USE OF COMPONENT ANALYSES TO IDENTIFY ACTIVE VARIABLES IN TREATMENT PACKAGES FOR CHILDREN WITH FEEDING DISORDERS

We evaluated the separate components in treatment packages for food refusal of 4 young children. First, treatment packages were implemented until food acceptance improved. Next, a component analysis was conducted within a multielement or reversal design to identify the active components that facilitated food acceptance. The results indicated that escape extinction was always identified as an active variable when assessed; however, other variables, including positive reinforcement and noncontingent play, were also identified as active variables for 2 of the children. The results suggest that the component analysis was useful for identifying variables that affected food acceptance.     

Cross-cultural consistency of coding the strange situation

This study tested whether or not cross-cultural differences in attachment classification distributions result from systematic differences in coding practices. First, we investigated whether or not the interactive scales have been scored consistently in several different cross-cultural samples. Second, the Richters, Waters, and Vaughn (1988) functions were applied to address the question of whether or not attachment classifications were consistently based upon the same pattern of interactive behaviors. Third, cross-cultural coding differences were described from a multivariate perspective. Data sets from seven investigators in six countries were available for analysis. Analyses on this “multinational data set” revealed that except for distance interaction, the interactive scales in the two reunion episodes were scored in accordance with the original coding rules. Furthermore, a good to reasonable agreement appeared to exist between the original classifications and those computed by the functions, except for infants older than 20 months of age. The multivariate principal component analysis showed that classification groups across cultures were more alike than cultures across classification groups. Our data showed, therefore, that attachment classifications have been consistently coded across cultures.     

Risky choice as a function of amount and variance in food supply.

In Experiment 1, 4 rats earned their daily food ration by choosing on a trials basis between a "risky" and a "riskless" lever. The risky lever produced either 15 45-mg food pellets or no pellets, and on average provided five pellets per choice. The riskless lever always produced three pellets. Across conditions, the number of trials per session was varied. Body weight and choice of the risky lever decreased as the number of trials per session decreased, even though body weight could only be defended by increased choice of the risky lever. In Experiment 2, trials per session were fixed, but the number of pellets delivered by the risky and riskless levers was either at the same level as in Experiment 1 or tripled from those levels. Now choice of the risky lever was inversely related to the size of reinforcement and to body weight. The results of these experiments show that risk aversion covaries with the amount of food available in a session and the daily variance in the amount of food earned.     

Probing the effects of individual components in multiple component prevention programs

Assessing the contributions of individual components in multi-component interventions poses complex challenges for prevention researchers. We review the strengths and weaknesses of designs and analyses that may be useful in answering three questions: (1) Is each of the individual components contributing to the outcome? (2) Is the program optimal? and (3), Through what processes are the components of the program achieving their effects? Factorial and fractional factorial designs in which a systematically selected portion of all possible treatment combinations is implemented are used to address question 1. Response surface designs in which each component is quantitatively scaled are explored in relation to question 2. Mediational analysis, a hybrid of experimental and correlational approaches, is considered in relation to question 3. Design enhancements are offered that may further strengthen some of these techniques. These techniques offer promise of enhancing both the basic science and applied science contributions of prevention research.     

An algorithm for comparing medians

An algorithm is presented for computing a test statistic for comparing medians based on a small-sample size estimate of the variance of the usual sample median.     

短时距估计中的标量特性

使用单任务研究程序,采用预期式研究范式和再现时距的研究方法,从心理物理学的视角,通过三个实验系统地考查了人类短时距估计的标量特性、变异源、时距估计中的转换点和韦伯函数的形态等问题。结果表明,刺激物的运动、变化、速度和物理时距是被试进行短时距估计的重要变异源;被试在实验中表现出高估较短时距和低估较长时距的倾向,时距估计的转换点为11.1s;计时过程中得到的韦伯函数是个分段连续函数, 韦伯函数的拐点有两个12s和21s,这两点与本研究得到的时距估计转换点具有部分一致性     

测评中的共同方法偏差

共同方法变异是指由于测量方法而非所测构想造成的变异。共同方法变异会对测评和测评间的相关产生严重影响,甚至会使研究导致错误结论。本文介绍了学界对共同方法偏差的研究,内容包括：(1)共同方法偏差在多大程度上和以何种方式影响测评研究结果;(2)共同方法偏差的潜在来源及其程序控制。     

条件推理中否定前件下信念偏差发生阶段的ERP研究

以日常生活中的条件推理语句为实验材料,采用大、小前提和结论依次呈现的“推断-判断”范式,利用事件相关电位(event-related brain potential, ERP)技术探讨了条件推理中否定前件下信念偏差效应的脑内时程动态变化。结果发现：在行为反应上,较信念促进,信念阻碍下的正确率更低反应时更长;在脑电上,两条件(信念阻碍和信念促进)诱发的ERP波形仅在大前提加工阶段出现明显的分离。这表明该推理下的信念偏差效应可能早在对大前提的语义表征阶段就已发生。     

The Impact of Treatment Components Suggested by the Psychological Flexibility Model: A Meta-Analysis of Laboratory-Based Component Studies

An important aspect of psychotherapy research is the examination of the theoretical models underlying intervention approaches. Laboratory-based component research is one useful methodology for this endeavor as it provides an experimental means of testing questions related to intervention components and the change process they engage with a high level of control and precision. A meta-analysis was conducted of 66 laboratory-based component studies evaluating treatment elements and processes that are suggested by the psychological flexibility model that underlies Acceptance and Commitment Therapy (acceptance, defusion, self as context, committed action, values, and present moment), but also touches on a variety of contextual forms of cognitive behavior therapy. Significant positive effect sizes were observed for acceptance, defusion, present moment, values, mixed mindfulness components, and values plus mindfulness component conditions compared to inactive comparison conditions. Additional analyses provided further support for the psychological flexibility model, finding larger effect sizes for theoretically specified outcomes, expected differences between theoretically distinct interventions, and larger effect sizes for component conditions that included experiential methods (e.g., metaphors, exercises) than those with a rationale alone. Effect sizes did not differ between at-risk/distressed and convenience samples. Limitations with the meta-analysis and future directions for laboratory-based component research are discussed.     

Practicing Elements Versus Practicing Coordination: Changes in the Structure of Variance

ABSTRACT

The authors explored effects of practice of a 2-finger accurate force production task on components of finger force variance quantified within the uncontrolled manifold (UCM) hypothesis, V_UCM, that had no effect on total force and V_ORT that affected total force. A variable task with graded instability was designed to encourage use of variable solutions. Two groups of subjects (n = 9 each) were tested prior to a 1.5-hr practice session, after the session, and 2 weeks later (retention test). Group 1 practiced 1 finger at a time, while Group 2 practiced the task with 2 fingers (index and middle) pressing together. Both groups showed comparable improvements in the performance indices. Both groups showed a decrease in V_ORT, while only Group 2 showed an increase in V_UCM. These effects persisted during the retention test. The results show that practicing elements and practicing redundant groups of elements may lead to similar changes in performance (i.e., in the variability of the total force produced by the set of fingers), accompanied by dramatically different changes in the structure of variance: A drop in V_UCM after the single-finger practice and an increase following the 2-finger practice. The strong retention effects promise applications of the method to rehabilitation.