Visual realism enhances realistic response in an immersive virtual environment

Participants in an immersive virtual environment interact with the scene from an egocentric point of view that is, where there bodies appear to be located rather than from outside as if looking through a window. People interact through normal body movements, such as head-turning,reaching, and bending, and within the tracking limitations move through the environment or effect changes within it in natural ways.

The effect on lower spine muscle activation of walking on a narrow beam in virtual reality

To what extent do people behave in immersive virtual environments as they would in similar situations in a physical environment? There are many ways to address this question, ranging from questionnaires, behavioral studies, and the use of physiological measures. Here, we compare the onsets of muscle activity using surface electromyography (EMG) while participants were walking under three different conditions: on a normal floor surface, on a narrow ribbon along the floor, and on a narrow platform raised off the floor. The same situation was rendered in an immersive virtual environment (IVE) Cave-like system, and 12 participants did the three types of walking in a counter-balanced within-groups design. The mean number of EMG activity onsets per unit time followed the same pattern in the virtual environment as in the physical environment-significantly higher for walking on the platform compared to walking on the floor. Even though participants knew that they were in fact really walking at floor level in the virtual environment condition, the visual illusion of walking on a raised platform was sufficient to influence their behavior in a measurable way. This opens up the door for this technique to be used in gait and posture related scenarios including rehabilitation.

First person experience of body transfer in virtual reality

Altering the normal association between touch and its visual correlate can result in the illusory perception of a fake limb as part of our own body. Thus, when touch is seen to be applied to a rubber hand while felt synchronously on the corresponding hidden real hand, an illusion of ownership of the rubber hand usually occurs. The illusion has also been demonstrated using visuomotor correlation between the movements of the hidden real hand and the seen fake hand. This type of paradigm has been used with respect to the whole body generating out-of-the-body and body substitution illusions. However, such studies have only ever manipulated a single factor and although they used a form of virtual reality have not exploited the power of immersive virtual reality (IVR) to produce radical transformations in body ownership.

Visual realism enhances realistic response in an immersive virtual environment - Part2

Does realistic lighting in an immersive virtual reality application enhance presence, where participants feel that they are in the scene and behave correspondingly? Our previous study indicated that presence is more likely with real-time ray tracing compared with ray casting, but we could not separate the effects of overall quality of illumination from the dynamic effects of real-time shadows and reflections. Here we describe an experiment where 20 people experienced a scene rendered with global or local illumination. However, in both conditions there were dynamically changing shadows and reflections. We found that the quality of illumination did not impact presence, so that the earlier result must have been due to dynamic shadows and reflections. However, global illumination resulted in greater plausibility - participants were more likely to respond as if the virtual events were real. We conclude that global illumination does impact the responses of participants and is worth the effort.

Valoraci��n experiencial del aprendizaje tras formaci��n virtual.

[eng] An observable study on the behaviour in the laboratory of Pharmaceutical Technology II (pharmaceutical pilot plant), with two groups of students of 3rd course (proactive aptitude and valuation of the"knowledge to do acquired") is carried out. The variable between groups is that one has realised a training (by means of self-study of an interactive application multimedia, especially designed), without tutorship on behalf the teacher in front of the other group that carried out the same training with the same material but with the guide of the teacher in the computer lab. On the one hand it is valued if there is some effect differentiator between both types of training, by means of the accounting of the correct results obtained in a previous test to the entrance in the pilot plant and by another one the valuation that the professors made responsible for the groups of practices in situ. The results demonstrate the previous hypothesis that there must not be significant differences between the groups, beyond the inherent ones to personality of the students itself (interest and personal implication by the subject). On the other hand the test for the observation in the laboratory did not facilitate the distinction of objective differences. [spa] Se lleva a cabo un estudio observacional sobre el comportamiento de los estudiantes (aptitud pro-activa y valoraci��n del ���saber hacer adquirido���) en el laboratorio de Tecnolog��a Farmac��utica II (planta piloto farmac��utica) de dos grupos de estudiantes de 3er curso. La variable entre los dos grupos es que uno ha realizado una formaci��n no presencial (mediante el autoestudio de una aplicaci��n interactiva multimedia, especialmente dise��ada), sin tutor��a por parte del profesor, frente al otro grupo que llev�� a cabo la misma formaci��n con el mismo material pero con la gu��a del profesor en el aula de inform��tica. Por una parte se valora si hay alg��n efecto diferenciador entre ambos tipos de formaci��n, mediante la contabilizaci��n de los resultados correctos obtenidos en un test previo a la entrada en la planta piloto y por otro la valoraci��n que hicieron los profesores responsables de los grupos de pr��cticas in situ. Los resultados demuestran la hip��tesis previa de que no deb��an existir diferencias significativas entre los grupos, m��s all�� de las inherentes a la propia personalidad de los estudiantes (inter��s e implicaci��n personal por el tema). Por otra parte el test para la observaci��n en el laboratorio no facilit�� la distinci��n de diferencias objetivas.

Generaci�� d���un entorn virtual de treball per un robot St��ubli TX60

L���objectiu del treball ��s emular virtualment l���entorn de treball del robot St��ubli Tx60 quehi ha al laboratori de rob��tica de la UdG (dins les possibilitats que ofereix el software adquirit).Aquest laboratori intenta reproduir un entorn industrial de treball en el qual es realitzal���assemblatge d���un conjunt de manera cent per cent automatitzada.En una primera fase, s���ha dissenyat en tres dimensions tot l���entorn de treball que hi hadisponible al laboratori a trav��s del software CAD SolidWorks. Cada un dels conjuntsque conformen l���estaci�� de treball s���ha dissenyat de manera independent.Posteriorment s���introdueixen tots els elements dissenyats dins el software St��ubliRobotics Suite 2013. Amb tot l���anterior, cal remarcar que l���objectiu principal del treball consta de duesetapes. Inicialment es dissenya el model 3D de l���entorn de treball a trav��s del software SolidWorks i s���introdueix dins el software St��ubli Robotics Suite 2013. Enuna segona etapa, es realitza un manual d�����s del nou software de rob��tica

Elearning y la educaci��n postmoderna: trayectorias y experiencias del estudiantado virtual

La emergencia y din��mica del Elearning, en los actuales escenarios de educaci��n superior, evidencia una importante transformaci��n acontecida en el marco de la sociedad de la informaci��n: la utilizaci��n de las TIC en los procesos de construcci��n del conocimiento. Este cambio ha ido de la mano, en primer lugar, de la mejora en la calidad y la oferta formativa existente, una oferta que ha buscado ser m��s inclusiva y representativa de las actuales demandas sociales. Y en segundo lugar, se trata de una modalidad que ha intentado adaptarse a las actuales caracter��sticas del estudiantado digital y del digitalizado (Prensky, 2006), cuyo rol en los proceso de ense��anza, tiende a ser m��s activo que en los modelos de formaci��n tradicional. El presente art��culo, se focaliza en esta segunda dimensi��n, analizando como el Elearning intenta ser un elemento de mediaci��n entre las transformaciones actuales que se dan en la educaci��n superior y la emergencia de un nuevo estudiantado virtual, cada vez m��s activo y aut��nomo.

Body Image in Eating Disorders: The Influence of Exposure to Virtual-Reality Environments.

The aim of this article was to study the effect of virtual-reality exposure to situations that are emotionally significant for patients with eating disorders (ED) on the stability of body-image distortion and body-image dissatisfaction. A total of 85 ED patients and 108 non-ED students were randomly exposed to four experimental virtual environments: a kitchen with low-calorie food, a kitchen with high-calorie food, a restaurant with low-calorie food, and a restaurant with high-calorie food. In the interval between the presentation of each situation, body-image distortion and body-image dissatisfaction were assessed. Several 2���x���2���x���2 repeated measures analyses of variance (high-calorie vs. low-calorie food���x���presence vs. absence of people���x ED group vs. control group) showed that ED participants had significantly higher levels of body-image distortion and body dissatisfaction after eating high-calorie food than after eating low-calorie food, while control participants reported a similar body image in all situations. The results suggest that body-image distortion and body-image dissatisfaction show both trait and state features. On the one hand, ED patients show a general predisposition to overestimate their body size and to feel more dissatisfied with their body image than controls. On the other hand, these body-image disturbances fluctuate when participants are exposed to virtual situations that are emotionally relevant for them.

La gesti��n de libros electr��nicos de la Biblioteca Virtual de la Universitat Oberta de Catalunya

La comunicaci��n que se presenta, muestra c��mo se lleva a cabo la gesti��n de los procesos t��cnicos de los libros electr��nicos en la Biblioteca Virtual (en adelante BV) de la Universitat Oberta de Catalunya (en adelante UOC). La BV est�� integrada en el Campus Virtual y en las aulas virtuales de la Universidad. La principal particularidad de la docencia en la UOC se encuentra en el hecho de que se realiza, en su totalidad, por medio de un Campus Virtual.La BV de la UOC pone especial ��nfasis en la adquisici��n de libros digitales para mejorar el acceso de los usuarios a sus recursos y colecciones en una universidad con un modelo de aprendizaje caracterizada por su virtualidad (el 13 de abril de 2011, el Consejo de Gobierno acord�� priorizar la adquisici��n de documentos en formato electr��nico). La irrupci��n de los libros electr��nicos en la BV ha comportado una revisi��n de los procesos t��cnicos, de manera que los circuitos de adquisici��n, catalogaci��n y gesti��n de la colecci��n digital trabajen de forma coordinada. En primer lugar, se describe el entorno en el que se adquieren y se utilizan los libros electr��nicos, los distintos escenarios de adquisici��n y modelos de compra con los que se puede encontrar la BV de la UOC. Se valora el importante papel que desempe��a el proveedor en la compra de libros electr��nicos. La BV siempre intenta encontrar un equilibrio entre las necesidades de los usuarios, las posibilidades del mercado y los recursos disponibles. Las compras pueden o no ser consorciadas. Cuando se trata de compra consorciada de libros electr��nicos se han de sopesar las ventajas e inconvenientes que esta gesti��n conlleva, tanto econ��micas c��mo de acceso a los contenidos. Cuando un libro est�� disponible desde distintas plataformas, hay que estudiar cu��l es la que se adec��a mejor a las necesidades de la BV. A la hora de decidir el modelo de compra a utilizar hay que considerar diferentes elementos, como la adquisici��n individual o en paquetes, la compra directa o subscripci��n, etc. En segundo lugar, se describen los circuitos internos y tratamientos t��cnicos que experimentan los libros electr��nicos. La gesti��n de estos procesos la llevan a cabo, en mayor o menor medida, los responsables de los servicios de Adquisici��n, Catalogaci��n y gesti��n de la Colecci��n Digital, dependiendo de c��mo se haya realizado la adquisici��n (a perpetuidad o subscripci��n). Por ��ltimo, se muestran las distintas opciones de acceso que tiene la BV de la UOC a los libros electr��nicos, utilizando para ello un sistema de autenticaci��n de usuarios mediante IP (a trav��s de un porxy WAM). Los puntos de acceso a los libros electr��nicos son: el cat��logo de la BV, el quick set de libros electr��nicos de Metalib, el listado A-Z de SFX, la herramienta de descubrimiento Summon y, adem��s, un nuevo acceso desde el nuevo Web de la BV de la UOC. El acceso a los libros electr��nicos de la BV de la UOC es una cuesti��n que a��n no est�� totalmente resuelta. Desde la nueva Web de la BV se est�� trabajando para conseguir un punto de acceso ��nico. La principal raz��n por la que no siempre es posible este ��nico punto de acceso es la existencia o inexistencia de las funcionalidades de metab��squeda en los libros electr��nicos que ofrece cada proveedor. A pesar de la complejidad del nuevo contexto del libro electr��nico, la BV de la UOC sigue apostando por los nuevos formatos de lectura, que en el 2013 ha representado el 32,30% del fondo bibliogr��fico y un 45% sobre el presupuesto dedicado para el 2013. Este proceso se realiza trabajando estrechamente con el profesorado, mediante los contenidos disponibles en la ��Biblioteca en el aula�� y potenciando la flexibilidad de los gestores y la construcci��n de nuevos flujos de trabajo que permitan optimizar y facilitar la transici��n de la lectura de libros tradicionales a la consulta de monograf��as en formato electr��nico.

Extended Endoscopic Endonasal Approaches for Cerebral Aneurysms: Anatomical, Virtual Reality and Morphometric Study

Introduction. The purpose of the present contribution is to perform a detailed anatomic and virtual reality three-dimensional stereoscopic study in order to test the effectiveness of the extended endoscopic endonasal approaches for selected anterior and posterior circulation aneurysms. Methods. The study was divided in two main steps: (1) simulation step, using a dedicated Virtual Reality System (Dextroscope, Volume Interactions); (2) dissection step, in which the feasibility to reach specific vascular territory via the nose was verified in the anatomical laboratory. Results. Good visualization and proximal and distal vascular control of the main midline anterior and posterior circulation territory were achieved during the simulation step as well as in the dissection step (anterior communicating complex, internal carotid, ophthalmic, superior hypophyseal, posterior cerebral and posterior communicating, basilar, superior cerebellar, anterior inferior cerebellar, vertebral, and posterior inferior cerebellar arteries). Conclusion. The present contribution is intended as strictly anatomic study in which we highlighted some specific anterior and posterior circulation aneurysms that can be reached via the nose. For clinical applications of these approaches, some relevant complications, mainly related to the endonasal route, such as proximal and distal vascular control, major arterial bleeding, postoperative cerebrospinal fluid leak, and olfactory disturbances must be considered

Identifying Specific Cues and Contexts Related to Smoking Craving for the Development of Effective Virtual Environments

Craving is considered the main variable associated with relapse after smoking cessation. Cue Exposure Therapy (CET) consists of controlled and repeated exposure to drug-related cues with the aim of extinguishing craving responses. Some virtual reality (VR) environments, such as virtual bars or parties, have previously shown their efficacy as tools for eliciting smoking craving. However, in order to adapt this technology to smoking cessation interventions, there is a need for more diverse environments that enhance the probability of generalization of extinction in real life. The main objective of this study was to identify frequent situations that produce smoking craving, as well as detecting specific craving cues in those contexts. Participants were 154 smokers who responded to an ad hoc self-administered inventory for assessing craving level in 12 different situations. Results showed that having a drink in a bar/pub at night, after having lunch/dinner in a restaurant and having a coffee in a cafe or after lunch/dinner at home were reported as the most craving-inducing scenarios. Some differences were found with regard to participants' gender, age, and number of cigarettes smoked per day. Females, younger people, and heavier smokers reported higher levels of craving in most situations. In general, the most widely cited specific cues across the contexts were people smoking, having a coffee, being with friends, and having finished eating. These results are discussed with a view to their consideration in the design of valid and reliable VR environments that could be used in the treatment of nicotine addicts who wish to give up smoking.

La asignatura virtual."Fundamentos de Cirug��a en Internet"

Introducci��n: Internet permite desarrollar un nuevo modelo de clase te��rica basado en la ense��anza no presencial y asincr��nica. Objetivo: Publicaci��n virtual de un tema de 'Fundamentos de Cirug��a' y evaluaci��n de los resultados de uso y participaci��n de los 80 alumnos matriculados. Material y M��todos: Se dise��aron tres partes: teor��a, cuestionario de autoevaluaci��n, y foro de preguntas. La teor��a consist��a en hipertexto y gr��ficos, con cuatro tipos de asistentes de aprendizaje: 1) remarcadores de informaci��n esencial; 2) informaci��n no esencial adicional; 3) mnemot��cnicos; 4) ampliaci��n conceptos complejos. El cuestionario consist��a en diez preguntas. La pantalla de respuesta ofrec��a las respuestas correctas comentadas, la puntuaci��n del alumno, y los centiles de cada nota. El foro de preguntas se basaba en el servidor Ez-Board. El profesor s��lo explic�� el sistema y los aspectos principales de la lecci��n. Los alumnos pod��an consultar el material indefinidamente y el foro de preguntas estuvo activo durante dos meses. Resultados: El sistema facilit�� la clase por parte del profesor y fue muy bien recibida por los alumnos. Se contabilizaron 239 visitas en dos meses, originadas en la Universidad en 80% de los casos. 16 alumnos usaron el asistente interactivo explicativo. El cuestionario fue respondido por 52 alumnos: 36 alumnos 1 vez y 16 alumnos 2 o m��s veces. El foro recibi�� 337 visitas. Se hicieron 38 preguntas de alumnos y 46 respuestas del profesor y otros especialistas. Conclusiones: 1) Dise��o y funcionamiento correcto; 2) Excelente acogida y participaci��n; 3) Probable mejora en el aprendizaje y adquisici��n de conocimientos.

A Virtual Laboratory Structure for Developing Programming Labs

Virtual Laboratories are an indispensablespace for developing practical activities in a Virtual Environment. In the field of Computer and Software Engineering different types of practical activities have tobe performed in order to obtain basic competences which are impossible to achieve by other means. This paper specifies an ontology for a general virtual laboratory.The proposed ontology provides a mechanism to select the best resources needed in a Virtual Laboratory once a specific practical activity has been defined and the maincompetences that students have to achieve in the learning process have been fixed. Furthermore, the proposed ontology can be used to develop an automatic and wizardtool that creates a Moodle Classroom using the practical activity specification and the related competences.

A Threat to a virtual hand elicits motor cortex activation

We report an experiment where participants observed an attack on their virtual body as experienced in an immersive virtual reality (IVR) system. Participants sat by a table with their right hand resting upon it. In IVR, they saw a virtual table that was registered with the real one, and they had a virtual body that substituted their real body seen from a first person perspective. The virtual right hand was collocated with their real right hand. Event-related brain potentials were recorded in two conditions, one where the participant"s virtual hand was attacked with a knife and a control condition where the knife only struck the virtual table. Significantly greater P450 potentials were obtained in the attack condition confirming our expectations that participants had a strong illusion of the virtual hand being their own, which was also strongly supported by questionnaire responses. Higher levels of subjective virtual hand ownership correlated with larger P450 amplitudes. Mu-rhythm event-related desynchronization in the motor cortex and readiness potential (C3-C4) negativity were clearly observed when the virtual hand was threatened as would be expected, if the real hand was threatened and the participant tried to avoid harm. Our results support the idea that event-related potentials may provide a promising non-subjective measure of virtual embodiment. They also support previous experiments on pain observation and are placed into context of similar experiments and studies of body perception and body ownership within cognitive neuroscience.

A Threat to a virtual hand elicits motor cortex activation

We report an experiment where participants observed an attack on their virtual body as experienced in an immersive virtual reality (IVR) system. Participants sat by a table with their right hand resting upon it. In IVR, they saw a virtual table that was registered with the real one, and they had a virtual body that substituted their real body seen from a first person perspective. The virtual right hand was collocated with their real right hand. Event-related brain potentials were recorded in two conditions, one where the participant"s virtual hand was attacked with a knife and a control condition where the knife only struck the virtual table. Significantly greater P450 potentials were obtained in the attack condition confirming our expectations that participants had a strong illusion of the virtual hand being their own, which was also strongly supported by questionnaire responses. Higher levels of subjective virtual hand ownership correlated with larger P450 amplitudes. Mu-rhythm event-related desynchronization in the motor cortex and readiness potential (C3-C4) negativity were clearly observed when the virtual hand was threatened as would be expected, if the real hand was threatened and the participant tried to avoid harm. Our results support the idea that event-related potentials may provide a promising non-subjective measure of virtual embodiment. They also support previous experiments on pain observation and are placed into context of similar experiments and studies of body perception and body ownership within cognitive neuroscience.