The growth of stability: postural control from a development perspective

This study compared central nervous system organizational processes underlying balance in children of three age groups: 15-31 months, 4-6 years, and 7-10 years, using a movable platform capable of antero-posterior (A-P) displacements or dorsi-plantar flexing rotations of the ankle joint. A servo system capable of linking platform rotations to A-P sway angle allowed disruption of ankle joint inputs, to test the effects of incongruent sensory inputs on response patterns. Surface electromyography was used to quantify latency and response patterns. Surface electromyography was used to quantify latency and amplitude of the gastrocnemius, hamstrings, tibialis anterior, and quadriceps muscle responses. Cinematography provided biomechanical analysis of the sway motion. Results demonstrated that while directionally specific response synergies are present in children under the age of six, structured organization of the synergies is not yet fully developed since variability in timing and amplitude relationships between proximal and distal muscles is high. Transition from immature to mature response patterns was not linear but stage-like with greatest variability in the 4- to 6- year-old children. Results from balance tests under altered sensory conditions (eyes closed and/or ankle joint inputs altered) suggested that: (a) with development a shift in controlling inputs to posture from visual dependence to more adult-like dependence on a combination of ankle joint and visual inputs occurred in the 4- to 6-year-old, and reached adult form in the 7- to 10-year-old age group. It is proposed that the age 4-6 is a transition period in the development of posture control. At this time the nervous system (a) uses visual-vestibular inputs to fine tune ankle-joint proprioception in preparation for its increased importance in posture control and (b) fine tunes the structural organization of the postural synergies themselves.     

Reflex responses of human lip muscles to mechanical stimulation during speech

The role played by reflex pathways in the production of movement has been a significant issue for motor control theorists interested in a wide variety of motor behaviors. From studies of locomotion and chewing, it appears that gains in reflex pathways can be altered so that activity in these pathways does not produce destabilizing responses during movement. In speech production, recent experimental evidence has been interpreted to suggest that autogenetic lip reflexes (perioral reflexes) are suppressed during sustained phonation or speech production. The present study was conducted to assess the effects of phonation, direction of movement, and ongoing speech production on reflex responses of lip muscles. The present results suggest, in contrast to earlier work, that this reflex pathway is not suppressed or absent because the amplitude of the observed response depends upon the activation levels of the various muscles of the lower lip and, therefore, indirectly on the nature of the gesture the subject is instructed to produce.     

Symmetry and transitivity of conditional relations in monkeys (Cebus apella) and pigeons (Columba livia)

In Experiment 1 six monkeys were tested with discriminative relations that were backward relative to their training in a 0-second conditional (“symbolic”) matching procedure. Although there was some indication of backward associations, the evidence was generally weak, and statistical evaluations did not reach conventional significance levels. Unlike children, who show backward associations to the point of symmetry, monkeys and pigeons display at best only weak and transient backward associations. In Experiment 2 associative transitivity was assessed across two sets of conditional matching tasks. All four monkeys tested demonstrated strong transitivity. In contrast, in Experiment 3 there was no evidence of transitivity in three pigeons tested under conditions closely comparable to those of Experiment 2. These results may identify some key features of interspecies differences and contribute to analyses of serial learning in animals.     

A scale for measuring persistence in children

Persistence and its assessment have been studied since the 1920s. One common approach in measuring persistence has been through testing the subject's ability to solve difficult or monotonous problems. Another approach has been through questionnaires. Although persistence is very important in academic achievement and in the general development of personality, no questionnaires have been developed for measuring persistence in children. The present research concerns the development of such a scale. It includes 40 items and was tested on 322 Israeli children aged 7-13. The internal reliability of the scale (Cronbach alpha) was .66, and the test-retest reliability after 6 months was .77. The scale differentiated active gymnasts from non-gymnasts as well as persistent gymnasts from dropout gymnasts. In addition, significant correlations were found between the scale and the need-persistence measure of the Rosenzweig Picture Frustration Study, Locus of Control, and other measures. We discuss these findings along with the significance of persistence in everyday life.     

Testing the dimensionality of the self-consciousness scales

The self-consciousness scale of Fenigstein, Scheier, and Buss (1975) was subjected to internal and external consistency tests based on the classical test theory model. The scale was found to have five underlying dimensions: two for private self-consciousness (viz., self-reflectiveness and internal state awareness), two for public self-consciousness, and one for social anxiety. The confirmatory factor analysis procedures employed by Burnkrant and Page (1984) are shown to be fallible as indicators of unidimensionality. Theoretical implications of newly identified dimensions in the public self-consciousness subscale are discussed.     

攻击的社会性认知学习的调节

这项研究探索了小学儿童的攻击与影响儿童是否采取攻击行为的社会认知的两个等级的联系.给攻击性和非攻击性的儿童(平均年龄为11.3岁)提供二个调查表,让他们进行回答.一个调查表是测量儿童对自己进行攻击的能力及相应的行为的认识(即自我实力的认识),而另一个调查表则测量儿童对攻击性行为会得到的奖励和惩罚的后果的认识.     

悖论,类型论以及解救悖论的其它方法(续)

罗素的观点看来是主张,类型论提供了避免一切悖论的方法,此外类型论在本质上还是这种方法的理论基础。让我们依次来考虑这两点。晚近的作者在所谓“语义悖论”和集合论悖论之间作出了区分,而罗素没有这样做。埃匹曼尼德悖论被称为语义悖论,因为它在本质上涉及到真的概念(谎话是不真的);并且“真”被称作一种语义关系,因为它是     

运动心理学的历史和当前的研究课题

一、历史运动心理学的基础在于运动学习和动作操作。1920年之前,就有少数人单独地进行一些零星分散的调查。这些调查推动了各种心理变量影响动作操作的研究。首先在美国发表的是观众对自行车比赛的影响。在1918年,伊利诺斯大学的心理学家C·R·格里菲斯对足球运动员和篮球运动员的反应时进行了比较,这仅仅为以后的研究播下了一些种子。在此期间,其它国家(苏联、德国和日本)也有类似的研究。 1920—1940年间,有些人对运动心理学的研究发生了特殊的兴趣。美国的运动心理学之父 C·R·     

欧州关于领导问题的研究

欧洲学者对于领导问题始终保持着兴趣。现代的有关研究有别于美国,更注重理论探讨,所考查的因素也更为广泛。英国伦敦塔维斯托克人类关系所的研究将组织看作为“社会-技术”系统,而领导就负责管理系统内各子系统间以及与环境间边界关系的过程。英国阿斯顿大学则认为是组织的整体结构而不是个别管理者的领导行为方式决定了组织的运行。斯图亚特的学说介乎两者之间,它将领导分为必须完成的、自愿完成的任务和限制完成任务的因素三种成分,这样领导既是被决定的,又是可作出选择的。在欧洲对领导问题中参与过程的研究很流行。几项大规模的调查表明参与性决策具有差异性和阶段性,因而海勒-维尔波特提出权变理论。领导问题的研究应朝着能够对在某一具体情景下领导者应如何行动作出预测的方向进行。     

模态逻辑的某些认知解释

Ⅰ我们的信念(至少)在两方面是模糊的:所相信的命题是模糊的(含有模糊的概念),相信与不相信的界限是模糊的,就是说相信这个概念本身是模糊的。通过下面的语句我们来说明后一种类型的模糊性。(1)光比声音传播的速度快。(2)大量的维生素 C 预防流感。(3)奥尔弗·帕尔梅将在1980年出任瑞典总理。(4)大卫·休谟身高五英尺六英寸。