Planned Straight or Biased to Be So? The Influence of Visual Feedback on Reaching Movements

Abstract

Behavioral studies consistently find that subjects move their hand along straight paths despite considerations that suggest reaches should be curved. Literature on this topic makes it clear that the experimentally displayed feedback influences how subjects reach. Could the standard visual feedback, a displayed cursor, explain the lack of path curvature in experimental results? To address this question, we conducted three experiments to examine reach behavior in the absence of the standard visual feedback. In the first experiment, we found significant increases in curvature as visual feedback was progressively extinguished across groups. A second experiment revealed that practiced reaches became curved after the standard visual feedback was removed. A final experiment found that subjects’ reaches made before and after a brief display of visual feedback were similar, indicating a preference for specific curved trajectories. Our results suggest that the consistently straight reaches often observed could be due to a bias to move the displayed cursor straight, which when removed reveal subject-specific preferences for reaches that are often curved.     

The effects of video feedback on running form

Correct running form is important for injury prevention; as such, correct form promotes continued engagement in running as a long-term form of exercise. Researchers have shown video feedback to be an effective strategy to improve athletic form for a variety of sports, but it has not been evaluated in any behavior analytic research as a method for improving running form. The purpose of this study is to evaluate the effectiveness of video feedback to improve running form for regular runners. During baseline, each participant was video recorded while running without any feedback (verbal or video). During intervention, the researcher recorded the participant, then showed them the video and provided feedback on correct or incorrect form, according to a 9-step task analysis. Results show that all three participants achieved 100% correct steps on the task analysis when video feedback was used to maintain their form during follow-up.     

Stuttering and sensory gating: a study of acoustic startle prepulse inhibition

It was hypothesized that stuttering may be related to impaired sensory gating, leading to overflow of superfluous disturbing auditory feedback and breakdown of the speech sequence. This hypothesis was tested using the acoustic startle prepulse inhibition (PPI) paradigm. A group of 22 adults with developmental stuttering were compared with controls regarding the degree of PPI. No significant differences were found between the stuttering adults and the control group; the groups showed similar means and distribution. Likewise, no relation between the degree of PPI and the effect of altered auditory feedback on stuttering was found. In summary, the results of the study indicate that there is no relation between stuttering and PPI.     

Effects of public posting,goal setting,and oral feedback on the skills of female soccer players

We evaluated the effects of public posting, goal setting, and oral feedback on the skills of 3 female high school soccer players during practice scrimmages. The dependent variables were the percentage of appropriate responses when the player (a) kept and maintained possession of the ball, (b) moved to an open position during a game restart (e.g., goal or corner kick), and (c) moved to an open position after passing the ball. We also assessed the extent to which changes in practice performances generalized to games. A social validity questionnaire was completed by both players and coaches to assess the acceptability of the intervention's goals, procedures, and outcomes. Results indicate that the intervention was effective in improving performances during practice scrimmages but produced limited generalization to game settings.     

Feedback and its effectiveness in a computer-aided personalized system of instruction course

In a computer-managed version of Keller's personalized system of instruction, students received frequent feedback from more advanced students within the course. Overall accuracy of student-provided feedback was 87%, and students complied with 61% of the feedback.     

The assumed effects of positive feedback paired with success on motivation to do a task: The cases of characters with high and low initial levels of interest

This study investigated the effects of positive feedback paired with success on motivation to do a task, and examined whether this differed according to whether the person performing the task had a high or low initial level of interest in that task. Subjects (448 junior college students) were asked to rate (from 0–10) the level of motivation of characters in four different stories. Subjects believed that positive feedback would encourage the character to do a task regardless of initial level of interest. However, when positive feedback could not be expected, ratings for motivation fell. Ratings for motivation were further analyzed when no positive feedback could be expected, either after an earlier experience of positive feedback paired with success or after success only (no feedback). In the case of a low initial level of interest, it was assumed that motivation would be increased after positive feedback, but in the case of a high initial level of interest motivation was assumed to be decreased by an earlier experience of positive feedback paired with success. These results suggest that the effect of positive feedback paired with success will differ according to the level of a person's initial interest.     

当前医患关系紧张的经济学分析及对策

从经济学的角度对医患关系紧张的形成机制进行分析,揭示目前医患关系紧张的恶性循环是"正反馈"效应的负面体现。要形成医患关系的良性循环,首要的任务就是从制度层面上来找突破口,并以提倡患者理性医疗和加强医生的人文教育作为支持,使"正反馈"效应得到正面体现,从而实现医患关系的和谐。     

第二语言学习中的反馈

在第二语言学习中,反馈指针对学习者的言语行为给予学习者的评价性信息。该文阐释了反馈的概念、类型以及反馈在第二语言学习中的角色,并从反馈的时机与对象、对学习者注意力的引导、学习者认知资源的限制、情感支持等方面分析了有效反馈的特征,最后对反馈研究对我国第二语言学习与教学的意义及以后的研究方向进行了探讨     

音乐情感交流研究中的透镜模型

介绍了研究音乐情感交流的透镜模型和透镜模型等式及其在音乐教育中的应用。透镜模型旨在解释演奏者如何通过多种或然且部分过剩的线索表达情感,听者如何使用这些线索识别演奏者表达的情感。透镜模型等式（LME）将演奏者和听者线索利用的回归模型联系起来。以透镜模型为理论基础,LME为数学基础产生了用于改善音乐演奏中的情感交流的认知反馈法（CFB）,即在演奏者演奏结束之后,向演奏者反馈其线索利用与欣赏者的线索利用相比较的结果,以提高演奏者与听者线索利用的一致性