Religious Coping and Heart Transplantation: From Threat to Health

Previous research has established the existence of homogeneous religious coping profiles in cardiac-transplantation candidates labeled as the deferring/collaborators, self-directors, and the eclectic religious copers. However, their prospective impact on outcome has not yet been established. This paper examines potential differences between pre-cardiac transplantation religious coping cluster groups on post-cardiac transplantation quality of life (physical functioning, mental health, and general health). Results indicated that the religious coping profiles of deferring/collaborators and self-directors had significantly better scores on mental health and general health than did the eclectics. Implications for religious-coping research and clinical practice are discussed.     

Comparing Locomotion With Lever-press Travel In An Operant Simulation Of Foraging

An operant model of foraging was studied. Rats searched for food by pressing on the left lever, the patch, which provided one, two, or eight reinforcers before extinction (i.e., zero reinforcers). Obtaining each reinforcer lowered the probability of receiving another reinforcer, simulating patch depletion. Rats traveled to another patch by pressing the right lever, which restored reinforcer availability to the left lever. Travel requirement changed by varying the probability of reset for presses on the right lever; in one condition, additional locomotion was required. That is, rats ran 260 cm from the left to the right lever, made one response on the right lever, and ran back to a fresh patch on the left lever. Another condition added three hurdles to the 260-cm path. The lever-pressing and simple locomotion conditions generated equivalent travel times. Adding the hurdles produced longer times in patches than did the lever-pressing and simple locomotion requirements. The results contradict some models of optimal foraging but are in keeping with McNair's (1982) optimal giving-up time model and add to the growing body of evidence that different environments may produce different foraging strategies.     

MEMORY PROCESSES IN DELAYED SPATIAL DISCRIMINATIONS: RESPONSE INTENTIONS OR RESPONSE MEDIATION?

Pigeons were trained on a pair-comparison task in which left versus right choices were reinforced following different sequences of two center-key stimuli. Choice accuracy was higher when retention intervals occurred after the entire sequence than when they separated the two stimuli comprising it, and this effect occurred independently of whether the initial and terminal stimuli came from the same or different dimensions. The initial stimulus from the prior trial was a source of proactive interference only in groups for which the retention interval separated the two sequence stimuli. By contrast, differential delay-interval behavior was observed only in groups for which the retention interval followed presentation of the entire sequence. These results indicate that coding processes in delayed discriminations are influenced by the location of the retention interval, and that response mediation affects retention performances if the reinforced choice can be determined prior to the interval.     

Stochastic ordering using the latent trait and the sum score in polytomous IRT models

In a restricted class of item response theory (IRT) models for polytomous items the unweighted total score has monotone likelihood ratio (MLR) in the latent trait. MLR implies two stochastic ordering (SO) properties, denoted SOM and SOL, which are both weaker than MLR, but very useful for measurement with IRT models. Therefore, these SO properties are investigated for a broader class of IRT models for which the MLR property does not hold.In this study, first a taxonomy is given for nonparametric and parametric models for polytomous items based on the hierarchical relationship between the models. Next, it is investigated which models have the MLR property and which have the SO properties. It is shown that all models in the taxonomy possess the SOM property. However, counterexamples illustrate that many models do not, in general, possess the even more useful SOL property.Hemker's research was supported by the Netherlands Research Council, Grant 575-67-034. Junker's research was supported in part by the National Institutes of Health, Grant CA54852, and by the National Science Foundation, Grant DMS-94.04438.     

追踪作业中几种心理负荷评估指标敏感性的研究

本研究在模拟追踪作业情境下 ,对主任务绩效测定、主观评定和若干生理测量在心理负荷评估中的敏感性进行了实验。实验采用重复测量的被试者内设计 ,2 0名被试 (男女各半 )在六档负荷下分别从事五分钟追踪作业。所选用的指标有追踪作业平均误差距离、追踪警告次数、主观负荷评定、心率、心率变异和血压。结果发现 :1主任务绩效在评估追踪作业心理负荷中具有最高的敏感性 ,主观评定次之 ,心率变化率和心率变异变化率也随负荷变化 ,血压指标随负荷变化的趋势不明显 ;2除血压指标外 ,其余各指标之间均存在明显的相关 ,这提示它们在评估追踪作业心理负荷中具有较大的可靠性。