Changes in the relationship between movement velocity and movement distance in primary focal hand dystonia

The authors examined the relationship between movement velocity and distance and the associated muscle activation patterns in 18 individuals with focal hand dystonia (FHD) compared with a control group of 18 individuals with no known neuromuscular condition. Participants performed targeted voluntary wrist and elbow flexion movements as fast as possible across 5 movement distances. Individuals with FHD were slower than controls across all distances, and this difference was accentuated for longer movements. Muscle activation patterns were triphasic in the majority of individuals with FHD, and muscle activation scaled with distance in a similar manner to controls. Cocontraction did not explain movement slowing in individuals with dystonia, but there was a trend toward underactivation of the 1st agonist burst in the dystonic group. The authors concluded that slowness is a consistent feature of voluntary movement in FHD and is present even in the absence of dystonic posturing. Underactivation of the 1st agonist burst appears to be the most likely reason to explain slowing.     

Statistical properties of four effect-size measures for mediation models

This project examined the performance of classical and Bayesian estimators of four effect size measures for the indirect effect in a single-mediator model and a two-mediator model. Compared to the proportion and ratio mediation effect sizes, standardized mediation effect-size measures were relatively unbiased and efficient in the single-mediator model and the two-mediator model. Percentile and bias-corrected bootstrap interval estimates of ab/s _Y , and ab(s _X )/s _Y in the single-mediator model outperformed interval estimates of the proportion and ratio effect sizes in terms of power, Type I error rate, coverage, imbalance, and interval width. For the two-mediator model, standardized effect-size measures were superior to the proportion and ratio effect-size measures. Furthermore, it was found that Bayesian point and interval summaries of posterior distributions of standardized effect-size measures reduced excessive relative bias for certain parameter combinations. The standardized effect-size measures are the best effect-size measures for quantifying mediated effects.     

兒童第一和第二信号系統的相互动力傳遞的实驗研究

<正> 巴甫洛夫关于两种信号系統的学說指出,我們关于周围环境的感觉和表象乃是現实的第一信号系統,而詞则构成現实的第二信号系統;第二信号系統是在第一信号系統的基础上形成起来的,它們二者是密切联系着、相互作用着的。由于巴甫洛夫的这一偉大学說的啟示,在高級神經活动生理学和心理学这两个領域里已展开了和展开着一系列关于两种信号系統相互作用的实驗研究。     

Children: Yes or No,A Decision-Making Program for Women

This article describes how a workshop for career women who were experiencing difficulty in deciding whether or not to have a child was designed, conducted, and evaluated.