Phase Correction Following a Perturbation in Sensorimotor Synchronization Depends on Sensory Information

In models of sensorimotor synchronization, it is generally assumed that phase correction occurs in response to information about sensorimotor asynchrony or relative phase. Without such feedback, a phase perturbation in the motor activity should not be followed by phase correction. Alternatively, internally generated temporal expectations could provide a basis for phase correction in the absence of feedback. To test those hypotheses, the author conducted an experiment in which participants (N = 8) tapped their finger in synchrony with isochronous auditory sequences containing a single shifted event onset, after which there could be a gap of up to 3 missing events. Participants were instructed to not react to the shifted event and to continue tapping regularly during any gap. The shifted event caused an involuntary phase shift of the following tap. The shift was corrected if the sequence continued, but during a gap, the shift persisted without correction. Those results confirm that sensory feedback is necessary for phase correction to occur.     

A self-determination theory approach to adults’ healthy body weight motivation: A longitudinal study focussing on food choices and recreational physical activity

This study focuses on body weight motivation based on self-determination theory. The impact of body weight motivation on longitudinal changes in food choices, recreational physical activity and body mass index was explored. A sample of adults (N = 2917, 47% men), randomly selected from the telephone book, completed a questionnaire in two consecutive years (2012, 2013), self-reporting food choices, recreational physical activity and body weight motivation. Types of body weight motivation at T1 (autonomous regulation, introjected regulation, and external regulation) were tested with regard to their predictive potential for changes in food choices, recreational physical activity and body mass index (BMI). Autonomous motivation predicted improvements in food choices and long-term adherence to vigorous recreational physical activity in both genders. Introjected motivation predicted long-term adherence to vigorous recreational physical activity only in women. External motivation predicted negative changes in food choices; however, the type of body weight motivation had no impact on BMI in overweight adults in the long term. Autonomous goal-setting regarding body weight seems to be substantial for healthy food choices and adherence to recreational physical activity.     

A cross-sectional study of changes in Norwegian adolescents' body image from 1992 to 2002

The present study examines changes in adolescents’ body image over a 10-year period. Both satisfaction with appearance in general, and satisfaction with different aspects of appearance (e.g., face, muscle tone, and weight) are considered. We analyzed data from two general population studies of 13–19-year-old Norwegians, “Young in Norway 1992” (N = 10,460, response rate = 97.0%) and “Young in Norway 2002” (N = 11,371, response rate = 92.3%). These studies used identical sampling procedures, data collection procedures, and measures of body image. The analyses showed a polarization in adolescents’ body image — concurrent with an increase in the proportion of adolescents with a very negative body image, there was an increase in the proportion of adolescents with a very positive body image. The greater proportion of adolescents with a very negative body image could partly be explained statistically by the increased body mass index (BMI) in the same period. Girls had a more problematic body image than boys, both in 1992 and in 2002. Whether the strength of this gender difference changed or not depended on the aspect of appearance considered.     

面向读者的写作:马克思主义哲学的写作模式反思

哲学写作具有不向大众诉说、把公开的esotericism说辞与隐微的esotericism说辞结合起来、启蒙和改造民众等多种模式。启蒙以来日益得以伸张的面向大众的写作模式因为大众社会的产生和大众人的成批出现而受到反思。马克思的写作模式是不面向一般民众的．其学术写作更是坚持了很强的专业性。当前的马克思主义哲学写作应该放弃诸多的无对象写作,多作有对象的学术写作。     

Religion and Science in America: Populism versus Elitism

Historian James Gilbert argues that the dialogue between science and religion is an important dynamic in the creation of contemporary American culture. He traces the dialogue not only in the confines of the academic world but also in popular culture. The science-religion dialogue reveals a basic tension between the material and the spiritual that helps define the core of the American psyche: fascination with material progress yet commitment to traditional religious beliefs. Gilbert's cultural narrative traces the dialogue in a unique way because of the attention given to popular renditions of science and religion in evangelical films used by the military, in televised science programs, in science-fiction literature, and at the Seattle World's Fair in 1962. Gilbert suggests that the discussion between science and religion is significant because it is part of the process of creating new cultural structures necessitated by social, scientific, and technological developments. The tensions between religiously informed commonsense science and professional science work to create new cultural forms in a democratic society. Religion and science in dialogue are part of the process of cultural creation. Dogmatism on the part of either scientists or religionists is countered by the democratic process itself.     

The coordinated movement of the spine and pelvis during running

Previous research into running has demonstrated consistent patterns in pelvic, lumbar and thoracic motions between different human runners. However, to date, there has been limited attempt to explain why observed coordination patterns emerge and how they may relate to centre of mass (CoM) motion. In this study, kinematic data were collected from the thorax, lumbar spine, pelvis and lower limbs during over ground running in n = 28 participants. These data was subsequently used to develop a theoretical understanding of the coordination of the spine and pelvis in all three body planes during the stance phase of running. In the sagittal plane, there appeared to be an antiphase coordinate pattern which may function to increase femoral inclination at toe off whilst minimising anterior–posterior accelerations of the CoM. In the medio-lateral direction, CoM motion appears to facilitate transition to the contralateral foot. However, an antiphase coordination pattern was also observed, most likely to minimise unnecessary accelerations of the CoM. In the transverse plane, motion of the pelvis was observed to lag slightly behind that of the thorax. However, it is possible that the close coupling between these two segments facilitates the thoracic rotation required to passively drive arm motion. This is the first study to provide a full biomechanical rationale for the coordination of the spine and pelvis during human running. This insight should help clinicians develop an improved understanding of how spinal and pelvic motions may contribute to, or result from, common running injuries.     

Dynamic stability during running gait termination: Predictors for successful control of forward momentum in children and adults

Reported differences between children and adults with respect to COM horizontal and vertical position to maintain dynamic stability during running deceleration suggest that this relationship may not be as important in children. This study challenged the current dynamic stability paradigm by determining the features of whole body posture that predicted forward velocity and momentum of running gait termination in adults and children. Sixteen adults and 15 children ran as fast as possible and stopped at pre-determined location. Separate regression analyses determined whether COM posterior and vertical positions and functional limb length (distance between COM and stance foot) predicted velocity and momentum for adults and children. COM posterior position was the strongest predictor of forward velocity and momentum in both groups supporting the previously established relationship during slower tasks. COM vertical position also predicted momentum in children, not adults. Higher COM position in children was related to greater momentum; consistent with previously reported differences between children and adults in COM position across running deceleration. COM vertical position was related to momentum but not velocity in children suggesting that strategies used to terminate running may be driven by demands imposed not just by velocity, but also the mass being decelerated.     

Sex and age group differences in the associations between sleep duration and BMI from adolescence to young adulthood

Objective: We examine concurrent and longitudinal associations between sleep duration (SD) and body mass index (BMI) from adolescence to young adulthood, controlling for physical activity and internalising symptoms. Sex and age group differences (early adolescent group ages 12–15 years and late adolescent group ages 16–18 years) are examined.

Design: A randomly selected community-based sample of youth (N = 662; 48.3% males) were surveyed biannually from 2003 (T1) to 2014 (T6).

Results: We found sex and age group differences for the concurrent and longitudinal associations between SD and BMI. For males, shorter SD at baseline was concurrently related to higher BMI. For females, shorter SD at baseline was associated with longitudinal increases in BMI, for the late adolescent group only.

Conclusion: Findings show that the association between SD and BMI, previously shown in childhood, continues to be significant in adolescence and young adulthood. Developmentally appropriate and sex-specific strategies for motivating and supporting healthy sleep habits in adolescence that may help to prevent weight gain into young adulthood are discussed.     

Habituation to a stressor predicts adolescents' adiposity

Background and Objectives: Stress is associated with gains in adiposity. One factor that determines how much stress is experienced is how quickly an adolescent reduces responding (habituates) across repeated stressors. The purpose of this study was to determine the association of body mass index (BMI) percentile and the rate of habituation to a stressor. Design: Thirty-four adolescents completed anthropometric measures and a habituation protocol using a within study design. Methods: The habituation protocol measured the rate of decline in perceived stress and heart rate (HR) across four, two-minute serial subtraction trials. Results: Multivariate linear regression revealed the habituation rate of the HR predicted BMI percentile after adjusting for gender, socioeconomic status, and initial HR (β?=?17.2, p?Conclusions: Slower habituation to a laboratory stressor was associated with greater BMI percentiles in adolescents.     

The interactive effects of age,education, and BMI on cognitive functioning

We examined the moderating effects of age and cognitive reserve on the relationship between body mass index (BMI) and processing speed, executive function, and working memory based on the literature suggesting that obese individuals perform more poorly on measures of these abilities. Fifty-six healthy, dementia-free community-dwelling older (mean age 65.72 ± 7.40) and younger (mean age 21.10 ± 2.33) adults completed a neuropsychological battery and reported height and weight. Mixed effects models were used to evaluate the interactive effects of age, education (a proxy for cognitive reserve), and BMI on cognitive scores. Higher education was protective for executive deficits in younger, but not older adults. Age differences in executive functions were reduced at higher education levels but increased in individuals with higher BMI. Results suggest the inter-relationships between cognitive reserve – as measured by education – and BMI differ across age, and that obesity may accelerate the cognitive aging process.