As a second example, consider the problem of segmenting the world that we see into distinct objects. So, when you see something like this, you don't see an undifferentiated blob of shapes and colors, rather you see different objects that stand in relationship with one another. You might see a man, a house, a couple of birds. How did we do this? What are the cues that generate the distinctions that segment one object from another? Well, this was a great topic of study by psychologists many decades ago, the Gestalt psychologists. The Gestalt psychologists proposed principles that lead us to segment one thing from another. So, one example of such a principle is proximity. Things that are close together relative to other things tend to be seen as distinct. So, you would naturally see this, there's an indefinite number of ways you could in principle break up these circles. But the natural temptation set us three groups, and we segment these into three groups because the objects naturally cluster together as being close in space, or this. Again there's also two ways you might break this up, but you're naturally prone to break this up into two things, in fact, you might even see this as two objects maybe one jutting into another or one lying on top of another. The objects gets segmented into two because there are distinct patterns. So, here it's similarity that causes you to divide one thing from another. There's closure. So, one natural way to to see this is as a square laying on top of the circle. Why? Because the square is closes up, it's a natural form. So, while it's logically possible to see the circle as broken up with adjusting edge on the top left corner, that's not how you normally do it, enormously as one object on top of another. Similarly, there's good continuation. So, the simplest continuation of these lines has a leading to b and c leading to d. There's nothing logically round though, saying here are two complicated lines, one goes from a to c and other one goes from d to b, it's just not natural. We make the simplest continuation, it is common movement. You would naturally see these to clusters as two different groups. Finally, good form. So, imagine you see the objects on the far left, you see it's a plus side, it's a natural sign, there's a natural symmetry to it, there is clean right angles and so on. What is this? Well that could be a single thing too, it could be like a board with another board sticking into it and built as a single thing, or just a single carving of a certain unusual shape, but for that case, you'd be more likely to see it as two things. Say one piece of wood on top of another piece of wood, and this is because the lack of good form causes you to see things that way. If you go back to this original picture as an exercise, you could see how clues like similarity proximity and like could help you distinguish different things from other things. So, for instance, the walkway that the man is walking on, the patterns on the walkway are similar, and this is why you might see the whole walkway as a single distinct thing separate from the man and separate from the house. Now, sometimes these principles can lead to some clever illusions, and what's interesting is you probably see a triangle in the middle a light triangle. It turns out that triangle is an illusion. The Pac-Man on the side are consistent with a triangle coming out of it, and so your mind find this such a beautiful natural simple form, it fills it in creating an object where none exists, and here's another case with a square. To see that as an illusion to see that there's really no lighted square in the middle of it, if the Pac-Man go away, the impression in the square goes away too.
