Currently, there are many occasions to communicate with each other in the collaborative virtual environment. However, it is more difficult to keep high-motivation for participating in communication in such virtual environment than in face-to-face environment. It is considered that the reasons are 1) the difficulty of understanding how their own motivations are and 2) the boring expression due to the fixed view point. To address this issue, we display electroencephalogram information to a virtual space by forward-backward model - zoom in/out of whole virtual space. According to the results of experiment, our system successfully provides an environment in which people can keep high-motivations for participating in communication.