It has been suggested that human behavior in general and cognitive performance in particular emerge from coordination between multiple temporal scales. In this article, we provide quantitative support for such a theory of interaction-dominant dynamics in human cognition by using wavelet-based multifractal analysis and accompanying multiplicative cascading process on the response series of 4 different cognitive tasks: simple response, word naming, choice decision, and interval estimation. Results indicated that the major portion of these response series had multiplicative interactions between temporal scales, visible as intermittent periods of large and irregular fluctuations (i.e., a multifractal structure). Comparing 2 component-dominant models of 1/f(alpha) fluctuations in cognitive performance with the multiplicative cascading process indicated that the multifractal structure could not be replicated by these component-dominant models. Furthermore, a similar multifractal structure was shown to be present in a model of self-organized criticality in the human nervous system, similar to a spatial extension of the multiplicative cascading process. These results illustrate that a wavelet-based multifractal analysis and the multiplicative cascading process form an appropriate framework to characterize interaction-dominant dynamics in human cognition. This new framework goes beyond the identification of 1/f(alpha) power laws and non-gaussian distributions in response series as used in previous studies. The present article provides quantitative support for a paradigm shift toward interaction-dominant dynamics in human cognition.

This study compared the relative contributions of growing body dimensions, age, and walking experience in the development of walking skill in 9- to 17-month-old infants (N = 210), 5-6-year old kindergartners (N = 15), and college students (N = 13). Kinematic measures derived from participants' footprints showed characteristic improvements in walking skill. As children became bigger, older, and more experienced, their steps became longer, narrower, straighter, and more consistent. Improvements reflected a narrowing base of support and increasing control over the path of progression. Although both infants' age and the duration of their walking experience contributed to improvements in walking skill, experience was the stronger predictor. This finding suggests that practice is the more important developmental factor for helping infants to conquer their weak muscles and precarious balance.

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Background: There has been a rapid increase in research on the use of virtual reality (VR) and gaming technology as a complementary tool in exercise and rehabilitation in the elderly population. Although a few recent studies have evaluated their efficacy, there is currently no in-depth description and discussion of different game technologies, physical functions targeted, and safety issues related to older adults playing exergames. Objectives: This integrative review provides an overview of the technologies and games used, progression, safety measurements and associated adverse events, adherence to exergaming, outcome measures used, and their effect on physical function. Methods: We undertook systematic searches of SCOPUS and PubMed databases. Key search terms included "game", "exercise", and "aged", and were adapted to each database. To be included, studies had to involve older adults aged 65 years or above, have a pre-post training or intervention design, include ICT-implemented games with weight-bearing exercises, and have outcome measures that included physical activity variables and/or clinical tests of physical function. Results: Sixty studies fulfilled the inclusion criteria. The studies had a broad range of aims and intervention designs and mostly focused on community-dwelling healthy older adults. The majority of the studies used commercially available gaming technologies that targeted a number of different physical functions. Most studies reported that they had used some form of safety measure during intervention. None of the studies reported serious adverse events. However, only 21 studies (35%) reported on whether adverse events occurred. Twenty-four studies reported on adherence, but only seven studies (12%) compared adherence to exergaming with other forms of exercise. Clinical measures of balance were the most frequently used outcome measures. PEDro scores indicated that most studies had several methodological problems, with only 4 studies fulfilling 6 or more criteria out of 10. Several studies found positive effects of exergaming on balance and gait, while none reported negative effects. 2 function in older adults, with few reported adverse events. As there is large variability between studies in terms of intervention protocols and outcome measures, as well as several methodological limitations, recommendations for both practice and further research are provided in order to successfully establish exergames as an exercise and rehabilitation tool for older adults.

The effects of infants' age, body dimensions, and experience on the development of crawling was examined by observing 28 infants longitudinally, from children's first attempts at crawling until they began walking. Although most infants displayed multiple crawling postures en route to walking, development did not adhere to a strict progression of obligatory, discrete stages. In particular, 15 infants crawled on their bellies prior to crawling on hands and knees, but the other 13 infants skipped the belly-crawling period and proceeded directly to crawling on hands and knees. Duration of experience with earlier forms of crawling predicted the speed and efficiency of later, quite different forms of crawling. Most important, infants who had formerly belly crawled were more proficient crawling on hands and knees than infants who had skipped the belly-crawling period. Transfer could not be explained by differences in infants' age or body dimensions alone. Rather, experience using earlier crawling patterns may have exerted beneficial effects on hands-and-knees crawling by shoring up underlying constituents common to all forms of crawling postures.