Does exercise-induced muscle damage impair subsequent motor skill learning?

Motor skill learning is a fundamental aspect of human behavior based on the calibration of internal models via sensory information such as proprioception. Some conditions, as exercise-induced muscle damage (EIMD), disrupt proprioceptive information, and may cause learning impairment. Such possible relation between EIMD and motor skill learning has not yet been investigated and it is the aim of this study. For this purpose, thirty male university students (19.3 ± 1.8 years) were equally assigned to two groups: EIMD and CON group. The EIMD group received a treatment to induce muscle damage consisting of a weight lifting protocol directed to the agonist muscles related to the task prior to the pretest and to the learning sessions. EIMD was verified and compared between groups and along the process (0–168 h) by means of the degree of delayed onset muscle soreness (DOMS), perceived total quality recovery and maximal isometric strength (MIS). To investigate motor skill learning, both groups practiced a dart throwing task for four sessions with 150 trials in each session. Recovery status and DOMS were recovered at 96 h in the EIMD group, and MIS was not recovered throughout 168 h. In contrast, muscle damage parameters were not altered across 168 h in the CON group. Accuracy and consistency were compared within and between groups in a pretest posttest design. The EIMD group showed less accurate and consistent results on the long term (delayed posttest). Results confirmed our hypothesis that EIMD, a common condition in sports and in rehab practices, may hinder motor skill learning, possibly due to neurological aspects such as proprioceptive information, its relation to central nervous system reorganization and internal model consolidation.     

Psychometrics in Psychological Research: Role Model or Partner in Science?

This is a reaction to Borsboom's (2006) discussion paper on the issue that psychology takes so little notice of the modern developments in psychometrics, in particular, latent variable methods. Contrary to Borsboom, it is argued that latent variables are summaries of interesting data properties, that construct validation should involve studying nomological networks, that psychological research slowly but definitely will incorporate latent variable methods, and that the role of psychometrics in psychology is that of partner, not role model. Requests for reprints should be sent to Klaas Sijtsma, Department of Methodology and Statistics, FSW, Tilburg University, PO Box 90153, 5000 LE, Tilburg, The Netherlands.     

Alcohol use among adults in Kenya: Results from the National Non-Communicable Diseases Risk Factor survey, 2015

The aim of this study was to assess the prevalence and correlates of alcohol use among Kenyan adults. We analysed data from the Kenya cross-sectional national Non-Communicable Diseases Risk Factor survey, 2015. The survey sampled 4 469 adults (median age 38.0 years, interquartile range = 23, age range of 18–69 years). Results indicate that 6.7% were hazardous or harmful alcohol users and 12.8% past month binge-drinkers. In adjusted logistic regression analysis, being male, middle aged, belonging to the Luhya or Kalenjin ethic group, tobacco use, and having hypertension increased the odds for hazardous or harmful alcohol use. Socio-demographic and health factors appear to influence risk for hazardous or harmful alcohol use among adults in Kenya.     

Integration of internal and external facial features in 8- to 10-year-old children and adults

Investigation of whole-part and composite effects in 4- to 6-year-old children gave rise to claims that face perception is fully mature within the first decade of life (Crookes & McKone, 2009). However, only internal features were tested, and the role of external features was not addressed, although external features are highly relevant for holistic face perception (Sinha & Poggio, 1996; Axelrod & Yovel, 2010, 2011). In this study, 8- to 10-year-old children and adults performed a same–different matching task with faces and watches. In this task participants attended to either internal or external features. Holistic face perception was tested using a congruency paradigm, in which face and non-face stimuli either agreed or disagreed in both features (congruent contexts) or just in the attended ones (incongruent contexts). In both age groups, pronounced context congruency and inversion effects were found for faces, but not for watches. These findings indicate holistic feature integration for faces. While inversion effects were highly similar in both age groups, context congruency effects were stronger for children. Moreover, children's face matching performance was generally better when attending to external compared to internal features. Adults tended to perform better when attending to internal features. Our results indicate that both adults and 8- to 10-year-old children integrate external and internal facial features into holistic face representations. However, in children's face representations external features are much more relevant. These findings suggest that face perception is holistic but still not adult-like at the end of the first decade of life.     

大学生人格与网络行为:网络道德人际SEM模型

利用在线调查和纸笔测查两种方式分别对208名大学生网络使用情况、网络道德行为和社会交往特点等进行了调查,考察了大学生上网的行为特点和网络行为的心理机制,检验了有关大学生在线行为的理论模式.结果发现:(1)网络交往行为中性别的影响在一定程度上是存在的,男性比女性对网络交往更积极和主动,也给予更正性的评价;(2)根据大学生网络行为的特点和心理机制,验证了大学生网络行为的网络道德人际SEM模型.     

追踪研究中的内生性问题：来源与应对

相对于横断研究,追踪研究中更有可能同时存在多种内生性问题来源。双变量追踪研究在心理学因果分析中发挥了重要的作用,然而其中的内生性问题却未得到应有的关注,这可能会影响推论的准确性。追踪研究中内生性问题的来源视乎模型而定,主要包括遗漏变量、变量选择和样本选择、解释变量的测量误差、动态面板和变量之间的相互关系。本文以代表性追踪模型CLPM为例,展示了内生性问题的影响,讨论了在原模型中运用工具变量来建模以应对内生性问题的可行性,目的是使心理学研究者能够关注追踪研究中的内生性问题,更好地运用追踪模型进行因果分析。