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1.
A brain–computer interface (BCI) can connect humans and machines directly and has achieved successful applications in the past few decades. Many new BCI paradigms and algorithms have been developed in recent years. Therefore, it is necessary to review new progress in BCIs. This paper summarizes progress for EEG-based BCIs from the perspective of encoding paradigms and decoding algorithms, which are two key elements of BCI systems. Encoding paradigms are grouped by their underlying neural meachanisms, namely sensory- and motor-related, vision-related, cognition-related and hybrid paradigms. Decoding algorithms are reviewed in four categories, namely decomposition algorithms, Riemannian geometry, deep learning and transfer learning. This review will provide a comprehensive overview of both modern primary paradigms and algorithms, making it helpful for those who are developing BCI systems.  相似文献   

2.
Behavioral phenotyping of transgenic and knockout mice requires rigorous, formal analyses. Well-characterized paradigms can be chosen from the established behavioral neuroscience literature. This review describes (1) a series of neurological and neuropsychological tests which are effectively used as a first screen for behavioral abnormalities in mutant mice, and (2) a series of specific behavioral paradigms, clustered by category. Included are multiple paradigms for each category, including learning and memory, feeding, analgesia, aggression, anxiety, depression, schizophrenia, and drug abuse models. Examples are given from the experiences of the authors, in applying these experimental designs to transgenic and knockout mice. Extensive references for each behavioral paradigm are provided, to allow new investigators to access the relevant literature on behavioral methodology.  相似文献   

3.
I suggest five research paradigms fundamental in the mathematical sciences that seem relevant to the hunt for explanations of genetic susceptibility to complex diseases. I discuss a few ways in which these paradigms are, or are not, currently being followed in complex disease genetics. This essay is intended to provoke discussion and not to resolve any problems. It represents a written version of remarks that I made as “Discussant’’ at a session at the 1997 National Institutes of Health Research Festival.  相似文献   

4.
5.
This paper distinguishes between scopal affix paradigms and compositional affix paradigms, two notions confused in the literature. The Yi languages (Tibeto-Burman: China) exhibit maximally scopal paradigms which reflect the cognitive layers of the sentence in the mind of the speaker. In spite of this prototypical pattern, the paradigm is full of noncompostional pairs of morphemes.  相似文献   

6.
Despite a growing number of studies, the neurophysiology of adult vocabulary acquisition is still poorly understood. One reason is that paradigms that can easily be combined with neuroscientfic methods are rare. Here, we tested the efficiency of two paradigms for vocabulary (re-) acquisition, and compared the learning of novel words for actions and objects. Cortical networks involved in adult native-language word processing are widespread, with differences postulated between words for objects and actions. Words and what they stand for are supposed to be grounded in perceptual and sensorimotor brain circuits depending on their meaning. If there are specific brain representations for different word categories, we hypothesized behavioural differences in the learning of action-related and object-related words. Paradigm A, with the learning of novel words for body-related actions spread out over a number of days, revealed fast learning of these new action words, and stable retention up to 4 weeks after training. The single-session Paradigm B employed objects and actions. Performance during acquisition did not differ between action-related and object-related words (time*word category: p?=?0.01), but the translation rate was clearly better for object-related (79%) than for action-related words (53%, p?=?0.002). Both paradigms yielded robust associative learning of novel action-related words, as previously demonstrated for object-related words. Translation success differed for action- and object-related words, which may indicate different neural mechanisms. The paradigms tested here are well suited to investigate such differences with neuroscientific means. Given the stable retention and minimal requirements for conscious effort, these learning paradigms are promising for vocabulary re-learning in brain-lesioned people. In combination with neuroimaging, neuro-stimulation or pharmacological intervention, they may well advance the understanding of language learning to optimize therapeutic strategies.  相似文献   

7.
Since the publication of Kuhn's The Structure of Scientific Revolutions in 1962, the notion of paradigms has shaped the way that philosophy views scientific discovery and how changes in what is regarded as empirical fact occur. This drew heavily on examples from the history of the natural sciences to support Kuhn's hypothesis. However, some argue that medicine is different from the natural sciences. Gillies has proposed another theory of how paradigms apply to medicine; that of composite paradigms. In doing so, Gillies uses the example of Helicobacter pylori and the shift from the excess-acid theory to the current bacterial-infection theory of gastric ulcers to illustrate these fundamental differences between medicine and the natural sciences. Upon analysis of Gillies' claim, it is evident that traditional Kuhnian paradigms are also composite and that the manner in which Gillies proposes disease is classified is insufficient in describing medicine. Furthermore, new local paradigms are demonstrably introduced and the change was accompanied by many of the markers of paradigmatic change including changes in worldview, resistance, incommensurability and the introduction of new questions that could not have existed under the previous paradigm. Whilst this change may not be on the scale of the Chemical revolution, it can still be considered paradigm shift. Thagard also proposes an alternate view of discovery using the case of H. pylori. This has much in common with Kuhnian paradigms but Thagard's theory offers further elucidation and refinement. This allows it to better characterise all of the associated features of discovery relevant in the case of H. pylori, thus provides a preferable tool for examination of this important recent discovery.  相似文献   

8.
Systems Biology has a mission that puts it at odds with traditional paradigms of physics and molecular biology, such as the simplicity requested by Occam’s razor and minimum energy/maximal efficiency. By referring to biochemical experiments on control and regulation, and on flux balancing in yeast, we show that these paradigms are inapt. Systems Biology does not quite converge with biology either: Although it certainly requires accurate ‘stamp collecting’, it discovers quantitative laws. Systems Biology is a science of its own, discovering own fundamental principles, some of which we identify here.  相似文献   

9.
Time perception is defined as a subjective judgment on the elapsed time of an event. It can change according to both external and internal factors. There are two main paradigms of time perception; retrospective time perception (RTP) and prospective time perception (PTP). Two paradigms differ from each other according to whether the subject has knowledge on the importance of passage of time in the given task. Since RTP paradigm studies are harder to conduct, studies on RTP paradigm is far fewer than studies on PTP. Thus in the current study, both RTP and PTP paradigms are investigated. Also, time perception is discussed in relation to internal clock model and cognitive load. Emotional motion videos are used to create cognitive load and manipulate internal clock. Results showed the effect of emotion on time perception. Another major finding is that shorter videos are perceived longer whereas longer videos are perceived shorter as in accordance with Vierordt’s Law. However, there was no difference between RTP and PTP paradigms. These results indicate that emotional videos change our internal clock while a number of changes in a motion video create cognitive load causing disturbance of time perception.  相似文献   

10.
Metacommunity theory has advanced understanding of how spatial dynamics and local interactions shape community structure and biodiversity. Here, we review empirical approaches to metacommunities, both observational and experimental, pertaining to how well they relate to and test theoretical metacommunity paradigms and how well they capture the realities of natural ecosystems. First, we show that the species-sorting and mass-effects paradigms are the most commonly tested and supported paradigms. Second, the dynamics observed can often be ascribed to two or more of the four non-exclusive paradigms. Third, empirical approaches relate only weakly to the concise assumptions and predictions made by the paradigms. Consequently, we suggest major avenues of improvement for empirical metacommunity approaches, including the integration across theoretical approaches and the incorporation of evolutionary and meta-ecosystem dynamics. We hope for metacommunity ecology to thereby bridge existing gaps between empirical and theoretical work, thus becoming a more powerful framework to understand dynamics across ecosystems.  相似文献   

11.
Since its development about 40 years ago (1981–2021), Morris water maze has turned into a very popular tool for assessing spatial learning and memory. Its many advantages have ensured its pertinence to date. These include its effectiveness in evaluating hippocampal-dependent learning and memory, exemption from motivational differences across diverse experimental manipulations, reliability in various cross-species studies, and adaptability to many experimental conditions with various test protocols. Nonetheless, throughout its establishment, several experimental and analysis loopholes have galvanized researchers to assess ways in which it could be improved and adapted to fill this gap. Therefore, in this review, we briefly summarize these developments since the early years of its establishment through to the most recent advancements in computerized analysis, offering more comprehensive analysis paradigms. In addition, we discuss the adaptability of the Morris water maze across different test versions and analysis paradigms, providing suggestions with regard to the best paradigms for particular experimental conditions. Hence, the proper selection of the experimental protocols, analysis paradigms, and consideration of the assay’s limitations should be carefully considered. Given that appropriate measures are taken, with various adaptations made, the Morris water maze will likely remain a relevant tool to assess the mechanisms of spatial learning and memory.  相似文献   

12.
Why is the human brain fundamentally limited when attempting to execute two tasks at the same time or in close succession? Two classical paradigms, psychological refractory period (PRP) and task switching, have independently approached this issue, making significant advances in our understanding of the architecture of cognition. Yet, there is an apparent contradiction between the conclusions derived from these two paradigms. The PRP paradigm, on the one hand, suggests that the simultaneous execution of two tasks is limited solely by a passive structural bottleneck in which the tasks are executed on a first-come, first-served basis. The task-switching paradigm, on the other hand, argues that switching back and forth between task configurations must be actively controlled by a central executive system (the system controlling voluntary, planned, and flexible action). Here we have explicitly designed an experiment mixing the essential ingredients of both paradigms: task uncertainty and task simultaneity. In addition to a central bottleneck, we obtain evidence for active processes of task setting (planning of the appropriate sequence of actions) and task disengaging (suppression of the plan set for the first task in order to proceed with the next one). Our results clarify the chronometric relations between these central components of dual-task processing, and in particular whether they operate serially or in parallel. On this basis, we propose a hierarchical model of cognitive architecture that provides a synthesis of task-switching and PRP paradigms.  相似文献   

13.
A well-known phenomenon in Swedish is that some adjectives are ‘defective’ in the sense that they are not possible in neuter gender. In previous explanations, it has usually been argued that the defective forms could be distinguished from non-defective forms by phonological and/or semantic criteria. Showing that such proposals cannot account for the data, I will argue that the defective paradigms are caused by a number of phonological constraints which block morphological productivity not only in defective forms, but also in many nondefective forms. Thus, contrary to what has traditionally been assumed, common patterns of vowel shortening and dental assimilation in Swedish adjective paradigms are not the result of productivity, but the result of a type of creative generalization where new formations require a sufficient degree of communicative need in order to be perceived as grammatical.  相似文献   

14.
It is typical of the present time, that two practically unknown chemists, one from a veterinary college and the other from an agricultural institute, pass judgement on the loftiest problems of Chemistry, those which will probably never be solved, particularly the question of the position of atoms in space, and they undertake such a paradigm with an impudence and assurance that absolutely astonish the true scientist H. Kolbe [1] New paradigms and new truths in science are not usually adopted because opponents are eventually convinced of their persuasive character, but, more often, because opponents gradually die; the new paradigms are readily adopted by the new generation of students as the laws of nature, just as the dead opponents accepted the old paradigm M. Planck [2] Received, accepted: 23 January 1998  相似文献   

15.
Psychophysicists use spatial or temporal two-alternative forced-choice (2AFC) paradigms interchangeably. Thus, experiments with the same general goal are carried out using one or the other paradigm by distinct or even the same research groups. For example, this situation has occurred both in studies on visual sensitivity in dyslexia and in studies on lateral interactions in peripheral vision. Conflicting results in either field (e.g. whether or not dyslexics have a visual deficit and whether or not peripheral detection is facilitated by the presence of flankers) appear to be resolved on the surmise that spatial and temporal 2AFC paradigms indeed produce different results. We designed experiments in which peripheral detection thresholds for Gabor patches (in the presence or absence of suprathreshold flankers) could be measured using completely equivalent spatial and temporal 2AFC paradigms so that any resultant difference can be unequivocally attributed to the effect of the paradigms themselves. The results showed that spatial 2AFC renders significantly lower sensitivity than temporal 2AFC when the target is presented along with suprathreshold flankers, but about the same sensitivity as temporal 2AFC when the target is presented alone. In the end, this resulted in statistically significant facilitation in peripheral vision only when measured with temporal 2AFC. Separate experiments at each of several peripheral locations revealed that the presence and magnitude of this effect varies not only with psychophysical paradigm but also with retinal locus.  相似文献   

16.
深部脑刺激(deep brain stimulation,DBS)已成为治疗帕金森病等运动障碍疾病的常规方法之一,并且在许多其他神经和精神疾病的治疗中也具有良好的应用前景.但是,目前常规DBS采用单通道恒定脉冲间隔的高频刺激(high frequency stimulation,HFS),刺激模式缺少多样化,限制了DBS在临床上的推广应用.为了开发更多DBS刺激模式,用于改善疗效、拓展应用范围、并节省刺激器的电能,近年来研究人员基于去同步调控机制,在脉冲序列的时间模式和空间排布两方面开发了DBS新模式.主要包括:变频序列(包括规则变频和随机变频)、不同空间位点上的多通道异步刺激以及变频和多通道两者的结合.这些新刺激模式能够提高DBS的临床疗效、降低刺激能耗,在帕金森病以及癫痫、强迫症和微意识障碍等其他脑疾病的治疗中都展现了良好的应用前景.更值得关注的是,多通道异步刺激不仅在刺激期间具有更好的即时疗效,而且刺激结束后还能长时间保持疗效,具有刺激后效应.这个特性突破了常规DBS主要为即时效应的局限性,展现了DBS新前景.本文在概述常规DBS模式及其去同步调控机制的基础上,综述变频脉冲刺激和...  相似文献   

17.
Decentralised or ‘redistributed’ manufacturing represents an attractive choice for production of some cell and gene therapies (CGTs), in particular personalised therapies. Decentralised manufacturing splits production into various locations or regions and in doing so, imposes organisational changes on the structure of a company. This confers a significant advantage by democratising supply, creating jobs without geographical restriction to the central hub and allowing a more flexible response to external pressures and demands. This comes with challenges that need to be addressed including, a reduction in oversight, decision making and control by central management which can be critical in maintaining quality in healthcare product manufacturing. The unwitting adoption of poor business strategies at an early stage in development has the potential to undermine the market success of otherwise promising products. To maximise the probability of realising the benefits that decentralised manufacturing of CGTs has to offer, it is important to examine alternative operational paradigms to learn from their successes and to avoid their failures. Whilst no other situation is quite the same as CGTs, some illustrative examples of established manufacturing paradigms are described. Each of these shares a unique attribute with CGTs which aids understanding of how decentralised manufacturing might be implemented for CGTs in a similar manner. In this paper we present a collection of paradigms that can be drawn on in formulating a roadmap to success for decentralised production of CGTs.  相似文献   

18.
For nearly a century the experimental analysis of learning in animals has been divided into niche-related and general-process approaches, each emphasizing different procedures and conceptual strategies. After considering several current forms of rapprochement, I outline evidence for the integrative hypothesis that niche-related learning provides the basis for results in traditional general-process learning paradigms. Although the full ramifications of this view are not developed here, its advantages include: a clearer relation between laboratory and field results; conceptual and pragmatic guidance in developing new paradigms, and applying old ones to different species and circumstances; clarification of the laws, limits, and anomalies in general-process paradigms; and a more efficient path for inter-relating the study of learning with neurophysiology, genetics, and evolution.  相似文献   

19.
The mainstream view in natural resource management in African drylands has been that local people are responsible for natural resource degradation. Today, alternative views or new paradigms are emerging in several fields. These new paradigms, which support decentralization of natural resource management, are discussed in relation to the ongoing decentralization process in Mali. During the colonial period, heavily centralized governments were installed in all the French colonies. This structure was maintained by Malian governments after independence. However, following the recent transition to democracy, a decentralizing reform is being implemented. It is presently not clear whether these reforms will lead to mere deconcentration, involving the redistribution of administrative responsibilities within the central government, or whether Mali is heading toward real decentralization, devolving decision making powers to local communities. The gestion de terroir approach, which may be a useful tool in achieving decentralization in farming communities, would, in pastoral areas, cause more damage than benefit.  相似文献   

20.
世界范围的细菌耐药性呼吁新的抗菌策略,光生物调节作用是有效的候选手段之一。论述了光生物调节作用抗菌效应的研究现状和应用前景。中性粒细胞可以通过吞噬杀菌,也可以通过产生胞外菌阱杀菌。还从活性氧和信号转导所介导的中性粒细胞杀菌作用讨论了光生物调节作用的抗菌机理,为其在临床抗菌中的应用提供理论依据。  相似文献   

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