Virtalis Helps Scientists Understand How the Brain Builds Images
VIRTALIS has advised and supplied upgraded Virtual Reality (VR) hardware to a University research team conducting experiments into how the brain represents a 3D scene.
Dr. Glennerster and his Virtual Reality Research Group, based at Reading University, sought technical help from Virtalis when their laboratory was first set up at The University of Oxford seven years ago. Now the Virtalis team has advised on and supplied the latest Head Mounted Display (HMD) as the research enters a new phase. Dr. Andrew Glennerster, Director of Research for the Virtual Reality Research Group, explained: “Our previous HMD used cathode ray tube technology and was quite heavy for participants to use. The NVIS SXIII we have just started using incorporates LCD technology to give a much crisper, brighter picture with fewer distortions in the pixel array. Our researchers, who have only been using it for a fortnight, report that it is easy to calibrate and a great deal more comfortable to wear.”
In the latest series of experiments by the Research Group, which is in the data gathering phase, the scientists are attempting to answer whether people generate a 3D model of the world in their heads or do they instead store a representation that is more like a set of images. “We are attempting to find out what rules the brain applies to the images they see”, said Glennerster. “For this reason, we have made as simple a VR image as possible. We aren’t trying to reflect real life or have objects behave as they would ordinarily do. VR allows you to do this and is a crucial tool in this area of science.”
The VR scene devised by the Research Group is very simple – just three very long lines, with no apparent top or bottom and an unchanging width in the image as the participant moves around the scene. This simplicity makes it possible to distinguish the predictions of the two models. The preliminary results from the latest phase of experiments have just been presented at the European Conference on Visual Perception conference by Dr. Lyndsey Pickup.
The complete freedom to move within the virtual environments the team designs is seen as very important. The Research Group has just begun using a Vicon MX3 system with tracker software to track both head and eye movements. “The Vicon tracking system represents a great improvement in accuracy and latency over our previous head trackers”, explained Glennerster. “In an earlier set of experiments about the size and depth of objects, we were able to prove that most participants fail to notice a fourfold increase in room size when it is expanded in a particular way. This raised challenging questions about the way humans represent 3D space. Information from a continually changing retinal image must contribute to a stable representation of the scene, but we have little idea, as yet, what form that representation takes. There are many potentially exciting applications that could follow from this research. One of the most exciting is the possibility of helping blind people build up their own representation of the world from cameras under their control.”
Virtual Reality Research Group
Department of Psychology, University of Reading and Department of Physiology, Anatomy and Genetics, Oxford