[MUSIC] You describe VR using this three illusions, which is something we will discuss later this week as well. But here, would you like to just briefly tell us about the three illusions that you have been using to describe VR? >> Okay, so, in virtual reality, since the early 90s, people have been using the concept of presence to describe this feeling of being there, to describe the feeling of being in the place. But, unfortunately, over many years, this concept has been mixed up with many things that in reality don't have really much to do with it. Which are feelings of enjoyment, or engagement, or excitement and so on. They're all important, but they're not the same thing. So I started using the term, place illusion, to describe this feeling of being in a virtual place, even though you know you are not there. So, again, I was talking before about sensory motor contingencies. When you have visual sensory motor contingencies, they are more or less like in real life, this affords the possibility of the brain to make the decision that this is where I am. The virtual place rather than the real place. So place illusion is the first one of these illusions. And place illusion can occur even if nothing is happening in the environment, I'm just in a virtual world, I look around, I see the virtual reality and the brain says, okay, this is the way you are. There's another aspect of this, which is the dynamic aspect. So suppose this events happening on virtual reality, like a crowd walking along, or cars going by, or leaves rustling in a forest in the wind. The next question is, does this seem to me to be really happening? So the second illusion, I call plausibility, which is how real do I take the events to be? And this is separate, because I can really be in a place, I can have the feeling to really be in a place, but I don't believe anything that's happening there. So an example of this is, let's say, in the real world, you're driving along and you see a policeman standing on a corner. And so, you slow down because you're driving a bit too fast. Then, as you get closer, you realize, actually, it's not really a policeman, it's a life size cardboard cutout. So before you had plausibility. This is a policeman, I slow down. As you get closer you see, it's just a cardboard cutout so I'm going to speed up again. You lost the plausibility. So plausibility is the second illusion. It's the illusion that the events that I am receiving, that I am engaged in are really happening. And the third illusion is something very, very, unique to virtual reality, which has to do with your own body. So go back to the ideas sensory mode to contingencies. One of the things I can do is look down. But what do I see in real world when I look down? I see my body. So in virtual reality it can be programmed that when you look down, you see a virtual body completely substituting your real body. And this can give rise to a third illusion, which is the illusion of body ownership. The illusion of that virtual body is your body. And as we'll discuss in another time, how the form of that body is, the shape and size and look of that body is, and have quite big consequence for your own attitudes, behaviors, and so on. So the three illusions are place illusion. I'm here. Plausibility illusion. What's happening is really happening. And body ownership illusion. This is my body. >> Very interesting. I think this is probably a perfect ending point for the first part of immersion. We'll come back to the second part of discussion where we'll go further on place illusion and plausibility illusion. [MUSIC]