Response-related potentials during semantic priming: the effect of a speeded button response task on ERPs

This study examines the influence of a button response task on the event-related potential (ERP) in a semantic priming experiment. Of particular interest is the N400 component. In many semantic priming studies, subjects are asked to respond to a stimulus as fast and accurately as possible by pressing a button. Response time (RT) is recorded in parallel with an electroencephalogram (EEG) for ERP analysis. In this case, the response occurs in the time window used for ERP analysis and response-related components may overlap with stimulus-locked ones such as the N400. This has led to a recommendation against such a design, although the issue has not been explored in depth. Since studies keep being published that disregard this issue, a more detailed examination of influence of response-related potentials on the ERP is needed. Two experiments were performed in which subjects pressed one of two buttons with their dominant hand in response to word-pairs with varying association strength (AS), indicating a personal judgement of association between the two words. In the first experiment, subjects were instructed to respond as fast and accurately as possible. In the second experiment, subjects delayed their button response to enforce a one second interval between the onset of the target word and the button response. Results show that in the first experiment a P3 component and motor-related potentials (MRPs) overlap with the N400 component, which can cause a misinterpretation of the latter. In order to study the N400 component, the button response should be delayed to avoid contamination of the ERP with response-related components

Lower bounds for 1-, 2- and 3-dimensional on-line bin packing algorithms

In this paper we discuss lower bounds for the asymptotic worst case ratio of on-line algorithms for different kind of bin packing problems. Recently, Galambos and Frenk gave a simple proof of the 1.536 ... lower bound for the 1-dimensional bin packing problem. Following their ideas, we present a general technique that can be used to derive lower bounds for other bin packing problems as well. We apply this technique to prove new lower bounds for the 2-dimensional (1.802...) and 3-dimensional (1.974...) bin packing problem

Observations of the J = 2→1 transitions of ¹²C¹⁶O and ¹²C¹⁸O towards galactic H II regions

Observations are reported of the J = 2→1 transitions of CO and 12C18O at 230 and 219 GHz respectively from a number of galactic sources. A map of the central 1/2° × 1/2° of the Orion A molecular cloud is presented. The spectra are interpreted to derive molecular densities and abundance ratios in the molecular clouds observed

Ondenkbaar ver weg & onvoorstelbaar dichtbij

Wat zijn de karakteristieken van een klassiek-gereformeerde visie op wat het betekent om God te kennen? Wat is de realiteit van het kennen van God in een agnostisch denkklimaat? Kun je eigenlijk wel zeggen dat je God kent, en hoe doe je dat dan? Waarom denken we eigenlijk dat onze kennis van God betrouwbare kennis is? Vanuit een klassiek-gereformeerd perspectief heeft het kennen van God een cognitief element, een relationeel element en een praktisch element. Het kennen van God is altijd kennis van de drie-enige God en in het kennen staat Gods eer en de redding van de mens centraal. Kennis van God is mogelijk omdat God Zich openbaart en het impliceert nooit het begrijpen van God. Betrouwbare kennis van God is in een klassiek-gereformeerde visie altijd gebaseerd op de Bijbel, waarvan men overtuigd raakt door het werk van Gods Geest. Onder twee groepen jongeren uit twee verschillende gemeentes uit de christelijke-gereformeerde kerken zijn interviews gehouden. Aan deze jongeren is gevraagd of zij denken dat het mogelijk is om God te kennen, welke middelen zij gebruiken om God te leren kennen en welke twijfels ze ervaren. De uitkomsten van de gesprekken met de jongeren zijn vergeleken met de beschreven karakteristieken van een klassiek gereformeerde visie op het kennen van God. In deze vergelijking bleek inhoudelijk grote overeenstemming tussen de manier waarop christelijke-gereformeerde jongeren spreken over het kennen van God en een klassiek-gereformeerde visie op het kennen van God. Tegelijk bleken er ook enkele belangrijke verschillen, die vanuit de ontwikkelingspsychologie, de sociologie en de theologie zijn bekeken

Sanitation under challenge: contributions from the social sciences

This paper reviews the contribution the social sciences can make to the challenge of providing access to sustainable sanitation services and infrastructures for billions of people, in both the over- and underdeveloped parts of the world. The paper reviews and discusses three particular social scientific topics relevant for the sanitation challenge: the nature of socio-technical change, the issue of multilevel governance, and the role of the citizen-consumer. It is argued that sanitation is as much a social as it is a technical issue, and that the role of social scientific knowledge needs to be strengthened and given more attention in this context. The key contribution from the social sciences is to be found in its capacity to help widen the narrow, technical definitions of sanitation by including actors and their needs and belief systems, and by highlighting the alternative socio-technical tools and governance arrangements that are instrumental in moving beyond some of the dead-end roads of traditional water engineering and sanitation provisio

Shot Noise in Linear Macroscopic Resistors

We report on a direct experimental evidence of shot noise in a linear macroscopic resistor. The origin of the shot noise comes from the fluctuation of the total number of charge carriers inside the resistor associated with their diffusive motion under the condition that the dielectric relaxation time becomes longer than the dynamic transit time. Present results show that neither potential barriers nor the absence of inelastic scattering are necessary to observe shot noise in electronic devices.Comment: 10 pages, 5 figure