Acting rehearsal in collaborative multimodal mixed reality environments

This paper presents the use of our multimodal mixed reality telecommunication system to support remote acting rehearsal. The rehearsals involved two actors, located in London and Barcelona, and a director in another location in London. This triadic audiovisual telecommunication was performed in a spatial and multimodal collaborative mixed reality environment based on the 'destination-visitor' paradigm, which we define and put into use. We detail our heterogeneous system architecture, which spans the three distributed and technologically asymmetric sites, and features a range of capture, display, and transmission technologies. The actors' and director's experience of rehearsing a scene via the system are then discussed, exploring successes and failures of this heterogeneous form of telecollaboration. Overall, the common spatial frame of reference presented by the system to all parties was highly conducive to theatrical acting and directing, allowing blocking, gross gesture, and unambiguous instruction to be issued. The relative inexpressivity of the actors' embodiments was identified as the central limitation of the telecommunication, meaning that moments relying on performing and reacting to consequential facial expression and subtle gesture were less successful.

Proxemics with multiple dynamic characters in an immersive virtual environment

An experiment was carried out to examine the impact on electrodermal activity of people when approached by groups of one or four virtual characters at varying distances. It was premised on the basis of proxemics theory that the closer the approach of the virtual characters to the participant, the greater the level of physiological arousal. Physiological arousal was measured by the number of skin conductance responses within a short time period after the approach, and the maximum change in skin conductance level 5 s after the approach. The virtual characters were each either female or a cylinder of human size, and one or four characters approached each subject a total of 12 times. Twelve male subjects were recruited for the experiment. The results suggest that the number of skin conductance responses after the approach and the change in skin conductance level increased the closer the virtual characters approached toward the participants. Moreover, these response variables were inversely correlated with the number of visits, showing a typical adaptation effect. There was some evidence to suggest that the number of characters who simultaneously approached (one or four) was positively associated with the responses. Surprisingly there was no evidence of a difference in response between the humanoid characters and cylinders on the basis of this physiological data. It is suggested that the similarity in this quantitative arousal response to virtual characters and virtual objects might mask a profound difference in qualitative response, an interpretation supported by questionnaire and interview results. Overall the experiment supported the premise that people exhibit heightened physiological arousal the closer they are approached by virtual characters.

What makes one person paranoid and another person anxious? The differential prediction of social anxiety and persecutory ideation in an experimental situation

The study shows that social anxiety and persecutory ideation share many of the same predictive factors. Non-clinical paranoia may be a type of anxious fear. However, perceptual anomalies are a distinct predictor of paranoia. In the context of an individual feeling anxious, the occurrence of odd internal feelings in social situations may lead to delusional ideas through a sense of" things not seeming right". The study illustrates the approach of focusing on experiences such as paranoid thinking rather than diagnoses such as schizophrenia.

Beaming into the rat world: enabling real-time intereaction between rat and human each at their own scale

Immersive virtual reality (IVR) typically generates the illusion in participants that they are in the displayed virtual scene where they can experience and interact in events as if they were really happening. Teleoperator (TO) systems place people at a remote physical destination embodied as a robotic device, and where typically participants have the sensation of being at the destination, with the ability to interact with entities there. In this paper, we show how to combine IVR and TO to allow a new class of application. The participant in the IVR is represented in the destination by a physical robot (TO) and simultaneously the remote place and entities within it are represented to the participant in the IVR. Hence, the IVR participant has a normal virtual reality experience, but where his or her actions and behaviour control the remote robot and can therefore have physical consequences. Here, we show how such a system can be deployed to allow a human and a rat to operate together, but the human interacting with the rat on a human scale, and the rat interacting with the human on the rat scale. The human is represented in a rat arena by a small robot that is slaved to the human"s movements, whereas the tracked rat is represented to the human in the virtual reality by a humanoid avatar. We describe the system and also a study that was designed to test whether humans can successfully play a game with the rat. The results show that the system functioned well and that the humans were able to interact with the rat to fulfil the tasks of the game. This system opens up the possibility of new applications in the life sciences involving participant observation of and interaction with animals but at human scale.

Beaming into the rat world: enabling real-time intereaction between rat and human each at their own scale

Immersive virtual reality (IVR) typically generates the illusion in participants that they are in the displayed virtual scene where they can experience and interact in events as if they were really happening. Teleoperator (TO) systems place people at a remote physical destination embodied as a robotic device, and where typically participants have the sensation of being at the destination, with the ability to interact with entities there. In this paper, we show how to combine IVR and TO to allow a new class of application. The participant in the IVR is represented in the destination by a physical robot (TO) and simultaneously the remote place and entities within it are represented to the participant in the IVR. Hence, the IVR participant has a normal virtual reality experience, but where his or her actions and behaviour control the remote robot and can therefore have physical consequences. Here, we show how such a system can be deployed to allow a human and a rat to operate together, but the human interacting with the rat on a human scale, and the rat interacting with the human on the rat scale. The human is represented in a rat arena by a small robot that is slaved to the human"s movements, whereas the tracked rat is represented to the human in the virtual reality by a humanoid avatar. We describe the system and also a study that was designed to test whether humans can successfully play a game with the rat. The results show that the system functioned well and that the humans were able to interact with the rat to fulfil the tasks of the game. This system opens up the possibility of new applications in the life sciences involving participant observation of and interaction with animals but at human scale.

Coloração do fruto, distúrbios fisiológicos e doenças em maçãs 'Gala' e 'Fuji' pulverizadas com aminoetoxivinilglicina

O objetivo deste trabalho foi avaliar os efeitos da pulverização pré-colheita de macieiras 'Gala' e 'Fuji' com aminoetoxivinilglicina (AVG) sobre a qualidade dos frutos e a ocorrência de distúrbios fisiológicos e doenças. O experimento foi conduzido nos anos de 2005 e 2006, com pulverização de AVG (30 dias antes do início da colheita comercial dos frutos) nas doses de 0; 125 e 250 mg L-1, sendo que, na segunda safra, também foi utilizada a dose de 62,5 mg L-1. Em maçãs 'Gala', o aumento na dose de AVG reduziu o desenvolvimento de coloração vermelha e a permeância à perda de água na casca. Nesta mesma cultivar, em frutos avaliados após armazenamento refrigerado (três meses a 0±0,5ºC/90-95% UR), seguido de uma semana de vida de prateleira (20±4ºC/60-70% UR), o tratamento pré-colheita com AVG aumentou a incidência de "bitter pit", porém reduziu a incidência de escaldadura, rachadura peduncular e podridões. Em maçãs 'Fuji', o aumento na dose de AVG reduziu a incidência e a severidade de pingo-de-mel em frutos colhidos tardiamente. A pulverização com AVG aumentou a severidade de mancha foliar de 'Gala' (Glomerella cingulata).

Comunicação científica qualidade de frutos da pereira-japonesa colhidos em duas regiões de Santa Catarina, Brasil

O trabalho foi desenvolvido em Caçador (1067 unidades de frio -UF- durante a vernalização) e em São Joaquim (1999 UF), nas safras de 2006/07 e 2007/08, com objetivo de comparar a qualidade de frutos produzidos por diferentes cultivares de pereira-japonesa, nos dois locais, e colhidas em diferentes estágios de maturação. A deficiência na quantidade e na qualidade do frio durante a vernalização ocasionou a brotação de flores sem a presença de folhas até a fase "J" na cv. Kousui, afetando a fase inicial de desenvolvimento dos frutinhos. Também propiciou reduzido número de gemas florais por planta e baixa quantidade de flores por gema. Região com adequada quantidade de horas de frio durante a vernalização exige raleio mais intenso devido ao maior número de frutos por planta. A colheita de frutos antes de atingirem o ponto ideal de maturação fisiológica implica a produção de frutos de menor peso, menor teor de sólidos solúveis totais, maior firmeza e menos saborosos. Já os frutos colhidos após o ponto de colheita ideal podem apresentar os distúrbios fisiológicos "pingo-de-mel" e "degenerescência interna por senescência da polpa". O teor de SST foi definido mais pelo genótipo da cultivar, mas para algumas variou entre os anos. As cvs. Housui e Kousui tendem a apresentar maior °Brix que a cv. Nijisseiki. Melhor qualidade comercial foi apresentado por frutos da cv. Housui. O número de sementes por fruto variou entre cultivares e anos. A cv. Housui apresentou baixa fecundidade quando analisada pelo número médio de sementes produzidas por fruto (<3,0); a cv. Kousui apresentou baixa fecundidade em São Joaquim, mas fecundidade intermediária (3,1 a 5,0 sementes por fruto) em Caçador; a cv. Suisei apresentou fecundidade intermediária, e a cv. Nijisseiki apresentou alta fecundidade (>5,1 sementes por fruto),

An Analysis of Eye Scanpath Entropy in a Progressively Forming Virtual Environment

A sign of presence in virtual environments is that people respond to situations and events as if they were real, where response may be considered at many different levels, ranging from unconscious physiological responses through to overt behavior,emotions, and thoughts. In this paper we consider two responses that gave different indications of the onset of presence in a gradually forming environment. Two aspects of the response of people to an immersive virtual environment were recorded: their eye scanpath, and their skin conductance response (SCR). The scenario was formed over a period of 2 min, by introducing an increasing number of its polygons in random order in a head-tracked head-mounted display. For one group of experimental participants (n 8) the environment formed into one in which they found themselves standing on top of a 3 m high column. For a second group of participants (n 6) the environment was otherwise the same except that the column was only 1 cm high, so that they would be standing at normal ground level. For a third group of participants (n 14) the polygons never formed into a meaningful environment. The participants who stood on top of the tall column exhibited a significant decrease in entropy of the eye scanpath and an increase in the number of SCR by 99 s into the scenario, at a time when only 65% of the polygons had been displayed. The ground level participants exhibited a similar decrease in scanpath entropy, but not the increase in SCR. The random scenario grouping did not exhibit this decrease in eye scanpath entropy. A drop in scanpath entropy indicates that the environment had cohered into a meaningful perception. An increase in the rate of SCR indicates the perception of an aversive stimulus. These results suggest that on these two dimensions (scanpath entropy and rate of SCR) participants were responding realistically to the scenario shown in the virtual environment. In addition, the response occurred well before the entire scenario had been displayed, suggesting that once a set of minimal cues exists within a scenario,it is enough to form a meaningful perception. Moreover, at the level of the sympathetic nervous system, the participants who were standing on top of the column exhibited arousal as if their experience might be real. This is an important practical aspect of the concept of presence.

The Impact of a Character Posture Model on the Communication of Affect in an Immersive Virtual Environment

This paper presents the quantitative and qualitative findings from an experiment designed to evaluate a developing model of affective postures for full-body virtual characters in immersive virtual environments (IVEs). Forty-nine participants were each requested to explore a virtual environment by asking two virtual characters for instructions. The participants used a CAVE-like system to explore the environment. Participant responses and their impression of the virtual characters were evaluated through a wide variety of both quantitative and qualitative methods. Combining a controlled experimental approach with various data-collection methods provided a number of advantages such as providing a reason to the quantitative results. The quantitative results indicate that posture plays an important role in the communication of affect by virtual characters. The qualitative findings indicated that participants attribute a variety of psychological states to the behavioral cues displayed by virtual characters. In addition, participants tended to interpret the social context portrayed by the virtual characters in a holistic manner. This suggests that one aspect of the virtual scene colors the perception of the whole social context portrayed by the virtual characters. We conclude by discussing the importance of designing holistically congruent virtual characters especially in immersive settings.

Concentração e época de aplicação de aminoetoxivinilglicine (AVG) na maturação de macieiras 'Fuji Suprema'

O efeito de aminoetoxivinilglicine (AVG), comercialmente disponível com o nome de Retain®, foi avaliado em macieiras da cultivar Fuji Suprema durante quatro ciclos agrícolas. Foram estudadas a época de aplicação e a concentração em uma ou em múltiplas aplicações, visando a avaliar o efeito no retardamento da maturação dos frutos, queda pré-colheita dos frutos, produção de frutos, massa média de frutos, resistência da polpa, conteúdo de sólidos solúveis, acidez titulável, índice de iodo-amido, cor da epiderme dos frutos, incidência de pingo-de-mel, incidência de rachadura peduncular e danos de sol. O AVG foi aplicado uma, duas, quatro semanas antes do ponto de colheita e no ponto de colheita, em concentrações variando de 60 a 120 g ha-1. Todos os tratamentos retardaram a maturação dos frutos, sendo que aplicados duas e uma semana antes do ponto de colheita concentraram a mesma na última data de colheita. O atraso da maturação foi acompanhado da manutenção da resistência da polpa e degradação do amido. A massa média dos frutos aumentou significativamente em comparação ao tratamento-testemunha. O desenvolvimento da coloração vermelha dos frutos foi retardado proporcionalmente ao atraso da maturação. As aplicações de AVG com diferentes concentrações e épocas de aplicação em uma ou duas vezes não diferiram entre si quanto à queda de frutos em pré-colheita na cultivar Fuji, contudo todos os tratamentos com AVG foram significativamente inferiores ao tratamento-testemunha.

Crescimento vegetativo e características dos frutos de cinco cultivares de abacaxi na região de Bauru-SP

Avaliaram-se o crescimento vegetativo e a produção de cultivares novas e tradicionais de abacaxi na região de Bauru. As cultivares estudadas foram: 'Smooth Cayenne', 'Jupi', 'Imperial', 'Gold' e 'Gomo de Mel'. As mudas foram obtidas por cultura de tecidos pela empresa BIONOVA a partir de plantas-matrizes cedidas pela Embrapa Mandioca e Fruticultura Tropical e por produtores comerciais e passaram por um período de 100 dias de aclimatação em telado acondicionadas em tubetes. O plantio no campo foi realizado em canteiros revestidos com 'mulching' plástico preto em janeiro de 2007. O delineamento foi em blocos casualizados, com quatro repetições. Cada parcela apresentou 32 plantas, e o sistema de plantio foi em linhas duplas, no espaçamento 0,30 x 0,50 x 1,0 m. A avaliação dos tratamentos foi baseada na determinação do nível de crescimento vegetativo (massa e comprimento da folha 'D' e diâmetro do caule) e nas características físicas dos frutos. Os resultados obtidos foram submetidos à análise de variância e ao teste de Tukey, a 5% de probabilidade. Nas condições ambientais da região de Bauru (SP), e considerando o uso de mudas obtidas por cultura de tecidos, os resultados deste trabalho indicaram a superioridade das cultivares 'Gold', 'Smooth Cayenne' e 'Jupi' em relação a 'Imperial' e 'Gomo de Mel', com crescimento vegetativo maior e produção de frutos mais pesados.

Virtual hand illusion induced by visuomotor correlations

Our body schema gives the subjective impression of being highly stable. However, a number of easily-evoked illusions illustrate its remarkable malleability. In the rubber-hand illusion, illusory ownership of a rubber-hand is evoked by synchronous visual and tactile stimulation on a visible rubber arm and on the hidden real arm. Ownership is concurrent with a proprioceptive illusion of displacement of the arm position towards the fake arm. We have previously shown that this illusion of ownership plus the proprioceptive displacement also occurs towards a virtual 3D projection of an arm when the appropriate synchronous visuotactile stimulation is provided. Our objective here was to explore whether these illusions (ownership and proprioceptive displacement) can be induced by only synchronous visuomotor stimulation, in the absence of tactile stimulation.

Drumming in immersive virtual reality: the body shapes the way we play

It has been shown that it is possible to generate perceptual illusions of ownership in immersive virtual reality (IVR) over a virtual body seen from first person perspective, in other words over a body that visually substitutes the person's real body. This can occur even when the virtual body is quite different in appearance from the person's real body. However, investigation of the psychological, behavioral and attitudinal consequences of such body transformations remains an interesting problem with much to be discovered. Thirty six Caucasian people participated in a between-groups experiment where they played a West-African Djembe hand drum while immersed in IVR and with a virtual body that substituted their own. The virtual hand drum was registered with a physical drum. They were alongside a virtual character that played a drum in a supporting, accompanying role. In a baseline condition participants were represented only by plainly shaded white hands, so that they were able merely to play. In the experimental condition they were represented either by a casually dressed dark-skinned virtual body (Casual Dark-Skinned - CD) or by a formal suited light-skinned body (Formal Light-Skinned - FL). Although participants of both groups experienced a strong body ownership illusion towards the virtual body, only those with the CD representation showed significant increases in their movement patterns for drumming compared to the baseline condition and compared with those embodied in the FL body. Moreover, the stronger the illusion of body ownership in the CD condition, the greater this behavioral change. A path analysis showed that the observed behavioral changes were a function of the strength of the illusion of body ownership towards the virtual body and its perceived appropriateness for the drumming task. These results demonstrate that full body ownership illusions can lead to substantial behavioral and possibly cognitive changes depending on the appearance of the virtual body. This could be important for many applications such as learning, education, training, psychotherapy and rehabilitation using IVR.

Avaliação da resistência de 47 acessos de mangueira aos fungos Fusicoccum aesculis e Neofusicoccum parvum

A mangicultura praticada no Submédio do Vale do São Francisco é considerada um dos principais destaques no comércio externo do País. Dentre as diversas variedades cultivadas, a Tommy Atkins é a que representa a maior parte das exportações. Entretanto, a magnitude das perdas por podridões pós-colheita, causadas por fungos Botryosphaeriaceae, é sempre uma grande preocupação para exportadores e importadores da fruta. A busca por métodos de controle mais eficazes e limpos é uma tendência mundial. Nesse sentido, o objetivo deste trabalho foi avaliar a reação de frutos, de 47 acessos de mangueiras, quanto à resistência aos fungos Fusicoccum aesculis e Neofusicoccum parvum. As inoculações foram realizadas mediante deposição de disco do meio de cultura batata-dextrose-ágar (BDA), contendo estruturas do patógeno sobre duas posições opostas na região equatorial da manga, mantido, posteriormente, por 24 horas em câmara úmida. Foram realizadas medições das lesões até o sétimo dia, com uma régua milimetrada. Com os registros dos crescimentos das lesões, foram calculadas as taxas diárias de crescimento da lesão (TDCL's) para cada acesso. As maiores TDCLs foram observadas nos acessos 'Roxa' e 'Lita', quando inoculados com F. aesculis, e nos acessos 'Roxa', 'Ruby', 'Papo de peru', 'CPAC 22/93', 'Pingo-de-ouro', 'Pêssego' e 'M13269', quando inoculados com N. parvum. Os acessos 'Nego-não-chupa', 'Manga-d'água', 'Juazeiro VI', 'Juazeiro VII' e 'Favo-de-mel' foram os que apresentaram, concomitantemente, as menores TDCLs para ambos os patógenos e diferenças significativas em relação aos demais acessos.

Extending body space in immersive virtual reality: a very long arm illusion

Recent studies have shown that a fake body part can be incorporated into human body representation through synchronous multisensory stimulation on the fake and corresponding real body part- the most famous example being the Rubber Hand Illusion. However, the extent to which gross asymmetries in the fake body can be assimilated remains unknown. Participants experienced, through a head-tracked stereo head-mounted display a virtual body coincident with their real body. There were 5 conditions in a between-groups experiment, with 10 participants per condition. In all conditions there was visuo-motor congruence between the real and virtual dominant arm. In an Incongruent condition (I), where the virtual arm length was equal to the real length, there was visuo-tactile incongruence. In four Congruent conditions there was visuo-tactile congruence, but the virtual arm lengths were either equal to (C1), double (C2), triple (C3) or quadruple (C4) the real ones. Questionnaire scores and defensive withdrawal movements in response to a threat showed that the overall level of ownership was high in both C1 and I, and there was no significant difference between these conditions. Additionally, participants experienced ownership over the virtual arm up to three times the length of the real one, and less strongly at four times the length. The illusion did decline, however, with the length of the virtual arm. In the C2-C4 conditions although a measure of proprioceptive drift positively correlated with virtual arm length, there was no correlation between the drift and ownership of the virtual arm, suggesting different underlying mechanisms between ownership and drift. Overall, these findings extend and enrich previous results that multisensory and sensorimotor information can reconstruct our perception of the body shape, size and symmetry even when this is not consistent with normal body proportions.