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.     

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.     

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.     

Temporospatial analysis of explicit and implicit processing of negative content during word comprehension

Although divergences between explicit and implicit processing of affective content during word comprehension have been reported, the underlying nature of those differences remains in dispute. Prior studies focused on either the timing or the spatial location of the effects. The present study examined the precise dynamics of the processing of negative words when attention is directed to affective content or to non-emotional properties by capitalizing on fine temporal resolution of the event-related potentials (ERPs) and recent advances in source localization. Tasks were used that required accessing knowledge about different semantic properties of negative and neutral words. In the direct task, participants’ attention was directed towards emotional information. By contrast, subjects had to decide whether the words’ referent could be touched or not in the indirect task. Regardless of being processed explicitly or implicitly, negative compared to neutral words were associated with more errors and greater key pressure responses. Electrophysiologically, affective processing was reflected in larger amplitudes to negative words in a late positive component (LPC) at the scalp level, and in increased activity in the pre-supplementary motor area (pre-SMA) at the voxel level. Interestingly, an interaction between emotion and type of task was observed. Negative words were associated with more errors, larger anterior distributed LPC amplitudes and increased activity in the posterior cingulate cortex (PCC) in the direct compared to the indirect task. This LPC effect was modulated by the concreteness of the words. Finally, a task effect was found in a posterior negativity around 220 ms, with enhanced amplitudes to words in the direct compared to the indirect task. The present results suggest that negative information contained in written language is processed irrespective of controlled attention is directed to it or not, but that this processing is reinforced in the former case.     

Inter-individual and intra-individual variability of the N2 component: On reliability and signal-to-noise ratio

The nogo N2 component, an anterior negative peak supposed to be generated in the anterior cingulate cortex, has been used as an indicator of conflict monitoring and response conflict in basic and clinical research. Here, we investigate the reliability and the signal-to-noise ratio (SNR) of inter-individual differences of the N2 amplitudes as well as of intra-individual standard deviations of N2 amplitudes. Effects of the number of nogo epochs, type of summary measure (peak vs. average amplitude), and filter cut-offs (1–12 Hz vs. 1–30 Hz) are investigated. A sample of N = 32 participants, performed a go/nogo task. Excellent Cronbach’s alpha coefficients (?.90) were obtained for the fronto-central average N2 amplitude at 40 nogo epochs and for the peak N2 amplitude at 60 nogo epochs. The SNR was higher for the average nogo N2 amplitude compared to the peak N2 amplitude. Split-half reliability coefficients of the intra-individual standard deviation of the nogo N2 amplitudes were at least moderate. Based on these results we provide suggestions for a reliable N2 measurement. Moreover, although intra-individual variability has often been conceived as noise the present findings support the idea that intra-individual N2 variability incorporates systematic variance.     

Do intermediate- and higher-order principal components contain useful information to detect subtle changes in lower extremity biomechanics during running?

Recently, a principal component analysis (PCA) approach has been used to provide insight into running pathomechanics. However, researchers often account for nearly all of the variance from the original data using only the first few, or lower-order principal components (PCs), which are often associated with the most dominant movement patterns. In contrast, intermediate- and higher-order PCs are generally associated with subtle movement patterns and may contain valuable information about between-group variation and specific test conditions. Few investigations have evaluated the utility of intermediate- and higher-order PCs based on observational cross-sectional analyses of different cohorts, and no prior studies have evaluated longitudinal changes in an intervention study. This study was designed to test the utility of intermediate- and higher-order PCs in identifying differences in running patterns between different groups based on three-dimensional bilateral lower-limb kinematics. The results reveal that differences between sex- and age-groups of 128 runners were observed in the lower- and intermediate-order PCs scores (p < 0.05) while differences between baseline and following a 6-week muscle strengthening program for 24 runners with patellofemoral pain were observed in the higher-order PCs scores (p < 0.05), which exhibited a moderate correlation with self-reported pain scores (r = −0.43; p < 0.05).     

Judging complex movement performances for excellence: A principal components analysis-based technique applied to competitive diving

Athletes rely on subjective assessment of complex movements from coaches and judges to improve their motor skills. In some sports, such as diving, snowboard half pipe, gymnastics, and figure skating, subjective scoring forms the basis for competition. It is currently unclear whether this scoring process can be mathematically modeled; doing so could provide insight into what motor skill is. Principal components analysis has been proposed as a motion analysis method for identifying fundamental units of coordination. We used PCA to analyze movement quality of dives taken from USA Diving’s 2009 World Team Selection Camp, first identifying eigenpostures associated with dives, and then using the eigenpostures and their temporal weighting coefficients, as well as elements commonly assumed to affect scoring – gross body path, splash area, and board tip motion – to identify eigendives. Within this eigendive space we predicted actual judges’ scores using linear regression. This technique rated dives with accuracy comparable to the human judges. The temporal weighting of the eigenpostures, body center path, splash area, and board tip motion affected the score, but not the eigenpostures themselves. These results illustrate that (1) subjective scoring in a competitive diving event can be mathematically modeled; (2) the elements commonly assumed to affect dive scoring actually do affect scoring (3) skill in elite diving is more associated with the gross body path and the effect of the movement on the board and water than the units of coordination that PCA extracts, which might reflect the high level of technique these divers had achieved. We also illustrate how eigendives can be used to produce dive animations that an observer can distort continuously from poor to excellent, which is a novel approach to performance visualization.     

Toy-oriented changes during early arm movements IV: shoulder-elbow coordination

Our recent work on the initial emergence of reaching identified a mosaic of developmental changes and consistencies within the hand and joint kinematics of arm movements across the pre-reaching period. The purpose of this study was to test hypotheses regarding the coordination of hand and joint kinematics over this same pre-reaching period. Principal component analysis (PCA) was conducted on hand, shoulder, and elbow kinematic data from 15 full-term infants observed biweekly from 8 weeks of age through the week of reach onset. Separate PCAs were calculated for spatial variables and for velocity variables in trials with a toy and without a toy. From the PCA results, we constructed ‘variance profiles’ to reflect the coordinative structure of the hand, shoulder, and elbow. By coordinative structure is meant here the relative contribution of each joint to the factors revealed by the PCA. Shifts in these profiles, which reflected coordination changes, were compared across the hand and joints within each pre-reaching phase (Early, Mid, Late) as well as across phases and trial conditions (no-toy and toy). Results identified both surprising consistencies and important developmental changes in coordination. First, over development, spatial coordination changed in different ways for the shoulder and elbow. Between the Early and Late phases, spatial coordination at the shoulder showed more adult-like coordination during both spontaneous movements and movements with a toy present. In contrast, elbow spatial coordination became more adult-like only during movements with a toy and less adult-like during spontaneous movements. Second, over development, velocity coordination became more adult-like at both joints in movements with and without a toy present. We propose that the features of coordination that changed over development suggest explanations for the differential roles and developmental trajectories of the control of arm movements between the shoulder and elbow. We propose that features that remained consistent over development suggest the presence of developmentally important constraints inherent in arm biomechanics, which may simplify arm control for reaching. Taken together, these findings highlight the critical role of spontaneous arm movements in the emergence of purposeful reaching.