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721.
High impact running improves learning   总被引:1,自引:0,他引:1  
Regular physical exercise improves cognitive functions and lowers the risk for age-related cognitive decline. Since little is known about the nature and the timing of the underlying mechanisms, we probed whether exercise also has immediate beneficial effects on cognition. Learning performance was assessed directly after high impact anaerobic sprints, low impact aerobic running, or a period of rest in 27 healthy subjects in a randomized cross-over design. Dependent variables comprised learning speed as well as immediate (1 week) and long-term (>8 months) overall success in acquiring a novel vocabulary. Peripheral levels of brain-derived neurotrophic factor (BDNF) and catecholamines (dopamine, epinephrine, norepinephrine) were assessed prior to and after the interventions as well as after learning. We found that vocabulary learning was 20 percent faster after intense physical exercise as compared to the other two conditions. This condition also elicited the strongest increases in BDNF and catecholamine levels. More sustained BDNF levels during learning after intense exercise were related to better short-term learning success, whereas absolute dopamine and epinephrine levels were related to better intermediate (dopamine) and long-term (epinephrine) retentions of the novel vocabulary. Thus, BDNF and two of the catecholamines seem to be mediators by which physical exercise improves learning.  相似文献   
722.
Many open domain question answering systems answer questions by first harvesting a large number of candidate answers, and then picking the most promising one from the list. One criterion for this answer selection is type checking: deciding whether the candidate answer is of the semantic type expected by the question. We define a general strategy for building redundancy-based type checkers, built around the notions of comparison set and scoring method, where the former provide a set of potential answer types and the latter are meant to capture the relation between a candidate answer and an answer type. Our focus is on scoring methods. We discuss nine such methods, provide a detailed experimental comparison and analysis of these methods, and find that the best performing scoring method performs at the same level as knowledge-intensive methods, although our experiments do not reveal a clear-cut answer on the question whether any of the scoring methods we consider should be preferred over the others.  相似文献   
723.
A number of recent experiments have demonstrated that a movement structure develops during the course of learning a movement sequence that provides the basis for transfer. After learning a movement sequence participants have been shown to be able to effectively produce the sequence when movement demands require that the sequence be rescaled in amplitude or produced with an unpractised set of effectors. The purpose of the present experiment was to determine whether participants, after learning a complex 16-element movement sequence with a 0.567-kg load, could also effectively produce the sequence when the load was decreased (0.0 kg) or increased (1.134 kg). The results indicated that participants were able to effectively compensate for decreased and increased load with virtually no changes in performance characteristics (displacement, velocity, acceleration, and pattern of element durations) while electromyographic (EMG) signals demonstrated that smaller (reduced load) or larger forces (increased load) were spontaneously generated to compensate for the change in load. The muscle activation patterns of the biceps and triceps as well as the level of coactivation appeared to be generally upscaled to generate and dissipate the changes in force requirement needed to compensate for the increased load.  相似文献   
724.
This study examined the equivalence of the conventional and computerized versions of the Beck Depression Inventory-II (BDI-II), taking into account that computer aver-sion may negatively impact computer-administered BDI-II scores by elevating them. Participants were 180 psychology undergraduate students from a medium-sized midwestern university. Participants were divided into four experimental groups. Each group was administered the BDI-II twice in various combinations (conventional only, computerized only, conventional and computerized and vice versa). All participants completed measures of computer aversion and computer experience. Participants who received both versions of the BDI-II were also asked to specify their preference for method of administration. Independent samples t-test results indicated that the com-puterized and paper-and-pencil versions of the BDI-II may be considered equivalent in terms of measurement validity. Implications for future research are discussed. Portions of this article were presented at the 1999 meetings of the American Psychological Association, Boston. The authors thank Dr. Michael Granaas for statistical assistance with the Latin Squares analysis.  相似文献   
725.
Livestock production has been confronted with several epidemics over the last decades. The morality of common animal disease strategies—stamping out and vaccination—is being debated and provokes controversies among farmers, authorities and the broader public. Given the complexity and controversy of choosing an appropriate control strategy, this article explores the potential of nano-enabled diagnostics in future livestock production. At first glance, these applications offer promising opportunities for better animal disease surveillance. By significantly shortening the reaction time from diagnosis to appropriate control, they could complement the current disease management strategies. Although nano-enabled diagnostics will not make livestock disease eradication strategies redundant or completely free of the culling of infected animals, these diagnostics could significantly reduce the number of culled animals and animal suffering. This article aims to demonstrate that the ethical assessment of advanced diagnostics can build on the experiences with decision making in biomedical ethics where nonmaleficence, beneficence, autonomy and justice serve as important benchmarks. Nano-enabled diagnostics may be an ethically sound solution if it can resolve the dilemma between stamping out and vaccination in favor of the latter and if it can balance the autonomy–paternalism dilemma between farmers and authorities. The technology should allow to be switched on and off by farmers, whilst simultaneously allowing for a weak paternalism on behalf of authorities in order to benefit the farmer and broader society and to protect them from harm.
Johan EversEmail:
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726.
727.
An experiment tested the effects of dyad membership and the prospect of completing a motor‐skills task on alcohol placebo consumption and task confidence. Participants (n = 115) completed a taste preference task while alone or in dyads. Half the individuals and half the dyads expected to subsequently complete a motor‐skills task and rated task confidence pre and post‐consumption. Individuals expecting the task consumed less than those in the non‐task condition and felt less confident in their abilities post‐consumption. Among those expecting the task, dyad members' consumption did not reduce and their post‐consumption confidence was higher than individuals'. Findings suggest dyad membership can lead to overconfidence. Attempts to reduce alcohol related harms must balance the protective properties of dyads with risks of overconfidence.  相似文献   
728.
Research has shown that exposure to the national flag alters people's behavior and political and intergroup judgments. In several field studies conducted in an area of France with a strong regional identity, we examined the effect of the presence of the regional flag versus the national flag versus no flag on behaviors. Various situations (e.g., money solicitation, implicit helping behavior, food tasting) were tested in Brittany, on the French west Atlantic coast. Car drivers, passersby in the street, and patrons in bakeries were exposed to no flag versus the French flag versus the Brittany flag held by requesters or presented on a product or on a car. Findings showed that the regional flag increased helping behavior dramatically. Other studies also revealed that the presence of the Brittany flag reduced aggressiveness and influenced preference for food products. The power of a flag as a symbol that could increase in‐group membership is discussed.  相似文献   
729.
Ample research demonstrated that empathizing with someone in need promotes helping that person. Two studies examined whether this effect of empathy on helping behavior holds across different emotional reactions expressed by a target in need. Results of Study 1 indicate that perspective taking with a sad needy target increased empathic concern which, in turn, fostered helping the individual. This relation was not found for participants taking the perspective of angry or disgusted needy targets. Study 2 provides further support for the underlying mechanism of the results of Study 1. Perspective taking with a sad needy target increased empathizers’ empathic concern because perception of target neediness was increased. Again, this pattern was not found for perspective taking with an angry needy target. The findings correspond to theorizing on the role of emotions in person perception. Hence, the current research provides insights regarding the boundary conditions of the empathy-helping association.  相似文献   
730.
There is minimal research on metacognition in alcohol‐intoxicated participants. Study 1 examined metacognition across sober, intoxicated, and placebo groups, with the intoxicated group's breath alcohol concentration reaching 0.074 g/210 L on average immediately prior to the metacognition task. Participants answered cued recall general knowledge questions and provided confidence ratings and feeling‐of‐knowing judgments. They then completed a recognition (i.e., multiple choice) version of the same task, indicating an answer and a confidence rating for each question. Findings suggest that metacognitive accuracy generally did not vary across intoxication levels, although the control group's retrospective confidence judgments better discriminated between accurate and inaccurate responses than the alcohol groups in the recognition task. Study 2 surveyed academic psychologists about their expectations regarding the relation between alcohol and metacognition. Study 1's results were counter to their expectations, as respondents generally predicted a relation would be present. We discuss the implications for alcohol and memory.Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   
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