Probing the allocation of attention in implicit (motor) learning

We investigated the attention demands associated with implicit and explicit (motor) learning and performance using a probe reaction time paradigm. Two groups of participants learned a golf putting task over eight blocks of 50 trials performed from different distances. One group (errorless learning) began putting from the shortest distance (25 cm) and moved progressively back to the furthest distance (200 cm). A second group (errorful learning) began putting from the furthest distance (200 cm) and moved progressively closer (25 cm). Retention tests were used to assess learning in the two conditions, followed by transfer tests in which participants used either an unusual putter or a very unusual putter. Transfer to the unusual putters had an equivalent effect on the performance of both errorless and errorful learners, but probe reaction times were unaffected in the errorless learners, suggesting that execution of their movements was associated with reduced attention demands. Reducing errors during initial learning trials may encourage an implicit mode of learning and lower the demand for cognitive resources in subsequent performance.     

Mortality in relation to changes in physical activity in middle-aged to older Chinese: An 8-year follow-up of the Guangzhou Biobank Cohort Study

BackgroundPhysical activity (PA) is generally encouraged. Studies from developed countries in the West have shown that maintenance of adequate PA or increasing PA are associated with lower mortality risk. It is unclear whether these associations apply to an older Chinese population. Hence, we examined the changes in PA prospectively among a middle-aged and older Chinese population over an average of 4 years and explored their subsequent mortality risks.MethodsMetabolic equivalent scores of PA among participants in the Guangzhou Biobank Cohort Study were calculated. Participants were divided into 3 groups related to PA level, and changes in PA were classified into 9 categories. Information on vital status and causes of death from March 2008 to December 2012 (the first repeated examination) until December 31, 2017, was obtained via record linkage with the Death Registry.ResultsOf 18,104 participants aged 61.21 ± 6.85 years (mean ± SD), 1461 deaths occurred within 141,417 person-years. Compared to participants who maintained moderate PA, those who decreased PA from moderate or high levels to a low level had increased risks for all-cause mortality (hazard ratio (HR) = 1.47, 95% confidence interval (95%CI): 1.11–1.96). Participants who maintained a high level of PA (HR = 0.83, 95%CI: 0.70–0.98) or increased PA from low to high levels (HR = 0.71, 95%CI: 0.52–0.97) showed lower all-cause mortality risks. Those who maintained low PA levels showed a higher all-cause mortality risk, whereas those who increased their PA levels showed a non-significantly lower risk. Similar results were found for cardiovascular disease risk.ConclusionEven at an older age, maintaining a high PA level or increasing PA from low to high levels results in lower mortality risks, suggesting that substantial health benefits might be achieved by maintaining or increasing engagement in adequate levels of PA. The increased risk of maintaining a low PA level or decreasing PA to a low level warrants the attention of public health officials and clinicians.     

Exploring reading-spelling connection as locus of dyslexia in Chinese

This paper advances the argument that in learning to read/spell Chinese characters and words, it is important for learners to understand the role of the component parts. These constituents consist of phonetic and semantic radicals, or bujians, made up of clusters of strokes in their proper sequence. Beginning readers/spellers need to be sensitive to the positional hierarchy and internal structure of these constituent parts. Those Chinese children diagnosed with developmental dyslexia tend to have more difficulties in spelling Chinese characters and in writing to dictation than in reading. A lexical decision study with two groups of tertiary students differing in their Chinese language ability was carried out to test their efficiency in processing real and pseudo characters as a function of printed frequency of the characters, and the consistency of their component semantic radicals. There is some evidence that even for adult readers differing in their Chinese language ability, lexicality, frequency of characters and the consistency of the semantic radicals affect accurate and rapid character identification. Suggestions for research and teaching approaches are made to enhance the analysis and synthesis of the phonetic and semantic radicals to promote efficient reading and spelling in Chinese.     

Robust stabilization of uncertain time-delay systems containing nonlinear saturating actuators

The robust stabilization problem for a class of uncertain linear time-delay systems containing sector saturating actuator is considered in this paper. The uncertain time-delay systems under consideration are described by state differential equations with time-varying unknown-but-bounded uncertain parameters and delayed state. The delay is assumed to be constant bounded but unknown. The new criterion of delay-dependent robust stabilizability for uncertain time-delay systems is presented and the corresponding robust memoryless state feedback controller is derived in terms of the solutions of several linear matrix inequalities (LMIs). Numerical example is presented to illustrate the obtained results. Project supported by the Natural Science Key Foundation of China (NSFC: 69934030) and the Excellent (Youth) Teacher for Teaching and Research Award Foundation in Institutions of China.     

Effects of arch-support orthoses on ground reaction forces and lower extremity kinematics related to running at various inclinations

ABSTRACT

While foot orthoses are commonly used in running, little is known regarding biomechanical risk potentials during uphill running. This study investigated the effects of arch-support orthoses on kinetic and kinematic variables when running at different inclinations. Sixteen male participants ran at different inclinations (0°, 3° and 6°) when wearing arch-support and flat orthoses on an instrumented treadmill. Arch-support orthoses induced longer contact time, larger initial ankle dorsiflexion, maximum ankle eversion, and knee sagittal range of motion (RoM) (p < 0.05). As incline slopes increased, vertical impact peak and loading rate, stride length, and ankle coronal RoM decreased, but contact time, stride frequency, initial ankle dorsiflexion and inversion, maximum dorsiflexion, initial knee flexion, and ankle sagittal RoM increased (p < 0.05). Furthermore, knee sagittal RoM was lowest when running at an inclination of 3°. The interaction effect indicated that in arch-support condition, participants running at 6° induced higher maximum ankle eversion than running at 0° (p < 0.05), while no differences were found in flat orthosis condition. These findings suggest that the use of arch-support orthoses would influence running biomechanics that is related to injury risks. Running at higher inclination led to more alterations to biomechanical variables than at lower inclination.     

Professor-student communications: Why they should be privileged communications

Relationships between professors and students are well-known to be important aspects of the university experience. A successful professor-student relationship is founded on open and honest communication, which may not be possible if the content of conversations between the parties is not guaranteed to be confidential. In this article the authors argue for consideration of professor-student communications as privileged communications and consider the legal and ethical issues involved. Based on a review of the rationale, scope and exceptions to existing forms of privileged communications, the importance of such for professor-student communications is proposed.     

Parent–Child Shared Time From Middle Childhood to Late Adolescence: Developmental Course and Adjustment Correlates

The development and adjustment correlates of parent–child social (parent, child, and others present) and dyadic time (only parent and child present) from age 8 to 18 were examined. Mothers, fathers, and firstborns and secondborns from 188 White families participated in both home and nightly phone interviews. Social time declined across adolescence, but dyadic time with mothers and fathers peaked in early and middle adolescence, respectively. In addition, secondborns’ social time declined more slowly than firstborns’, and gendered time use patterns were more pronounced in boys and in opposite‐sex sibling dyads. Finally, youths who spent more dyadic time with their fathers, on average, had higher general self‐worth, and changes in social time with fathers were positively linked to changes in social competence.