Constrained paths based on the Farey sequence in learning to juggle

In this article we report the results of a study conducted to investigate the learning dynamics of three-ball juggling from the perspective of frequency locking. Based on the Farey sequence, we predicted that four stable coordination patterns, corresponding to dwell ratios of 0.83, 0.75, 0.67, and 0.50, would appear in the learning process. We examined the learning process in terms of task performance, taking into account individual differences in the amount of learning. We observed that the participants acquired individual-specific coordination patterns in a relatively early stage of learning, and that those coordination patterns were preserved in subsequent learning, even though performance in terms of number of successful consecutive throws increased substantially. This increase appeared to be related to a reduction in spatial variability of the juggling movements. Finally, the observed coordination patterns were in agreement with the predicted patterns, with the proviso that the pattern corresponding to a dwell ratio of 0.50 was not realized and only a hint of evidence was found for the dwell ratio of 0.67. This implies that the dwell ratios of 0.83 and 0.75 in particular exhibited a stable coordination structure due to strong frequency locking between the temporal variables of juggling.     

Soldiers Lead Themselves to More Success: A Self-Leadership Intervention Study

Neck and Manz (1999) Neck, C. P., & Manz, C. C. (1999). In search of the self-led soldier: Army leadership in the twenty-first century. In J. G. Hunt, G. E. Dodge, & L. Wong (Eds.), Out of the box leadership: Transforming the twenty-first army and other top organizations (pp. 153–176). Stamford, CT: JAI Press. [Google Scholar] elaborated in their article “In Search of the Self-Lead Soldier” on the need for continuous improvement of personnel qualities such as increase in self-efficacy, increase of performance, and decrease of perceived strain. Self-leadership is a tool that fosters exactly these personal resources. This study examines self-leadership training effects on soldiers participating in a military training course over 14 weeks. It is the first self-leadership training study to evaluate performance improvement using objective criteria (examination marks, physical tests) in intervention and control group consisting of soldiers of the Austrian army. Its design features a large sample (N = 130), duration of self-leadership training over 10 weeks, and evaluation over 4 time points. The intervention group accomplished significantly higher educational achievements in examinations and physical tests. Also levels of self-efficacy were significantly higher and levels of strain were marginally to significantly lower.     

What Goes Up Apparently Needn't Come Down: Asymmetric Predictions of Ascent and Descent in Rankings

In eight studies, we document an upward mobility bias, or a tendency to predict that a rise in rankings is more likely than a decline. This asymmetry was observed in predictions of classroom performance, NBA and NFL standings, business school rankings, and employee performance rankings. The bias was found for entities people care about and want to see improve their standing, as well as entities in which people are not invested. It appears to result from people's tendency to give considerable weight to a focal agent's intentions and motivation, but to give less weight to the intentions of competitors and other factors that would thwart the focal agent's improvement. We show that this bias is most pronounced for implicit incremental theorists, who believe that performance is malleable (and hence assign more weight to intentions and effort). We discuss implications of this asymmetry for decision making and for an understanding of the underdog bias. Copyright © 2015 John Wiley & Sons, Ltd.     

Inter-individual variability in metacognitive ability for visuomotor performance and underlying brain structures

Metacognition refers to the ability to discriminate between one’s own correct and incorrect decisions. The neurobiological underpinnings of metacognition have mainly been studied in perceptual decision-making. Here we investigated whether differences in brain structure predict individual variability in metacognitive sensitivity for visuomotor performance. Participants had to draw straight trajectories toward visual targets, which could unpredictably deviate around detection threshold, report such deviations when detected, and rate their confidence level for such reports. Structural brain MRI analyses revealed that larger gray-matter volume (GMV) in the left middle occipital gyrus, left medial parietal cortex, and right postcentral gyrus predicted higher deviation detection sensitivity. By contrast, larger GMV in the right prefrontal cortex but also right anterior insula and right fusiform gyrus predicted higher metacognitive sensitivity. These results extend past research by linking metacognitive sensitivity for visuomotor behavior to brain areas involved in action agency (insula), executive control (prefrontal cortex) and vision (fusiform).     

Effective coordination in medical emergency teams: The moderating role of task type

Coordination in health care action teams is an important factor in clinical performance and patient safety. Implementing a high-fidelity in situ simulation study, we investigated the performance-relevant effects of task distribution, provide information without request (PIWR) and closed-loop communication (CLC) in 68 medical emergency teams (METs) composed of fully qualified clinicians. We differentiated between two task types: algorithm-driven and knowledge-driven tasks. We assigned two different emergency tasks to each task type. We proposed not only a direct relationship between the three coordination behaviours and clinical performance, but also a moderating role for the type of task. Only CLC was related to performance and also moderated by task type. There was no relationship between the coordination behaviours task distribution and PIWR and performance. We discuss the differential effects of the three coordination behaviours on performance and emphasize the importance of the task in team research. In particular, we highlight theoretical and practical implications.     

Extraversion and job performance: How context relevance and bandwidth specificity create a non-linear,positive, and asymptotic relationship

The personality factor of extraversion has been associated with performance in some occupations (e.g., sales), and it has been one of the most consistent personality predictors of leadership. Recent research indicates that extraversion could have a non-linear relation with performance. At the same time, many researchers have contended that scholars should utilize measures of personality narrower than factors and that the bandwidth and relevance of personality should fit both the criterion and the context of a study. We argue and find that by examining an aspect of extraversion (i.e., social potency) in a particular vocational context (i.e., enterprising job demands), non-linear, asymptotic (diminishing marginal benefits) effects will be demonstrated on a relevant type of performance (i.e., enterprising job performance). We review implications, limitations, and avenues for future research.     

A bilateral advantage for maintaining objects in visual short term memory

Research has shown that attentional pre-cues can subsequently influence the transfer of information into visual short term memory (VSTM) (Schmidt, B., Vogel, E., Woodman, G., & Luck, S. (2002). Voluntary and automatic attentional control of visual working memory. Perception & Psychophysics, 64(5), 754–763). However, studies also suggest that those effects are constrained by the hemifield alignment of the pre-cues (Holt, J. L., & Delvenne, J.-F. (2014). A bilateral advantage in controlling access to visual short-term memory. Experimental Psychology, 61(2), 127–133), revealing better recall when distributed across hemifields relative to within a single hemifield (otherwise known as a bilateral field advantage). By manipulating the duration of the retention interval in a colour change detection task (1 s, 3 s), we investigated whether selective pre-cues can also influence how information is later maintained in VSTM. The results revealed that the pre-cues influenced the maintenance of the colours in VSTM, promoting consistent performance across retention intervals (Experiments 1 & 4). However, those effects were only shown when the pre-cues were directed to stimuli displayed across hemifields relative to stimuli within a single hemifield. Importantly, the results were not replicated when participants were required to memorise colours (Experiment 2) or locations (Experiment 3) in the absence of spatial pre-cues. Those findings strongly suggest that attentional pre-cues have a strong influence on both the transfer of information in VSTM and its subsequent maintenance, allowing bilateral items to better survive decay.     

Identifying expectations about the strength of causal relationships

When we try to identify causal relationships, how strong do we expect that relationship to be? Bayesian models of causal induction rely on assumptions regarding people’s a priori beliefs about causal systems, with recent research focusing on people’s expectations about the strength of causes. These expectations are expressed in terms of prior probability distributions. While proposals about the form of such prior distributions have been made previously, many different distributions are possible, making it difficult to test such proposals exhaustively. In Experiment 1 we used iterated learning—a method in which participants make inferences about data generated based on their own responses in previous trials—to estimate participants’ prior beliefs about the strengths of causes. This method produced estimated prior distributions that were quite different from those previously proposed in the literature. Experiment 2 collected a large set of human judgments on the strength of causal relationships to be used as a benchmark for evaluating different models, using stimuli that cover a wider and more systematic set of contingencies than previous research. Using these judgments, we evaluated the predictions of various Bayesian models. The Bayesian model with priors estimated via iterated learning compared favorably against the others. Experiment 3 estimated participants’ prior beliefs concerning different causal systems, revealing key similarities in their expectations across diverse scenarios.     

Emergent Power Hierarchies and Group Performance

In newly formed groups, informal hierarchies emerge automatically and readily. In this study, we argue that emergent group hierarchies enhance group performance (Hypothesis 1) and we assume that the more the power hierarchy within a group corresponds to the task‐competence differences of the individual group members, the better the group performs (Hypothesis 2). Twelve three‐person groups and 28 four‐person groups were investigated while solving the Winter Survival Task. Results show that emerging power hierarchies positively impact group performance but the alignment between task‐competence and power hierarchy did not affect group performance. Thus, emergent power hierarchies are beneficial for group performance and although they were on average created around individual group members' competence, this correspondence was not a prerequisite for better group performance.