Tests for linear trend in the smallest eigenvalues of the correlation matrix

A test for linear trend among a set of eigenvalues of a correlation matrix is developed. As a technical implementation of Cattell's scree test, this is a generalization of Anderson's test for the equality of eigenvalues, and extends Bentler and Yuan's work on linear trends in eigenvalues of a covariance matrix. The power of minimumx ² and maximum likelihood ratio tests are compared. Examples show that the linear trend hypothesis is more realistic than the standard hypothesis of equality of eigenvalues, and that the hypothesis is compatible with standard decisions on the number of factors or components to retain in data analysis.This work was supported by National Institute on Drug Abuse Grants DA01070 and DA00017. The assistance of Maia Berkane and several anonymous reviewers is gratefully acknowledged.     

An invariant relation between changing over and reinforcement

Although concurrent schedules may arrange reinforcers irregularly, relatively large numbers of reinforcers are obtained when an animal changes from one schedule to the other. This paper proposes a quantitative relation that predicts the proportion of reinforcers obtained when an animal is working on a schedule and the proportion when the animal changes over to a schedule. Basically the relation states that the number of reinforcers obtained while an animal works on a schedule varies directly with the relative amount of time spent working on that schedule; and the number of reinforcers obtained when an animal changes to a schedule varies directly with the relative amount of time spent on the alternate schedule. An important aspect of this relation is that when relative reinforcement rates are less than .50, more reinforcers are obtained just after an animal changes to a schedule than at all other times when this schedule is engaged. Data obtained both from a stat-bird and a live pigeon were in close agreement with the quantitative predictions. The relation between changing over and reinforcement held across several procedural changes that included changes in relative reinforcement rate, changes from independent to interdependent scheduling procedures, and changes in the variable-interval reinforcement distributions. The results are discussed in terms of the effects of the local distribution of reinforcement on responding. The local reinforcement distribution can affect local response rates and affects the resulting matching relation. This arrangement has implications for explanations of choice.     

智慧的特质论与状态论：分歧、统整与新解

特质论与状态论之争是智慧研究领域新兴的热门话题。特质论认为智慧是稳定且不易干预的人格特质;状态论认为智慧是一种相对容易波动的心智状态,短期内可以改变且容易受外在情境的影响。基于人格心理学研究的“密度分布说”则为特质论与状态论之争提供了系统的整合模型。受此启发,本研究在以往理论的基础上提出“特质-状态正态分布假说”,旨在进一步补充完善“密度分布说”并为特质论与状态论研究提供新的理论视角。未来研究仍需结合多种智慧测量手段,加强纵向追踪研究,探索智慧本质观与密度分布说的关系,开展相应的跨文化研究。     

Maximum likelihood estimation of latent interaction effects with the LMS method

In the context of structural equation modeling, a general interaction model with multiple latent interaction effects is introduced. A stochastic analysis represents the nonnormal distribution of the joint indicator vector as a finite mixture of normal distributions. The Latent Moderated Structural Equations (LMS) approach is a new method developed for the analysis of the general interaction model that utilizes the mixture distribution and provides a ML estimation of model parameters by adapting the EM algorithm. The finite sample properties and the robustness of LMS are discussed. Finally, the applicability of the new method is illustrated by an empirical example. This research has been supported by a grant from the Deutsche Forschungsgemeinschaft, Germany, No. Mo 474/1 and Mo 474/2. The data for the empirical example have been provided by Andreas Thiele of the University of Frankfurt, Germany. The authors are indebted to an associate editor and to three anonymous reviewers ofPsychometrika whose comments and suggestions have been very helpful.     

Distribution of Traumatic and Other Stressful Life Events by Race/Ethnicity, Gender, SES and Age: A Review of the Research

Much research has shown that reports of stressful life events are related to a wide variety of psychiatric and physical health outcomes. Relatively little research exists, however, on the distribution of the events according to gender, age, racial/ethnic background, and socioeconomic status (SES). Such information would help identify groups at greatest risk for further investigation. This paper presents a review of the relevant studies. We find that traumatic (e.g., life threatening) events appear to be more frequent for men, while men and women differ more consistently on types rather than on overall numbers of stressful events other than traumatic. Traumatic and other stressful events tend to be more frequent in low SES and racial/ethnic minorities groups, and finally, both traumatic and other stressful events are reported more by younger age groups in samples 18 years of age and older. The limitations and implications of these findings for further research and preventive interventions are discussed, especially the need for more detailed information about individual events.     

Infant illness severity and family adjustment in the aftermath of NICU hospitalization

Up to 15% of parents have an infant who will spend time in a neonatal intensive care unit (NICU). After discharge, parents may care for a medically fragile infant and worry about their development. The current study examined how infant illness severity is associated with family adjustment. Participants included parents with infants who had been discharged from the NICU 6 months to 3 years prior to study participation (N = 199). Via a Qualtrics online survey, parents reported their infants’ medical history, parenting stress, family burden, couple functioning, and access to resources. Multivariable regression analyses revealed that more severe infant medical issues during hospitalization (e.g., longer length of stay and more medical devices) were associated with greater family burden, but not stress or couple functioning. Infant health issues following hospitalization (i.e., medical diagnosis and more medical specialists) were associated with greater stress, poorer couple functioning, and greater family burden. Less time for parents was associated with increased stress and poorer couple functioning. Surprisingly, parents of infants who were rehospitalized reported less stress and better couple functioning, but greater family burden. Family-focused interventions that incorporate psychoeducation about provider−patient communication, partner support, and self-care may be effective to prevent negative psychosocial sequelae among families.     

Specific effects of acute moderate exercise on cognitive control

The main issue of this study was to determine whether cognitive control is affected by acute moderate exercise. Twelve participants [4 females (VO_{2 max} = 42 ml/kg/min) and 8 males (VO_{2 max} = 48 ml/kg/min)] performed a Simon task while cycling at a carefully controlled workload intensity corresponding to their individual ventilatory threshold. The distribution-analytical technique and the delta plot analysis [Ridderinkhof, K. R. (2002). Activation and suppression in conflict tasks: Empirical clarification through distributional analyses. In W. Prinz & B. Hommel (Eds.), Common mechanisms in perception and action. Attention and performance (Vol. 19, pp. 494–519). Oxford: Oxford University Press.] were used to assess the role of selective response inhibition in resolving response conflict. Results showed that cognitive processes appeared to be differently affected by acute moderate exercise. Reaction time results confirmed that performance is better (faster without change in accuracy) when the cognitive task is performed simultaneously with exercise. Between-trial adjustments (post-conflict and post-error) highlighted that cognitive control adjustments are also fully efficient during exercise. However, the effect of congruency (Simon effect) appeared to be more pronounced during exercise compared to rest which suggests that the response inhibition is deteriorated during exercise. The present findings suggest that acute moderate exercise differently affects some specific aspects of cognitive functions.     

Withholding Hydration and Nutrition in Newborns

In the twenty-first century, decisions to withhold or withdraw life-supporting measures commonly precede death in the neonatal intensive care unit without major ethical controversy. However, caregivers often feel much greater turmoil with regard to stopping medical hydration and nutrition than they do when considering discontinuation of mechanical ventilation or circulatory support. Nevertheless, forgoing medical fluids and food represents a morally acceptable option as part of a carefully developed palliative care plan considering the infant’s prognosis and the burdens of continued treatment. Decisions to stop any form of life support should focus on the clinical circumstances, not the means used to sustain life.     

社会距离与分配差距对儿童有利不公平厌恶的影响

选取60名8-10岁儿童,采用迫选式独裁者游戏,考察个体与博弈对象的社会距离以及分配差距对儿童有利不公平厌恶的影响。结果发现：（1）在有利不公平条件下,与博弈对象社会距离越近,儿童对不公平分配提议的拒绝率越高;（2）分配差距越大,儿童对不公平分配提议的拒绝率越高;（3）社会距离和分配差距交互作用显著,在中等分配差距条件下,儿童对不公平分配提议拒绝率的社会距离效应最为明显。结果表明,社会距离和分配差距对儿童有利不公平厌恶有显著影响,在中度分配差距下社会距离具有更加明显的调节作用。     

知情权与新生儿重症监护病房(NICU)患儿父母的信息交流技巧

在新生儿重症监护病房(neonatal intensive care unit,NICU)中接受治疗的危重新生儿约90%结果良好,而这些患儿的父母100%都在此过程中遭受不同程度的心理创伤.患儿父母及其家人应被充分告知患儿的病情、治疗方案及可能的预后,这是他们拥有的知情权.在临床工作中,怎样运用良好的信息交流技巧让患儿父母充分理解病情、配合治疗又不过分紧张这对患儿的康复比对患儿实施具体的诊疗方案更重要.从患儿父母、医护人员、人文关怀的角度探讨NICU医护人员与患儿父母之间信息交流的技巧.