How we experience immersive virtual environments: the concept of presence and its measurement

This paper reviews the concept of presence in immersive virtual environments, the sense of being there signalled by people acting and responding realistically to virtual situations and events. We argue that presence is a unique phenomenon that must be distinguished from the degree of engagement, involvement in the portrayed environment. We argue that there are three necessary conditions for presence: the (a) consistent low latency sensorimotor loop between sensory data and proprioception; (b) statistical plausibility: images must be statistically plausible in relation to the probability distribution of images over natural scenes. A constraint on this plausibility is the level of immersion;(c) behaviour-response correlations: Presence may be enhanced and maintained over time by appropriate correlations between the state and behaviour of participants and responses within the environment, correlations that show appropriate responses to the activity of the participants. We conclude with a discussion of methods for assessing whether presence occurs, and in particular recommend the approach of comparison with ground truth and give some examples of this.

Oxidative potential of particles in different occupational environments: a pilot study

The oxidative potential (OP) of particulate matter has been proposed as a toxicologically relevant metric. This concept is already frequently used for hazard characterization of ambient particles but it is still seldom applied in the occupational field. The objective of this study was to assess the OP in two different types of workplaces and to investigate the relationship between the OP and the physicochemical characteristics of the collected particles. At a toll station, at the entrance of a tunnel ('Tunnel' site), and at three different mechanical yards ('Depot' sites), we assessed particle mass (PM4 and PM2.5 and size distribution), number and surface area, organic and elemental carbon, polycyclic aromatic hydrocarbon (PAH), and four quinones as well as iron and copper concentration. The OP was determined directly on filters without extraction by using the dithiothreitol assay (DTT assay-OP(DTT)). The averaged mass concentration of respirable particles (PM4) at the Tunnel site was about twice the one at the Depot sites (173±103 and 90±36 µg m(-3), respectively), whereas the OP(DTT) was practically identical for all the sites (10.6±7.2 pmol DTT min(-1) μg(-1) at the Tunnel site; 10.4±4.6 pmol DTT min(-1) μg(-1) at the Depot sites). The OP(DTT) of PM4 was mostly present on the smallest PM2.5 fraction (OP(DTT) PM2.5: 10.2±8.1 pmol DTT min(-1) μg(-1); OP(DTT) PM4: 10.5±5.8 pmol DTT min(-1) μg(-1) for all sites), suggesting the presence of redox inactive components in the PM2.5-4 fraction. Although the reactivity was similar at the Tunnel and Depot sites irrespective of the metric chosen (OP(DTT) µg(-1) or OP(DTT) m(-3)), the chemicals associated with OP(DTT) were different between the two types of workplaces. The organic carbon, quinones, and/or metal content (Fe, Cu) were strongly associated with the DTT reactivity at the Tunnel site whereas only Fe and PAH were associated (positively and negatively, respectively) with this reactivity at the Depot sites. These results demonstrate the feasibility of measuring of the OP(DTT) in occupational environments and suggest that the particulate OP(DTT) is integrative of different physicochemical properties. This parameter could be a potentially useful exposure proxy for investigating particle exposure-related oxidative stress and its consequences. Further research is needed mostly to demonstrate the association of OP(DTT) with relevant oxidative endpoints in humans exposed to particles.

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.

Effects of Enriched Physical and Social Environments on Motor Performance, Associative Learning, and Hippocampal Neurogenesis in Mice.

We have studied the motor abilities and associative learning capabilities of adult mice placed in different enriched environments. Three-month-old animals were maintained for a month alone (AL), alone in a physically enriched environment (PHY), and, finally, in groups in the absence (SO) or presence (SOPHY) of an enriched environment. The animals' capabilities were subsequently checked in the rotarod test, and for classical and instrumental learning. The PHY and SOPHY groups presented better performances in the rotarod test and in the acquisition of the instrumental learning task. In contrast, no significant differences between groups were observed for classical eyeblink conditioning. The four groups presented similar increases in the strength of field EPSPs (fEPSPs) evoked at the hippocampal CA3-CA1 synapse across classical conditioning sessions, with no significant differences between groups. These trained animals were pulse-injected with bromodeoxyuridine (BrdU) to determine hippocampal neurogenesis. No significant differences were found in the number of NeuN/BrdU double-labeled neurons. We repeated the same BrdU study in one-month-old mice raised for an additional month in the above-mentioned four different environments. These animals were not submitted to rotarod or conditioned tests. Non-trained PHY and SOPHY groups presented more neurogenesis than the other two groups. Thus, neurogenesis seems to be related to physical enrichment at early ages, but not to learning acquisition in adult mice.

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.

Running mechanical alterations during repeated treadmill sprints in hot versus hypoxic environments : a pilot study.

We determined if performance and mechanical running alterations during repeated treadmill sprinting differ between severely hot and hypoxic environments. Six male recreational sportsmen (team- and racket-sport background) performed five 5-s sprints with 25-s recovery on an instrumented treadmill, allowing the continuous (step-by-step) measurement of running kinetics/kinematics and spring-mass characteristics. These were randomly conducted in control (CON; 25°C/45% RH, inspired fraction of oxygen = 20.9%), hot (HOT; 38°C/21% RH, inspired fraction of oxygen = 20.9%; end-exercise core temperature: ~38.6°C) and normobaric hypoxic (HYP, 25°C/45% RH, inspired fraction of oxygen = 13.3%/simulated altitude of ~3600 m; end-exercise pulse oxygen saturation: ~84%) environments. Running distance was lower (P < 0.05) in HOT compared to CON and HYP for the first sprint but larger (P < 0.05) sprint decrement score occurred in HYP versus HOT and CON. Compared to CON, the cumulated distance covered over the five sprints was lower (P < 0.01) in HYP but not in HOT. Irrespective of the environmental condition, significant changes occurred from the first to the fifth sprint repetitions (all three conditions compounded) in selected running kinetics (mean horizontal forces, P < 0.01) or kinematics (contact and swing times, both P < 0.001; step frequency, P < 0.001) and spring-mass characteristics (vertical stiffness, P < 0.001; leg stiffness, P < 0.01). No significant interaction between sprint number and condition was found for any mechanical data. Preliminary evidence indicates that repeated-sprint ability is more impaired in hypoxia than in a hot environment, when compared to a control condition. However, as sprints are repeated, mechanical alterations appear not to be exacerbated in severe (heat, hypoxia) environmental conditions.

Urban environments and situated institutions : everyday governance in west Bengal

How do processes of power shape the urban environment in small Indian cities? On a day-to-day basis, who actually controls access to and the use of environmental resources? How is this done? Answering these questions contributes to our ability to develop a nuanced understanding the urban condition. In order to investigate these questions an actor-oriented approach is developed, drawing on the anthropological literatures on everyday governance and the everyday state. This conceptual framework informs an urban political ecology approach oriented towards everyday practices and the micro-politics of the (re)production of urban socio-natures. This thesis employs a mixed methods approach to qualitative research. Three cases are presented to explore: para (neighbourhood) clubs as governance actors, the governance of the urban pondscape, and the urban political ecology of solid waste management. These case studies serve to highlight how power shapes the (re)production of urban socio-natures through the everyday environmental governance practices of a complex network of governance actors. This work further demonstrates how multiple intersectionalities, including class, caste and access to political and social authority, shape these practices and their outcomes. Finally, the manner in which balances of power, place making and the formation of subject positions may both result from and shape everyday environmental governance practices and their outcomes is explored. This empirical investigation makes a number of contributions to the literature. It has explores the hereto-understudied topics of environmental governance in small cities in India, the urban political ecologies of non-piped water and of solid waste, and the role of clubs as governance actors. It further contributes to conversations within the literature on how to deepen and broaden Urban Political Ecology by engaging with everyday practices, and cases of ordinary, not-openly contested socio-natures. -- Comment les processus de pouvoir influencent-ils l'environnement urbain dans les petites villes indiennes ? Au quotidien, qui contrôle l'accès et l'utilisation des ressources environnementales ? Comment ce contrôle s'exerce-t-il ? Répondre à ces questions contribue au développement d'une compréhension nuancée de la condition urbaine. Afin d'explorer ces questions une approche actor-oriented de la gouvernance quotidienne est développée, faisant appel aux littératures anthropologiques de la gouvernance quotidienne et de l'everyday state. Ce cadre conceptuel établit ainsi une approche d'Urban Political Ecology orientée vers les pratiques quotidiennes et la micro- politique de la (re) production des socio-natures urbaines. Cette thèse emploie des méthodes qualitatives mixtes. Trois cas sont présentés afin d'étudier : les clubs para (quartier) comme acteurs de la gouvernance; la gouvernance de la pondscape urbaine; et l'urban political ecology de la gestion des déchets solides. Ces études de cas permettent de mettre en lumière la façon dont le pouvoir influence la (re)production des socio-natures urbaines par le biais des pratiques quotidiennes de gouvernance environnementale d'un réseau complexe d'acteurs. Ce travail démontre également comment plusieurs intersectionnalités, y compris la classe, la caste et l'accès au pouvoir politique et social, façonnent ces pratiques de gouvernance et leurs produits. Finalement, cette recherche explore la manière dont les équilibres de pouvoir, la fabrication de lieux et la formation de la position du sujet peuvent à la fois résulter de et contribuer à façonner les pratiques quotidiennes de gouvernance environnementale et leurs produits. Cette investigation empirique fait ainsi plusieurs contributions à la littérature. Elle explore les questions jusque-là sous-étudiées de la gouvernance environnementale dans les petites villes en Inde, de l'urban political ecology de l'eau non courante et des déchets solides, ainsi que du rôle des clubs comme acteurs de la gouvernance. Celle-ci contribue également à des débats sur la façon d'approfondir et d'élargir l'urban political ecology en travaillant sur les pratiques quotidiennes, et sur des cas de socio-natures ordinaires, pas ouvertement contestées.

CRM and higher education : developing a monitoring system to improve relationships in e-learning environments

Peer-reviewed

Broadening the CRM domain of application to higher educational (e-learning) environments

In this paper, we reflect about the broadening of the field of application of CRM from the business domain to a wider context of relationships in which the inclusion of non-profit making organizations seems natural. In particular, we focus on analyzing the suitability of adopting CRM processes by universities and higher educational institutions dedicated to e-learning. This is an issue that, in our opinion, has much potential but has received little attention in research so far.

Lifelong learning teachers' needs in virtual learning environments

Peer-reviewed

Identifying pedagogical, technological and organizational barriers in virtual learning environments

Virtual learning environments are online spaces where learners interact with other learners, teachers, resources and the environment in itself. Although technology is meant to enhance the learning process, there are important issues regarding pedagogical and organizational aspects that must be addressed. In this paper we review the barriers detected in a virtual university which exclusively uses Internet as the main channel of communication, with no face-to-face requirements exceptthose related to final evaluation.

User Centered Desing in E-Learning Environments : from Usability to Learner Experience

The advent of the Internet had a great impact on distance education and rapidly e-learning has become a killer application. Education institutions worldwide are taking advantage of the available technology in order to facilitate education to a growing audience. Everyday, more and more people use e-learning systems, environments and contents for both training and learning. E-learning promotes educationamong people that due to different reasons could not have access to education: people who could nottravel, people with very little free time, or withdisabilities, etc. As e-learning systems grow and more people are accessing them, it is necessary to consider when designing virtual environments the diverse needs and characteristics that different users have. This allows building systems that people can use easily, efficiently and effectively, where the learning process leads to a good user experience and becomes a good learning experience.

Capturing user behavior in e-learning environments

Peer-reviewed