Effects of Electromyostimulation on Knee Extensors and Flexors Strength and Steadiness in Older Adults

It is known that electromyostimulation (EMS) alone or superimposed over voluntary contraction (EV) can effectively improve muscle strength. However, the effect of this type of training on the ability to control force production at submaximal levels is unknown. The authors examined the effects of EV training on steadiness in force production of knee extensors and flexors in older adults. Forty participants, including 20 men and 20 women, 60–77 years of age, were randomly allocated into a control group (CG) and an electromyostimulation superimposed over voluntary contraction (EVG) group. The EVG performed 30 bilateral isometric knee extension and flexion contractions per session, 3 training sessions per week, for 6 weeks. The variations in force production, expressed in absolute (standard deviation [SD]) and relative (coefficient of variation [CV]) terms, were assessed in isometric contractions at 5%, 15% and 25% maximal voluntary contraction (MVC) levels. Results indicated that MVC increased in knee extension and flexion in EVG (p < .05) after the training; steadiness CV also improved at 15% MVC in knee flexion (p < .05) but no significant changes were found in knee extension and steadiness SD. The training-induced changes in MVC were not correlated to steadiness CV that might indicate different mechanisms underlying these adaptations.     

Bidirectional Mediating Role of Loneliness in the Association Between Shyness and Generalized Pathological Internet Use in Chinese University Students: A Longitudinal Cross-Lagged Analysis

Abstract

This 1-year longitudinal study examined the bidirectional mediating role of loneliness in the association between shyness and generalized pathological Internet use (GPIU) in a sample of 291 Chinese university students (143 men, mean age =?19.07?years). A fully cross-lagged panel design was used in which shyness, loneliness, and GPIU were assessed at 3 time points separated by 6-month intervals (named T1, T2, and T3). The results indicated that relationships among shyness, loneliness, and GPIU were dynamic and bidirectional. Specifically, T1 shyness positively predicted increased T2 loneliness, T2 shyness positively predicted increased T3 loneliness, and T2 loneliness positively predicted increased T3 shyness. Additionally, T1 GPIU positively predicted increased T2 loneliness, T2 GPIU positively predicted increased T3 loneliness, and T2 loneliness positively predicted increased T3 GPIU. Loneliness was found to play a bidirectional mediating role in the association between shyness and GPIU. Specifically, T1 shyness and T3 GPIU were mediated through increased loneliness at T2, and T1 GPIU and T3 shyness were mediated through increased loneliness at T2. Furthermore, relationships among shyness, loneliness, and GPIU were the same across the 2 groups, with the strength of relationships being stronger for men.     

Childhood Abuse and Neglect in an Outpatient Clinical Sample: Prevalence and Impact

The study examined the prevalence of five types of childhood trauma in a sample of adult clients (n = 497) as well as their long-term relation to trauma symptoms in adulthood. Results showed a high prevalence of abuse and neglect with emotional abuse and neglect being the most common ones. Emotional abuse was the best and strongest predictor of trauma symptoms in adulthood, including anxiety, depression, defensive avoidance, as well as internal confusion and emptiness. The results indicated that experience of emotional abuse is no less significant than that of physical and sexual abuse in its long-term impact. Clinical implication was provided.     

The Association Between Adult Attachment Styles and Conflict Resolution in Romantic Relationships

This study examined whether adult attachment was predictive of conflict resolution behaviors and satisfaction in romantic relationships. It adopted a two-dimensional conceptualization for both adult attachment style (model of self, model of others) and conflict resolution behaviors (concern for self, concern for others). Both adult attachment dimensions, Avoidance and Anxiety, were predictive of conflict resolution behaviors and relationship satisfaction. Gender differences existed in conflict resolution behaviors, but they were not as strong a predictor as attachment characteristics of conflict resolution and relationship satisfaction. No gender differences were found in attachment styles.     

Team–Member Exchange and Work Engagement: Does Personality Make a Difference?

Purpose

Adopting a person–situation interactionist framework, this study examined the joint effects of employee personality (i.e., extraversion, neuroticism, and conscientiousness) and social exchange relationships with peers (i.e., team–member exchange; TMX) in predicting work engagement.

Methodology

This study is based on survey responses from 235 Chinese employees collected at two time points with 3 months in between. We conducted moderated regression analyses to test the hypotheses that employees higher in extraversion or conscientiousness or lower in neuroticism would demonstrate a stronger TMX–work engagement relation.

Findings

Results from this study showed that the three focal personality traits moderated the TMX–engagement relation simultaneously. Specifically, the positive TMX–engagement relation was stronger for employees with higher extraversion or lower neuroticism than that for their counterparts. Interestingly, the TMX–engagement relation was positive for employees lower in conscientiousness but negative for those higher in conscientiousness.

Implications

These findings support the notion that lateral social exchange relationships in the workplace (i.e., TMX) are an important antecedent of work engagement and, more importantly, their beneficial effects on work engagement are contingent on certain types and/or levels of personality traits.

Originality/Value

This study not only advances our understanding of presumed antecedents of work engagement but also opens a new door for future research on work engagement by highlighting the importance of a person–situation interactionist framework.     

How Speech Modifies Visual Attention

Auditory distractions can have serious consequences in critical situations such as driving. Mobile phones, radios, media players, and information devices that interpret and produce speech are increasingly common in vehicles, but the threats to visual attention are not yet fully understood. In three experiments, we found that most speech tasks had relatively small adverse effects on the detection of a briefly presented target among distractors across a 60° subarea of the visual field. Although there was a little impact on detectability, moderately difficult speech tasks slowed responding relative to silence. Our most demanding condition—generating and speaking a word beginning with the last letter of another word—had the greatest effects on accuracy and latency, with responding slowed by about 900 ms. An impairment of this magnitude presents a significant threat to safe driving and calls into question the belief that hands‐free voice‐controlled devices are the answer to the problem of driver distraction. Copyright © 2013 John Wiley & Sons, Ltd.     

Core Knowledge Employee Creativity and Firm Performance: The Moderating Role of Riskiness Orientation,Firm Size,and Realized Absorptive Capacity

In this study, we examine when creativity is positively or negatively related to firm performance. Building on the creation–implementation tension theorized in the literature and the attention capacity perspective, we argue that the relationship between creativity and firm performance is contingent on riskiness orientation, firm size, and realized absorptive capacity. Data were collected from 761 core knowledge employees, 148 CEOs, and 148 HR executives from 148 high‐technology firms. The results indicated that core knowledge employee creativity was negatively related to firm performance when riskiness orientation was high. The relationship was positive when realized absorptive capacity was high. Finally, the relationship was more positive in small firms than in large firms. We discuss the implications of our findings for creativity research and managerial practices.     

汉语学龄前儿童正字法意识的发展

本研究选择北京地区幼儿园3岁、4岁、5岁儿童各31、48、33名, 采用单部件意识测验和部件位置及功能意识测验系统探查了学龄前儿童的正字法意识各个层面的发展状况。单部件意识测验包括部件替换、部件缺失和部件旋转三个部分; 部件位置及功能意识测验分为假字和非字两个部分, 而非字又包括两形非字和形声非字。结果发现单部件意识测验中, 5岁组儿童在部件替换水平上的得分显著高于3岁组儿童, 而3岁组与4岁组、4岁组与5岁组儿童之间无显著差异; 部件缺失和部件旋转水平上, 三个年龄段的儿童的得分表现出明显的增长趋势。部件位置及功能意识测验中, 假字得分在三个年龄段之间无显著差异; 非字得分随年龄增长显著提高。这些结果表明, 单部件意识在学前期处于不断发展的阶段, 其中对部件替换的非字的拒绝能力发展较早, 部件缺失和部件旋转非字的拒绝能力发展较晚; 部件位置及功能意识在学前期已经开始发展, 3岁儿童已经具有假字符合正字法规则的认识, 但对非字违反部件位置合法性和功能完整性的认识直到4岁左右才开始萌芽, 5岁还未成熟。     

伤害回避的脑机制及其生物基础

伤害回避是指个体对厌恶刺激信号做出强烈的反应,并学会被动地回避惩罚的一种倾向,这一倾向使得个体反复思考未来的结局,并谨慎小心地对待不确定情景中的事件,进而更有可能诱发情感障碍。伤害回避涉及的神经网络包括三个子网络,即额顶叶-前扣带皮层的连接、皮层-杏仁核的连接和白质通道的结构性连接,这三个子网络分别与羞怯感-易疲劳性、预期担心以及不确定环境中的害怕情绪有关。而其生物基础则包括单一基因多态性和基因多态间的交互作用。今后的研究应该集中在深化伤害回避神经网络与生物基础间的联合机制、研究三种及以上基因多态间的交互作用、考察其他因素对基因效应的调节作用、注重伤害回避四种亚型相关神经网络之间的连接、探讨5-HT4等其他几种5-羟色胺受体多态性与伤害回避的关系以及分析伤害回避内部机制在抗抑郁治疗中的作用等方面。