BrainBasher: a BCI Game

Brain-computer interaction (BCI) is starting to focus on healthy subjects. This research adresses the effects of using this novel input modality to control a simple game, and also looks into the beneficial effects of bringing game elements into BCI experiments. A simple BCI game has been developed and evaluated with fifteen subjects using the Game Experience Questionnaire (GEQ) developed at the Eindhoven Game Experience Lab. Three variations of the game were evaluated for comparison: the original game with BCI input, one with keyboard input, and one with a more clinical look leaving out all extraneous information. The keyboard-controlled game was considered easy and boring, whereas using BCI for input resulted in a more challenging, immersive and richer experience. The design and additional information presented by the game also resulted in higher immersion compared to the clinical design

Wess-Zumino-Witten model off criticality

We study the renormalization group flow properties of the Wess-Zumino-Witten model in the region of couplings between $g^2=0$ and $g^2=4\pi/k$, by evaluating the two-loop Zamolodchikov's $c$-function. We also discuss the region of negative couplings.Comment: 8 page

Thermoelectric performance of multiphase XNiSn (X = Ti, Zr, Hf) half-Heusler alloys

Quantitative X-ray powder diffraction analysis demonstrates that mixing Ti, Zr and Hf on the ionic site in the half-Heusler structure, which is a common strategy to lower the lattice thermal conductivity in this important class of thermoelectric materials, leads to multiphase behaviour. For example, nominal Ti0.5Zr0.5NiSn has a distribution of Ti1−xZrxNiSn compositions between 0.24 ≤ x ≤ 0.70. Similar variations are observed for Zr0.50Hf0.5NiSn and Ti0.5Hf0.5NiSn. Electron microscopy and elemental mapping demonstrate that the main compositional variations occur over micrometre length scales. The thermoelectric power factors of the mixed phase samples are improved compared to the single phase end-members (e.g. S2/ρ = 1.8 mW m−1 K−2 for Ti0.5Zr0.5NiSn, compared to S2/ρ = 1.5 mW m−1 K−2 for TiNiSn), demonstrating that the multiphase behaviour is not detrimental to electronic transport. Thermal conductivity measurements for Ti0.5Zr0.5NiSn0.95 suggest that the dominant reduction comes from Ti/Zr mass and size difference phonon scattering with the multiphase behaviour a secondary effect

Een pilotstudie naar de interacties tussen broedende weidevogels en Brandganzen

De voor Nederland zo typerende natte graslanden van het laagveen- en zeekleigebied worden momenteel bevolkt door twee karakteristieke groepen vogels. Hun habitatvoorkeur komt sterk overeen, maar voor het overige verschillen ze duidelijk van elkaar. De in hun broedseizoen van dierlijk voedsel afhankelijke weidevogels gaan sterk in populatieomvang achterui

Actual and Imagined Movement in BCI Gaming

Most research on Brain-Computer Interfaces (BCI) focuses\ud on developing ways of expression for disabled people who are\ud not able to communicate through other means. Recently it has been\ud shown that BCI can also be used in games to give users a richer experience\ud and new ways to interact with a computer or game console.\ud This paper describes research conducted to find out what the differences\ud are between using actual and imagined movement as modalities\ud in a BCI game. Results show that there are significant differences\ud in user experience and that actual movement is a more robust way of\ud communicating through a BCI

Atherosclerotic Calcification: Determinants and Clinical Neurological Consequences

__Abstract__ Atherosclerosis is a highly frequent vascular disease that exerts huge influence on the health care system. Major clinical conditions caused by atherosclerosis are ischemic heart disease (myocardial infarction) and stroke, both top causes of global morbidity and mortality in middle-aged and elderly persons. Due to the aging of the population, the global burden of atherosclerosis, and thereby of its clinical consequences, will continue to rise in the coming decades. The purpose of my thesis is to expand the knowledge on determinants - or risk factors - and neurological consequences of atherosclerosis, with a specific focus on differences across vessel beds. The research described in my thesis was performed within the framework of the Rotterdam Study;21 a large prospective, population-based cohort study aimed at investigating determinants of various chronic diseases in the elderly. Using CT-imaging in this population-based setting, I studied atherosclerosis in four major vessel beds: the coronary arteries, aortic arch and the extracranial and intracranial part of the internal carotid arteries

Evaluatie Opvangbeleid 2005-2008 overwinterende ganzen en smienten. Deelrapport 11. Effect van Brandganzen op broedende weidevogels

Deze studie onderzoekt op welke wijze de tijdsbesteding van broedende weidevogels en de vegetatie van de broedhabitat wordt beïnvloed door de aanwezigheid overwinterende en in Nederland broedende Brandganzen. De nabijheid van Brandganzen werd door weidevogels als bedreigend voor hun eieren ervaren. Begrazing door Brandganzen had een negatief effect op hoogte en drooggewicht van de vegetatie vlak voor en tijdens de broedperiode van weidevogels waardoor mogelijk de nestplaatskeuze van weidevogels kan worden beïnvloed. Het effect van Brandganzen op de vestiging van weidevogels is in deze studie onderbelicht gebleven en ook is niet gekeken naar het effect op kuikenoverleving. De resultaten moeten daarom met enige voorzichtigheid geïnterpreteerd worden. Aldus resultaten van Alterra in samenwerking met Altenburg & Wymeng

User Experience Evaluation in BCI: Filling the Gap

Brain-computer interface (BCI) systems can improve the user experience (UX) when used in entertainment technologies. Improved UX can enhance user acceptance, improve quality of life and also increase the system performance of a BCI system. Therefore, the evaluation of UX is essential in BCI research. However, BCI systems are generally evaluated according to the system aspect only so there is no methodology to evaluate UX in BCI systems. This paper gives an overview of such methods from the human-computer interaction field and discusses their possible uses in BCI research

How much control is enough? Optimizing fun with unreliable input

Brain-computer interfaces (BCI) provide a valuable new input modality within human- computer interaction systems, but like other body-based inputs, the system recognition of input commands is far from perfect. This raises important questions, such as: What level of control should such an interface be able to provide? What is the relationship between actual and perceived control? And in the case of applications for entertainment in which fun is an important part of user experience, should we even aim for perfect control, or is the optimum elsewhere? In this experiment the user plays a simple game in which a hamster has to be guided to the exit of a maze, in which the amount of control the user has over the hamster is varied. The variation of control through confusion matrices makes it possible to simulate the experience of using a BCI, while using the traditional keyboard for input. After each session the user �lled out a short questionnaire on fun and perceived control. Analysis of the data showed that the perceived control of the user could largely be explained by the amount of control in the respective session. As expected, user frustration decreases with increasing control. Moreover, the results indicate that the relation between fun and control is not linear. Although in the beginning fun does increase with improved control, the level of fun drops again just before perfect control is reached. This poses new insights for developers of games wanting to incorporate some form of BCI in their game: for creating a fun game, unreliable input can be used to create a challenge for the user