The Effects of Head-Centric Rest Frames on Egocentric Distance Perception in Virtual Reality

It has been shown through several research investigations that users tend to underestimate distances in virtual reality (VR). Virtual objects that appear close to users wearing a Head-mounted display (HMD) might be located at a farther distance in reality. This discrepancy between the actual distance and the distance observed by users in VR was found to hinder users from benefiting from the full in-VR immersive experience, and several efforts have been directed toward finding the causes and developing tools that mitigate this phenomenon. One hypothesis that stands out in the field of spatial perception is the rest frame hypothesis (RFH), which states that visual frames of reference (RFs), defined as fixed reference points of view in a virtual environment (VE), contribute to minimizing sensory mismatch. RFs have been shown to promote better eye-gaze stability and focus, reduce VR sickness, and improve visual search, along with other benefits. However, their effect on distance perception in VEs has not been evaluated. To explore and better understand the potential effects that RFs can have on distance perception in VR, we used a blind walking task to explore the effect of three head-centric RFs (a mesh mask, a nose, and a hat) on egocentric distance estimation. We performed a mixed-design study where we compared the effect of each of our chosen RFs across different environmental conditions and target distances in different 3D environments. We found that at near and mid-field distances, certain RFs can improve the user\u27s distance estimation accuracy and reduce distance underestimation. Additionally, we found that participants judged distance more accurately in cluttered environments compared to uncluttered environments. Our findings show that the characteristics of the 3D environment are important in distance estimation-dependent tasks in VR and that the addition of head-centric RFs, a simple avatar augmentation method, can lead to meaningful improvements in distance judgments, user experience, and task performance in VR

Second life : cibermercado, factores humanos y nuevas formas de vivir en las redes sociales

La presente tesis doctoral trata de Second Life que es un mundo en internet. Aquí se analiza el cibermercado, para ver si hay oferta y demanda, se reconocen los elementos que constituyen el Market Place, se analiza la construcción de otro yo llamado avatar y la estética de los mundos para ver si existen influencias de la publicidad y la sociedad de consumo, en el comportamiento de las personas. También se analizan las redes sociales en Second Life para ver si las personas pueden expresar sus sentimientos y emociones y si existe alguna forma de manipulación de los mundos en donde se encuentran estas redes sociales que puedan hacer que los seres humanos se despersonalicen. En la investigación se aplican conceptos de psicología y economía para reflexionar, a la luz de las Ciencias Sociales y Humanas, sobre el papel que Second Life ha tenido en las personas que viven en ella y si ésta es una forma de simulación o de evasión de la vida real.The following doctoral thesis is about Second Life, a world in internet, where cibermarket is analyzed to know if there is supply and demand, Market Place elements are recognized, the construction of another ¨me¨ called avatar and the aesthetic of the worlds are observed to see the influence of publicity and the consumerism in people´s behavior. Social networking is also studied in Second Life in order to see if the people can express their feelings and emotions, if there is a way of manipulation of the worlds where social networks take place making human beings impersonal. In this research psychology and economy concepts are applied on the rolethat SecondLifehas had onpeople livingin it andif itis a form ofsimulation orescape fromreal life.Doctor en Ciencias Sociales y HumanasDoctorad