Judgmental forecasts of time series affected by special events: does providing a statistical forecast improve accuracy?

Time series found in areas such as marketing and sales often have regular established patterns which are occasionally affected by exogenous influences, such as sales promotions. While statistical forecasting methods are adept at extrapolating regular patterns in series, judgmental forecasters have a potential advantage in that they can take into account the effect of these external influences, which may occur too infrequently for reliable statistical estimation. This suggests that a combination of statistical method and judgment is appropriate. An experiment was conducted to examine how judgmental forecasters make use of statistical time series forecasts when series are subject to sporadic special events. This was investigated under different conditions which were created by varying the complexity of the time series signal, the level of noise in the series, the salience of the cue, the predictive power of the cue information and the availability and presentation of the statistical forecast. Although the availability of a statistical forecast improved judgment under some conditions, the use the judgmental forecasters made of these forecasts was far from optimal. They changed the statistical forecasts when they were highly reliable and ignored them when they would have formed an ideal base‐line for adjustment. Copyright © 1999 John Wiley & Sons, Ltd.     

Using auditory feedback in body weight training

Auditory feedback has been successfully used to enhance performance in several sports such as golf and dance. The current study used auditory feedback procedures (i.e., a clicker) to improve the performance of 3 students performing a handstand. Handstands are part of a discipline called body weight training, that uses only the weight of an individual's own body to gain strength and body control. A multiple baseline design across four components was used to evaluate the effectiveness of auditory feedback. The results showed that auditory feedback was effective. The students and the trainer were highly satisfied with the auditory feedback procedure. Implications for future research are discussed.     

Promoting the development of verbal responses using instructive feedback

Shillingsburg, Frampton, Cleveland, and Cariveau (2018) taught listener and tact by feature, name–feature intraverbal, and feature–name intraverbal responses across sets and reported emergence of responses that were not directly trained for 6 individuals diagnosed with autism spectrum disorder (ASD). The current study was a systematic replication with the addition of instructive feedback (IF) with 2 children diagnosed with ASD. During trials for previously mastered listener by name responses (e.g., “Point to Tennessee” and child selects a picture of Tennessee), the experimenters provided related IF (e.g., “The capital of this state is Nashville”). After 3 sessions, we evaluated the effects of IF on related verbal responses (e.g., listener by feature, tact by feature, name–feature intraverbal, and feature–name intraverbal) across sets probes. We observed increased correct responses for related verbal responses; replicating Shillingsburg et al. Results suggest that the inclusion of IF may increase the efficiency of verbal behavior programming.     

The Influence of Contraction Types on the Relationship Between the Intended Force and the Actual Force

Abstract

It has been demonstrated that the intended force (subjective estimation of force) does not always match to actual force without external feedback. The purpose of this study was to compare the influence of ballistic and tonic contractions on the relationship between the intended and actual force. Subjects produced isometric force at requested percentages of their MVC (20, 40, 60 and 80%) based on subjective estimation of force under two conditions (tonic and ballistic conditions). The tonic condition was to maintain force production, whereas the ballistic condition was to produce force as fast as possible. As a result, the actual force amplitude, the coefficient of variance and EMG amplitude were larger under the ballistic contraction compared with the tonic condition, even the same intended force levels. These results suggest that different motor unit activity and control systems in the ballistic and tonic contractions could alter the relationship between the intended force and the actual force.     

基于即时反馈的反应抑制训练对青少年和成人执行功能的训练效应和迁移效应

本研究以基于即时反馈的Stop Signal范式为训练任务, 考察3周训练是否对青少年和成人的执行功能产生训练效应和迁移效应。发现青少年、成人实验组和积极控制组都出现了训练效应。两个实验组均产生了对反应抑制Go/No-go任务的迁移效应; 但只有青少年实验组出现了对干扰抑制Stroop任务的迁移效应。成人实验组和积极控制组都出现了对2-back任务的迁移效应; 但只有青少年实验组出现了在2-和3-back任务上的迁移效应。所有组别都未能出现对推理能力的迁移。研究证明从青春期到成年期, 基于即时反馈的反应抑制训练能够对执行功能产生训练和迁移效应, 但迁移仅限于抑制和工作记忆等基础成分, 无法改善推理能力。     

A pseudo-dynamic search ant colony optimization algorithm with improved negative feedback mechanism

To solve low convergence precision and slow convergence speed, a pseudo-dynamic search ant colony optimization algorithm with improved negative feedback mechanism (PACON) is proposed. Firstly, the algorithm introduces an angle in the pheromone transfer rule. Through the rule for calculating the angle, multiple cities with smaller angles are also included in the next candidate city list. It affects the probability of city selection and enhances the algorithm’ performance to avoid local optimization. Secondly, the algorithm updates the pheromone concentrations on the worst and optimal path simultaneously, and enhances the weights of the pheromone concentrations on the optimal path. It improves the convergence speed of the algorithm. Based on experiments adopting TSPLIB data sets, the results demonstrate the improved algorithm improves the convergence accuracy by at least 1.26% and increases the convergence speed by at least 9.5%, both on large-scale and small-scale urban data. The novel algorithm will improve convergence precision and speed better.     

奖赏刺激的脑电反应特征跨文化差异:一个ERP研究

本研究从文化--社会神经科学的角度出发,采用事件相关电位的方法来探究不同文化背景下的个体对具有进化和社会文化代表性的正性刺激—奖赏刺激的脑电反应特征是否具有差异。本研究采用the Door Task实验范式考察了26名中国人和24名高加索白人对不同反馈反应的脑电特征跨文化差异。结果显示,负性反馈条件下诱发的FRN平均波幅比正性反馈条件诱发的平均脑电波幅更负,这种正负反馈的波幅差异只在中国被试中有体现。在P3成分上,在正性反馈条件下,中国被试诱发的脑电波幅大于西方被试,负性反馈条件下,两组无显著差异。研究结果表明,相对于西方被试,中国被试对奖赏反馈刺激可能具有较高的敏感性。这说明中西方文化下的个体对正负性反馈刺激的加工的脑电反应特征存在显著的差异。     

不同类型反馈对儿童学习效果的影响及性别差异

儿童阶段是对外部反馈最敏感的阶段。以往研究发现,不同类型反馈（积极/消极反馈）和不同性质的强化物（物质/社会性强化）对儿童学习效果存在交互作用,并且对不同性别儿童的影响有所不同。本研究通过两个实验,采用联结学习范式以考察不同类型反馈对8~10岁儿童学习效果的影响。首先考察了积极反馈和消极反馈对儿童学习效果的影响,进而在积极、消极反馈的基础上加入了物质、社会性强化物,探究物质、社会性强化条件下积极、消极反馈对儿童学习效果影响的性别差异。结果表明,对于8~10岁儿童来说,消极反馈比积极反馈对儿童学习效果的影响更大。并且,物质、社会性强化物对儿童反馈学习效果的影响存在性别差异,对于男孩来说,在物质性强化条件下,消极反馈更能促进其学习;而对于女孩来说,在社会性强化物下,消极反馈更能促进她们的学习。该研究为如何运用反馈促进儿童学习提供了实证依据。     

Combined Audience and Video Feedback With Cognitive Review Improves State Anxiety and Self-Perceptions During Speech Tasks in Socially Anxious Individuals

This study investigated the effects of combined audience feedback with video feedback plus cognitive preparation, and cognitive review (enabling deeper processing of feedback) on state anxiety and self-perceptions including perception of performance and perceived probability of negative evaluation in socially anxious individuals during a speech performance. One hundred and forty socially anxious students were randomly assigned to four conditions: Cognitive Preparation + Video Feedback + Audience Feedback + Cognitive Review (CP + VF + AF + CR), Cognitive Preparation + Video Feedback + Cognitive Review (CP + VF + CR), Cognitive Preparation + Video Feedback only (CP + VF), and Control. They were asked to deliver two impromptu speeches that were evaluated by confederates. Participants’ levels of anxiety and self-perceptions pertaining to the speech task were assessed before and after feedback, and after the second speech. Compared to participants in the other conditions, participants in the CP + VF + AF + CR condition reported a significant decrease in their state anxiety and perceived probability of negative evaluation scores, and a significant increase in their positive perception of speech performance from before to after the feedback. These effects generalized to the second speech. Our results suggest that adding audience feedback to video feedback plus cognitive preparation and cognitive review may improve the effects of existing video feedback procedures in reducing anxiety symptoms and distorted self-representations in socially anxious individuals.     

Synergies and Motor Equivalence in Voluntary Sway Tasks: The Effects of Visual and Mechanical Constraints

The authors used two analyses developed within the framework of the uncontrolled manifold hypothesis to quantify multimuscle synergies during voluntary body sway: analysis of intertrial variance and analysis of motor equivalence with respect to the center of pressure (COP) trajectory. Participants performed voluntary sway tasks in the anteroposterior direction at 0.33 and 0.66 Hz. Muscle groups were identified in the space of muscle activations and used as elemental variables in the synergy analyses. Changing mechanical and vision feedback–based constraints led to significant changes in indices of sway performance such as COP deviations in the uninstructed, mediolateral direction and indices of spontaneous postural sway. In contrast, there were no significant effects on synergy indices. These findings show that the neural control of performance and of its stability may involve different control variables and neurophysiological structures. There were strong correlations between the indices of motor equivalence and those computed using the intercycle variance analysis. This result is potentially important for studies of patients with movement disorders who may be unable to perform multiple trials (cycles) at any given task, making analysis of motor equivalence of single trials a viable alternative to explore changes in stability of actions.