Title : Gaze-contingent multi-resolutional displays in Human visual system research

Project Lead : Santiago Santiago Martn Gonzlez From : University of Oviedo (None)

Dates : from -- to 2015-02-09 19:25:31

Description :

Motivation and objectives :
Motivation: Human vision has many interesting characteristics. One of them is that Human eyes subtend a wide field-of-view and provide high resolution detail at the center of gaze (fovea) with decreasing resolution in the remaining area (periphery). This characteristic of Human vision suggests that most of our computing power can be concentrated to render the small foveal area. That is, limited computing resources are sufficient to draw low resolution images on the periphery. This would allow us to decrease (or re-orient) the computational load, especially in a CAVE system. Gaze-contingent multi-resolutional displays is the term used in the literature for this approach to computer graphics (e.g. Loschky et al, 2005) This result has also direct application in the Human visual system research field. There are many related examples: study of saccadic eye movements; development of activities and computer games to measure and improve stereopsis in patients with amblyopia (lazy eye); study of the vestibular system, which contributes to balance in most mammals. In a previous VISIONAIR project (70-Gaze-contingent multi-resolutional graphic library - Santiago Martn Gonzlez, December 2012), the proposer developed a graphic library able to tackle this research in a CAVE environment. The main results of that project have been: - The library, called GLSVe (graphic library stereo vision engine) is running stable on the UCL Reactor Facilities and also in a less complex system at University of Oviedo. It takes advantage of shaders technology to achieve the goal. - A modified version of the test carried out by Loschky et al. (Loschky, L.; McConkie, G.; Yand, J. and Miller, M. The limits of visual resolution in natural scene viewing. Visual Cognition, 12 (6), pp 1057-1092, 2005) has been successfully reproduced using that library in a CAVE environment. The results are pending of publication in a scientific journal. This second project faces some technical challenges not solved yet (mainly the integration of the eye-tracking system) and proposes new scientific studies using this novel device. Objectives: The UCL facilities provide both a CAVE and an eye-tracking device. The second one has not been tested yet using our library, and that must be the first objective of the project. The conjunction of both devices enhances the field of research. The system will be tested again in a scientific challenge. The results obtained thus far are related with the limits of visual acuity as a function of distance from the foveal region, in a binocular but plane scene (in the sense that viewed objects are at the same depth). Our intention now is to study how convergence reduces visual acuity (i.e. spatial frequency detection) in objects positioned in front or behind the fixation point.

Teams :
IdeasCAD research group is a young research team, conducted by Dr. Santiago Martin and Dr. Ramon Rubio. Both are lecturers at the Engineering Graphic area of the University of Oviedo. They share academic interests and have complementary research fields. IdeasCAD is focused in the design, simulation, and manufacturing cycle. Ecodesign, generative design, virtual reality, reverse engineering, human factors and additive manufacturing are key words for IdeasCAD. Those techniques are applied not only in the industrial field but also in other areas like education or medical research. In this project, the group is reinforced with the collaboration of Prof. Manuel J. Blanco, full professor of Perceptual Psicology, University of Santiago (Spain), specialized in psychophysical vision understanding. He is author of some publications related with this project, as the ones referred here: Leirs, L. I. y Blanco,M. J. (2013): Eye movements and eye dominance. 17th Eye Movement Conference, Lund (Sweden). Blanco, M. J. y Soto, D. (2009). Unconscious perception of a flash can triger line motion illusion. Experimental Brain Research, 192, 605-613. DOI: 10.1007/s00221-008-1564-9 Blanco, M. J., Valle-Incln, F., Corral, J. y Serrano-Pedraza, Ignacio (2009). What drives the first dominance phase in binocular rivalry?. Spanish Journal of Psychology, 11, 1-2. Valle-Incln, F., Blanco, M. J., Leirs, L. I. y Soto, D. (2008). A new method to assess eye dominance. Psicolgica, 29: 55-64. Valle-Incln, F., Blanco, M. J. y Leirs, L. I. (2007). Monocularly biased access to the consciousness. Spanish Journal of Psychology, 10, 485.

Dates :
starting date : 07 July, 2014
ending date : 18 July, 2014

Facilities descriptions :
http://visionair-browser.g-scop.grenoble-inp.fr/visionair/Browser/Catalogs/REACTOR.UK.html

Recordings & Results :
This work builds on a previous TNA visit (in 2012) using the visitor's gaze-contingent software library at the cave in UCL. This library, Graphic Library Stereo Vision Engine (GLSVe) is a C# library based on OpenGL, and uses OpenTK as wrapper. It supports vertex and fragment shader programming and is designed to facilitate computer graphics and virtual reality scenarios with detailed control over stereo representations.] In particular it enables the development of a rendering system based on gaze direction, the idea being that human vision does not see visual detail evenly across the visual field (for example spatial acuity and colour perception change rapidly away from the centre of view) so we might want to alter the level of detail in peripheral regions. During the previous TNA visit we had managed to use the system in the cave, with rendering moderated by head-tracking data. The aim of this TNA was to supplement this with the addition of eye-tracking data, create a demonstrator for the system and run some pilot tests.

Conclusions :
- Developed a new system for mounting the Arrington eye-tracker on shutterglasses. This was not a planned activity, but necessitated due to an exisiting mounting frame being unsuitable for our experiments - Developed a system that combines eye-tracking and head tracking data to alter rendering around the fixation point - Developed and conducted proof-of-concept tests in the CAVE. - Currently writing a journal article based on applying this system in CAVE environments




Project Images :





Other project resources :

ACTIVITY REPORT.pdf