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.     

Evaluating video modeling and video modeling with video feedback to enhance the performance of competitive dancers

This study evaluated the use of video modeling and video modeling plus video feedback to enhance four adolescents' performance of a dance movement. Intervention was evaluated in a multiple baseline across participants design. This study found that video modeling enhanced performance from baseline, but the addition of video feedback produced further increases. For one participant, improvement was dependent on the perspective of the video model. Implications of these findings and suggestions for future research are discussed.     

Automatic grading and hinting in open-ended text questions

Open-ended text questions provide better assessment of learner’s knowledge, but analysing answers for this kind of questions, checking their correctness, and generating of detailed formative feedback about errors for the learner are more difficult and complex tasks than for closed-ended questions like multiple-choice.The analysis of answers for open-ended questions can be performed on different levels. Analysis on character level allows to find errors in characters’ placement inside a word or a token; it is typically used to detect and correct typos, allowing to differ typos from actual errors in the learner’s answer. The word-level or token-level analysis allows finding misplaced, extraneous, or missing words in the sentence. The semantic-level analysis is used to capture formally the meaning of the learner’s answer and compare it with the meaning of the correct answer that can be provided in a natural or formal language. Some systems and approaches use analysis on several levels.The variability of the answers for open-ended questions significantly increases the complexity of the error search and formative feedback generation tasks. Different types of patterns including regular expressions and their use in questions with patterned answers are discussed. The types of formative feedback and modern approaches and their capabilities to generate feedback on different levels are discussed too.Statistical approaches or loosely defined template rules are inclined to false-positive grading. They are generally lowering the workload of creating questions, but provide low feedback. Approaches based on strictly-defined sets of correct answers perform better in providing hinting and answer-until-correct feedback. They are characterised by a higher workload of creating questions because of the need to account for every possible correct answer by the teacher and fewer types of detected errors.The optimal choice for creating automatised e-learning courses are template-based open-ended question systems like OntoPeFeGe, Preg, METEOR, and CorrectWriting which allows answer-until-correct feedback and are able to find and report various types of errors. This approach requires more time to create questions, but less time to manage the learning process in the courses once they are run.     

La cross-évaluation : une approche d’évaluation et de développement des processus de travail inter-équipes

Organizational agility has become an increasing focus for companies and has led to the emergence of new developmental methods. This article presents the cross-evaluation as an approach to evaluating and developing inter-team interface efficacity. Though 360 degrees feedback collective processes are being evaluated, and during reflexive workshops they decide what improvements to make in their team functioning. Based on a literature review and more specifically on the theories of social identity and groupthink this article describes the scientific bases of the cross-evaluation method and the biases that can be involved and how to reduce them. It suggests new avenues of research and practical suggestions for practitioners about an inter-team development method.     

叠音人名的婴儿图式效应及其对人际信任的影响

叠音人名是一种特有的人名形式,但鲜有研究考察其心理特征。本研究通过4个实验探讨叠音人名的婴儿图式效应及其对人际信任的作用机制。实验1采用特质推断指标,结果发现个体认为叠音人名的主人更像婴儿。实验2采用反应类别指标,结果表明叠音人名产生了更强烈的积极情绪。实验3表明叠音人名不影响人际信任。实验4表明在获得正性反馈后,个体不会增加对叠音人名个体的人际信任;在获得负性反馈后,个体则会减少对叠音人名个体的人际信任。上述结果表明,叠音人名可以引发婴儿图式效应,叠音人名与结果反馈类型共同影响人际信任。     

Feedback functions, optimization, and the relation of response rate to reinforcer rate

The present experiment arranged a series of inverted U-shaped feedback functions relating reinforcer rate to response rate to test whether responding was consistent with an optimization account or with a one-to-one relation of response rate to reinforcer rate such as linear system theory's rate equation or Herrnstein's hyperbola. Reinforcer rate was arranged according to a quadratic equation with a maximum at a unique response rate. The experiment consisted of two phases, during which 6 Long Evans rats lever pressed for food. In the first phase of the experiment, the rats responded on six fixed-interval-plus-quadratic-feedback schedules, and in the second phase the rats responded on three variable-interval-plus-quadratic-feedback schedules. Responding in both phases was inconsistent with a one-to-one relation of response rate to reinforcer rate. Instead, different response rates were obtained at equivalent reinforcer rates. Responding did vary directly with the vertex of the feedback function in both phases, a finding consistent with optimization of reinforcer rate. The present results suggest that the feedback function relating reinforcer rate to response rate imposed by a reinforcement schedule can be an important determinant of behavior. Furthermore, the present experiment illustrates the benefit of arranging feedback functions to investigate assumptions about the variables that control schedule performance.     

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.