Postural leaning direction challenges the manifestation of tendon vibration responses at the ankle joint

In this study, we examined the interaction between central and peripheral proprioceptive afferent pathways by applying ankle tendon vibration during postural leaning in different directions. Twenty young participants stood for 60s over the midline of two adjacent force platforms in (a) neutral stance distributing Body Weight (BW) equally between the platforms, (b) forward leaning transferring 80% of BW to the front platform and (c) backward leaning transferring 80% of BW to the rear platform. Participants controlled the degree of leaning by receiving on-line visual feedback of BW distribution matched to a target line. Vibration (80 Hz, 1.5–1.8 mm) was applied over the Achilles or tibialis anterior tendon during the middle 20s of standing. This induced a postural shift towards the vibration side and an increase in the variability of the BW distribution that was greater in backward compared to forward leaning. EMG responses to tendon vibration were independent of the leaning direction. Antagonistic activity also increased in response to vibration, the amplitude of this increase however was direction dependent. These results favor the hypothesis about the central co-modulation of the vibration evoked proprioceptive inflow based on postural and visual feedback rather than muscle tension constraints.     

When Fluency Signals Truth: Prior Successful Reliance on Fluency Moderates the Impact of Fluency on Truth Judgments

Repeated statements are more frequently judged to be true. One position relates this so‐called “truth effect” to metacognitive experiences of fluency, suggesting that repeated statements are more frequently judged to be true because they are processed more fluently. Although most prior research focused on why repetition influences truth judgments, considerably less is known about when fluency is used as information. The present research addresses this question and investigates whether reliance on fluency is moderated by learning experiences. Specifically, we focus on changes in the reliance on fluency over the course of time. A series of experiments reveals that fluency is more likely to be used in truth judgments when previous reliance on fluency has resulted in valid judgments, compared with when previous reliance on fluency was misleading. These findings suggest that reliance on fluency in judgments is a finely tuned process that takes prior experiences with fluency‐based judgments into account. Copyright © 2013 John Wiley & Sons, Ltd.     

抑郁个体对社会反馈的加工：研究现状及存在问题

抑郁症伴随着严重的社会功能障碍。本文以“社会反馈”这一重要社会性信息为切入点,综述了抑郁症患者及抑郁倾向人群对社会反馈的体验、期待及情绪调节障碍的研究现状,发现抑郁个体对社会奖赏存在快感缺失,对社会排斥、社会拒绝等负性反馈表现出过敏化,对社会奖赏的期待降低,且可能存在情绪调节困难。目前此领域存在社会与非社会反馈神经机制的异同不清楚、异常脑区与社会反馈加工障碍的因果关系难以确定以及无法排除抑郁症患者和抑郁倾向人群存在不同社会反馈加工模式的可能性等问题。     

上司地位知觉对下属默契的影响——反馈寻求行为和观点采择的作用

下属默契指的是下属与上司间不经言传而暗相投合的状态,它能潜移默化地提升下属绩效。因此,探讨下属默契的产生原因,对组织有着重要意义。鉴于此,本文以目标动机模型为理论基础,探讨了上司地位知觉对下属默契的影响及其内部机制。通过对186名企业员工的调查分析发现,上司地位知觉对下属默契有显著的正向影响;反馈寻求行为在此过程中起部分中介作用;此外,下属的观点采择能力调节了反馈寻求行为与下属默契间的正向关系。     

反馈类型和反馈时间对动作技能获得的影响

基于简单直线运动任务和复杂曲线追踪任务,在运动技能获得阶段考察不同反馈类型和反馈时间对操作绩效的影响。结果发现,在复杂曲线轨迹追踪任务中,接受运动轨迹反馈的被试组比接受偏差数值反馈组的成绩更好;即时反馈和延迟反馈组的操作绩效间没有显著差异。在简单直线运动任务中,提供落点偏差的图形反馈组成绩始终优于提供“近/远”信息的文本反馈组;在练习初期,即时反馈组成绩更好。说明,反馈信息的具体-抽象程度影响被试运动技能获得,提供具体直观的轨迹/图形反馈利于运动技能获得;反馈时间对运动技能的影响因任务难度而异。     

反馈时间、反馈类型和掩蔽类型对概率类别学习的影响

通过操纵反馈时间(即时,延迟)、反馈类型(简单,丰富)和掩蔽类型(塔罗牌,空白矩形),考察概率类别学习的学习机制。结果发现:(1)被试的学习成绩在即时反馈条件下显著优于在延迟反馈条件下;(2)在即时反馈条件下,仅给予简单反馈,被试虽能出色地完成天气预报任务,但是不能正确地判断卡片预测晴天的概率,倾向内隐学习;(3)在其他条件下,被试能正确地判断卡片预测晴天的概率以及各卡片在天气预报任务中预测天气的重要程度,表明被试能外显地意识到这些线索的作用。综上,概率类别学习采用的是双系统学习机制,既依赖内隐学习,又依赖外显学习。     

Direct remembering,mediated remembering,and atypical forgetting functions

Atypical forgetting functions have been demonstrated in several recent studies of delayed matching to sample, in which experimental conditions are altered partway through the retention interval. The forgetting functions are atypical in that accuracy or discriminability is not always a negatively accelerated monotonic function of increasing retention interval duration, but may increase at later times in the retention interval. Atypical forgetting functions reflect changes in levels of discrimination. A switch from a lower level to a higher level of discrimination, or vice versa, can occur at any time in the retention interval. The behavioral theories of remembering proposed by Nevin, Davison, Odum, and Shahan (2007), and White and Brown (2014), offer quantitative predictions of forgetting functions that differ in intercept or slope. Both theories are able to account for atypical forgetting functions, by assuming time‐independent changes in the mediating effect of attending to sample and comparison stimuli (in Nevin et al.'s model) or in the direct effect of the context of reinforcement of the conditional discrimination (in White & Brown's model). Despite differences in their main assumptions, the theories have an edge over any theory that assumes that forgetting is time‐dependent.     

Response acquisition by zebrafish (Danio rerio) with delayed reinforcement

Zebrafish (Danio rerio) is a common vertebrate animal model in biomedical research and is a promising species for studying how genes interact with environmental factors in determining behavior. The present study investigated how reinforcement parameters affect zebrafish behavior by assessing response acquisition with delayed reinforcement, which has been studied with other species (e.g., rats, pigeons, humans, etc.) but not with zebrafish. Twenty‐four experimentally naïve subjects were exposed to a tandem fixed‐ratio 1 differential‐reinforcement‐of‐other‐behavior x‐s schedule of reinforcement, where x varied across subjects. There were six different delay‐to‐reinforcement durations and sets of four fish were assigned to each delay duration. All of the fish assigned to a 0‐, 0.5‐, or 1‐s delay acquired responding. Two fish acquired responding with a 3‐s delay and one fish appeared to have acquired it with a 6‐s delay although the latter result was less clear. None acquired responding with a 12‐s delay. These results suggest that zebrafish behavior is sensitive to delays to reinforcement and the time frame over which reinforcement is effective may be limited approximately to 6 s. This time frame is shorter than that found with other species. Practical and theoretical implications of the present finding are discussed.     

Equivalence class formation as a function of preliminary training with pictorial stimuli

The present experiment investigated the effects of preliminary training with pictorial stimuli on the subsequent formation of three 5‐member equivalence classes (A?B?C?D?E) in 84 university students assigned to seven groups of 12. In the Abstract (ABS) group, all stimuli were abstract shapes. In the Picture (PIC) group, the C stimuli were pictures, and the remaining stimuli were the same abstract shapes as in the ABS group. For the remaining five groups, all stimuli were the same abstract shapes as in the ABS group. However, across groups, preliminary training involved either the establishment of conditional relations with simultaneous (SMTS) or delayed (DMTS) matching‐to‐sample with 0 s, 3 s, 6 s, or 9 s between the abstract C stimuli and the meaningful pictures. For the ABS and the PIC groups, 16.7% and 83.3% of participants formed classes, respectively. Preliminary training with SMTS and DMTS with 0 s, 3 s, and 6 s produced a linear increase in the likelihood of equivalence class formation, 41.7%, 50%, and 75%, respectively. Increasing the duration of delay further from 6 s to 9 s produced a substantial decline, 50%. This experiment extends knowledge about how including meaningful pictures enhances equivalence class formation.     

A comparison of prompts and feedback for promoting handwashing in university restrooms

We compared the effects of prompts versus feedback on handwashing behavior across six restrooms at a large university. We evaluated the effects using two separate multiple baseline designs across three men's and three women's restrooms. Results indicate that feedback was more effective for increasing handwashing.