On optimal smoothing and derivative estimation from noisy displacement data in biomechanics

Estimating derivatives from noisy displacement data is a notoriously ill-posed problem in signal processing and biomechanics. Following the work of Wood and Jennings (1978) and Hatze (1979, 1981), the present paper describes the use of optimally regularized, natural quintic splines for estimating smoothed positions, velocities, and accelerations from equidistantly sampled, noisy position measurements. It appears that the nature of the boundary conditions of the data is of some importance, since various algorithms used hitherto result in artefacts throughout the data if the true derivatives at the record ends differ significantly from zero. Natural quintic splines do not suffer from this disadvantage below the third derivative.The ill-posed character of movement analysis has some interesting implications for movement synthesis and optimization, similar to the indeterminacy of muscular co-contraction from merely external, biomechanical measurements.     

高中生感知教师支持与学习投入的关系:学业自我效能感和成就目标定向的链式中介作用

采用感知教师支持、学习投入、学业自我效能感和成就目标定向问卷对498名高中生进行问卷调查,探讨感知教师支持对学习投入的影响,以及学业自我效能感和成就目标定向的链式中介效应。结果显示：（1）感知教师支持能通过学业自我效能感间接预测高中生学习投入,感知教师支持可以通过掌握趋近、表现趋近、表现回避间接预测高中生学习投入;（2）学业自我效能感→掌握趋近、学业自我效能感→表现趋近、学业自我效能感→表现回避三者分别在感知教师支持与学习投入之间起链式中介作用,学业自我效能感→掌握回避的中介效应则不显著。上述结果表明,感知教师支持不仅能分别通过学业自我效能感、掌握趋近、表现趋近、表现回避预测高中生学习投入,还能通过学业自我效能感和成就目标定向的链式中介作用间接预测高中生学习投入。     

Beyond the relational principle of reinforcement

Behavior under baseline conditions in which the contingency is absent can shed some light on the individual's performance under a schedule, but is insufficient as a basis for prediction of performance. This insufficiency of the baseline data runs counter to a recent formalization of the relational principle of reinforcement (Donahoe, 1977). A more satisfactory predictive model must incorporate not only the baseline level of the instrumental response and that of the contingent response, but also the schedule requirements, the character of each response in relation to the other, and the behavior required in simply switching from each to the other.     

Effects of attack and uncontrollable noise on aggression

After being either attacked or treated in a more neutral manner by an experimental confederate, male subjects shocked the confederate while being stimulated by loud noise. Among previously attacked subjects, possession of control over offset of the noise led to the delivery of shocks significantly shorter in duration than those given by subjects who did not have control. Mere predictability of noise offset did not have the same effect. Subjects who could control the noise did not differ from those who heard no noise with respect to the duration of shocks given. Noise had no effect on shock duration among nonattacked subjects. In a follow-up study subjects who were given bogus information that they were aroused by noise were less punitive toward an attacking confederate than subjects given no such information. The overall conclusion is that noise facilitates aggression in subjects who have been instigated to aggress to the degree that noise-produced arousal is misattributed to the instigating stimulus.     

The use of a self-control package to enhance temporal generality of a parent training program

The purpose of the present study was to examine the effectiveness of a self-control package in enhancing temporal generality of a parent training program. Sixteen mothers and their clinic-referred noncompliant children were assigned to either a parent training alone group, or a parent training plus self-control group. All mother-child dyads were treated individually by teaching the mother to reward compliance and other prosocial behavior, and to use time-out for noncompliance. In addition, mothers who also received self-control training learned to self-monitor their use of their new parenting skills and to reinforce themselves for use of the skill during a 2 month follow-up period. Assessment consisted of four home observations by independent observers prior to treatment, after treatment, and at a 2 month follow-up. The data indicated that the children in the parent training plus self-control group were significantly more compliant and less deviant at the 2 month follow-up than the children in the parent training alone group. Parental behavior did not differ between the two groups at the follow-up.     

Development of comprehension of sentences with “because” or “if”

The comprehension of sentences with “because” or “if” was investigated in children aged 2;9–11;11. Imitation, comprehension (choosing one of two picture sequences to go with a sentence), recognition (judging sentences with connective or structure differences as heard before or not), and synonymy (judging equivalence of meaning in sentences with different connectives or structures) tasks were administered, along with logical ordering, reversibility, and classification tasks. Above-chance responding in the comprehension task occurred by age 8, and in recognition and synonymy by age 10. Cognitive performance predicted 28.4% of the variance in the linguistic scores and cognitive success was concurrent with or preceded linguistic success. Comprehension of “because” and “if” appears to develop gradually, and is related to the development of certain operative rules.     

Visual processing of multielement arrays and selective backward masking

In the first of two selective masking experiments, 7-letter rows were followed at several ISIs by a mask or no-mask and a bar-marker partial report cue. The results suggest that the arrays were processed ends-first and then, in general, from both ends towards the middle. In the second experiment, bar-marker partial report cues were presented at the onset or offset of 6-letter/1-digit or 7-letter rows. The subjects could not anticipate the category of the to-be-reported item with the alphanumeric displays. With a delayed cue, selective masking was obtained with both mixed category and pure letter arrays, but with simultaneous cuing, masking was always distributed across all serial positions. The results suggest that the subjects: (a) abstracted some information about category from the mixed arrays during an initial parallel stage of processing, (b) selectively attended to mainly the cued item with simultaneous probes with homeogeneous and mixed category displays, and (c) employed an ends-first processing strategy with both types of arrays when the bar-marker partial report cue was delayed.     

Relationship between response to graded exposure and marital satisfaction in agoraphobics

Agoraphobics who were satisfied in their marriage responded well to graded exposure and maintained their improvement to 3-months follow-up. Satisfaction with self and partner remained unchanged in patient and spouse. Agoraphobics who were dissatisfied with their marriage improved initially with graded exposure but later lost most of their gains and reported no change in general neurotic symptoms. Marital dissatisfaction also remained unchanged. Patients' dissatisfaction with their spouses, measured before therapy, predicted outcome in the sample as a whole.     

A comparison between the development of the appearance-reality distinction in the People's Republic of China and the United States

A study of the appearance-reality distinction in American 3- to 5-year-olds was replicated with Chinese 3- to 5-year-olds. The error patterns, age changes, and absolute levels of performance were similar in the two samples. It was speculated that the acquisition of this distinction may be a universal, possibly age-linked development that is probably fueled by experiences with appearance-reality discrepancies that are available in all cultures.     

The ecological approach to perceiving as a foundation for understanding the development of knowing in infancy

The ecological thesis of direct realism is used as a framework for examining the development of knowing in human infancy. When information for perceiving is defined ecologically (i.e., relative to the situational context and to the physical dimensions, capabilities, and needs of the perceiver), knowing need not be construed as the act of using representations to give meaning to acts or percepts. Knowing, alternatively, is the act of noticing affordances, situation and perceiverspecific meanings of objects, according to their value to the perceiver for achieving specific goals. Changes with development in infant sensorimotor functioning may, in this view, be explained by a process of increasing economy in noticing potentially available affordances, rather than a process of constructing a representational system for making present something not present. Studies of three infant skills widely attributed to the onset of representation are examined with regard to this ecological thesis. Results indicate that the noticing of affordances is critically involved in each of these skills.