Assessing the Zone of Comfort in Stereoscopic Displays using EEG

The conflict between vergence (eye movement) and accommodation (crystalline lens deformation) occurs in every stereoscopic display. It could cause important stress outside the "zone of comfort", when stereoscopic effect is too strong. This conflict has already been studied using questionnaires, during viewing sessions of several minutes. The present pilot study describes an experimental protocol which compares two different comfort conditions using electroencephalography (EEG) over short viewing sequences. Analyses showed significant differences both in event-related potentials (ERP) and in frequency bands power. An uncomfortable stereoscopy correlates with a weaker negative component and a delayed positive component in ERP. It also induces a power decrease in the alpha band and increases in theta and beta bands. With fast responses to stimuli, EEG is likely to enable the conception of adaptive systems, which could tune the stereoscopic experience according to each viewer

TOBE: Tangible Out-of-Body Experience

We propose a toolkit for creating Tangible Out-of-Body Experiences: exposing the inner states of users using physiological signals such as heart rate or brain activity. Tobe can take the form of a tangible avatar displaying live physiological readings to reflect on ourselves and others. Such a toolkit could be used by researchers and designers to create a multitude of potential tangible applications, including (but not limited to) educational tools about Science Technologies Engineering and Mathematics (STEM) and cognitive science, medical applications or entertainment and social experiences with one or several users or Tobes involved. Through a co-design approach, we investigated how everyday people picture their physiology and we validated the acceptability of Tobe in a scientific museum. We also give a practical example where two users relax together, with insights on how Tobe helped them to synchronize their signals and share a moment

Modeling On and Above a Stereoscopic Multitouch Display

International audienceWe present a semi-immersive environment for conceptual design where virtual mockups are obtained from gestures we aim to get closer to the way people conceive, create and manipulate three-dimensional shapes. We developed on-and-above-the-surface interaction techniques based on asymmetric bimanual interaction for creating and editing 3D models in a stereoscopic environment. Our approach combines hand and nger tracking in the space on and above a multitouch surface. This combination brings forth an alternative design environment where users can seamlessly switch between interacting on the surface or in the space above it to leverage the bene t of both interaction spaces

Pom1 gradient buffering through intermolecular auto-phosphorylation.

Concentration gradients provide spatial information for tissue patterning and cell organization, and their robustness under natural fluctuations is an evolutionary advantage. In rod-shaped Schizosaccharomyces pombe cells, the DYRK-family kinase Pom1 gradients control cell division timing and placement. Upon dephosphorylation by a Tea4-phosphatase complex, Pom1 associates with the plasma membrane at cell poles, where it diffuses and detaches upon auto-phosphorylation. Here, we demonstrate that Pom1 auto-phosphorylates intermolecularly, both in vitro and in vivo, which confers robustness to the gradient. Quantitative imaging reveals this robustness through two system's properties: The Pom1 gradient amplitude is inversely correlated with its decay length and is buffered against fluctuations in Tea4 levels. A theoretical model of Pom1 gradient formation through intermolecular auto-phosphorylation predicts both properties qualitatively and quantitatively. This provides a telling example where gradient robustness through super-linear decay, a principle hypothesized a decade ago, is achieved through autocatalysis. Concentration-dependent autocatalysis may be a widely used simple feedback to buffer biological activities

Distinct levels in Pom1 gradients limit Cdr2 activity and localization to time and position division.

Where and when cells divide are fundamental questions. In rod-shaped fission yeast cells, the DYRK-family kinase Pom1 is organized in concentration gradients from cell poles and controls cell division timing and positioning. Pom1 gradients restrict to mid-cell the SAD-like kinase Cdr2, which recruits Mid1/Anillin for medial division. Pom1 also delays mitotic commitment through Cdr2, which inhibits Wee1. Here, we describe quantitatively the distributions of cortical Pom1 and Cdr2. These reveal low profile overlap contrasting with previous whole-cell measurements and Cdr2 levels increase with cell elongation, raising the possibility that Pom1 regulates mitotic commitment by controlling Cdr2 medial levels. However, we show that distinct thresholds of Pom1 activity define the timing and positioning of division. Three conditions-a separation-of-function Pom1 allele, partial downregulation of Pom1 activity, and haploinsufficiency in diploid cells-yield cells that divide early, similar to pom1 deletion, but medially, like wild-type cells. In these cells, Cdr2 is localized correctly at mid-cell. Further, Cdr2 overexpression promotes precocious mitosis only in absence of Pom1. Thus, Pom1 inhibits Cdr2 for mitotic commitment independently of regulating its localization or cortical levels. Indeed, we show Pom1 restricts Cdr2 activity through phosphorylation of a C-terminal self-inhibitory tail. In summary, our results demonstrate that distinct levels in Pom1 gradients delineate a medial Cdr2 domain, for cell division placement, and control its activity, for mitotic commitment

Interaction avec des environnements virtuels affichés au moyens d'interfaces de visualisation collective

Les interfaces de visualisation collective à base de grands écrans permettent à plusieurs participants, localisés en un lieu unique, d'être immergés dans un même environnement virtuel (EV). Malgré leur potentiel pour le travail de groupe, ces interfaces restent souvent sousutilis ées, car les utilisateurs n'ont pas la possibilité d'interagir facilement et efficacement avec les EV qu'ils sont en train de visualiser. Nous nous proposons d'étudier les caractéristiques des interfaces de visualisation collective afin de définir un ensemble de recommandations pour l'interaction avec des EV. A partir de ces recommandations, nous critiquons les interfaces d'action existantes et proposons une nouvelle interface appelée le CAT. Le CAT est une interface d'action à six degrés de liberté fonctionnant à partir de modes de résistances isotoniques et isométriques. Un plateau mobile articulé autour d'un pied fixe permet la réalisation de tâches d'interaction 3D (navigation, manipulation). Une tablette graphique, fixée sur le plateau permet la réalisation de tâches d'interaction 2D (sélection, contrôle du système). La structure du CAT favorise une interaction non contraignante, rapide et efficace pour des utilisateurs novices. Une évaluation formelle a permis de montrer que le CAT était plus performant qu'une spacemouse pour des tâches de manipulation d'objets 3D, et que les préférences des utilisateurs étaient en sa faveur. Le CAT a été utilisé pour des applications de revue de projet et de théâtre interactif. Cette nouvelle interface d'action favorise le développement d'applications concrètes utilisant des EV affichés au moyen d'interfaces de visualisation collective.Large-displays used as collective visualization interfaces allow several co-located participants to be immersed in virtual environments (VE). In spite of their potential for group works, large-displays are often under-used because the users cannot interact easily and e_ciently with the visualized VE. The study of the characteristics of the large-displays allows us to propose a set of recommendations for interaction with the VE. From these recommendations, we criticize the existing input devices, and propose a new input device : the CAT (Control Action Table). The CAT is a 6 degrees of freedom device mixing isotonic and isometric resistance modes. It consists of a freestanding sensitive top, which can be orientated in space. The manipulation of this top allows to perform 3D tasks (manipulation, navigation). A tablet, _xed on the top, allows to perform 2D tasks (selection, system control). The CAT design favours a nonconstraining, quick and e_cient interaction for novice users. A user study has shown that the CAT is more e_cient than a standard 6 DOF rate controller for 3D manipulation tasks, and that the user preferences are in its favour. The CAT has been used for applications of project review and interactive theatre. This new input device favours the development of real applications using VE visualized on large-displays

Teaching spatial thinking to visually impaired students using augmented reality: Introducing the VISTE project

National audiencePeople living with visual impairments face important challenges related to orientation and mobility which might even prevent them from travelling autonomously. Indeed, it is difficult to navigate in an unknown space in the absence of vision or to acquire knowledge about spaces before travelling. Historically, raised-line paper maps with braille text have been used to teach geography to visually impaired children, but these maps possess significant limitations. Accessible interactive maps have been designed with the aim to overcome these limitations. In the VISTE project, we aim at exploring an innovative augmented reality framework to design an accessible interactive map that will then be used in special education schools for teaching spatial thinking to visually impaired children.Les personnes non-voyantes et malvoyantes font face à des défis importants liés à l'orientation et à la mobilité qui pourraient notamment les empêcher de voyager en autonomie. En effet, il est difficile de naviguer dans un espace inconnu en l'absence de vision ou d'acquérir des connaissances sur les espaces avant de voyager. Historiquement, les cartes en relief avec du texte en braille ont été utilisées pour enseigner la géographie aux élèves déficientes visuelles, mais ces cartes présentent des limites importantes, comme par exemple un nombre limité d'informations pouvant être présentées. Des cartes interactives accessibles ont été conçues dans le but de surmonter ces limitations. Dans le projet VISTE, nous visons à explorer une technologie novatrice de réalité augmentée pour concevoir une carte interactive accessible qui sera ensuite utilisée dans les écoles spécialisées pour enseigner la géographie à des enfants déficients visuels

PapARt : interactive 3D graphics and multi-touch augmented paper for artistic creation

International audienceStandard physical pen-and-paper creation and computer graphics tools tend to evolve in separate tracks. In this paper, we propose a new interface, PapARt, that bridges the gap between these two worlds. We developed a system that allow users to visualize, ma- nipulate and edit a 3D scene projected onto a paper sheet. Using multitouch and tangible interfaces, users can directly interact with the 3D scene to prepare their drawings. Then, thanks to the pro- jection of the 3D scene directly on the final surface medium, they can draw using standard tools while relying on the underlying 3D scene. Hence, users benefit from both the power of interactive 3D graphics and fast and easy interaction metaphors, while keeping a direct link with the physical material. PapARt has been tested dur- ing a large scale exhibition for general public. Such an interface, which combines computer-assisted drawing and free form user ex- pressiveness on a standard sheet of paper, opens new perspectives for enhancing user creation

Spatial Interfaces and Interactive 3D Environments for Immersive Musical Performances

International audienceThe power of interactive 3D graphics, immersive displays, and spatial interfaces is still under-explored in domains where the main target is to enhance creativity and emotional experiences. This article presents a set of work the attempts to extent the frontiers of music creation as well as the experience of audiences attending to digital performances. The goal is to connect sounds to interactive 3D graphics that musicians can interact with and the audience can observe