Oscillatory neural activity in the gamma frequency range (>30Hz) has been shown to accompany a wide variety of cognitive processes. So far, there has been limited success in assigning a unitary basic function to these oscillations, and critics have raised the argument that they could just be an epiphenomenon of neural processing. We propose a new framework that relates gamma oscillations observed in human, as well as in animal, experiments to two underlying processes: the comparison of memory contents with stimulus-related information and the utilization of signals derived from this comparison. This model attempts to explain early gamma-band responses in terms of the match between bottom-up and top-down information. Furthermore, it assumes that late gamma-band activity reflects the readout and utilization of the information resulting from this match. 相似文献
The foundations of law have been the object ofintense philosophical scrutiny since antiquity.Most importantly, it has been asked whetherthere are really any foundations other thansheer force to be found once more comfortingillusions are abandoned. This paperinvestigates four influential theorists ofradical legal philosophy and postmodern thought(Benjamin, Schmitt, Luhmann, Derrida) who dealwith this problem in comparable ways despitetheir different theoretical outlooks. Themerits of these theories having been assessed,mentalism in ethics and law is introduced as apossible alternative to both the widespreadfoundationalism of the past and theanti-foundationalism of the postmodern present. 相似文献
Missing values at the end of a test typically are the result of test takers running out of time and can as such be understood by studying test takers’ working speed. As testing moves to computer-based assessment, response times become available allowing to simulatenously model speed and ability. Integrating research on response time modeling with research on modeling missing responses, we propose using response times to model missing values due to time limits. We identify similarities between approaches used to account for not-reached items (Rose et al. in ETS Res Rep Ser 2010:i–53, 2010) and the speed-accuracy (SA) model for joint modeling of effective speed and effective ability as proposed by van der Linden (Psychometrika 72(3):287–308, 2007). In a simulation, we show (a) that the SA model can recover parameters in the presence of missing values due to time limits and (b) that the response time model, using item-level timing information rather than a count of not-reached items, results in person parameter estimates that differ from missing data IRT models applied to not-reached items. We propose using the SA model to model the missing data process and to use both, ability and speed, to describe the performance of test takers. We illustrate the application of the model in an empirical analysis.
In work done at the German Criminological Research Institute of Lower Saxony (KFN) various methods have been used to investigate how specific inappropriate media usage patterns affect academic performance in children and adolescents. The findings are paralleled by current international research indicating a negative relationship between these two variables. Based on a cross‐sectional survey of 5,529 fourth grade students and a longitudinal panel study with 1,157 primary schoolchildren, a key finding can be demonstrated: the more time students spend on consuming media and the more violent its contents are, the worse are their marks at school, even when controlling for vital factors such as family, educational, or immigrant background. In particular, boys who gender‐specifically are better equipped with electronic media devices, who partially have extensive media usage times and who strongly prefer violent media content, are at the risk of showing poor school performance. In fact, a decrease in academic performance of boys can be observed in German school statistics. By presenting first results of a school‐based intervention programme, a promising approach to the reduction of detrimental effects of electronic media use on school performance is introduced. 相似文献
A general class of labeled sequent calculi is investigated, and necessary and sufficient conditions are given for when such a calculus is sound and complete for a finite-valued logic if the labels are interpreted as sets of truth values (sets-as-signs). Furthermore, it is shown that any finite-valued logic can be given an axiomatization by such a labeled calculus using arbitrary "systems of signs," i.e., of sets of truth values, as labels. The number of labels needed is logarithmic in the number of truth values, and it is shown that this bound is tight. 相似文献
We construct a faithful interpretation of ukasiewicz's logic in product logic (both propositional and predicate). Using known facts it follows that the product predicate logic is not recursively axiomatizable.We prove a completeness theorem for product logic extended by a unary connective of Baaz [1]. We show that Gödel's logic is a sublogic of this extended product logic.We also prove NP-completeness of the set of propositional formulas satisfiable in product logic (resp. in Gödel's logic). 相似文献
Using a conditioned food avoidance learning paradigm, six squirrel monkeys (Saimiri sciureus) and six common marmosets (Callithrix jacchus) were tested for their ability to (1) reliably form associations between visual or olfactory cues of a potential food and its palatability and (2) remember such associations over prolonged periods of time. We found (1) that at the group level both species showed one-trial learning with the visual cues color and shape, whereas only the marmosets were able to do so with the olfactory cue, (2) that all individuals from both species learned to reliably avoid the unpalatable food items within 10 trials, (3) a tendency in both species for quicker acquisition of the association with the visual cues compared with the olfactory cue, (4) a tendency for quicker acquisition and higher reliability of the aversion by the marmosets compared with the squirrel monkeys, and (5) that all individuals from both species were able to reliably remember the significance of the visual cues, color and shape, even after 4 months, whereas only the marmosets showed retention of the significance of the olfactory cues for up to 4 weeks. Furthermore, the results suggest that in both species tested, illness is not a necessary prerequisite for food avoidance learning but that the presumably innate rejection responses toward highly concentrated but nontoxic bitter and sour tastants are sufficient to induce robust learning and retention. 相似文献