Research and Development for Assessment of Cognitive Function with Immersive Virtual Reality System

Cognitive function is very important for our social life. Cognitive dysfunction often disturbs healthy life of patients. In addition, it is difficult to predict the problems patients face in their actual daily life. Therefore, assessment of cognitive function is required in this ageing society. Such assessments aim to evaluate negative influences caused by a variety of cognitive dysfunctions. Conventionally, such assessments have been performed primarily based on neuropsychological tests. The effectiveness of these assessments has been proved to date, nonetheless, it is also known that these tests cannot directly predict the problems patients face in actual daily life. This is because the tests are performed on the desk. Also, the execution of the tests often burden the patients. Recently, it has been proposed that virtual reality (VR) technology could be utilized for the assessment of cognitive function, as it is possible to perform the assessment under more realistic environment than conventional paper-and-pencil based assessments. There are some preceding studies that reported assessments of cognitive function using VR technology. For example, a virtual cooking system [1], a virtual shopping system [2] and a virtual system of supermarket [3] have been reported. Since 2008, a 2-D virtual shopping test (VST) system has been developed at Kobe University, Japan [4] [5] [6]. In the VST, the user executes shopping and some other tasks. This system uses the virtual shopping mall created with computer graphics. VST adopts a touch panel screen as its user-friendly interface (Fig. 1). This user interface helps the user (mostly elderly people) to operate the system easily (Fig. 2). It has been revealed that this system is effective for assessment of higher cognitive function [7]. In this study, we developed a prototype of 3-D VST, which is a development of the past 2-D system. We selected immersive display system named “CAVE” as equipment for presenting 3-D images. There are two reasons why we selected a 3-D environment. First, reality is one of the most important elements of the assessment of cognitive functions with VR. We assume that the more realistic VST becomes, the better test we can execute. Second, we try to test if CAVE is useful for the assessment of cognitive function. In order to utilize CAVE as a device presenting VR, we need a new user interface instead of a touch screen. User interfaces used in such assessment systems should be intuitive and easy to use. Therefore we put emphasis on the user interface in this development.