Virtual Reality Produced in the Brain

External world is physical world, where objects, electromagnetic waves, air waves and temperatures exist. In contrast, we feel that objects have colors, sounds, hotness or coldness, smell and taste. These feelings are qualia, which must be virtual realities occurring in mind. The presence of food, enemies, friends and partners are recognized through virtual realities. Role of the sensory system seems to correlate these two worlds consistently. However, the mechanism to produce virtual reality has not been clarified. Purpose of the present study is to understand mind based on material. Here, we review outline of the sensory system in humans. We show that sensory receptors is a keyboard that make impulses as trigger signal when adequate stimuli is applied, and that sensory system works like a keyboard instrument, which induces virtual reality. Thereafter, we state strategy to clarify the material basis of virtual reality using unicellular organism.