Hi, I'm Eric Muller of the Exploratorium Teacher Institute, and I'm going to show you how to do this activity called peripheral vision. In this activity you're going to test your peripheral vision and we're going to test four different things. We're going to see how well you can detect motion, shape, color, and text. This is a great activity to do with a friend or in a classroom, and you'll be able to get some usable data. Here are all the materials you're going to need. An assortment of colored pens or pencils, a pen to write text with, a white piece of paper, masking tape, and a pair of scissors. The first thing you want to do is you want to make a target. Here's a few examples I made. Over here on this one I made a blue triangle with a very short three letter word in the center. Try experimenting with different shapes, colors and words. It's a good idea to have a few of these on hand. Now, we're going to build a giant protractor. You could use something like this, but I have a more fun way of doing it using body parts. I'm going to be testing my left eye, so if I call this my zero degree line, and I hold my other arm out perpendicular, that's 90 degrees. But we need more detail than that. There's a really cool way of figuring out the detail, and that's using your arm. Turns out, you hold your arm out, from your thumb to your pinky, that's about 20 degrees. Making a fist, from one side of your fist to the other, that's 10 degrees. We're going to use the fist and your outstretched arm in order to make our protractor. The next thing you want to do is tear off seven pieces of tape. Make sure you're sitting at a table that's as long as your arm. First thing I'm going to do is make my zero line. So since I'm going to test my left eye, I'm going to go straight on the table right below me. It's just below my left eye and I'm going to look straight out, that's going to be my zero line. Now, what I can do is I can start measuring it off using my handy dandy measuring tool. So this is my left arm held out all the way and from my thumb to my picky is 20 degrees. I'm going to mark that spot, and I can move on. [SOUND] 40 degrees, [SOUND] 60 degrees, [SOUND] 80 degrees, my fist, right on the edge, 90 degrees. It's also a good idea just to mark them. 0, 20, 40, 60, 80, 90. Now, we're going to go out, grab a friend, and we're going to get started on this experiment. I'll be right back. Come on in Sarah, and we're going to experiment on you. We're going to test your peripheral vision. >> Okay. >> Okay. >> Mm-hm. >> This is Sarah. She's my colleague in the Teacher Institute here at the Exploratorium. So what I need you to do, Sarah, is I need you to kind of scoot right up here, and I want that piece of tape just below your left eye. We could test either eye, but we're only going to test your left eye on this one. So what I'm going to do is I'm going to put a object like this piece of paper on your left thumb. It's going to be taped on there, and this object is going to have a shape, it's going to have a certain color, and it's going to have a three letter word on it. And you're going to move it into your field of view, and you're going to take your right thumb, put it right there at the zero mark. An you're going to let me know as this comes into view, when you see the following things. When you see the motion of that object coming into your field of view, when you see the color of the object, when you see the shape of the object, or when you can read that three letter text on it. This is not the one I'm going to use, I'm going to use a different one, she doesn't know what it is. And when you actually noticed one of those things, just stop a little bit, and I'm going to put a piece of tape down, and mark it so that we can collect some data about what you are seeing. >> Great. >> Okay, so now we're going to put the target on her thumb. I'm going to put a piece of tape on it so it'll stick to her thumb. And now we're ready to go. Her hand is way out of her peripheral vision so we can start from over here. Usually, when I do this activity, I'm actually sitting in the front looking straight at them to make sure they don't look at the target. But I'm going to sit from over here, and I'm going to collect the data from over here. Okay, so what I need you to do, Sarah, is you're going to slowly move that end and you're going to check for motion, color, shape, and text. Ready? >> Yeah, motion. >> Wow, you're way out there for motion, okay. >> Okay, color. >> Color? What color is it? >> Green. >> Green is right. >> Shape. >> What shape is it? >> Rectangle. >> It is a rectangle. >> [LAUGH] >> Did you look at it? >> I did. >> You looked at it. Okay, you blew it. So it's always great to have another target handy because people will blow this all the time. So we're going to start again. By the way, what was the answer? >> Dog. >> Dog. We're going to do it another time and I'm going to use a different target. It's really hard, right when the target comes right close to that thumb to just do that little quick peek off to the side, but you can't. We're going to do this again. So let me know when you see either the motion, color, shape or text of the object. >> Okay. >> Ready? >> Yep. >> Okay. Go ahead. >> I see motion. >> You see motion. Right about this here? Don't look away, go really slow too. >> I see color, I think. >> Do you know what the color is? >> Blue? >> All right. >> Shape. >> What's the shape? >> Triangle. >> Okay, and let me know when you see the text, and don't look away. I mean don't look, yeah. >> Opposite now. [LAUGH] >> Right about there, you're almost running top in your thumb there. Are you surprise in what you've got for your answer there? >> Yes, well, I'm surprise that I couldn't see it in terms of right- >> Right in the field, yeah. >> [INAUDIBLE] >> Yeah, it turns out that as you get clear, clear vision is only within few degrees straight ahead of your line of sight. So your motion was probably about 100 degrees out which is great. Your color was probably around 65 degrees, sorry your color was about 55 degrees out and your, this was the shape? >> Mm hm. >> And your shape was probably about 35 degrees out. Yeah, but look at the difference between where you found all this and where you actually able to read the text. >> Well, there's a lot of space between where I can see motion and when I could actually detect the color. >> Yeah. >> So- >> Yeah, it's pretty big areas over here. >> Well, thanks. >> Yeah, thanks. We've got some data, too. So we just did it with one person but what's really cool is you can do this with a whole bunch of people. You can do it with your friends, your colleagues, a whole classroom. Collect data, average it out. See what you come out with. You can try a different colors, different shapes, you try with different eyes. We only used the left eye, but you can try one person, one eye to the right eye. You can see how that goes. You can compare, contrast the whole bunch of different features. Try it out. See what you come up with. So this is what's going on. Imagine this is your eye. And this is your pupil. If you're looking straight on at something, light will go right through the front to the back of the eye. As light comes from the side it comes through the pupil, and it starts hitting the sides of the eye. You have sensors in the back of your eye on a part of your eye called the retina. You have two different kinds of sensors called rods and cones. Rods are either on or off or black and white. Cones just have color. They actually detect red, green, and blue light. Turns out, those sensors are not evenly distributed on the back of your eye. Scientists have actually cut into human eyes and actually counted the density of those rods and cones. This graph might look complicated but it's a diagram of the density of rods and cones on the back of your eye. Right in the very center is where you're looking straight on. Off over here on these edges this is when the light is coming in from the side. If you notice, over here the number of rods and cones are very low. So you don't see much, but the rod number starts going up rapidly, but the cone number doesn't for quite some time. Over here, these pictures represent the distribution of rods and cones. As you can see, when you're on the outer edge of the eye, you have a lot of rods but you don't have a lot of cones. As you start getting closer and closer in, the number of cones starts going up, but the number of rods go up too. The number of rods go up substantially but there is a point at which the rod number and density goes way down and the cone number goes way up. That's only in the very center of your eye it's called the fovea. Scientist refer to your fovea which is packed with millions and millions of cones as the most valuable real estate in your body. It's where you see the world perfectly clear and that's the only place to see it perfectly clear. So this distribution of rods and cones seem to make sense from an evolutionary context. [SOUND] Rods are much more sensitive to light energy and to motion. So out here on the periphery, that's when you need to know if something is rustling in the woods or something is out in the forest, or if somebody's coming from around the corner. As you move forward toward the center of your vision you start getting more and more detailed information. Some more cones are getting activated, more rods get activated but it's not really until you're looking straight on, when you have your highest concentration of cones will you see the world really clear and crisp. What does that mean in regards to perception? Well, I only have a very small portion in my vision that is clear. Everything else is fuzzy out there. My brain puts it all together and it makes me think that everything is clear and detailed out there but really it's only a small portion of my vision. [SOUND] Try this experiment, have fun. It's really cool. [MUSIC]
