayesian procedure to estimate the three-parameter normal ogive model and a generalization of the procedure to a model with multidimensional ability parameters are presented. The procedure is a generalization of a procedure by Albert (1992) for estimating the two-parameter normal ogive model. The procedure supports analyzing data from multiple populations and incomplete designs. It is shown that restrictions can be imposed on the factor matrix for testing specific hypotheses about the ability structure. The technique is illustrated using simulated and real data. The authors would like to thank Norman Verhelst for his valuable comments and ACT, CITO group and SweSAT for the use of their data.