Parent and actometer measures of motor activity level in the young infant

Motor activity level is one dimension of infant temperament for which parental judgment can be validated against a truly independent criterion. Two studies were conducted, the first involving a 27-min sample of behavior in a structured, attention-getting situation, and the second involving a 24-hr sample of in-home behavior. In both studies, parent perception of the 3- or 4-month-old as measured by the Activity Level (AL) scale of the Rothbart Infant Behavior Questionnaire was compared to the composited readings from four mechanical motion recorders (actometers) worn, one per limb, by the infant. The AL scale did not correlate with the actometer measure, r=.05 and R=.00, and the expected convergence of the 3-month version of the IBQ activity scale with its mechanical counterpart was not found. In the 24-hr study, birth order and ponderal index were significantly correlated with 24-hr actometer scores; first-borns and thin infants were most active.     

Measuring activity using actometers: A methodological study

Actometers are men's self-winding mechanical wristwatches that have been modified such that they measure activity rather than time. Actometers can be used to obtain longitudinal naturalistic measures of activity concerning a variety of clinical populations. However, no systematic methodological research has been conducted with regard to the site of attachment and the duration of measurement necessary to ensure valid results. This article presents the results of a methodological study designed to answer these questions. The mean activity levels associated with the Left Wrist and Ankle were nearly equal to those associated with the Right Wrist and Ankle. The Ankle readings were substantially greater than the Wrist readings because the subjects' legs were longer than their arms. The data from Week 2 were the same as those from Week 1.     

Evaluating public posting,goal setting,and rewards to increase physical activity in children

In this study, we evaluated several components of a pedometer-based intervention with children in an elementary-school-aged classroom, across 24-h sessions. The intervention included combinations of self-monitoring, goal setting, feedback, and reinforcement, and data were analyzed at both the classroom level (i.e., average daily step totals) and the individual level (i.e., daily step totals), across phases. The highest levels of physical activity were observed when components of self-monitoring, public posting, goal setting, and feedback with reward were applied concurrently.     

Effects of acute endurance,strength, and coordination exercise interventions on attention in adolescents: A randomized controlled study

ObjectivesThe aim of this study was to compare three different modes of an acute bout of exercise – endurance, strength, and coordination – in their effects on adolescents' attention.DesignThis was a preregistered, prospective, randomized intervention study with four groups and two distinct measurement occasions.MethodEighty adolescent students aged 15–18 years were randomized to one of three exercise intervention groups (endurance, strength, coordination) or to a non-exercise, control group. The exercise interventions lasted for 25 min. The random assignment to the study groups was stratified according to participants' age and gender. Before and after the exercise intervention, all participants completed the revised d2-test of attention. A 4 × 2 repeated measures ANOVA with contrast-coded test was used as the main analysis method.ResultsAttentional test performance increased from before to after the exercise intervention for all exercise groups, as compared with the control group. The three exercise groups improved equally and did not differ in their attentional scores after the intervention.ConclusionsAn acute bout of exercise was in general beneficial for adolescent students' attention, while the mode of the provided exercise training was not decisive. School directors and teachers are encouraged to incorporate exercise-related breaks into their school plan.     

Resilience characterized and quantified from physical activity data: A tutorial in R

Consistent physical activity is key for health and well-being, but it is vulnerable to stressors. The process of recovering from such stressors and bouncing back to the previous state of physical activity can be referred to as resilience. Quantifying resilience is fundamental to assess and manage the impact of stressors on consistent physical activity. In this tutorial, we present a method to quantify the resilience process from physical activity data. We leverage the prior operationalization of resilience, as used in various psychological domains, as area under the curve and expand it to suit the characteristics of physical activity time series. As use case to illustrate the methodology, we quantified resilience in step count time series (length = 366 observations) for eight participants following the first COVID-19 lockdown as a stressor. Steps were assessed daily using wrist-worn devices. The methodology is implemented in R and all coding details are included. For each person’s time series, we fitted multiple growth models and identified the best one using the Root Mean Squared Error (RMSE). Then, we used the predicted values from the selected model to identify the point in time when the participant recovered from the stressor and quantified the resulting area under the curve as a measure of resilience for step count. Further resilience features were extracted to capture the different aspects of the process. By developing a methodological guide with a step-by-step implementation, we aimed at fostering increased awareness about the concept of resilience for physical activity and facilitate the implementation of related research.     

论儿童心理发展的动力及其机制

本文依据马克思主义的唯物史观和唯物辩证法原理,从儿童的实际社会生活过程出发,运用系统方法论证了儿童心理发展的动力是主客体之间的结构性矛盾,而由“主体──活动──客体”三项格式构成的反馈回路系统则是心理发生发展的动力场。本文还运用儿童心理发展的控制论模型,从活动的机能性方面探讨了同化和顺应之间的平衡化动力机制,揭示了主客体之间矛盾运动的原理和过程;平衡化机制是受社会文化历史的发展规律支配的。