Contribution of binocular vision to the performance of complex manipulation tasks in 5–13 years old visually-normal children

Individual studies have shown that visuomotor coordination and aspects of binocular vision, such as stereoacuity and dynamic vergence control, continue to improve in normally developing children between birth and early teenage years. However, no study has systematically addressed the relationship between the development of binocular vision and fine manipulation skills. Thus, the aim of this cross-sectional study was to characterize performance of complex manipulation tasks during binocular and monocular viewing. Fifty-two children, between 5 and 13 years old, performed 2 manipulation tasks: peg-board and bead-threading under randomized viewing conditions. Results showed that binocular viewing was associated with a significantly greater improvement in performance on the bead-threading task in comparison to the peg-board task and the youngest children showed the greatest decrement in task performance under the monocular viewing condition when performing the bead-threading task. Thus, the role of binocular vision in performance of fine manipulation skills is both task- and age-dependent. These findings have implications for assessment of visuomotor skills in children with abnormal binocular vision, which occurs in 2–3% of otherwise typically developing children.     

Higher order balance control: Distinct effects between cognitive task and manual steadiness constraint on automatic postural responses

In the present experiment, we aimed to evaluate the interactive effect of performing a cognitive task simultaneously with a manual task requiring either high or low steadiness on APRs. Young volunteers performed the task of recovering upright balance following a mechanical perturbation provoked by unanticipatedly releasing a load pulling the participant’s body backwards. The postural task was performed while holding a cylinder steadily on a tray. One group performed that task under high (cylinder’ round side down) and another one under low (cylinder’ flat side down) manual steadiness constraint. Those tasks were evaluated in the conditions of performing concurrently a cognitive numeric subtraction task and under no cognitive task. Analysis showed that performance of the cognitive task led to increased body and tray displacement, associated with higher displacement at the hip and upper trunk, and lower magnitude of activation of the GM muscle in response to the perturbation. Conversely, high manual steadiness constraint led to reduced tray velocity in association with lower values of trunk displacement, and decreased rotation amplitude at the ankle and hip joints. We found no interactions between the effects of the cognitive and manual tasks on APRs, suggesting that they were processed in parallel in the generation of responses for balance recovery. Modulation of postural responses from the manual and cognitive tasks indicates participation of higher order neural structures in the generation of APRs, with postural responses being affected by multiple mental processes occurring in parallel.     

Trait predictors of placebo responses in itch

This study investigated trait predictors of placebo responses in the context of inflammatory skin reactions. This was a randomized, cross-over, experimental study using a deceptive placebo protocol. A healthy sample of volunteers (N = 48) completed online personality measures, then attended two laboratory sessions in which short-term inflammatory skin reactions were induced. One was a control session and the other the ‘treatment’ session in which a placebo cream was administered with the suggestion of a reduced skin reaction. A placebo response was defined as smaller skin reactions in control vs. treatment sessions. The traits ego resiliency and neuroticism were selected as possible predictors of placebo responses. Traits were selected in consideration of the two-faceted transactional model of placebo responsiveness and in light of empirical and psychometric considerations ego resiliency emerged as a consistent predictor of placebo responses in itch (p < .05). This is the first study to identify trait predictors of placebo responses in inflammatory skin reactions. Ego resiliency may typify greater placebo responsiveness; however, this may only be in certain contexts. Matching treatment approaches to bio-behavioural response tendencies may be useful clinically if the placebo component of traditional treatments can be enhanced.     

Subliminal action priming modulates the perceived intensity of sensory action consequences

The sense of control over the consequences of one’s actions depends on predictions about these consequences. According to an influential computational model, consistency between predicted and observed action consequences attenuates perceived stimulus intensity, which might provide a marker of agentic control. An important assumption of this model is that these predictions are generated within the motor system. However, previous studies of sensory attenuation have typically confounded motor-specific perceptual modulation with perceptual effects of stimulus predictability that are not specific to motor action. As a result, these studies cannot unambiguously attribute sensory attenuation to a motor locus. We present a psychophysical experiment on auditory attenuation that avoids this pitfall. Subliminal masked priming of motor actions with compatible prime–target pairs has previously been shown to modulate both reaction times and the explicit feeling of control over action consequences. Here, we demonstrate reduced perceived loudness of tones caused by compatibly primed actions. Importantly, this modulation results from a manipulation of motor processing and is not confounded by stimulus predictability. We discuss our results with respect to theoretical models of the mechanisms underlying sensory attenuation and subliminal motor priming.     

Quick to Act,Quick to Forget: The Link Between Impulsiveness and Prospective Memory

Several traits of impulsiveness (e.g. lack of planning and perseverance, difficulty focusing attention) seem intimately connected to the skills required for successful prospective memory performance. This is the first study to examine whether the various inter‐correlated dimensions of impulsiveness are related to problems with prospective memory. Undergraduate students (N = 184) completed the Barratt Impulsiveness Scale 11, the Prospective Memory Questionnaire, the Prospective and Retrospective Memory Questionnaire, and two objective prospective memory tests. Results revealed consistent correlations between the various dimensions of impulsiveness (attentional, motor, non‐planning) and self‐reported problems with prospective memory. Subsequent regression analyses indicated that attentional impulsiveness is a unique predictor of self‐reported problems with internally cued prospective memory, and non‐planning impulsiveness is a unique predictor of self‐reported problems with episodic and overall prospective memory. Similarly, findings from the objective prospective tests showed that non‐planning impulsiveness was related to worse performance on the two prospective memory tests. Whereas non‐planning impulsiveness was also related to using fewer prospective memory‐aiding strategies, mediation analyses showed that use of these strategies does not account for any of the detected relationships. Because the findings suggest that a failure to plan does not underlie the detected effects, other potential explanations for the relationships are discussed. Copyright © 2013 European Association of Personality Psychology     

认知判断中手部动作模拟的fMRI研究

该研究采用功能磁共振成像技术,考察不同条件下进行工具认知判断时手部姿势对认知判断的影响及动作模拟的神经机制。实验发现：手部姿势存在显著的主效应,冲突手部姿势条件下反应时最慢,且冲突手部姿势条件下与不冲突手部姿势条件下、自然状态条件下反应时存在显著差异,自然状态条件与不冲突手部姿势条件下反应时不存在显著差异。另外,f MRI成像结果发现,额中回、额下回、顶下小叶以及辅助运动区在自然状态下有显著激活,表明个体在进行认知判断过程中有动作模拟过程;海马结构、扣带回及楔前叶等与记忆有关的脑区有显著激活,表明身体经验在认知过程的作用。总的研究表明,不同的手部姿势状态对认知判断有不同影响,冲突手部姿势会对动作模拟产生干扰作用,手部动作模拟的神经机制主要涉及镜像神经元区,且在认知判断时存在具身效应。     

The power of the imagination to affect peripersonal space representations

It is known that visual processing is altered for objects near the hands as well as for objects near the imagined position of the hands, indicating that the imagination can be used to remap peri-hand space. Little is known, however, about the physical conditions that allow for this remapping. In the present study, participants in one experiment performed visual searches through displays that were beyond reach while imagining that their hands were near the display. This imagined impossible posture slowed visual search rates, showing that imagination effectively remapped peri-hand space to be near the display. In another experiment, participants searched displays they were holding, but sometimes imagined their hands to be far away. This produced faster search rates, revealing a remapping of peri-hand space away from the monitor. The results provide new insights into the mechanisms involved in the representation of peri-hand space and about the power of imagined actions to influence body representations.     

How do cynical employees serve their customers? A multi-method study

In this multi-method study, we investigate how social job demands (i.e., social interruptions) and resources (i.e., colleague support) in the service context influence employee (negative) (re)actions to customers through cynicism towards the job. In addition, we investigate why customers are less satisfied with the provided service when employees endorse a cynical attitude. To test the hypothesized process, we used observer ratings of the employee–customer interactions regarding the number of interruptions and employee negative (re)actions during service encounters, employee self-reports of overall colleague support and daily cynicism, and customer-ratings of service quality. Participants were 48 service employees and 141 customers. Results of multi-level structural equation modelling analyses showed that whereas the number of observed social interruptions during service encounters related positively to cynicism, social support related negatively. Cynical employees exhibited more negative (re)actions towards their customers (e.g., expressed tension, were unfriendly). Consequently, the more negative (re)actions employees showed towards their customers, the less satisfied customers were with the service quality. The study contributes to the literature by explaining what makes service employees cynical about their work, and why cynical employees provide low-quality services.