Development of postural stability limits: Anteroposterior and mediolateral postural adjustment mechanisms do not follow the same maturation process

There is increasing evidence that indicates a critical transition period for the maturation of postural control from the ages of 6–7 years. Some studies suggest that this transitional period may be explained by a change from a ballistic toward a sensory strategy, but the cause remains unknown. The purpose of this study was to investigate the influence of the transition period on dynamic postural control in a natural self-initiated leaning task under different sensory conditions. We evaluated the center of pressure (COP) displacement during maximum leaning in four directions (forward, backward, rightward, leftward) under three sensory conditions (eyes open, eyes closed and eyes closed standing on a foam). Three groups were tested: young children (4 years old), older children (8–10 years old) and adults (21–42 years old). The maximum COP excursion along the anteroposterior and mediolateral axes and the COP amplitude were analyzed. Young children showed smaller maximum anteroposterior and mediolateral COP excursion than other groups. Older children also exhibited a significantly smaller maximum excursion along the mediolateral direction but performed similar to adults along the anteroposterior direction. In a similar manner, the analysis of the COP amplitude did not indicate any differences between the groups along the anteroposterior axis. In contrast, along the mediolateral axis, the results showed developmental differences. Furthermore, the effect of sensory conditions was similar across the children's groups. Our results suggest an important plasticity period for the maturation of postural control mechanisms. Notably, our findings support the idea that the postural mechanisms controlling the anteroposterior axis reach maturity before the mechanisms involved in controlling the mediolateral axis.     

A Measure of the Stability of Activities in a Family Environment

The Stability of Activities in the Family Environment (SAFE) measure was developed to assess aspects of the construct of family stability. An earlier version of the SAFE was revised to improve its psychometric properties and better elaborate the construct that underlies the measure. College students completed the revised SAFE and other measures of family functioning with respect to their families of origin and measures of current adjustment. Findings support the reliability, internal consistency, and factor structure of the SAFE. It is suggested that the results of the factor analyses and findings that different aspects of family stability demonstrated different patterns of relationships to indices of family functioning, are consistent with the presumption guiding the development of the SAFE that families achieve stability in diverse ways. The validity of the SAFE was further supported by its relationship to measures of current self-esteem and depression.     

论动态稳定

目前,人类认识在两方面取得了共识：一方面,认识到了可持续发展的意义．另一方面,认识到了可持续发展与稳定的关系,并提出稳定是压倒一切的主题。现在的问题是,对稳定主要是从平衡方面去理解：经济稳定就是经济平衡,自然稳定就是生态平衡等。实际上这仍然是一种静态的稳定,这种平衡的稳定是没有活力的,因而是同进化和发展的目标正相矛盾的。本文则指出,具有活力的稳定是一种非平衡的稳定,其在本质上是一种动态稳定,其同进化和发展的目标正相一致。     

Distinctive phonological features differ in relevance for both spoken and written word recognition

This paper discusses four experiments on Dutch which show that distinctive phonological features differ in their relevance for word recognition. The relevance of a feature for word recognition depends on its phonological stability, that is, the extent to which that feature is generally realized in accordance with its lexical specification in the relevant word position. If one feature value is uninformative, all values of that feature are less relevant for word recognition, with the least informative feature being the least relevant. Features differ in their relevance both in spoken and written word recognition, though the differences are more pronounced in auditory lexical decision than in self-paced reading.     

Age-related development of self-regulation: Evidence on stability and change in action orientation

Action (vs. state) orientation describes the ability to modulate affect and is at the core of goal-directed self-regulation. However, evidence on stability and change over time is scarce. In Study 1 (N = 368 couples), we investigated measurement invariance of action orientation (measured with the ACS-90) as well as rank-order stability and mean-level change over a period of four years. We report results from three samples with young adults (Study 2). Measurement invariance was obtained for an adjusted ACS-90 scale after removing 4 items. Rank-order stability was high. In both studies, one of two subscales – prospective action orientation – increased over time. Positive change was most consistent for middle-aged adults, implying that self-regulatory abilities improve during middle adulthood.     

Effects of hands-free cellular phone conversational cognitive tasks on driving stability based on driving simulation experiment

Driver distraction due to cellular phone usage is a major contributing factor to road crashes. This study compares the effects of conversational cognitive tasks using hands-free cellular phone on driving performance under three distraction conditions: (1) no distraction (no cellular conversation), (2) normal conversation (non-emotional cellular conversation), and (3) seven-level mathematical calculations. A car-following scenario was implemented using a driving simulator. Thirty young drivers with an average age of 24.1 years maintained a constant speed and distance between the subject vehicle and a leading vehicle on the driving simulator, and then respond to the leading vehicle’s emergency stop. The driving performances were assessed by collecting and statistically analyzing several variables of maneuver stability: the drivers’ brake reaction times, driving speed fluctuation, car-following distance undulation, and car-following time-headway undulation. The results revealed that normal conversation on a hands-free cellular phone impaired driving performance. The degree of impairment caused by normal calculation was equivalent to the distraction caused by Level 3 mathematical calculations according to the seven-level calculation baseline. The calculation difficulty of Level 3 is one double-digit figure plus a single-digit figure, and non-carry addition mental arithmetic is required, e.g., 44 + 4. The results indicated that an increase in the level of complexity of the calculation task was associated with an increase in brake reaction time. The seven-level calculation-task baseline could be applied to measure additional distraction effects on driving performance for further comparison.     

Intention inertia and the plasticity of planning

In this article, I examine Michael Bratman’s account of stability in his planning theory of intention (PTI). Future-directed intentions should be stable, or appropriately resistant to change, over time. Bratman claims that the norm of stability governs both intentions and plans. The aim of this article is to critically enrich Bratman’s account of stability by introducing plasticity as an additional norm of planning. I construct plasticity as a kind of stability of intentions which supplements Bratman’s notion of “reasonable stability.” Unlike the latter, plasticity applies mainly to cases in which plan states are abandoned without reconsideration. I focus on the intra-theoretical problems of PTI and elucidate: (1) the distinction between future-directed intentions and plans, (2) the conceptual difference between stability and inertia, which is only implicit in PTI, and (3) the role of the environment of the planner, which has a vestigial role in Bratman’s work. I also defend my incorporation of plasticity against one possible objection and support it in the context of Bratman’s later works. Although critical, my proposal is in moderate harmony with PTI.     

A Longitudinal Study of Predictors of Housing Stability,Housing Quality,and Mental Health Functioning Among Single Homeless Individuals Staying in Emergency Shelters

The current study examined risk and resilience factors at multiple levels that affect homeless individuals' ability to exit homelessness and achieve housing stability. It also examined the relationship between housing status, housing quality and mental health functioning. The methodology is a longitudinal study of single homeless individuals staying in emergency shelters in a medium‐sized Canadian city who were followed for a 2 year period. Data were collected from participants at a baseline interview when they were homeless and at a 2‐year follow‐up. There were 329 participants interviewed at baseline and 197 (59.9%) participants interviewed at follow‐up. Results from a structural equation modelling analysis found that having interpersonal and community resources were predictive of achieving housing stability. Specifically, having a larger social support network, access to subsidized housing, and greater income was related to achieving housing stability. On the other hand, having a substance use problem was a risk factor associated with a failure to achieving housing stability. Being female, feeling personally empowered, having housing that is perceived of being of higher quality were directly predictive of mental health functioning at follow‐up. Findings are discussed in the context of previous research and their policy implications.