Measuring Visual Apprehension with Virtual Reality Glasses

Team at the Cluster of Excellence Cognitive Interaction Technology (CITEC) develops new approach

Stroke patients often have difficulties in visually apprehending a situation: they recognize approaching bicycles too late, or bump their head because they did not avoid a low-hanging branch. A team from the Cluster of Excellence Cognitive Interaction Technology (CITEC) at Bielefeld University has developed a new method that can be used in any setting to measure, in a standardized way, how well people visually apprehend their environment. A unique aspect of this approach is that the researchers used virtual reality glasses for this type of measurement for the first time. The team has published its study in “Scientific Reports,” an online journal of the Nature Publishing Group.

Approximately 50 individuals took part in the study, which tested visual processing capabilities with the Oculus Rift virtual reality glasses. Photo: CITEC/Bielefeld University The method is suitable for both, healthy people and those suffering from cognitive disabilities. “People differ from one another in their visual apprehension abilities. With our method, we want to measure this ability in a way that is reliable and that reflects the current state of research” explains Prof. Dr. Werner Schneider, a professor of psychology. Dr. Schneider is leading the project together with computer scientist Prof. Dr. Mario Botsch. “Visual apprehension is essential for living,” says Schneider. “When driving in heavy traffic, for instance, the driver has to be able to comprehend the situation as fast as possible and make the right move.” How quickly someone notices the other cars, along with their positions and velocities, can be decisive in such situations. “This is visual apprehension – assessing relevant information about the surrounding environment using the sense of vision.”

Up to this point, the visual apprehension ability had been tested using computer monitors. “However, it is problematic to compare the results of various studies because factors such as the brightness of the room can always vary,” says Schneider. This makes it difficult to compare findings originating from laboratories at different universities and hospitals. “Reliable measurements are important, particularly in hospitals, when it comes to measuring, for instance, to which degree the cognitive abilities of patients with brain damage have improved from rehabilitation.”   

As a solution to this, Schneider and Botsch’s team tested the virtual reality glasses “Oculus Rift” and “HTC Vive”. The researchers use the more precise term “head-mounted displays” (HMDs) to refer to the glasses. Software companies are increasingly making use of these devices for 3-D computer games. “HMDs are also attractive for research,” says Botsch. “They offer the benefit of visualizing the virtual environment in a highly consistent and controllable manner. The size, color, and brightness of the virtual objects are identical for every trial.”

With their team, Schneider and Botsch have now clearly demonstrated that visual apprehension can be measured at least as reliably with HMD as with the standard cathode ray tube (CRT) monitor in a laboratory setting. In their experiment, the researchers presented a series of test stimuli (letters) to participants, each for a precisely controlled fraction of a second. The participants then reported which letters they had seen. From these data, the researchers determined how quickly each individual person had perceived the object, how much she/he was able to retain in short-term memory, and where their respective threshold of conscious perception is (i.e., sometimes letters shown very briefly were not perceived).

Dr. Rebecca Förster, Christian Poth, Prof. Dr. Mario Botsch, and Prof. Dr. Werner Schneider (from left) show how virtual reality glasses can be used for psychological measurements. Photo: CITEC/Bielefeld University. In their study, the team used the HMD Oculus Rift. Computer scientist Christian Behler, from Botsch’s research group “Computer Graphics and Geometry Processing”, implemented the software for the virtual reality glasses.

Approximately 50 individuals participated in the study and were tested both with the HMD glasses and with the CRT monitor. The study was performed under the guidance of the psychologists Rebecca Förster and Christian Poth, from Schneider’s research group “Neurocognitive Psychology”.
Their work was published in “Scientific Reports,” a multidisciplinary open-access journal for the natural sciences from the Nature publishing group.

Original Publication:
Rebecca M. Foerster, Christian H. Poth, Christian Behler, Mario Botsch, Werner X. Schneider: Using the virtual reality device Oculus Rift for neuropsychological assessment of visual processing capabilities. Scientific Reports, http://dx.doi.org/10.1038/srep37016, published on 21 November 2016

Contact:
Prof. Dr. Werner Schneider, Bielefeld University
Cluster of Excellence Cognitive Interaction Technology (CITEC)
Telephone: 0521 106-6934 (administrative office)
Email: wxs@uni-bielefeld.de

Prof. Dr. Mario Botsch, Bielefeld University
Cluster of Excellence Cognitive Interaction Technology (CITEC)
Telephone: 0521 106-12148 (Sekretariat)
Email: botsch@techfak.uni-bielefeld.de