Self-Optimization of Walking in Nondisabled Children and Children With Spastic Hemiplegic Cerebral Palsy

Children voluntarily adopt a frequency and movement pattern for walking. The force-driven harmonic oscillator (FDHO) model was used in this study for accurate prediction of the preferred walking frequency of nondisabled children and children with spastic hemiplegic cerebral palsy. Four potential optimality criteria with which the preferred walking pattern was forced to comply were examined: minimization of physiological costs, maximization of mechanical energy conservation, minimization of asymmetry in lower limb movements and minimization of variability of interlimb and intralimb coordination. Age and gender-matched nondisabled children (n = 6) and children with spastic hemiplegic cerebral palsy (n = 6) were tested under six frequency conditions of walking at a constant speed on a treadmill. For the nondisabled children, the results indicated that their preferred walking frequency could be accurately predicted by the FDHO model. They freely adopted a walking pattern that minimized physiological costs, asymmetry, and variability of inter- and intralimb coordination. For the children with spastic hemiplegic cerebral palsy, the prediction of preferred overground walking frequency required that the FDHO model be modified to account for muscle mass and leg length discrepancies between limbs and increased stiffness. Most of the children achieved the same optimality goals as the nondisabled when walking at the preferred frequency. However, the children were found to use different mechanisms to attain these goals: for example, a steeper increase observed in physiological cost at higher frequencies; a lowered center of gravity of the body, which allowed for angular symmetry; and greater variability of between-joint coordination in the nonaffected limb and less variability in the affected limb.     

Case vignette: cybertherapy

Dr. Neuro Transmitter, a psychotherapist in Paramus, New Jersey, provides services through an online, real-time consultation service known as CyberShrink, Inc., of Dallas, Texas. He is paid by the hour for his consultation services to subscribers who are billed by credit card through CyberShrink. One afternoon he logs on and is connected via private "chat channel" to a new subscriber to the service. She is Ann Hedonia of Simi Valley, California. Ten minutes into the session, Dr Transmitter recognizes that Ms. Hedonia is seriously depressed with suicidal ideation and is feeling on the edge of her ability to cope. He gently suggests that perhaps she ought to think about hospitalization near her home. Ms. Hedonia replies, "Even you don't care about me! That's it. I'm going to do it!" and disconnects. Discussion questions: Is offering psychotherapy services online ethical? What are Dr. Transmitter's obligations in general and at this particular moment to Ms. Hedonia? Suppose Ms. Hedonia has a complaint about Dr. Transmitter. From whom can she seek a remedy? Which state's laws apply regarding professional practice, confidentiality, or licensing qualifications? Must Dr. Transmitter be licensed in any state to offer this service?     

对人的尊严的挑战——试论P.辛格的优先权——实利主义

一个社会对其成员重视和承认的程度,首先表现为这个社会如何对待其成员中的弱者和受歧视的人。而在每个社会遭受歧视的人中,无疑也包括那些由于先天或后天的缘故患有精神上或肉体上的疾病而需要特别照顾的人。1989年以来,首先是这一社会群体的代言人,对他们的遭遇提出了强烈的抗议。而他们的抗议,又引发了德国舆论界对澳大利亚哲学家彼得·辛格的关注。特别是辛格关于可以对残疾人(既包括先天不足的婴儿,也包括老年人)施行强制性安乐死的论述,点燃了论战的烽火,更激起了一部分人的强烈抗议。残疾人的代盲人指出,辛格的“实用伦理学”不仅是对“残疾人”,而且从根本上讲是对人的错误认识。     

外向性格、场独立性及认知作业的操作

 取120名12岁儿童作被试.(a)调查外向性格、神经过敏症及场独立性之间的关系.(b)调查外向性格和场依存性对两个认知作业(推理和回忆散文)的影响.(c)研究人格特点和言语——表象学习方式之间的关系.     

The development of the Telic Dominance Scale

The development of a 42-item measure of a number of personality features derived from the theory of psychological reversals is reported. These personality features are (a) the extent to which a person is serious-minded, (b) the extent to which a person plans ahead and organizes himself in the pursuit of goals, and (c) the extent to which a person seeks to avoid arousal. These features together are seen to constitute a personality trait which is described as telic dominance. Data concerning the test-retest reliability, criterion-related and construct validity of the Telic Dominance Scale are presented, together with the scale and scoring key.     

Responding maintained under fixed-interval and fixed-time schedules of electric shock presentation

Following initial histories under a schedule of electric shock postponement, lever pressing in squirrel monkeys was maintained under fixed-interval and fixed-time schedules of electric shock presentation. No difference in either rate or pattern of responding was obtained when these schedules were presented as components of a multiple schedule. When they were presented singly for long periods of time, the fixed-interval schedule consistently maintained a higher response rate than the fixed-time schedule. The pattern of responding under both schedules was similar, typically consisting of a pause at the beginning of each interval followed by either a steady or a positively accelerating rate of responding. The results suggest that the response-shock dependency is of critical importance in the maintenance of high rates of responding under schedules of electric shock presentation, and support the general view that such responding may be conceptualized as operant behavior under control of many of the same variables that control responding under comparable schedules of food or water reinforcement.