Consistently modeling the same movement strategy is more important than model skill level in observational learning contexts

The experiment undertaken was designed to elucidate the impact of model skill level on observational learning processes. The task was bimanual circle tracing with a 90° relative phase lead of one hand over the other hand. Observer groups watched videos of either an instruction model, a discovery model, or a skilled model. The instruction and skilled model always performed the task with the same movement strategy, the right-arm traced clockwise and the left-arm counterclockwise around circle templates with the right-arm leading. The discovery model used several movement strategies (tracing-direction/hand-lead) during practice. Observation of the instruction and skilled model provided a significant benefit compared to the discovery model when performing the 90° relative phase pattern in a post-observation test. The observers of the discovery model had significant room for improvement and benefited from post-observation practice of the 90° pattern. The benefit of a model is found in the consistency with which that model uses the same movement strategy, and not within the skill level of the model. It is the consistency in strategy modeled that allows observers to develop an abstract perceptual representation of the task that can be implemented into a coordinated action. Theoretically, the results show that movement strategy information (relative motion direction, hand lead) and relative phase information can be detected through visual perception processes and be successfully mapped to outgoing motor commands within an observational learning context.     

How do visual and postural cues combine for self-tilt perception during slow pitch rotations?

Self-orientation perception relies on the integration of multiple sensory inputs which convey spatially-related visual and postural cues. In the present study, an experimental set-up was used to tilt the body and/or the visual scene to investigate how these postural and visual cues are integrated for self-tilt perception (the subjective sensation of being tilted). Participants were required to repeatedly rate a confidence level for self-tilt perception during slow (0.05°·s^− 1) body and/or visual scene pitch tilts up to 19° relative to vertical. Concurrently, subjects also had to perform arm reaching movements toward a body-fixed target at certain specific angles of tilt. While performance of a concurrent motor task did not influence the main perceptual task, self-tilt detection did vary according to the visuo-postural stimuli. Slow forward or backward tilts of the visual scene alone did not induce a marked sensation of self-tilt contrary to actual body tilt. However, combined body and visual scene tilt influenced self-tilt perception more strongly, although this effect was dependent on the direction of visual scene tilt: only a forward visual scene tilt combined with a forward body tilt facilitated self-tilt detection. In such a case, visual scene tilt did not seem to induce vection but rather may have produced a deviation of the perceived orientation of the longitudinal body axis in the forward direction, which may have lowered the self-tilt detection threshold during actual forward body tilt.     

Perceptual and motor contributions to the negative compatibility effect

The current study focused on contributions to the negative compatibility effect (NCE) from object-updating at the perceptual level and self-inhibition (i.e., automatic motor inhibition) at the response (motor) level. We hypothesized that contributions to the NCE from these two levels were moderated by the strength of stimulus and reaction (S–R) link: object-updating should have greater impact on the NCE with weak S–R links, but both object-updating and self-inhibition should impact on the NCE when the S–R links became strong. To test this hypothesis, in two experiments we used a novel type of stimuli and manipulated mask relevance (relevant versus irrelevant mask) and prime/target compatibility. Participants performed two tasks over three successive days. Results showed that under equivalent masking effectiveness between the two conditions of mask, a significant NCE was observed only in the relevant mask condition when the S–R links were weak, but both close to equal NCE sizes were observed in the two mask conditions when the S–R links were acquired through practice. The results indicated that perceptual and motor contributions to the NCE were moderated by the strength of S–R links, if the strength of the links was too weak to trigger the following inhibition, the NCE primarily originated from object-updating at the perceptual level; if the strength of the links was reinforced by practice, which exceeded the inhibitory threshold, the NCE originated from both object-updating and self-inhibition, but the latter was primarily responsible.     

A kinematic analysis of age-related changes in grasping to use and grasping to move common objects

Grasping is a complex action which requires high-level motor control. Although the impact of aging on grasping has been investigated in some studies, to date little is known as to how the aging process interacts with the purpose of the movement. The aims of the present study were (i) to investigate the effect of aging on grasping movements, and to explore on how this effect is modulated by (ii) the goal of the task, and by (iii) the characteristics of the target such as its location in the visual field, its orientation and its size. Young and elderly adults were asked to grasp to move or to grasp to use objects of different sizes and orientations, presented either in the central or the peripheral visual field. Movement duration did not differ between the two groups. However, elderly participants required a longer approach phase and showed a different grasping strategy, characterized by larger grip aperture and smaller percentage of wrist rotation in comparison to young adults. Elderly adults showed a decrease in accuracy when grasping objects presented in the peripheral, but not in the central visual field. A similar modulation of the kinematic parameters consisting in longer planning and execution phases in the grasp to use in comparison to the grasp to move condition was observed in both groups, suggesting that the effect of aging might be minimized and compensated in more goal-directed tasks.     

阻塞性睡眠呼吸暂停低通气综合征是引发道路交通事故的重要原因

为了分析我国道路交通事故是否与阻塞性睡眠呼吸暂停相关,以道路交通事故为主题查阅1993年~2012年万方数据库,并辅以手检同期《中华创伤杂志》和《中华流行病学杂志》,重点查阅全国性及地区性道路交通事故原因的论著,看其是否涉及阻塞性睡眠呼吸暂停问题。结果显示这期间共发表了相关论著43篇,全部论文在分析道路交通事故时均未提及阻塞性睡眠呼吸暂停这一重要原因,提示国内道路交通安全研究中忽略了一个与之关系密切的阻塞性睡眠呼吸暂停问题,建议今后将这个问题引入到道路交通安全管理项目中。     

Meta-analysis of the reduced relative feedback frequency effect on motor learning and performance

A fundamental motor learning principle conveyed in textbooks is that augmented terminal feedback frequency differentially affects motor learning and performance. The guidance hypothesis predicts that relative to a reduced frequency of feedback, providing learners with feedback following every practice trial enhances practice performance but degrades subsequent motor learning. This change in effectiveness for each relative feedback frequency is called a reversal effect, and because it is thought that practice variables can have distinct impacts on learning and performance, delayed retention tests are considered the gold standard in motor learning research. The objectives of this meta-analysis were to a) synthesize the available evidence regarding feedback frequency, performance, and motor learning to test whether there are significant changes in effectiveness from acquisition and immediate retention to delayed retention, b) evaluate potential moderators of these effects, and c) investigate the potential influence of publication bias on this literature. We screened 1662 articles found in PubMed and PsycINFO databases as well as with reference tracing and a targeted author search. A final sample of 61 eligible papers were included in the primary analysis (k = 75, N = 2228). Results revealed substantial heterogeneity but no significant moderators, high levels of uncertainty, and no significant effect of reduced feedback frequency at any time point. Further, multilevel analyses revealed no evidence of a significant change in effect from acquisition or immediate retention to delayed retention. Z-curve analysis suggested the included studies were severely underpowered. These results suggest that robust evidence regarding feedback frequency and motor learning is lacking.     

Approaching intersections: Gaze behavior of drivers depending on traffic,intersection type,driving maneuver,and secondary task involvement

Urban intersections are hotspots for crashes because they provide a location for several traffic streams and types of road users to cross. A main cause of crashes is the misinformation of drivers as they fail to sense relevant visual information. We aimed to analyze the gaze behavior of car drivers in a variety of intersection scenarios, bringing together the partial findings of previous research, and examine the interdependencies of the contributing factors to provide a database for driver modeling. In a driving simulator study with 59 participants, we varied intersection scenarios regarding drivers’ right of way (yield sign, green traffic light), intersection type (T junction, X intersection), surrounding traffic (none, irrelevant, relevant), and intended driving maneuver (left turn, right turn, going straight). A total of 25 intersection scenarios were presented in a within-subjects design to a control group and a group with a cognitive load task (counting back in numbers of two). Fixations were coded regarding defined areas of interest in the field of view and separated according to three segments of the intersection approach: 75–50 m, 50–25 m, and 25–0 m before entering the intersection. The results show that the effect of surrounding traffic, secondary task engagement, and the intended driving maneuver changed dramatically depending on the right of way of the driver. Surrounding traffic primarily affected gaze behavior in scenarios of ceding the right of way close to the intersection entry. The cognitive load task increased fixations on the road center especially in situations where the driver had the right of way, but less in situations of ceding the right of way. Interactions with the type of intersection were only apparent for different driving maneuvers. This study provides a detailed and comprehensive picture of drivers’ attentional processes when approaching intersections which is relevant for understanding and modeling of driver behavior in urban traffic.     

A longitudinal analysis of reciprocal relationships between actual and perceived motor competencies and physical self-concept in primary-school age children

Physical self-concept (PSC) and motor competencies are important factors in view of the development of a physically active lifestyle. There are research gaps regarding longitudinal studies of these relationships. This article presents findings of a longitudinal study (n = 200; 58% girls, M = 8.84 ± 0.63 years) at three primary schools. The aim of this study was to analyze the relationship between actual motor competencies (AMC) and perceived motor competencies (PMC) and PSC. Therefore, manifest path models in cross-lagged design were performed. Results show that correlations between PMC and AMC increased over time and were stronger in object control than in locomotor. Effects of AMC on PSC were more strongly mediated by PMC in object control than in locomotor. To promote physical activity, developing strategies should be aimed at the acquisition of AMC, particularly in object control, and PMC, especially in locomotor, during childhood.     

Stimulating performance: A scoping review on transcranial electrical stimulation effects on olympic sports

Transcranial electrical stimulation (tES) is widely used to explore the role of various cortical regions involved in a multitude of motor and cognitive processes. Recently, tES has been discussed as being able to potentially enhance performance in sports and even been suggested as a potential way of boosting performance in competitions. In this scoping review, we systematically investigate the literature on tES-induced performance modulations on Olympic sports. The aim is to create a critical overview of the emerging field of tES-enhanced sports performance. Further, methodological approaches, research desiderata, and potential directions for future research will be identified. The final dataset shows a large variation in methodology and a lack of research into the area. Further, partially sub-optimal choices in study design, methodology, and lacking consistency in reporting procedures may impede valid conclusions and obscured the effects of tES on Olympic sports. Consequently, we outline future directions and areas to improve research.     

事故驾驶员与安全驾驶员人格特征的比较研究

本研究采用柳井晴夫等人编制的新性格检查问卷,对６０名公交车驾驶员的人格特征进行了测量．结果表明：（１）事故组驾驶员与安全组驾驶员在五个人格特征上存在显著性差异,其中事故组驾驶员攻击性、神经质倾向较强,而持久性、协调性和同情性较差．（２）男性事故组驾驶员与安全组驾驶员在四个人格特征上存在显著性差异,其中事故组驾驶员攻击性和神经质倾向较强,但持久性和协调性较差。（３）女性事故组驾驶员与安全组驾驶员在两个人格特征上存在显著性差异,前者较后者攻击性强,但缺乏同情性．（４）性别在１２项人格特征上无显著性差异．本研究结果可为设计制定专门应用于交通领域的人格测验,以及对驾驶员的选拔、培训、教育和管理提供一定的理论依据．