Please read chapter 6. After reading the chapter, please respond to the following questions:
Next you will be asked what three things from the chapter that you found interesting?
1a) What did you find interesting?
1b) Why was it interesting to you?
2a) What did you find interesting?
2b) Why was it interesting to you?
3a) What did you find interesting?
3b) Why was it interesting to you?
4a) What one (1) thing did you find the least interesting?
4b) Why wasn't it interesting to you?
5) What did you read in the chapter that you think will be most useful to in understanding Sensation / Perception?
6) How, in what ways, does this chapter relate (build on) to the previous chapters?
7a) What topic would you like to learn more about?
7b) Why?
8) What ideas related to what you were reading (what did you think about) did you have while reading the chapter?
9) Once you are done with your post make list of the terms and terminology you used in your post.
Thanks,
--Dr. M
1a) What did you find interesting?
I thought the idea of occlusion was interesting. Occlusion is a cue to relative depth order, or when one object obstructs the view of a part of another object. It’s a cue to the presence of an otherwise invisible object. As a depth cue, occlusion gives information about the relative position of objects. Occlusion is present in almost every visual scene. Occlusion is a nonmetrical depth cue, it just gives us a relative orderings of occluders and occludees. A metrical depth cue is one that does provide information about distance in the third dimension.
1b) Why was it interesting to you?
I thought this was interesting because it specifically talked about that this wasn’t accidental viewpoints, which is what I thought of at first. But it’s interesting that we can be challenged to find a situation in normal life where nothing blocks the view of anything else. Because if you think about it, almost everything is set in front of something, or is somehow blocking something. A chair is blocking the view of a wall, a decoration blocking the wall, anything really is always blocking something.
2a) What did you find interesting?
I also thought the idea of texture gradient was interesting. Texture gradient is a depth cue based on the geometric fact that items of the same size form smaller images when they are farther away. An array of items that change in size smoothly across the image will appear to form a surface tilted in depth. This can be compared to relative height, which is a depth cue in which the observation that occurs at different distances from the viewer on the ground plane will form images at different heights in the retinal image. Objects father away will be seen as higher in the image.
2b) Why was it interesting to you? I thought the comparisons were interesting and the pictures in the text made it a little easier to understand. It almost made me think of optical illusions and how those effect how we see. The fact that texture fields provide an impression of three-dimensionality are really combinations of relative size and relative height cues. This is just all fascinating to me.
3a) What did you find interesting?
I also thought the correspondence problem was interesting to read about. Correspondence problem is the problem of figuring out which bit of the image in the left eye should be matched with which bit in the right eye. The problem is particularly vexing when the images consist of thousands of similar features. This can be compared to having a normal binocular vision where this problem doesn’t occur. The retinal images of the circles are labeled to make it clear which image on the left retina corresponds to which image on the right retina, but your visual system has no such labels.
3b) Why was it interesting to you?
I thought this was interesting because I wonder what it’s like to visually have this problem. It’s hard for me to imagine how frustrating it would be to visually not be able to have my eyes match up to one image. But it’s amazing that our eyes to have this power to match the images up to one image.
4a) What one (1) thing did you find the least interesting?
I generally just didn’t find this chapter interesting. It didn’t have a lot of things I could relate my life to and it was harder for me to understand. I thought a few parts about how we see things with space perception and binocular vision is interesting but overall it wasn’t something I enjoyed reading at all.
5) What did you read in the chapter that you think will be most useful to in understanding Sensation / Perception?
I think learning about the binocular fields will be useful in understanding sensation/perception. Binocular visual fields just states that we have two eyes that help us see the world. Binocular summation is the combination of signals from each eye in ways that make performance on many tasks better with both eyes than with either eye alone. I think this is just important to know because it’s basic information we use to build off of. We have to know the basics of our eyes to continue to learn more about them. I think just going over the very basic concepts was helpful in this chapter.
6) How, in what ways, does this chapter relate (build on) to the previous chapters?
This chapter relates to the previous chapters by focusing on the eye and how it perceives the world. It talked about the different ways we see objects with our vision and how limited we actually are visually. It talked about the way our eyes can be tricked through tricky images. It generally just went into more depth about the previous chapter.
7a) What topic would you like to learn more about?
I would like to talk more about motion parallax. Motion parallax is a depth cue that is based on head movement. The geometric information obtained from an eye in two different times is similar to the information from two eyes in different positions in the head at the same time. I just generally think this concept is interesting and want to expand on it.
8) What ideas related to what you were reading (what did you think about) did you have while reading the chapter?
I definitely thought about optical illusions while reading about texture gradient and relative height. It just made me think about how an image is said to be the same size as another, and they technically are, but how we see tricks us into thinking they are different sizes.
Terms: Occlusion, relative depth, depth cue, visual scene, nonmetrical depth cue, metrical depth cue, occluders, occludees, accidental viewpoint, texture gradient, depth, images, relative height, retinal image, optical illusions, three-dimensionality, relative height cues, correspondence problem, binocular vision, retina, space perception, binocular vision, sensation, perception, bino
The topic of binocular summation was interesting to me. This is that the combination of signals from each eye make various tasks easier to accomplish. I attempted the pen experiment from the text. With both eyes open putting the pen cap back on the pen was simple. However with one eye closed I missed a couple of times before I got the cap onto the pen. I tried it with each and had about the same result no matter which eye was closed. I think the reason is piqued my interest was because it is not something I have ever stopped to consider.
Absolute metrical depth cue was also interesting. This is more mathematical than the first topic. It is defined as a depth cue that provides quantifiable information about distance in the third dimension. The image in figure 6.2 a & b were what really caught my attention. When I first glanced at the photo as I turned the page I observed a women holding her hand out further in front of her body in the first photo and up close to her torso in the second. When I then read the section I looked again at the photos and realized there was absolutely nothing else in the photos besides my idea of how large a hand should be in proportion to the body and head that gave me that perception.
The section on illusions was the third thing I found most interesting. I always find myself looking at the optical illusions that people put on Facebook and then I try to figure out how it works. When observing the figure 6.44 I guessed the wrong pair of lines, it was actually just a guess, and even when I knew which pair was indeed the same length I had to get a ruler and measure them. I could not tell by just looking. This illusion called the Ponzo illusion, says that we over interpret the depth cues in a two dimensional image. The image of the two men on the tracks really appears to have a two men of different lengths. I also had to measure this one out as the man further away on the top of the track looked quite a bit longer than the other man closer lying in the tracks.
This chapter was quite a bit easier to read than last few chapters, most of it was very interesting. I am not sure if I am just getting smarter in this subject or if this was simply easier to read, if I had to guess I would choose the latter. The section I liked the least was the binocular vision and stereopsis. This was especially true when it got into horopter which is the location of objects whose images lie on corresponding points. Similarly and in this same section Panum’s fusional area which is the region of space in front of and behind the horopter in which binocular single vision is possible. I think that the author lost me with the phrase “If you are extremely fond of rather complicated geometry…”. I am definitely not fond of Geometry of any kind, especially not complicated geometry.
This chapter was a little different than previous in that it dealt more with activity and how we perceive objects. There was definitely less biology than in the previous chapters. However the previous chapters have built up how the eye and vision works physiology and this chapter begins to put some of it together.
I think I would like to learn more about binocular rivalry. This is a topic I am not at all familiar with and I did not completely understand it after reading about it in the text.
When I read the chapter I wondered if there is a way to not be tricked by illusions without getting out a ruler for instance to measure things that appear larger but are actually the same size.
Terms: binocular summation, signals, absolute metrical depth cue, perception, third dimension, Ponzo Illusion, illusions, binocular vision, stereopsis, horopter, Panum's fusional area, stereopsis, stereoblindness, binocular rivalry
1a) Familiar Size
1b) I thought this was an interesting concept because our minds are simply receiving information from the eyes about what we see, but from that we are inferring information based on previous experiences with the object at hand.
2a) Anamorphic Projection
2b) The art was really awesome to look at. I find it fascinating how one could draw or paint like that. So that it is only understandable or distinguishable from a certain angle or with a certain mirror.
3a) Binocular Rivalry
3b) I think that this is interesting because I used to think it was a “fun” game as a kid to try and focus on two things at once. You see film makers do it all the time, especially during a time of choice. It is really awesome to be able to put a name to something that I have been trying to do, and failing miserably at, since I was a child.
4a) The Bayesian Approach
4b) I do not do well with formulas. In psych stats, we are studying probability. So, as a result, when I read this part of the chapter I was over it before I even read it, unfortunately.
5) There were a few things that I think will be helpful later in the study of sensation and perception. Understanding things like the vanishing point and familiar size will help us later when we look at different ways that we perceive objects in the real world. Also I feel that texture gradient and relative height will also be helpful later in understanding why we view objects the way that we do.
6) This chapter definitely built off of chapter five by moving from how we perceive color and mixing that with art. Chapter 6 gave us the definitions for how we perceive the whole after learning about how we perceive the parts.
7a) Cyclopean
7b) I find the history of the term fascinating and would like to learn more about what it is.
8) While reading this chapter, I thought about my Thomsen’s disease. Thomsen’s disease is a muscular disorder that allows them to contract but makes it difficult when I try to release them. Many times it causes “double vision” and just makes it very difficult to focus on anything. Other times, it is difficult to shut or open my eyes because the lids are so contracted that it is very difficult to close my eyes or keep them open.
9) Key Terms: Familiar size, eyes, infer, anamorphic projection, binocular rivalry, the Bayesian approach, sensation, perception, vanishing point, texture gradient, relative height, color, Cyclopean
1) The first topic that I found interesting was binocular disparity versus monocular. Specifically the pen activity where you had to close one eye and try to put the cap on versus using both of your eyes to do the same activity. I found it really easy with my left eye closed and both eyes open, but not with my right eye closed. In this case stereopsis was better with both my eyes open, but I did ok with just my right eye. I found this interesting because I hadn’t really thought of it before, but there are some activities that I perform with one eye closed such as when I am running a spot light at my job or shooting a gun with a sight. But in both instances I realized that there is some sort of sight or target that assist with the shift of sight with one eye.
2) The part about perspective and vanishing points was quite familiar to me. We talked a lot about of it in art class when I was younger, but it isn’t something I consciously thought about before while viewing the world around me.
3) I also found the section talking about anamorphic projection quite interesting. I’ve never seen a painting in which the viewpoint could affect a part of the painting in that way. I’ve seen a painting entitled “Black” that shows a spectrum of colors when viewed from the side and is only black from the from one angle. I have also seen a lot of the sidewalk chock that uses the same principle.
4) I found that the discussion about stereopsis went on for along time and there was so much involved in it that I got a bit confused with it by the end. I felt like it was most of the chapter with other vocab sprinkled in.
5) I think understand where images fall on the eye and how they are combined will be the most useful. I also thought the part about the horopter was interesting and helpful because this effects the way images lie in the eye.
6) This chapter relates to other’s because the way that the world we perceive falls upon our eye (and fovea) is related to the structure of the eye itself. In addition, this chapter further enhances our knowledge about how the world around us is put together and perceived.
7) I would like to learn more about Stereograms because I had one as a kid but never knew the science behind them. I find things like “viewfinders” interesting because they are instruments designed to use the physical properties of our bodies to create a visual experience. I would also like to know more examples of anamorphic projection.
8) When reading about the stereograms I remembered using them quite often as a child. When the discussion about disparity and the difference between using one and two eyes I was thinking about when I use a spot light. Often times when lining up my sight I will go from one eye to two because it’s easier to do large adjustments with two eyes and the smaller adjustments with one eye, because I have to adjust my light and target to line up with the vision of one eye.
Terms Used: binocular disparity, monocular disparity, stereopsis, perspective, vanishing point, eye, perception, anamorphic projection, stereograms
1. It was pleasing to have learned about texture gradient and relative height. When I was younger there were some art works similar to figure 6.8 and 6.9 in my mother’s room, but instead of rabbits, it was black circles of different sizes; there were four of them and two stood out to me: one was a vertical line of circles with the largest circle at the bottom and that smallest at the top, and the other one was a horizontal line of circles with the largest one on the far right and the smallest one on the far left. I remember looking at them on the wall and wondered why the smaller circles of the vertical line looked further away, but not the smaller circles of the horizontal line. That is the reason why I found it interesting – I was able to find the answer to the question I had when I was younger. It is intriguing how, the same patterns and features and shapes and sizes, but when arranged differently, the perception of the whole image changes.
2. It was just as enjoyable to have read about anamorphic projection and the arts people can create with it. I want to know the techniques that are involved when one creates such art work. I thought about an art piece I saw at a museum, where it makes no sense until a reflective rod is placed at the centre of the drawing; the rod will reflect a portrait of Abraham Lincoln. I guess it is a similar idea – the actual picture will not make sense unless viewed a certain way. It is also interesting because in Canada, there are many 3D street art that makes no sense until you view it from a certain angle. I was able to relate many of my experiences with anamorphic projection, hence I found it interesting.
3. Free fusion fascinated me. I could not see what was described in the text, but it was interesting to read about the techniques of relaxing your eyes to see things differently. I cannot cross my eyes nor can I diverge my eyes. To be honest, I am also a little freaked out by the section as much as I found it interesting. I am not sure what I am seeing is normal, and not sure if the white squares pop out in depth or not, I stared at the two squares for almost an hour and still cannot see anything. Do I have stereoblindness? Ever since I found out my parents never told me about some vision problems I had when I was younger, I am always on high alerts, wondering whether my vision is normal.
4. I did not like the section of occlusion as much as the other sections. This section was very confusing to me. I was reading and I thought to myself: “are sensation and perception scientists’ job to make simple things complicated?” a rather simple image in figure 6.5, became confusing after I read the section. The section caught me off guard and threw me off my game, I needed to read it twice before getting the big picture of what was described in the section.
5. The most important part to understanding sensation and perception is the section where the textbook discusses about Euclidean geometry. The real world is Euclidean, where parallel lines remain parallel as they extend, and objects maintain their shapes and sizes everywhere. However, when the image of the real world is projected onto our retina, it is no longer Euclid. The reason to that is because the real world is three dimensional, and our retina is not only two dimensional, but also curved. Parallel lines do not stay parallel and shapes and sizes may appear different. To understand sensation and perception we need to appreciate the fact that we need to process the non-Euclidean input from our retina to perceive the Euclidean world.
6. This chapter is very different from the previous chapter, which discusses colour perception. However, both chapters talk about the interrelationship between the physical elements and the neurological processing. In the previous chapter, it is about how the external physical stimuli is processed by the nervous system before we can perceive colours; in this chapter the textbook discusses the relationship between the physical objects in the external world and how they are being processed through the visual system as well as the nervous system. Both chapters are based on the similar concepts, but discusses two different topics.
7. I want to be able to learn more about stereoblindness – to make sure I do not have it. I might go online and read more into it, perhaps do some self-diagnosis tests online if they have any, to see if I am seeing the same thing as other people. It is fascinating and creepy at the same time, how this class can make you realize what you perceive as normal, may be a disorder or an abnormalities.
8. I went on a lot of road trips with my father in Taiwan when I was younger, the freeway divider in Taiwan is actually made up of green rods of about 35cm in diameter, 1m in height, and 1m between each rod. When driving by the rods at 100km/hr, the rods disappeared. It was as though the rods was not there. However, when looking ahead, I could see the rods. The rods only disappeared when I was looking to the left out of the backseat window. I was very interested by it and would switch from looking out of the back seat window, to looking out of the windshield.
TERMS: stereoblindess, Euclidean, non-Euclidean, three-dimensional, two-dimensional, occlusion, free fusion, anamorphic projection, texture gradient, relative height
1a. The first concept in chapter six that I found interesting was the idea of the critical period and disorders of the visual system that occur when space perception and binocular vision development do not take place during the critical period of time. Researchers have found that normal development of adult binocular vision and stereopsis requires visual experience during the critical period discovered by Hubel and Wiesel. During this period in early visual development it is crucial that normal binocular visual stimulation is experienced by an individual for normal cortical development. During this critical period the visual cortex is susceptible to disorders that alter normal binocular visual experience. One such disorder known as strabismus and occurs when a child is born with two eyes that do not point to the same spot in the world. Another disorder known as esotropia occurs when one eye is pointed too far toward the nose and is commonly referred to as "cross eyes". Lastly the textbook explores a disorder known as exotropia. This occurs when the deviating eye is pointed too far to the side. All of these disorders are curable by performing a surgery that corrections the position of the eyes.
b. I found this interesting because it emphasized critical periods in humans and the consequence of this critical period in time being missed. This section also discussed disorders that can occur if a child does not develop binocular vision normally. I find these disorders interesting because they are applicable to real life situations that we will all experience at some point.
2a. The second concept in chapter six that I found interesting was the visual systems decision of what to see when presented with two images. Research suggests that the more interesting of the images will be the one that dominates your vision and specifically what a person is seeing. This competition found between the eyes is known as binocular rivalry. It occurs when there is competition between the two eyes for control of visual perception. Interestingly, the battle is never completely won by one eye.
b. I found this topic interesting because every time we look at something our eyes are experiencing different perceptual experiences and what we view as a whole is determined by the more interesting and vibrant stimuli presented. We experience binocular rivalry each time we see something in front of us and it is amazing that our brain and visual system can perceive so much information in a matter of seconds.
3a. The third concept that I found interesting in chapter six was binocular disparity. This term refers to the differences between the two retinal images of the environment around a person. Disparity is known as the basis for stereopsis which is a vivid perception of the three dimensionality of the world that is not available when referring to monocular vision. This allows the brain to extract depth information from the images portrayed by stereopsis. The ability for the brain to perceive depth is important for our ability to function successfully in our environments and to perceive the world around us accurately.
b. I found this concept interesting because it is involved in our ability to perceive depth and it also references the idea that our eyes see different things simultaneously. It is also important because it allows us to function optimally in our environments because it aids us in depth perception. I like topics in the textbook that allow me to assess real world applications that our visual systems provide us.
4ab. I found the topic of Euclidean concept to be a little boring because it covered the geometry of the world and the historical application of space perception an binocular vision. I specifically found this topic to be boring because it was drawn out and discussed concepts that I have never been introduced to before.
5. I believe that the knowledge of binocular disparity, binocular rivalry, and the critical period will be extremely useful in sensation and perception because they are important aspects of the visual system that I will need to be aware of as the class continues and does into depth. Specifically I believe that the knowledge of the critical period will be interesting to research and to connect to other areas of the visual cortex.
6. This chapter relates to the previous chapters in the textbook because it goes into further detail of the visual cortex. It delves deeper into the idea that our perception of visual stimuli is dependent upon our binocular vision. Each chapter is a stepping stone into the next that adds further detail. It was useful for recognizing previously mentioned parts of the visual system and my understanding of new aspects of the cortex mentioned in this chapter.
7ab. I would like to learn more about disorders of binocular vision such as strabismus and esotropia. I am interested in these topics because they occur commonly in individuals and are helpful for information about visual cortex.
8. While reading this chapter I thought about the number of people in the united states that suffer from binocular vision disorders and what diagnosis consists of. I am interested in learning more about the surgery for correction of these types of disorders because they will be extremely important for helping individuals suffering from these disorders function normally.
Terms: critical period, strabismus, esotropia, exotropia, binocular disparity, binocular rivalry, sensation, perception, visual cortex, binocular vision
1a) What did you find interesting?
1b) Why was it interesting to you?
I found Euclidean to be interesting. The geometry of the real world. This means that parallel lines remain parallel as they are extended in space, that objects maintain the same size and shape as they move around in that space, that the internal angels of a triangle always add to 180 degrees, and so forth. I find this interesting because it is how we see shapes and objects in the "real world". Sensation and perception is all about how we see and perceive things and the shapes in which we see things helps us determine what it is we are actually seeing and identify objects.
2a) What did you find interesting?
2b) Why was it interesting to you?
I find the topic of binocular summation to be interesting. It is defined as the combination of signals from each eye in ways that make performance on many tasks better with both eyes than with either eye alone. This principle may have provided the evolutionary pressure that first moved eyes to the front of some birds' and mammals' faces. I find this interesting because I have always found the theory of evolution to be interesting. As a biology major you are basically taught to believe in evolution; and natural selection is a huge part of that. Understanding why mammals evolved with having two eyes in the front of their head is extremely interesting.
3a) What did you find interesting?
3b) Why was it interesting to you?
I find anamorphosis to be very interesting, anamorphosis or anamorphic projection, illustrates that the ability to cope with distortion is limited. Anamorphosis uses the rules of linear perspective to create a two-dimensional image so distorted that it looks correct only when viewed from a special angle or with a mirror that counters the distortion. I'm not sure if this is of the same degree but I kind of thing of this as looking at abstract art. Often we look at something that looks like nothing to us but others see something amazing out of it. Or in psychology when we study tests such as the ink blot test; where we are to say what we see out of a small inkblot and everyone says something different and your answer determines specific things about you. This idea is amusing to me; how much can our mind recognize. How distorted can things be before we can't recognize them at all? It is amazing and interesting that when things are slightly distorted our mind can change them back to what they are supposed to look like; we can see images the way we are supposed to see them even if that isn't what they actually look like.
4a) What one (1) thing did you find the least interesting?
4b) Why wasn't it interesting to you?
I found RDSs to be uninteresting; mainly because they were slightly confusing to me. I know that you use them and you an free-fuse these images that are shown you are supposed to see a pair of squares, one sticking out like a bump, the other looking like a hold in the texture but I wasn't able to see what it was describing and the term got confusing and uninteresting to me in the reading.
5) What did you read in the chapter that you think will be most useful to in understanding Sensation / Perception?
Learning about the ideas of convergence: the ability of the two eyes to turn inward, often used in order to place the two images of a feature in the world on corresponding location in the two retinal images; and divergence: the ability of the two eyes to turn outward, often used in order to place the two images of a feature in the world on corresponding location in the two retinal images. I thought that both of these were helpful in understanding sensation and perception because the root or start of seeing and perceiving what we see is physically being able to see something. These terms help describe how our eyes function in order to turn and see what we are trying to see.
6) How, in what ways, does this chapter relate (build on) to the previous chapters?
It builds and relates to sensation and perception because it is going more in depth on how images are seen in our mind. How we see the shape of an object or how we see the 3D image to show us that it is a live object is giving us more emotion toward what we are actually seeing. These details of what we see that are covered in chapter three help gives us the sensation that we feel when actually seeing the object and understanding what it is.
7a) What topic would you like to learn more about?
7b) Why?
I would like to learn more about the correspondence problem. I think it is interesting that with our two eyes we only see one whole image. How is this split up and how do we not see double of everything since we actually have two eyes. This problem is defined as the problem in binocular vision of figuring out which bit of the image in the left eye should be matched with which bit of image in the right eye. I always wondered how this worked and why we can close one eye and see a whole image but have two eyes open and see the same image; it is interesting to me so I would like to learn more about it.
8) What ideas related to what you were reading (what did you think about) did you have while reading the chapter?
I thought about when I was younger and I used to wonder some of the same things that I was reading about through out the chapter. I feel like I had so many questions about how things worked but no one was ever really able to tell me the correct answers and I learned to just accept that things were the way they were because that is how they are supposed to be. It is really interesting to me to be able to explain why I can see what I see and relating it to sensation and perception each chapter teaches me something new.
9) Once you are done with your post make list of the terms and terminology you used in your post.
binocular disparity, binocular rivalry, sensation, perception, visual cortex, correspondence problem, sensation, perception, anamorphosis or anamorphic projection, realism, Euclidean, RDSs.
1a &b) What did you find interesting? The first item in this chapter I found interesting was the section on projective geometry. Projective geometry is geometry that describes the transformations that occur when the three-dimensional world is projected onto a two-dimensional surface. An example of this would be parallel lines do not converge in the real world, but they do in the two-dimensional projection of that world. Another example of this is shadowing. We can learn a lot from an objects place in the world by the location of its’ shadow placement. Another aspect of this placement is real world three-dimension is texture gradient. Texture gradient is a depth cue based on the geometric fact that items of the same size form smaller images when they are farther away. Visually smaller objects usually mean they are farther away in distance. The visually bigger items appear closer, these items are the same size. This refers to relative height, which is also a depth cue. It is an observation that objects at different distances from the viewer on the ground plane will form images at different heights in the retinal range.
2a & b) What did you find interesting? The second item I found interesting in this chapter was the section on aerial perspective. Aerial perspective is another depth cue based on the implicit understanding that light is scattered when we look through more atmosphere. As the book pictured for an example, a harbor next to some mountains, the mountains in the far background appeared a very light blue, or gray. As you look closer to the viewpoint of the observer, the objects getting closer get more saturated with details and also color. It depends greatly on what the atmospheric conditions are when viewing. By understanding occlusion, we have a better understanding of relative positions of items in the world. Occlusion also gives us another cue on edges.
3a & b) What did you find interesting? The third item I found interesting from this chapter was anamorphosis. Anamorphosis, or anamorphic projection uses the rules of linear perspective to create a two-dimensional image so distorted that it looks correct only when viewed from a special angle or with a mirror that counters the distortion. Looking through this section and reading about the artists that can render these results of the streets, was pretty amazing to see. It was also interesting to see that artists back in the 1500’s were doing this distorted anamorphic art. Being able to see the illusion only if you are positioned in the correct angle is pretty impressive. Our visual system is advanced but still can be tricked very easily!
4a & b) What one (1) thing did you find the least interesting? The one biggest disappointment in this chapter was the free fusion technique. Free fusion is the technique of converging (crossing) or diverging the eyes in order to view a stereogram without a stereoscope. It wasn’t that I didn’t like this section, I was more bummed at the fact that I couldn’t do it. As the author mentioned 3-5% of the population lacks the stereoscopic depth perception, this condition is known as stereoblindness. The author does say, that if you practice enough, anyone can do it, even people with glasses. (I thought that was the reason I couldn’t do it). The next few pages of the chapter after we first see the free fusion technique was interesting to read, but just disappointing that I couldn’t follow along with any of the exercises. Believe me I tried, I tried so much that I got a massive headache following this section of the chapter.
5) What did you read in the chapter that you think will be most useful to in understanding Sensation/Perception? The physiological basis of stereopsis section was probably the most technical part of this chapter. As I was reading this section, it referenced back to the previous chapters, which was important. As the book states, “the most fundamental requirement is that input from the two eyes must converge onto the same cell. This convergence doesn’t happen until the striate cortex, where most of the neurons are binocular.” Trying to understand that the two retinas have to provide the neural basis for the horopter, I believe will be very important to learn for future chapters. These cells are well suited to the task of matching images in the two eyes.
6) How, in what ways, does this chapter relate (build on) to the previous chapters? This chapter builds on previous chapters by referencing back to past terminology and structural components. Occlusion was a term that was in chapter 4, and in this chapter it gave much more relevance of how occlusion is important in the aspect of depth cues. Without depth cues are brains would not learn how to maintain our depth perception in unfamiliar environments. This chapter also referred back to the Bayesian Approach, which I did not care for much in chapter 4 and still don’t in this chapter!
7a & b) What topic would you like to learn more about? I would like to know more about the binocular vision and stereopsis in infants. The book categorized three specific criteria that they called laws. The first ‘law’; 1) as children get older, they get better at things; 2) whatever it is, girls do it before boys; 3) Everything develops along with everything else. It was interesting to read that over the last 25 years, the first two ‘laws’ are pretty much confirmed, and the third one is not. The development of stereopsis is surprising; infants are essentially blind to disparity until almost 4 months of age. From that point stereopsis appears almost instantly out of the blue. Researchers and scientists are trying to design methods for assessing this development. There are so many suggestions from the researchers and scientists that believe they have figured out the stages of this development, but none can say for sure which ages are the most profound. It would be interesting to see if there have been any twin studies done. Twin studies are very reliable and they serve as very good comparisons.
8) What ideas related to what you were reading (what did you think about) did you have while reading the chapter? The beginning of this chapter got me thinking about how humans and mammals have evolved to seeing with two eyes in the frontal position. I like how the book discussed the vision of a rabbit vs. humans. Rabbits are much more likely to get attacked because they can only see on their side and behind them. I couldn’t help but think of if humans had this type of vision, how everything in our world would be so much different, almost science-fiction-esque.
TERMS: projective geometry, three-dimensional, two-dimensional, texture gradient, relative height, depth cue, aerial perspective, occlusion, anamorphosis, free fusion, stereogram, stereoscope, stereoblindness, stereopsis, striate cortex, horopter, Bayesian Approach, binocular vision, visual system
I liked learning about binocular summation because I think it’s important to understand the differences between visual fields of varying species. The textbook gave the example of why it’s hard to sneak up on a rabbit. A rabbit’s visual field is like a planetarium dome, whereas, a human’s visual field is like a windshield. The rabbit’s visual field extends 360 degrees and they can even see straight up above them and down to the ground on the left and right, but not underneath their nose and mouth. In contrast, a human’s visual field is only about 190 degrees from left to right in front of them. Of those 190 degrees, both eyes cover about 110 degrees. Unlike rabbits, humans’ visuals fields only extend 60 degrees up and 80 degrees down. These differences are thought to be a result of evolution, allowing predators (humans) to see small, quick animals and objects in front of them to catch and eat. The rabbits along with other prey animals have the dome-shaped visual fields to avoid getting caught by the predators.
Not only is the location of the eyes on humans an advantage, but having two eyes instead of one, allows humans to perform many daily tasks with greater ease. This is called binocular disparity, which is the difference between the two retinal images of the same scene. Disparity is the basis for stereopsis, a vivid perception of the three-dimensional world that one cannot perceive with monocular vision. Stereopsis is the ability to use binocular disparity as a cue to depth. Depth cues are information about the third dimension (depth) of visual space, and they can be monocular or binocular. A monocular depth cue is available even when only one eye is being used to see the world. A binocular depth cue relies on information from both eyes.
I also found the concept of motion cues to be particularly interesting, especially the non-pictorial depth cue called motion parallax. A motion parallax is an important cue to depth based on head movement. The geometric information obtained from an eye in two different positions at two different times is similar to the information from two eyes in different positions in the head at the same time. The example used in the textbook to explain this concept was very helpful to me. It said to imagine yourself looking out a train window, and the scenes you see change each second as the train moves from left to right. The objects in the scene outside the train move right to left, with the closest objects appearing to move the farthest across your visual field, and the farthest objects appearing to barely move at all. Motion parallax is another cue that gives relative metrical information about how far away objects are from you. It can even provide a sense of depth in situations where other cues aren’t very effective.
While finding many concepts interesting to learn about, I didn’t enjoy reading about stereoblindness. Stereoblindness is an inablility to make use of binocular disparity as a depth cue. This term is typically used to describe individuals with vision in both eyes. An individual who loses one or both eyes is not usually referred to as stereoblind. The 3-5% of the population that lack stereoscopic depth perception have stereoblindness. This condition is usually a secondary effect of childhood visual disorders, like strabismus, in which both eyes are misaligned. I think this is an important topic to learn about from the chapter, but I just did not find it as interesting as some of the other concepts.
I think understanding the concept of binocular disparity will be very useful in helping me understand sensation and perception. Disparity is the basis for a vivid perception of the three-dimensionality of the world that is not available with only monocular vision. I think being able to use stereopsis is important for safety and survival in humans; thus we should take the time to learn about how most of our eyes are allowing us to perceive the world around us.
I think it’s interesting that this is a depth cue that is based on the geometric fact that items of the same size from smaller images when they are farther away. This allows a two-dimensional image to appear to have depth, more easily detected if the smaller images are grouped separately from the larger images.
I also would like more information about corresponding retinal points. I understand that this is a geometric concept stating that points on the retina of each eye where the monocular retinal images of a single object are formed are at the same distance from the fovea in each eye, but its worth exploring more.
Terms: binocular summation, visual fields, binocular disparity, retinal images, stereopsis, monocular vision, depth cues, motion cues, nonpictorial depth cue, motion parallax, stereoblindness, texture gradient, depth, corresponding retinal points, retina, monocular retinal images, fovea
1a) The first area that I found interesting in this chapter was right at the beginning. It discussed positivism and realism. Realism is a philosophical position arguing that there is a real world to sense. Positivism is a philosophical position arguing that all we really have to go on is the evidence of the senses, so the world might be nothing more than an elaborate hallucination.
1b) This intro into the chapter is interesting to me because the philosophical world fascinates me. I am always interested in the different theories of why we perceive the things in the way that we do. So when I read about the different positions arguing about the “real world” it always catches my attention.
2a)The next part that was interesting to me was the page on visual fields. We learn that predators like human, cats, etc. have better depth perception making it easier for them to see far away. This also allows us to notice movements better making it easier to see prey. For most vegetarian animals they have a different binocular visual field that allows them to see everything around them in 360 degrees, this gives an advantage of noticing when things try to sneak up on them, but is bad for seeing very far away.
2b) This was interesting because it shows us more about the benefits of our eye layouts and how it help different kinds of animals survive in the wild. It also helps us visualize better how other species view the world and in doing so betters our understanding of different kinds of perceptions of the animals.
3a) The next part that fascinated me was the depth cues texture gradient and relative light. Texture gradient is based on the geometric fact that items of the same size form smaller images when further away. An array of items that change in size smoothly across the image will appear to form a surface tilted in depth. Relative height is the observation that objects at different distances from the viewer on the ground plane will form images at different heights in the retinal image. Objects farther away will be seen as higher in the image.
3b) This was interesting to me because of the pictures and example used in the book. It really did a good job of showing how the different concepts work even when looking at a two dimensional drawing on a paper.
4a) This has been the most interesting chapter yet and there really wasn’t anything not interesting to me in it, but if I had to choose I would say the paragraph on convergence and divergence of the eyes.
4b) Only chose this because it is a simple area to understand and the least interesting part of the chapter.
5) The best part to understand sensation and perception from this chapter are the explanation of the different depth cues. This helps us to know why we see things the way we do which is a necessary part of understanding perception and sensation.
6) this chapter builds from chapter five by now adding motion of objects from just color before. Everything is slowly being put together to understand all parts of sensation and perception.
7a) I would like to further study binocular visual fields
7b) I found this the most interesting and I would like to know more of the different benefits from each kind of placement of the eyes.
8) Once again I find myself thing about the item surrounding me, like when I look from my current room into the dining room how the objects in there appear smaller when I know exactly how big they are really. It is just interesting to be able to apply these concepts to my surroundings
9) sensation, perception, visual field, binocular, realism, positivism, depth cues, convergence, divergence, texture gradient
1A&B) What did you find interesting?
In chapter six, I liked reading about the development of the visual system in infants. It must be interesting to study how the visual system is formed and to imagine what a very young infant must see before their visual system develops fully. I found this interesting because I like learning about human development.
2A&B) What did you find interesting?
There are several diagrams on page 151 showing the visual field of rabbits compared to humans. It’s interesting to read about the differing placement of eyes on creatures of prey and predators. As the book explains, rabbits are kind of low on the food chain, so they benefit from having a 360 degree visual field. In a similar fashion, predators benefit from having two eyes facing forward, increasing their chance of spotting dinner. What if humans had eyes on the side of their head, like rabbits? The portion of visual field that is seen by both eyes in rabbits is also much smaller than ours, especially compared to their entire visual field. Is there any research on visual disorders in rabbits, such as amblyopia or strabismus? How would one of these conditions limit a rabbit’s visual field? In this aspect, humans are lucky in their eye placement, that one of these conditions does not totally impair their vision because they still have one eye that covers much of the same visual field.
3A&B) What did you find interesting?
I also found metrical depth cues interesting. Relative metrical depth cues help us determine the relative distance between two objects. Absolute metrical depth cues tell us a measured size of an object. Like other concepts in the textbook, it’s hard to fathom our visual system is computing these distances without our conscious awareness. The text says we can’t really utilize absolute metrical depth cues with much precision. This topic reminded me of high school geometry, and find the height of a lamp given the property of triangles. I have to wonder how useful that would really be.
4A&B) What one (1) thing did you find the least interesting? Why?
I had some trouble with the concept of free fusion. I couldn’t figure out how to cross my eyes and see a third/fourth set of squares, which is kind of frustrating that I can’t see the concepts the book is talking about. Maybe a future edition could have a section at the back with the same figures and what you’re “supposed” to see. Growing up, my parents told us that it was really bad for you to cross your eyes. If true, why a scholarly text is suggesting we do something like that is confusing.
5) What did you read in the chapter that you think will be most useful to in understanding Sensation / Perception?
Although the past chapters have connected in some minor ways, in general it kind of seems like puzzle pieces that don’t fit together, so I’m really not sure what will be useful in future chapters. Bayes’ theorem has shown up a couple of times already, so we should expect to see that concept again.
6) How, in what ways, does this chapter relate (build on) to the previous chapters?
Thank goodness we’re finally getting to the part where we see pictures! For the most part, we’ve learned about the response of individual cells in a single eye and how they send messages to the brain about light, color, contrast, etc. In chapter six, binocular vision is discussed and how the brain makes sense of two pictures. Binocular vision has its evolutionary advantage as well, if somewhat obsolete these days. Aside from this advantage, there are several tricks that binocular vision play on us. The visual system uses several visual cues, Bayes’ theorem, and a committee-type system to determine what scenario is producing visual input.
7A&B) What topic would you like to learn more about? Why?
I’d like to learn more about esotropia. Esotropia is where one eye is turned too far toward the nose for the fovea to point at the object of focus. If esotropia begins at an early age, the brain adapts by suppressing the input from the eye which is turned in. I’d like to learn more about this because I know when I was younger, my eye would turn toward my nose quite often. I did have glasses which helped, but I don’t think this was the same as esotropia. According to the book, long-term strabismus interferes with stereopsis. I wonder what effect (if any) my abnormality had on my daily vision, and how that is different from the effect of strabismus.
8) What ideas related to what you were reading (what did you think about) did you have while reading the chapter?
For some reason, reading about binocular rivalry reminded me of trying on clothes at the store. Binocular rivalry is the battle between our eyes to determine what image or stimulus is dominant, but really they are “trying out” which image is the most likely representation of the world. It’ similar to how we can try on clothes at the store before we buy them, to see which ones might look the best.
9) Terms: Visual field, amblyopia, relative metrical depth cue, absolute metrical depth cue, esotropia, strabismus, fovea, stereopsis, binocular rivalry, Bayes theorem, free fusion,
1) The first item that I found particularly interesting wa actually the very first paragraph in the chapter about the person taking a picture of the baby bear and the mother bear becoming upset and coming after the photographer. I thought it was interesting to think about how the person really did know where they were going and didn’t run into any trees while trying to run from the bear and was able to reach safety. I think that we often don’t stop to think how we really do some of the things that we accomplish during our day. If you think about some of the things throughout your life have you ever had a moment back thought thinking how did I just do that without knowing the area that I just walked through.
2)The second thing that I found interesting was looking into how our vision field is limited to about 190 degrees and 110 degrees is made up of using both eyes. The binocular visual fields gave predator animals like humans a better chance to spot dinner. In vision binocular summation principle have provided the evolutionary pressure that eyes moved from the front of some birds and mammals faces. I found this interesting because we often don’t think about how much vision really only one eye can see. We often take it for granted that we have two eyes and don’t realize that we would perceive the world much differently if we were to only have one eye. I personally liked the demonstration on pg. 150 and seeing the different perception of our fingers if we were to open and close the other eye quickly.
3)The third thing that I found interesting was the section on motion cues, but more specifically Motion parallax. Motion parallax is an important depth cue that is based on head movement and differs from a one eye view to a two eye view. I also found that the example about laying under a tree and looking up with one eye open and seeing the detail of the leaf but not being able to tell if one branch is in front of the other was very interesting. I wanted to try it but since it is so cold I used a plant and the results were the same and differed between if you had one eye open versus two. With two eyes open you are more likely to see all of the detail and to be able to tell if one branch is in front of the other.
4)The part of the chapter that I found least interesting was Bayesian approach. Math has never been of my interest and especially anything to do with statistics. So this section I found very complex for me to read. Maybe not because of the topic in itself but more because I am not a fan of formulas and overall just found this part particularly hard to stay focused and read.
5)I think that a lot from this chapter will be important later in the learning of sensation and perception but more specifically looking into how each image is able to fall on the retina and how we actually use our vision and depend on it to reveal and help us through life threatening events.
6)This chapter looks and relates back to other chapters by looking further into vision and even more into detail on the eye itself. The eye is often able to have tricks played on it by looking how an object is perceived and learning further into what limitations we actually have with our vision.
7) One thing that I would like to look further into is stereoblindness. I found this very interesting and would like to look further into the causes and different ways people have to go through life with this disorder.
8)While reading this chapter it really made me stop and think about how much our eyesight actually does change with the difference in vision and perception of looking at an object or scenery with one eye only compared to both eyes and how objects can seem much closer or further away depending on the locations of your eyes.
9)Terms: Stereoblindness, Bayesian approach, sensation, perception, visual field, retina, motion cues, motion parallax, stereopsis, binocular, binocular summation, binocular disparity
1. There were many things that I found interesting in chapter six and one of these concepts was occlusion. Occlusion is basically when one object impedes the view of a part of another object. The book was saying that occlusion is present everywhere one looks. It is nearly impossible to look at an object without another object being in the way or affecting the view. There are different cues involved in occlusion. The nonmetrical depth cue gives us the ”relative orderings of occluders and occludees.” (pg. 153). “A metrical depth cue is one that does provide information about distance in the third dimension.” (pg. 153). I found this to be interesting because although I have never really thought about objects blocking other objects to be that high of importance; it really is. You see objects that you are familiar with all of the time but many times that object you are trying to look at has an obstructed view. It is pretty amazing that our brain tells us what our eyes are necessarily seeing. The example on page 152 of the triangle, square, and circle is a good example of this because although we cannot see the full picture of all of these shapes, our brain still knows what it is that we aren’t visually seeing.
2. Motion cues also held my interest. Motion parallax is a nonpictorial motion cue that is based on head movement. The example used in the book was very helpful when trying to understand the whole logic behind motion cues. The book said to imagine yourself looking out a train window and seeing a picture and then within seconds you see a completely different picture. Although the train was moving from left to right, the objects were moving from right to left. The term parallax made things even more interesting. Parallax is saying that objects closest to you shift position more than objects that are farther away. I find all of this interesting because humans are constantly in motion whether it be our whole body or just our head. Everything we see changes from second to second yet we never really take the time to think about what we are looking at. The position at which we are standing has a big effect on the way that we perceive things and I think this is one way that helps prove that many people see things differently than others.
3. The section on illusions really struck my interest as well. I see optical illusions all over the internet and I can never keep myself from wasting time and looking at all of these illusions. The two examples in the book threw my off because I am usually pretty good at face validity meaning I can look at something and know what I should be looking for. The Ponzo illusion says that we over interpret the depth cues in a two-dimensional image. This is exactly what I did when I tried to guess which two lines were the same lengths. I guessed the fourth image just like the book said even though the correct answer was image number two. I also found the train exercise to be interested. Two men of the same length were placed at different places on the train tracks and they appeared to be completely different lengths even though I knew they were both the exact same length. This is all interesting to me because I usually am really good at figuring out different illusions probably because they intrigue me so much. It is amazing that what we see can be totally different than what is actually in front of us.
4. The section where I had the least interest and also had the hardest time understanding was the section on binocular vision and stereopsis. At first I thought it was just because I had a hard time understanding what it was trying to say but the further I read I realized I didn’t care to understand the subject simply because I wasn’t interested in it. This whole section was pretty boring and hard to understand. When I don’t understand something easily I get discouraged and tend to just ignore what I am reading. This section went into detail about the retina and the fovea and those concepts just do not spark my interest.
5. I think a lot of subjects in the chapter are very important when we are trying to understand sensation and perception. The explanations of the different depth cues are very important because there are so many types yet they all have their own meaning and own job. Vanishing point and familiar size also have a huge impact on how one perceives something. We all see things different and understanding these concepts gives us more detail about why it is this way. Binocular visual fields also are important because what this states is basically we have two eyes that help us see the world. We have to learn the basics before we can move onto more in-depth information.
6. Chapter six build off the previous chapters because it once again is about vision. Although all of these chapters are about vision so far, chapter six is starting to get more involved in the idea about perception and how our eyes perceive things. We have learned about the eye and how it works and as the chapters continue we get further into how this relates to sensation and perception. Chapter six also talked about different issues we can run into when viewing an image such as different illusions and the idea of occlusion.
7. I would like to learn more about the correspondence problem. How is it possible that we have two separate eyes but we don’t see double of everything? This one question is something that I want to learn more about. I want to know how and why.
8. There were many examples in this book that I read about and different activities to do in the book so while I was involved in this I wasn’t really thinking about anything else. When I read part of each section my brain connected different aspects and put them together and made a light bulb go on in my head. I read some of these things and it instantly clicked about why things are a certain way. Other than that I wasn’t thinking about a whole lot. Throughout the entire chapter I was either thinking wow this is interesting or wow this is boring.
Terms: Occlusion, object, nonmetrical depth cue, metrical depth cue, occludees, occluders, nonpictorial motion, motion parallax, motion cue, parallax, sensation, perception, illusions, Ponzo illusion, binocular vision, stereopsis, vanishing point, familiar size, binocular vision, correspondence.
1a) What did you find interesting? 1b) Why was it interesting to you?
One thing I found interesting was how the brain reconstructs a three dimensional world from two non-Euclidean curved two dimensional retinal images. So what is the purpose of having two eyes? Having two eyes helps with depth perception, it allows us to expand our visual field permitting binocular summation, and redundancy if one eye happens to get damaged. Our vision is limited to 190 degrees, so if one eye is not working up to par, the other can try to compensate. I injured one of my eyes during basketball season so I had to wear a patch covering my eye, I actually got to the point where I was use to operating with one eye and when it healed, the vision I had been missing out on was amazing to have back.
2a) What did you find interesting? 2b) Why was it interesting to you?
The development of binocular vision and stereopsis interests me because I have always been curious on how much babies can see and when our vision peaks. The three laws by McKee sum it up quite nicely: as children get older they get better at things, whatever it is girls do it before boys, and everything develops along with everything else. Things are said to start out badly, then get better, then after a long time get worse again. Infants are blind to disparity until about 4 months of age. Stereopsis appears out of no where, but telling when by examination is a hard task. Hopefully we will find a better way to examine infants without harm so we can get some good results and be ethical.
3a) What did you find interesting? 3b) Why was it interesting to you?
Another interesting topic to me is how does our visual system decide what to see when two stimuli are present. The more interesting of the two will happen to be more dominant. By interesting we mean what is more salient to the cortical visual process. High contrast is more salient that low, bright is better than dim, and moving objects are more salient than stationary objects. The competition between the two eyes for visual perception is called binocular rivalry. Even though rivalry is achieved mostly in lab and experiements, when we see one elephant with one eye and one with the other, we fuse the image together to form one solid elephant image. These rivalrys when studied provide important information when analyzing the neuroscience of of perception.
4a) What one (1) thing did you find the least interesting? 4b) Why wasn't it interesting to you?
I found least interesting the example of rabbits and how they can see more, it is interesting how they described it, but I do realize certain animals are made to have an advantage or certain niches to make them more adapting to their surroundings. Their visual field shows everything around them compared to humans only being able to see a windshield so to speak. This wasn’t interesting to me because we can examine animals but experimenting on humans is a lot harder to do.
5) What did you read in the chapter that you think will be most useful to in understanding Sensation / Perception?
The ability to perceive and interact with the structure of space is one of the main goals of our visual system.
6) How, in what ways, does this chapter relate (build on) to the previous chapters?
Vision has been a main topic of interest, and chapter 6 has built on the previous chapters by referring to previous terms learned in other chapters and adding to them. Occlusion for example was described as a cue to the presence of an otherwise invisible edge. It is a depth cue that gives the relative position of objects. Each chapter relates to certain terms but go into more detail of the term farther down the line and when appropriate. Just like accommodation, our lens gets fatter as we observe a closer object.
7a) What topic would you like to learn more about? 7b) Why?
I would like to learn more about 3D movies, filmmakers use polarization and show two different images in the same frame to make them pop out. The glasses we wear contain crystals that enable the presentation of two images to emerge. Learning more about how 3D movies were a long time ago to how they are today will provide me with some detail on how far along we have gone in understanding our vision and developments we have made along time.
8) What ideas related to what you were reading (what did you think about) did you have while reading the chapter?
I thought about 3D movies and how awesome it would be to see how they make them and the process they go through. I also thought about how let alone I get a headache when my visual perception is being tricked, how do people draw 3D images without frustration by mentally tricking your vision all the time. Stereopsis also came to mind a lot and how our military uses it and understands it to provide them with an advantage on the battlefield.
9) Once you are done with your post make list of the terms and terminology you used in your post.
Euclidean, binocular, stereopsis, occlusion, accommodation, corresponding retinal points, binocular rivalry
1a) The first thing that I found interesting was linear perspectives and vanishing points.
1b) I found this interesting because I like drawing and artwork. The concept of parallel lines in the real world appearing to converge on a single point was a big part of my high school drawing classes. Applying this concept to art helps to create a more realistic drawing. Therefore, linear perspectives and vanishing points help to make my other interests possible.
2a) The next topic that I found interesting was anamorphosis.
2b) This was interesting to me because it is honestly incredibly amazing. It is amazing that a drawing can look so distorted from one point of view, can suddenly come into focus. It is interesting to think that by simply using linear perspective and how the human eye sees things, these truly confusing pictures take shape.
3a) The last item I found interesting was the stereoscope.
3b) The stereoscope is interesting to me because at first I had no idea why something like this would be created. Then I understood that it showed the presence of binocular disparity as a depth cue. It also showed that this exists no matter what produces the different images. I find it interesting that the toy my older relatives had was produced to prove a perceptual concept.
4a) The topic that I found least interesting Bayesian approach.
4b) I did not find this as interesting as the rest of the chapter because the rest of the chapter seems to cover more practical material. This approach, while I’m sure is useful to some, seems to be stating the obvious. I feel as though it is common knowledge that what we perceive is comprised of a current stimulus along with what we know of the world. Using previous knowledge is a much faster way that we can make sense of what we experience. Not doing this would result in confusion and a great deal of energy spent trying to understand a stimulus. Putting this information into an equation that decides the probability of the stimulus seems to be rather useless to me. I feel as though simply knowing the concept is enough to understand.
5) I think that the most useful concept in the chapter is the fact that the geometry of retinal images is non-Euclidean. Euclidean is the concept that parallel lines remain parallel long into space, and that objects remain the same size moving around, and essentially that the basic rules of geometry stay the same at all times. This is how the “real world” is. However, we receive our visual stimuli in non-Euclidean methods. This refers to binocular disparity, or two differing retinal images. When the two images combine in binocular summation, our depth perception improves. This improvement is called stereopsis. This is non-Euclidean because the usual rules of geometry don’t apply. For example, if you were to look down a hallway, the hallway would appear to get narrower the further you go, despite the actual walls being parallel. All in all, this concept lays the groundwork for why space perception and binocular vision is the way it is.
6) This chapter builds upon previous chapters by adding another piece to the puzzle of how we visually perceive our world. In previous chapters, we covered how the eyes see. In this chapter, we venture more into what the eyes see, and what the eye makes of that.
7a) I would like to learn more about anamorphosis.
7b) I would like to learn more about this because of why I am interested in it. I also want to learn about how it actually works. I want to learn to do it my self and understand the mechanics behind this form of art. The fact that it is even possible currently makes no sense to me, and it would please me to make sense of it all.
8) I thought a lot about visual games I would play with myself when I get bored. I focus on an object and close one eye at a time. I then switch to the other eye and repeat. I continue this in rapid motion and watch the object I happened to be focusing on move back and forth. I never gave this much thought until this chapter. I enjoy the fact that I now know it is due to binocular disparity.
Terms: Linear perspective; vanishing point; anamorphosis; binocular disparity; binocular summation; stereoscope; stereopsis; retinal images; Euclidean; perception; stimulus; Bayesian approach
1. The first thing I found interesting was the way the brain uses monocular cues to understand space as three-dimensional (3D). Occlusion is the fancy term for what the brain does when it finds edges. This is a technique of determining the order objects and using that information when avoiding colliding with the objects in the space. There are two different types of cues: nonmetrical and metrical. Metrical cues tell the brain the distance from the objects in question while Nonmetrical cues only give the brain a gestimate of the relative order of objects in our view.
2. The second thing found interesting was how important Size and Position cues are to the process by which our brains and eyes convert the 2d field of view we see into a 3D one. Size and Position cues provide the brain with distance by analyising size: the smaller the object, the farther away the object is (aka projective geometry). This Depth cue is also called relative size. The brain also forms the 3D view by using Texture Gradient, an idea that uses projective geometry while simluationiously using relative height. Relative height is a depth cue that says that objects higher in the field of view are farther away. Familiar size uses the brain’s knowledge of how big common objects are compared to other common objects. Familiar size is an example of an absolute metrical depth cue, while relative metrical depth cues use estimation to tell us the location of objects. Ariel perspective (aka haze) uses the knowledge that light is scattered throughout the atmosphere to understand that: the fuzzier an object in the field of view is, the farther away it is. Linear perspective use lines to tell the brain where the vanishing point is, and uses that vanishing point to determine distances. Another important part of this idea is the motion parallax, the idea that while the head is in motion-it is very difficult to correctly monitor the field of vision in 3D.
There are three key jobs of the eyes that play into how 3d our field of vision seems: Accommodation happens when the lenses get fatter while focusing on an object. Convergence is what happens when the eye rotates inward so it can focus; while Divergence is when they eye rotates outward to focus.
3. The third thing I found interesting was the part about how 3D glasses work, or don’t work in my case. The basic idea behind 3D movies has been around since Victorian times. The basic concept behind 3D is that when person’s eyes are separated, it is easier to make 2D images seem 3D. While I am against the use of this in general life(movies, TVs…), it could be very helpful to the military and doctors as it will help more accurately picture the insides of both machines and the body( for example: detecting cancer).
4. The thing I found least interesting was the bit about how 3D works in movies, yes I know it just listed as the 3 interesting thing but that was only because I have yet to see a movie where I was impressed with the 3D aspects of that movie. While I now know the mechanics of this process, it doesn’t interests me because I don’t think I can see movies in 3D, even with the new and improved glasses.
5. I think the stuff I talked about in questions 1 and 2 are most important because it took the basic way the book talked about the field of vision and expanded on how we make it seem 3D .
6. See my answer for 5.
7. I would like to explore whether or not 3D blindness is a thing or if my faulty vision (Nearsightedness) is to blame for the fact that I have to wait to see half of the new movies that come out these days because I refuse to pay an extra 5 dollars to decide between (A) taking off my everyday glasses so I can wear the 3D glasses that won’t work because I am nearsighted or (B) wearing the 3D glasses over my own glasses and still not see a 3D movie.
8. I thought about how my field of vision could be different from another persons’ since everybody has a different prescription.
9. Terms: monocular cues , space, three-dimensional , Occlusion, finds edges, order objects , Metrical cues , cues, Nonmetrical cues , Size and Position cues , projective geometry, Depth cue , relative size, Texture Gradient, relative height, field of view , Familiar size , absolute, metrical , relative metrical depth cues , Ariel perspective , haze, light, scattered, atmosphere, Linear perspective , vanishing point , motion parallax, Accommodation, lenses, inward, Convergence, Divergence, outward , 3D glasses.
I thought the Bayesian approach was very interesting, because it is mathematically quantifying something that I did not believe was possible to express in such a way. It describes the idea that our perception of the world is a combination of sensations and our prior knowledge about the context or situation that those sensations are a part of. The Bayesian approach is described through the Bayes' theorem: P(AlO) = P(A) X P(OlA)/P(O). This formula describes the likeliness that the world is in a certain state given a particular observation. I have spent many hours in philosophy classes discussing how our perception of the world is so often swayed by our preconceptions, but I had never realized that such an idea could be put in such concrete mathematical terms.
Building off of the Bayesian approach, I found the way our brain deals with illusions and the construction of space to be quite interesting. Illusions such as the Ponzo illusion play off of a disagreement between what we are receiving via sensations and what preconceptions we are holding about those sensations through depth cues. While the original Ponzo illusion presented in the book seemed like it was more representing the idea of the least noticeable difference in the size of the lines, the figure with the men on the train tracks really threw me for a loop. After reading the description saying the two men were the same size on the 2D page, I had to use my finger to measure them to see that they were in face the same size on the page. Even after being told that what I was seeing was an illusion, I still could not get my brain to see past it. Some people argue that it is simply the tilted lines of the diagrams causing the effect and not our held preconceptions on the sensations we are receiving, but that is subject to a fair amount of debate.
Again, similar to the previous topic, I found binocular rivalry and suppression to be very interesting. I realize that these could have all easily been included under the same topic of interest, but I found them all so interesting that such an action would not do them justice. I found this topic in particular interesting, because I present myself with binocular rivalry type experiments every single night as I am lying in bed trying to fall asleep. Binocular rivalry is when one's eyes see two different images, and a fight over which image is perceived begins. More often than not, the eye seeing the more "interesting" picture (brighter, moving, etc.) will be the dominant image and thus perceived by the brain. Sometimes, however, the opposing images will be in such a back and forth battle for perceptual dominance that the brain will see bits and pieces of both at the same time, rather than either one appearing whole. When I try this out myself, I often try as hard as I can to switch between the opposing images, attempting to will one to be dominant over the other back and forth. Sometimes I am able to for a few brief moments for each image, and sometimes I am not able to break the dominance of the more "interesting" image.
The part of the reading I found to be least interesting was about the development of binocular vision and stereopsis. While I think it would be life-altering to experience the progression from non-binocular vision to binocular vision with the cognitive ability to remember and appreciate it, learning about when it happens holds no interest to me. For the most part, I find developmental studies (not just psychology) to be quite uninteresting. That may change when I have my first child, but until then, I am more than happy focusing my studies on more interesting topics.
I think the Bayesian approach will help me best with understanding sensation and perception. It's one thing to sit down and talk about the hypothetical theories behind the difference between sensation and perception and a completely different thing to quantify it to a mathematical formula. This is what separates psychology from philosophy, and this is a line that I am often times unable to discern.
I would like to learn more about the mathematical formulas of sensation and perception in general. While the formulas themselves hold little interest to me, I would love to see what all has been boiled down to its mathematical roots in this field.
I spent most of the time I was reading this chapter thinking about the self-affirmation tendency behind a lot of our perceptions of the world. We tend to see what we want to see, whether that be the illusion of the men on the train tracks appearing different sizes because that's what our 3D inclined brains want to see, or Ponzo wanting to see that the lines appeared to be the same size in different pictures to different people because of perceptual cues and not because the difference in the length of the lines was almost undetectable.
Terms: Bayesian Approach, Bayes' Theorem, Sensation, Illusions, Space, Ponzo Illusion, Depth Cues, 2D, Tilted Lines, Binocular Rivalry, Suppression, Perception, Dominant Image, Binocular Vision, Stereopsis, 3D
1a) What did you find interesting?
What i found interesting first and formal is The monocular cues to three dimensional space.
1b) Why was it interesting to you?
i thought this was interesting because you still see the view of the world with one eye, where as other views, usually when you see with one eye, you have different view of the world.
2a) What did you find interesting?
I thought Positivism was interesting as well
2b) Why was it interesting to you?
it was interesting because it argues that all we really have to go on is the evidence of the senses, so the world might be nothing more than what we see in our own mind. i think this might be accurate because people who do have normal vision see the world differently, they have different realities.
3a) What did you find interesting?
i also thought that the linear perspective was very interesting as well.
3b) Why was it interesting to you?
i thought this was interesting because of the three dimensional cues, the parallel world that has the vanishing point and the pictorial depth cues.
4a) What one (1) thing did you find the least interesting?
what i found least interesting in this chapter would be the stereoscopes and the sterograms
4b) Why wasn't it interesting to you?
This was least interesting to me because i really didn't understand the way it was explained, or the purpose of it, i did however do the examples that were provided to understand this part better which gave me a little bit of an understanding but i still was as plugged into as i was in the other parts of the chapter.
5) What did you read in the chapter that you think will be most useful to in understanding Sensation / Perception?
The accommodation, the convergence and the divergence, i thought these three factors would be really useful in sensation and perception, accommdation is the process by which is the eye changes focus, when the lens get bigger, this comes in as when you see something by surprised you automatically expand your gaze without realizing it because you're in the moment.
6) How, in what ways, does this chapter relate (build on) to the previous chapters?
i think this relates to the last chapter in many ways, the last chapter was teaching us different ways of seeing colors, how different species interpret color and how helpful it is in some aspects that we see colors, while in this chapter basically tells us how to see from different angles, how to see different shapes, how we see things monocular vision or binocular, the distance and it explains why it's more important to see with both eyes and it helps us in the long run with that.
7a) What topic would you like to learn more about?
A topic i would like to learn more about is the linear perspective and the pictorial depth cues and pictures
7b) Why?
i want to learn more about these topics because, one i want to know how the three dimensional world works, and two, i want to know how artist can tell the distance cue on the pictures they present to make them presentable to their audiences.
8) What ideas related to what you were reading (what did you think about) did you have while reading the chapter?
when i was reading this chapter i was thinking about how the last chapter i thought every living thing had a correlation on how they perceived color and the difference must not be that much of a difference, but instead of this chapter, i thought that we didn't have that much of a difference when it comes to distances of objects, when it comes to the reality of things. but there's geometry in our vision, having two laterally separate eyes connected to a single brain also provides us with import information about depth through the geometry of the small differences between images in each eyes, also the difference between one individuals reality compare to the next person, i also didn't know that rabbits had such great visual field.
TERMS: Visual field, binocular, monocular, geometric presentation, Depth perception, Sterograms, Stereoscopes, Linear perception, vanishing point, Pictorial Depth cue, Relative Cues.
1A)Binocular
1B) I found this interesting because of how much different we actually see from other people and different animals. the rabbit being able to see 360 is incredible and to think what that would be like intrigues me. their are so many times we wish we could see right behind us for people sneaking up on us to try and scare us as a joke or to hurt us. something i start to think about is when we are in our cars and we miss something in our vision and get hit by another car or animal.
2A) texture gradient
2B) this really interest me because I have learned about this in the past multiple times. that if an object is smaller in a picture it is as if its further away. its amazing how our brain decades to interpret things. its how our brains have learned over the years. something that interests me is when we are first born how different do we see things.
3A) relative height
3B) i found this cool because it just goes to show how much of a difference there is in the way we see tings just on how the different angle we are at
4A) depth
4B) I did find this interesting but the thing for me was that there are so many different parts to it that it is kind of confusing.
5) the whole chapter is important to sensation and perception i would say. but i do believe that the depth is important because we use that every day for so much.
6) each chapter talks about site and how we see. however i think this chapter kind of takes a new approach. the other chapters have talked about the brain some. i feel like this chapter is talking more about actual site so the other chapters were the backbone to this chapter.
7A/B) I really want to know if how we see and understand what we see is due to our experiences and if so I am curious how we first see when we are baby's.
8) i was just thinking about life and how i have gone through it not thinking about site and how i see things but that there is so much to do with it.
9) sensation, perception, eyes, site, depth, relative height, texture gradient, binocular.
1. A) I thought positivism was interesting.
B) I thought this was interesting because it's a weird thought that the world is nothing more than a hallucination.
2. A) I thought that the example of anamorphic art in figure 6.20 was interesting.
B) I thought this was interesting because it looks so real. I imagine it's very difficult to make those flat surfaces/images look like they are three dimensional. I also thought it was interesting to show a different view of (c) which one was at the beginning of the chapter.
3. A) I thought that cyclopean was interesting.
B) The part that drew me to this was that the Cyclops of Homer's Odyssey was named after this. After that though, I thought it was interesting that we were unable to see the squares in the two images using monocular depth cues. The shapes actually get defined using binocular disparity. That leads to cyclopean.
4. A) I least liked reading about Bayesian approach.
B) I least liked this because I don't like using theorems and I think things using math are boring. This is known as Bayes' theorem and I don't like using calculations to figure things out.
5. I think that knowing about depth will be most useful and important. Definitions such as relative height, familiar size, relative metrical cue, and absolute metrical depth cue will be most useful with thinking about height and depth.
6. This chapter builds on about using depth and how that effects the way we see and perceive things .
7. A) I would like to learn more about suppression. Specifically I would like to learn about people who have strabismus.
B) I would like to learn more about this because I'm curious if this is something that people can live with or if there is treatment for it.
8. While reading this chapter I was thinking about how I see things and how when they are far they are small but the closer they get they will gradually get bigger.
9. Terms: suppression, strabismus, positivism, anamorphic art, cyclopean, monocular depth cues, binocular disparity, Bayesian approach, Bayes' theorem, relative height, familiar size, relative metrical depth cue, absolute depth cue, depth, perceive.
Chapter 6 - Reading Activity (10pts)
Three things interesting & why?
One - Positivism. A philosophical position position arguing that we all go on the evidence of the senses, thus the world might be nothing more than an elaborate hallucination. Also because if wanted to know about this concept we could “consult” the writing of science fiction author Philip K. Dick. I in fact looked up this author and found out he’s very famous indeed. He even has an award named after him. http://www.philipkdickaward.org/
Two - Monocular cues to three-dimensional space i.e. depth perception. I found the drawing of Relativity by M.C. Escher fascinating. Because of that I read and reread the different cues like depth cues, monocular, binocular depth cue and occlusion. I think it definitely will help me for the exam.
Three - Bayesian approach. I found this interesting for the fact that there is a mathematical formula yet is it something we automatically do through our perception and our knowledge of how the world already exists. The is a way to calculate, sum up and it is through the Bayes’ theorem which involves our current stimulus/perception.
Least favorite thing & why?
I try to stay on the positive side of things including my assignments. It’s difficult enough to read through the complex terms and similar meanings. Thus, I really can’t complain on that type of material. So what I am going to do tell about something else I found extremely interesting, binocular rivalry. Why? I guess because in psychology we sometimes go through times where we fight a war within ourselves, psychologically, I mean. And now to find out that we have many wars within ourselves, even our two eyes, given two different stimuli go through competition and just like all the other times, no one really wins.
Most beneficial and useful?
That having two eyes is an advantage for a number of reason, most having to do with depth perception. Also I found it useful to know that it is possible to reconstruct the three-dimensional world from a single two-dimensional image. And I also now know that two eyes have many advantages over just one like expanding the visual field, allowing binocular summation and providing redundancy if one eye is hurt or becomes damaged.
Builds on - All of the material continues to lead to the brain and it’s complex functions through sensation and perception. It constantly reminds me that society, humans do not even know the our brain, our eyes play a huge factor in how we live and see the world whether in two or three dimensional world.
I would like to learn more about … Depth perception/three-dimensional cues because I found that section so interesting especially that illustration.
How and what did I think about and feel?
I definitely thought more about how my brain and what my sensations provide me as far as knowledge. I felt as if I knew just a little bit more about sensation and perception after reading this chapter. I definitely appreciated positivism and three-dimensional cues.
Terms: Positivism, evidence, senses, hallucination, Philip K. Dick, science, monocular cues, three-dimensional space, relativity, M. C. Escher, depth cue, monocular cue, binocular depth cue, occlusion, exam, Bayesian approach, idea, perception, stimulus, mathematically, formula, calculate, observation, Bayes’ theorem, binocular rivalry psychology, illustration, dimensional cues, stimuli, positive, brain, sensation, cues, humans, eyes, depth perception.