As we have done already - after reading chapter 3 in Visual Intelligence, go through your text and find out how the text discusses the material in the reader and any additional detail it might offer. You will need to turn in a mind map in class on Tuesday so it might be a good idea to make a mind map before you start the next part of this project.
Try to adhere to the format below - keep the numbering for organization.
1) Discuss what you read in the reader. Think about what you learned from the reader. What were the main points the author was trying to make? What were some examples he used? What was the most interesting part of the chapter - etc.? Don't simply answer these questions; these are just some things to ask yourself before you start writing. I am pretty open to what you write about.
2) Discuss what you read in your text. How did the author of your text book go about addressing the related material? What did you find out about the topic that wasn't covered in the reader? What did you find interesting that was presented in the text? How difficult was it to find the related material in the text? Again don't specifically answer these questions, just use them as a way to think about the material. Feel free to experiment with your own style.
3) After you have had a chance to think about the material - what parts do you think you will remember and what parts do you think might fade from memory sooner.
4) Make a list of the terms and terminology you used in this post.
1.In Chapter 3, I feel the main idea was about constructing objects. The reader had examples with the triangle and the disk where you see a triangle or a disk in the middle of the pictures. Our eyes construct these images that other machines wouldn’t pick up on. There are also rules to our constructing objects that we can’t break. One rule is turning an unsymmetric image to a symmetric image. SBC makes these images symmetric. An example of SBC is the gray ink where the same color of gray looks different with different colors surrounding. Chapter 3 also talks about the structure of the eye because we focus the image on the retina. It went into more depth with talking about the rods and cons.
2.The only thing I found relevant in the text and the reader was the eye structure and SBC. The book also says that rods focus on dark and cons focus on color. The book went into more depth by saying that our eyes rods and cons construct every curve or surface seen. This is then sent to the brain. The book talked about SBC and it went farther by saying the light background darkens the perception of the gray spot because the receptors stimulated by the background send inhibition to the receptors.
3.I know I’ll remember the structure of the eye because I’ve learned that multiple times and have that down. I will remember the pictures that I saw in the reader because they still have the illusion to them. I think the rules to constructing images will fade from my memory because it’s a lot of different stuff to remember.
4.Construct, symmetric, SBC, retina, rods, cons, inhibition.
1. In chapter three of Visual Intelligence Hoffman starts out by explaining a case of a man who was poisoned by carbon monoxide and was left with visual Agnosia. He is able to pick out his family from a group only after hearing them talk. He can’t recognize faces. When looking at an image of a woman he said this is a woman because there is not hair on the arms. He couldn’t put the other aspects of the woman’s image together to see her. He sees aspects of images but can’t construct the full image. That’s one of Hoffman’s main points in the chapter is that visual objects are constructed. Hoffman then goes on to talk about subjective figures such as the Kanizsa triangle. I did my divergence this week on this particular triangle illusion and how we construct an image that really isn’t there. Hoffman also goes into the science behind sight a bit and talks about how the Optic Nerve sends impulses to the Lateral Geniculate Nucleus where it then sends the impulses to the Visual Cortex.
2. Finding the information in the text wasn’t too difficult it just wasn’t all in the same chapter. I found some information on dark adaptation in the text that I found interesting. They discuss how a person becomes more sensitive to light after being in the dark. Everyone has experienced walking into a dark place and your eyes take a minute to adjust so you can see in the dark. The book gave an example of doing a test where you sit in a closet or dark space and look at a chart they have in the book to determine how much light you need to see all the different shades of darkness on the chart by opening the door to let in light at different amounts. The book then goes on to explain that it’s the cones that are responsible for the rapid stage and the rods that are responsible for the second slower stage of adaptation.
3. After reading this chapter I think I will remember what I learned about object construction because of the personal example at the beginning of the chapter and the Kanizsa triangle, as well as the path that a visual impulse travels to reach the Visual Cortex. The reader gave a lot of other information that was relevant and related to the topics but not as memorable to me.
4. Agnosia, object construction, Kanizsa triangle, optic nerve, lateral geniculate nucleus, impulses, visual cortex, dark adaptation, cones, and rods.
1) The main point from the reader that I gathered is how our brain makes sense of complex objects by piecing the parts together. The author used many graphic examples to show how simple changes to a drawing change how our brain interprets the shape. Convex cusps help to define shapes for us. We also draw our perceptions from the principle of nonaccidental relations, or the fact that how we perceive images is based on past experiences and what is most likely occurring. Our brain takes all the pieces such as color, angles, and shapes to determine the complex objects. Sometimes our brain is tricked, or shows us images that are impossible based on the visual rules already set in our brain.
2) My book talks about how perception is based not only on physiological responses, but also past experiences. This means cognitive process of the brain take the stimuli and interpret it based on expectations. My book also addressed the information about the eye that was presented in the reader. The rod and cones information from my text was much more in depth and scientific. It was harder for me to understand right away. The LGN information was also presented in my textbook. I found the LGN information from my textbook easier to understand than my reader. The functions were bulleted off and written in a very concise format. The sentence that stuck with me most from my text is that the basic property of the LGN is to organize.
3) The information that I think I will remember best from the reader were the illusions. I found those most interesting. The illusions helped to illustrate the rules of perception, and helped me to understand them in context rather than just accepting them after reading them. The information that I think I will lose after the reading is the scientific explanation for vision. This information was complex, and involved many steps and scientific terminology that I didn’t find interesting. The axon and electrode process didn’t seem relatable and valuable to my everyday life.
4) Rods, cones, LGN, convex cusps, nonaccidental relations, illusions
Chapter 3 in the reader is primarily about visual constructs, and how our mind is capable of processing things even if they are not necessarily there. For example, the reader shows many examples of how we see brighter images such as, squares and triangles. This is known as simultaneous brightness contrast SBC. An example of this is the magic square. The SBC's were white images that were on a background of usually black and our brain constructed them, and made them appear bright. The reader also goes into things such as accidental, nonaccidental, unrelated, and related curves, which basically is our brain forming things that are familiar to us or that we have seen before. The reader also did an overview of the eye and the structure of the eye. The reader explained simple cells and complex cells which are found in the cortex. To me the most interesting part of this chapter was the part about SBC.
The text and the reader don't go perfectly together, so I had a hard time finding one chapter that related to a good portion of the reader. So instead I took some key points that I took out of chapter 3 of the reader, and started learning about that from the text. I was very interested in the SBC so I decided to look more up about that. In the text it is referred to as Simultaneous Color Contrast, and is defined as the appearance of the color can be changed because another color is present at the same time. It explains how "the color seen in a region of space is determined not only by the characteristics of the stimuli in that region, but also by those simultaneously present in surrounding areas." What I found most interesting was the successive color contrast and color constancy that was mentioned in the book that can lead us to see different colors.
I think what I will remember most is the SBC probably because I looked in up in the text as well as read about it in the reader. I probably won't remember all the description of the brain and the cells as well as this.
Terms: complex cells, simple cells, SBC, color contrast, color constancy, accidental, nonaccidental, unrelated, and related curves.
1)The main topics that the reader focused on were subjective surfaces and different rules associated with seeing them. It discussed how seeing these surfaces or shapes depends entirely on your visual intelligence for existence. Your eyes construct borders and different brightnesses that don't necessarily have to exist. Whether your eyes do this or not relies on different pieces of information that the setting presents including things such as convex and concave cusps, whether or not lines are parallel with each other, and what type of curves an object may have. Some examples given were photos by psychologist Morinaga of parallel curves and subjective squares by Marc Albert. The most interesting part of the chapter was the fact that a simple line or curve, or the change of position of a line or a curve can entirely change how an object is viewed. Your eye will see one thing and with one slight change, it will see another. To me, that is very interesting.
2) For the most part, I read about the make-up of the eye and how light can effect how you see in different settings. I also read some about illusions and making contours vanish. The second part was what I found most linked to the reader. It discussed how you could see a cube floating in space in front of a block of circles. This is done by creating illusory contours. It also talked about the Gestalt approach and how images that use the Gestalt laws can create illusions. It was a little more difficult to find information related to the reader, because the book is much more in depth about the different aspects of the eye and how we perceive things, but I think i was successful at finding some related information.
3) I think the things that I will remember the most are going to be the different examples of subjective surfaces and creating illusory contours, because those were the things that I found most interesting.
4) cusps, illusory contours, Gestalt, subjective surfaces,support ratio
1)This chapter really covered a lot of material but I thought some of the most important things that it covered were the structure of the eye and how the retina reflects light and sends it to the optical nerve. It also went inot great detail about subjective contours and surfaces. How changes in the slopes and outer boundries makes us construct different things according to the cusp and whether it is convex or concave.
2) I mostly read more about the construction of the eye and what the LGN and simple and complex cells were.
3) I will probably remember the structure of the eye the most because we covered it in class, in the cow eye exercise, the reader, and now the text.
4)Convex, concave, retina, LGN, cusp, optical nerve
1) The main argument that they talked about in the reader for chapter 3 was how people constructed different things through their eyes. He showed many different examples of different convex and concave cusps make a person think differently about random objects. Some of the examples he used were how people looked at a square with rounded edges versus a square with straight edges trying to see which one was easier to see. This goes along with the optical illusion article I found last week. It shows how everything really ties together and how your eye can misjudge different things all because of their color or shape surrounding a different image.
2) A lot of the stuff that I found were similar was when each book talked about the different parts of the eye and what each one focuses on or does. Both books talked about he LGN and the major role that it plays in what we see and how we relate or perceive different messages. I thought that the reader was a better read when talking about the LGN but my other book went into more detail about the rods and cones.
3) What really is sticking is how important gray shaded and different edges make on when we are trying to construct different images. I would have never thought of it like this or realized how important different objects can be when we are trying to judge distance or shapes. I think that the way we see and share information with our brain by using the LGN is also interesting and something that I will remember outside of this course.
4) Cusps convex & concave, LGN, Rule 11, Simple & Complex Cells, and illusions.
1) This chapter is about subjective construction. We don’t see objects around us we actually experience them through our senses and then we construct them from our receptor responses. The images we experience are subjective because they are discrete, meaning that these images are constructed from a collection of cone or rod responses to photons.
There are certain rules and restrictions to this visual construction process and for this reason we can’t construct whatever we want or manipulate our images at will, unless we suffered from Charles Bonnet syndrome or had a stroke. Some of this restrains are eliminated when visual processes are damaged, so it is possible to experience hallucinations or not be able to not experience the forms of objects at all.
To prove that we construct visual objects, the reader explains how subjective contours and subjective surfaces work. Examples such as Kanizsa’s triangles and Ehrenstein’s disks show evidence of our construction of figures or changes in brightness that no software can detect. The three rules that guide our construction of subjective figures explain that when we experience visual structures we tend to group them into a single object.
We not only construct subjective figures we also construct everything we see. All the examples in the reader were very explicit and demonstrated this claim. I liked that the reader didn’t have only scientific information and theories to explain subjective construction; it let me experience it myself.
2) The textbook included more specific information that I think I already forgot. It has a very different approach than the reader so it was difficult to find information related to the chapter. For example it has a whole chapter on receptors and neural processing and lots of formulas, definitions, and numbers such as the molecular weight of light-sensitive molecules. I was also able to find information about Mr. S, although he was addressed as Dr. P, and visual form agnosia, but didn’t have the same luck when looking for subjective experience or visual constructions.
3) I really got stuck on the idea that we construct everything we see because of all the examples shown in reader such as the different subjective figures and also the case of Mr. S and Mrs. B. I’ll also remember the information in regards the different rules and restrains our visual system follows and how our experience of objects is summarized to receptor responses of rods, cones, and photons in our brain. I think the materials I’ll forget sooner are all the scientific terminology and the more specific functioning of the brain.
4) Subjective construction, receptor responses, discrete, cone, rod, subjective contours, subjective surfaces, neural processing.
1. Chapter three talked about numerous things that were essential in looking at how we construct tings. Hoffman made the statement that we construct everything we see. Throughout this chapter he showed a great deal of examples on why that is the case. He opened up the chapter by talking about Mr. S and him coming in contact with carbon monoxide which indeed damaged his visual intelligence system. His ability to construct objects by colors lines and motions were destroyed. It pointed this out because he made the notion that are visual construction has been destroyed. One of the main points discussed in this chapter was analyzing how we construct objects and figures. In looking at the Kanizsa triangles, it talked about subjective contours and surfaces as being the two ways we construct visual objects. Psychologist Fred Schumann was the first person to conduct a study that used subjective contours and surfaces. Isoda Koryusai implements these aspects into his art work one being the crow and heron in the snow. Another example used was the two squares with the grey dot in them. This brings up the rule of simultaneous brightness contrast which compares the two disks and the color content of them to determine the size of the grey dot. Another key point was that of Thomas Shipley and Phillip Kellman. They talked about the cusps as having two types being concaves and convexs’. Convex points out of an object as concaves point into an object. This ties in with rule 11 construct subjective figures that occlude only if their convex cusps. In looking at the subjective squares, subjective borders become the target. To construct these in the right way, the principle of “nonaccidental relations” has to be applied in which Albert brought this to our attention. An example of this would be parallel curves. Rule 12 states that two visual structures have "nonaccidental relations" then they must be grouped and assigned to the common origin. This chapter also displayed some anatomy of the actual eye itself. Similar to the information shown during the cow’s eye dissection, it talked about the various functions of the eye. One in particular was the retina because he made the distinction that what we see are discrete images which cause you to construct based on the rules. Once you have constructed the image through your receptor responses it then sends the image to the final stage of processing known as the LGN. Then the LGN arrive at the primary visual cortex. In the construction of an object electrodes play a major part in the development of objects. They consist of three types of cells being simple, complex and hyper complex cells. Simple cells are excited by light in the bright bar regions. Complex cells are stimulated by oriental lines but have larger receptor fields. Hyper complex cells also care about oriented lines, but add the factor of length in the equation. My favorite part of the chapter was the arguments that were stated such as the argument of consensus and the argument of compliance which he proves to be false. Argument of consensus uses the example that we all see a table therefore none of us construct the table. The argument of compliance used the example of trying to put my fist through the table and not being able to causes me not to construct a table. I think an interesting question raised in this chapter was why don’t out constructs comply with our wishes? The answer is you construct things according to the rules. You’re not able to do to them what you wish, but if what you wish violates the rules of construction, you can construct what you see. The flip side of this is that it also can restrict what you can construct and what you do with your construction.
2. The text also showed the anatomy of the eye and the different functions used for their intended purposes. It spent some time in chapter 3 talking about the LGN and what it was used for. It has a six layer structure in which the neurons in the magnocellular layer are physically larger than the neurons in the parvocellular layers. The LGN acts as a relay station from the retina to the cortex. This text elaborated more about the different kinds of cells and their sole purpose. Some of them were horizontal cells and amacrine cells which are both retinal cells. Horizontal cells have a constant contact with photoreceptors and bipolar cells. Diffuse bipolar cells and midget bipolar cells which have processes to spread out and receive information from multiple cones, but the difference between the two is that midget bipolar cells are central retina cells that receive information about a single cell. In looking at the anatomy of the eye, it showed a wonderful picture of a human eye that would be taken at an eye exam. The author uses a lot of visual aids so that people would get a better understanding of what the material was talking about. He also uses a lot of analogies to relate the terms to everyday situations. I particularly liked his usage of the visual aids this way I can construct an image on how certain things are suppose to work. Something the reader didn’t spend hardly any time on was the rule of thumb. This states that in viewing your arms length, your thumb subtends an angle of about 2 degrees on the retina under the assumption that your thumb is 2cm. across and you arm extends about 57cm. I thought that the text went to in more in depth when describing the terms by using more scientific terminology. Thus, it wasn’t always easy to understand due to the vocabulary and punctuation. The visual aids helped in clarifying the information.
3. In absorbing and soaking in all this information, I would have to say that the basic anatomy of the eye would be the easiest for me to remember considering I worked at an eye doctors for two years. I’m pretty good with remembering names so the different psychologist presented in the reader wouldn’t be that difficult to remember, but the placement of some of their theories might get me mixed up. The different types of cells and their functions would be very difficult for me to remember due to the fact that there are so many of them which are used in multiple ways. Also the rules of construction presented in the reader are difficult to apply to certain figure shown. They are worded a little confusing which makes it harder to comprehend and use correctly.
4. TERMS: subjective contours, subjective surfaces, simultaneous brightness contrast, cusps, concave, convex, occlude, subjective borders, nonaccidental relations, Retina, receptor responses, receptor fields, LGN, Primary visual cortex, electrodes, simple cells, complex cells, hyper complex cells, argument of consenus, argument of compliance, neurons, magnocellular layer, parvocellular layers, horizontal cells, amacrine cells, Diffuse bipolar, midget cells, the rule of thumb.
1.In Chapter 3 Hoffman starts the chapter out with an interesting story about a man that was poisoned with carbon monoxide and was diagnosed with visual form agnosia. He knew what objects were and he could still identify them by sound, but he was unable to see them. This chapter's main focus is on construct objects. The book shows examples of subjective traingles that myself the reader can see, but are invisible to a photometer or image scanner, which is extremely interesting. Another example in the book is a picture of two disks with circulalr borders. Our eyes can pick up the brightness of the disks but those other machines still wouldn't be able to detect this. Chapter 3 also discuses the structure of the eye and states that when our eyes glance directly at an object, our eyes move so that the image of the object falls on the fovea and its cones. For seeing objects, cones don't work very well in low light, but rods work best in low light. The example in the book that explains this better is when looking directly at a star it casts images on the cones, and you are unable to see the star because of the low light. As for looking slightly away, the image casts on the rods which makes you able to see the star because they work best in low light. The information about the structure of the eye including the cones, rods, fovea, retina, etc., was the most interesting part of the chapter for me.
2.My Hoffman textbook and my Golstein text had the same information about the construction of they eye. Both books stated the concept of how cones and rods work in low light. The Goldstein text uses the example of looking directly at a light or looking slightly away. Also, both authors stated that rods focus on darks and cones focus on colors. Finding the information in my Goldstein text that associated with information in my Hoffman text was a little more difficult than i expected, but after reading for a while I did find some things that matched up.
3.I definitely will never forget the parts of the eye because of all the information in the books and from the cow eye disection blog. I also found the examples of the subjective triangles illusions to be really interesting so I think I will keep that knowledge with me. I don't think I will remember all the different rules as well as some of the other information that the reader discussed that I didn't talk about above, so it wasn't very interesting or important to me, therefore I definitely won't remember it.
4.Terms: cones, retina, rods, fovea, agnosia, illusions, construct
1) Chapter 3 of the reader talks about subjective surfaces. The main concept of the reader is that we create what we see and we begin to really get into that concept in this chapter. There are many examples of subjective surfaces in this chapter. We create these surfaces based on certain rules that are innate within us. It's still very difficult for me to fully accept this concept. When I look at things, I feel like I just see them. In this chapter, the author attempted to change my mind and although I understand and believe this concept, it is still difficult for me to look at things in this way.
The most interesting part of the chapter to me was the realization that we create images that are not really present like Kanizsa's triangles. Also, I never realized how much it takes for the brain to construct a simple line. The reader says it takes hundreds of millions of neurons. Along with that, it was interesting to hear that the mind is discrete because I've never heard the mind described in that way.
2) The text is much less detailed. It basically talks about our perception of images. One point made is that the retinal image is ambiguous. Non-visual information must be added to the visual to achieve vertical perception. The text says most of our percepts are overdetermined. There are a few examples of figures with broken lines in which we can still see the figure as a whole.
It wasn't difficult to find related information in the text but it is pretty boring compared to the reader.
3)I think I will remember the fact that we construct images or objects that aren't really there. This is dominant in both the reader and the text shown in examples like Kanizsa's triangles. I think ideas in the text will fade faster than ideas in the reader. The text spends more time on the anatomy of the eye and how it functions which is less interesting to me than the big concepts of vision.
Terms: subjective surfaces, innate, neurons, Kanizsa's triangles, perception, retinal image, ambiguous, vertical perception
1) Chapter 3 was filled with numerous topics. He starts out by explaining how we see objects. I liked story in the beginning about "Mr. S." who could not see objects. He could distinguish colors, motion, and edges, but it just did not connect to form an object. He explains that there is evidence of subjective contours and simultaneous brightness contrast. How we see object based on edges and corners that create the invisible object in the middle. He touches a little on the structure of the eye (retina, rods, cones) and also discussed how the LGN (lateral geniculate nucleus) processes results. I liked the fact that your retina has about 120 million rods and 7 million cones.
2) My textbook did not go into detail about objects as the reader did. It did talk about "Processing past the retina" which was also in the reader. It mentions the LGN. I learned that the visual receiving areas is also called the 'striate cortex' because of the presence of white striped that are created within this area of cortex by nerve fibers that run through it (makes me think of what human muscle looks like or a skinned fish; striated). I also learned that the 'superior colliculus' is an area that controls eye movements.
3) I think I will remember the fact about how many rods and cones are in our retina. I also liked the information I found in my text but not in the reader. I wasn't too thrilled with this chapter in the reader because it didn't have a lot of terms to go with the pictures, so it made it dull/hard to remember.
4) Superior colliculus, striate cortex, retina, rods, cones, LGN, objects
1) The reader seemed to be about how we, as people, construct objects with our eyes. The end result is something we see, but everything starts as countless dots that are grouped together due to our understanding of gestalt psychology (as I would assume) and we observe them as one collective group of dots.
The reader also informs us about how it was assumed at one point that our mind could only fill gaps in space and construct images with symmetrical objects, but examples in the reader showed us that our mind can "connect the dots", if you will, and put together an image of an object if it is irregular and asymmetrical.
2) The reader does an amazing job portraying perceptional issues when discussing the eye and how our eye develops and constructs images, but the text is far more efficient at discussing the physiological components of the eye such as the functioning of the retina, rods and cones. The text taught me that the human eye contains two types of photoreceptors (rods and cones). It explained that there are many more rods than cones (120 million rods)they are very sensitive, more so than cones, but not sensitive to color. There are only 6-7 million cones and they are the color receptors.
The information presented in the text is presented in a much more professional manner and is written purely in formal language. The information in the reader is written in words that the general reader can comprehend with little effort.
3) I was never very particularly fond of anatomy, and I have always tended to easily remember loosely worded information. I have no doubts that I will remember text from the reader much more readily than I would remember anything from the text book. Very specifically though, I'll remember much more about how the eye constructing images with dots, making dots into lines, and making lines into objects sooner than I'll remember very specific details about how the retina processes information.
4) Terminology: Retina, Rods, Cones, Photoreceptor, Symmetry, Irregular figures, Gestalt Psychology
1. Chapter three of Visual Intelligence discusses how your brain constructs the shapes and illusions you see due to experience with those shapes. To further this claim, the author makes use of subjective contours and subjective surfaces. The idea of subjective contours and surfaces is demonstrated in Kanizsa's triangles and Ehrenstein's disks, pictures from which we cognitively construct triangles and disks undetectable to photometers. The reason this occurs is because we construct borders and changes in brightness of the shapes. We create subjective figures by transforming unsymmetric shapes into symmetric ones that are partially covered by another shape. Probably one of the more interesting parts of this chapter to me was the idea of convex and concave cusps, because this seemed to be the most clear evidence why we are able to construct shapes out of some animations, but not from other similar animations from which we might expect construction to occur (mostly due to abrupt changes in slope). The part of the chapter that I had the most difficulty with was where rule 13 came into play; If three or more curves intersect at a common point in an image, interpret them as intersecting at a common point in space. I understand this rule by itself, however, the author begins to tie-in concepts from the last chapters into this rule and it gets a little confusing.
2. In my opinion, the text (Wolfe)is actually a lot less informative than the reader. It doesn't talk much about illusions (or even Kanizsa's triangles or Ehrenstein's disks), however, in chapter 4 the book has a segment on finding edges. This chapter covers illusory contours (a perceived contour, even though nothing changes from one side of the contour to the other in the image) and Gestalt contributions to perceiving and recognizing objects (mainly good continuation). Similar to the reader, this chapter deals with occlusion and symmetry.
3. Given what I've read from both visual intelligence and the S&P textbook, I think it will be hardest to remember the rules of construction listed in the reader. Taken individually, they are easy to understand, however applying them and using them in conjunction with one another gets a little tricky, therefore it might be easy to forget these rules.
4. Construction, Subjective contours, subjective surfaces, Kanizsa's triangles and Ehrenstein's disks, convex and concave cusps, occlusion, good continuation, Gestalt Psychology, Illusory contours.
As we have done already - after reading chapter 3 in Visual Intelligence, go through your text and find out how the text discusses the material in the reader and any additional detail it might offer. You will need to turn in a mind map in class on Tuesday so it might be a good idea to make a mind map before you start the next part of this project.
Try to adhere to the format below - keep the numbering for organization.
1) Chapter 3 made a lot of interesting points. What I read in the reader had to do a lot with the construction of objects and how our eyes construct those objects. While discussing construction of object the author goes into detail using subjective contours and subjective surfaces. Subjective contours is a phenomenon where boundaries are created within an image that makes you see an illusion that is not actually there. Subjective surfaces is a phenomenon that has missing boundaries. The figures used to describe subjective contours and subjective surfaces Kanizsa triangles and Ehrenstein's disks. Kanizsa's triangles has a clear border and is brighter than the background. Whereas; Ehrenstein's disks have clear circular borders. The main points that the author was trying to portray is that our eyes construct objects according to boundaries and that there are certain illusions that our eyes construct however; they may not always be accurate. I thought that it was interesting that because of the subjective contours and subjective surfaces that our eyes construct these images, however; because of the boundaries our eyes tend to see an image that really is non-existant. I thought it was also interesting about the history of subjective figures date back 22,000 B.C. To see how far illusionary images have come is so interesting. I would think that it would be very difficult to detect the illusionary images back then when they weren't even aware of the anatomy of the eye, and that it would be difficult to understand the illusionary images portrayed.
2) In the textbook (Sensation & Perception, Goldstein, 4th Edition) he doesn't go into much detail about subjective contours or subjective surfaces. However; he does describe the complexitiy of how we perceive objects. He continues to question and explain certain topics such as; how do we turn a 2-dimensional object into a 3-dimensional object? How three intersecting lines are part of the same object or are created by two different objects? and How do we determine the shapes of objects that are partially hidden? However; he doesn't really answer these questions, which I'm really curious to know the answers now. I wish that Goldstein would have explored the subjective contours and subjective surfaces further in detail because I'm curious to know from a different opinion, what he would have had to say about those illusionary phenomenon's. Although, he did present valuable questions, It would have a been nice for him to have talked about some more in depth issues that were discussed in the text.
3) I most definantly will remember the subjective contours/subjective surfaces, because after writing this blog it has made me think and analyze those illusionary phenomenons. I will also remember how the reader and textbook described the anatomy of the eye, I've learned about it previously, however; these two sources of information has presented the material in a way that was fairly easy to comprehend.
list of the terms and terminology you used in this post.
4) subjective contours, subjective surfaces, illusionary phenomenon.
1.) Chapter 3 in Visual Intelligence is mainly about how our eye constructs what we see after taking into account the perceived brightness, borders, cusps and contours, and the different parts of the eye that do this for us. Hoffman showed how this was done by giving different examples, such as Kanizsa's triangle, where the triangle shape in the center of the figure appears brighter than the rest of the background, although they were in fact the same color. He also showed a few other examples that Kanizsa and others made that showed similar phenomena. Hoffman then went into detail about what each part of the eye did. I learned probably the most new material from this second part of the chapter because I never really knew the specific functions of each part of the eye.
2.) My textbook (Goldstein's Sixth Edition) also described all of the functions of the eye, and although it presented more information, I feel that I got the same amount out of reading the reader as I did the text. The reader gave you the main ideas of what each part did, while the textbook gave a lot of details, which is beneficial for the the reader, but also kind of an overwhelming amount of knowlege to comprehend. I was kind of disappointed that I could not find any more information about Kanisza's triangle, but I think the the reader presented it very well and in a memorable way because it included the rules that explained it a little more. My text did show a few different figures that I thought were interesting dealing with foreground/background and which color (black or white) our eyes view as being the front and being behind and one really emphasized the importance of symmetry when our brain is determining which is which.
3.)I will remember Kanisza's triangle the most because I find that very interesting why our brain perceives the middle as being brighter than the outside and the conditions of the triangle that do and do not produce that effect (having borders vs. not having them on the inside.)
4.) visual construction, brightness, borders, cusps, contours, Kanizsa's triangle, foreground, background, symmetry
1) Chapter three of the reader continues with the theme that are all expert and unaware constructors of our reality. This chapter presents a careful argument using physiology, illusions, and construction gone awry, as with brain damage, to prove the case of construction in a number of ways.
The evidence that we are clever constructors includes physiological explanations of our anatomy. This portion of the chapter begins with early theories, beginning with Plato, that included introsimmision - objects literally entering the eye, to intromission - light or fire issuing form the eye, both of which are problematic, and finally settles on the discovery of Keppler in 1604 that the eyes function is to focus an image on the retina through refraction by spherical lenses, beginning with a "discrete array of light-sensitive cells called photo receptors"(Hoffman, 1998). This leads the argument toward the sheer massive number of rods and cones in our eyes whose job is to a approximate an image on these discretely packed cells resulting in a distinct cone responses - enabling us to approximate a visual image such as a line. The argument is further strengthened through discussion of the biological responses in certain areas of the brain - primarily the lateral geniculate nucleus (LGN) where processing begins, and then to the primary visual cortex (VI) where the line is finally (actually, instantaneously) constructed.
Visual illusions such as Kaniszsa's subjective triangle, which are evident to human constructors, but visible to human constructors/interpreters, present more compelling evidence that we are constantly taking in the stimuli and interpreting it according to intricate visual rules. The author presents a number of additional examples of how humans have been utilizing our ability to construct as exemplified in artwork and cave drawings for a very long historical period (Hoffman, 1998).
If the explanation of our anatomy, and illustration of our interpretation of illusions as compared to computer processors were not enough to prove the case, the author points out the fact that we are able to construct the reality similarly to every other person because we are doing so with the same set of biological hardware except when we can't... this chapter of the reader offers two example of brain damaged individuals who have lost the ability to construct normally and efficiently. In the case of Mr. S, carbon monoxide poisoning has destroyed his ability to construct a visual experience of object or people even though he could see perfectly well, and interpret people by the sound of their voice. In the other case of brain damage, Mrs. B's stroke demonstrated that when the creative powers of visual intelligence go unchecked by restraint we can vividly see and experience things that are not there (Hoffman, 1998).
2) The Goldstein text (2007) expands on the idea of light receptors. Light is a stimulus for vision and "light can be described as consisting of small packets of energy called photons". At first glance, this seems compatible with the very old theory of intromission, but its important to distinguish the fact that in intromission, it was thought that object literally entered the eye in some regard, whereas packets of light which activate light receptors for processing is something that works on the existing biological hardware for interpretation, rather than an external object entering as an uninterpretable object (one can't help but recall the platonic ideal of "forms" when this old way of thinking of outside stimuli).
Goldstein has many images of the anatomy of the idea to complement the reader, and to complement the class lectures on the visual portions of the brain. It was interesting to read about the Nobel prize winning work of Hubel and Wiesel, researchers who were able to elicit responses from particular cells, and pinpoint the specific location and properties of nuerons for the purpose of different processing aspects of our vision as we discussed in class lecture. The textbook is much more technical in this regard, though less readable except as a reference. THere is also a thorough discussion in the textbook of movement perception that, while illuminating in some regards; such as how we are able to distinguish objects from one another through motion (which is why some animals freeze when a predator is close - think Jurrasic Park, lol), it did not expand on the unrestrained aspects which caused Mrs. B to see objects movement when nothing was there (Goldstein, 2007).
3) I think that I will remember most the stories of Mr. S and Ms. B, and how our visual intelligence helps us to control and interpret what we see similarly to one another, unless something goes wrong. I will also remember the the way that cones are packed tightly together in a way that allows them to approximate a line, one that isn't really quite a line, but as it goes through our LGN and onto our VI we are able to see a clean crisp line through our interpretation of the image. From the text I hope to remember the anatomical structures of the brain, and I will certainly recall how motion is detected in specialized ways for processing in our brains.
4) Vocabulary: Photoreceptor, refraction, spherical lenses, intromission, extromission, receptive fields, restraint, photon.
1) Ch 3 in our reader was about the process our brain goes through to construct items. We call this subjective construction. Our brain rapidly goes through this construction in the blink of an eye. Hoffman sets up what he calls generic views. With these generic views we quickly set up and interpret a 3-D world. These generic views are interesting, we do not see the world as generic but the brain interprets the world so quickly we never think of these generic views.
2) The textbook was very specific almost to the point where it was overwhelming. The functions of the eye were a focal point for the text. The reader was very helpful in applying situations to these rules while the textbook just kind of stated them. It is good for a reference point. Surfaces and symmetry are discussed and it is nice to reference back to the reader and apply it. The textbook however takes a very different approach than the reader. It is alot more linear while the reader isn't as structured.
3) I will remember the cases of Ms. S and Mrs. B the most. They were nice reference points to apply the knowledge we learned
4) Subjective construction, receptor discrete, cusps, contours, subjective surfaces, objective surfaces, cones, rods,
1.Chapter three in our reader discusses a variety of justifications to explain how each individual is able to construct the objects he or she is able to see. The author demonstrates our ability to construct objects based on two primary defenses: subjective surfaces and subjective contours. Subjective surfaces provide concrete evidence, evident to our own eyes, that we are in fact able to construct visual objects. An example of subjective surface is seen in the explanation for the orientation of lines and the description of the visual anatomy and physiology of the eye. I found it interesting to learn about the different features of the eye that helps to construct the overall processing of an image based on the complex interactions within our eye and brain. Additionally, I found the explanation for the discrete packing of rods and cones within our retina the most interesting. Subjective contours was the author’s attempt to try to change how we feel when we construct objects, and enable us to actually construct the objects we see. Some examples of subjective contours are seen with Kanizsa’a triangles and Ehrenstein’s disks. Both of these examples illustrate how the existence of objects depends entirely on our visual intelligence. The part of subjective contours that I found to be most interesting related to the rule of symmetry which stated that we are only able to construct subjective figures if we transform unsymmetrical shapes into symmetric objects that are partly occluded. This was a concept I had never considered relevant when looking at subjective figures.
2.The chapter I found most relevant to chapter three in our reader dealt with patterns and edges in my text. This chapter discussed contour perception, visual acuity, spatial frequency analysis, contour interactions, feature extraction, perceptual organization and an explanation about the correlations between information, symmetry and good figures. The text was able to elaborate and provide a clearer explanation on many of the same concepts addressed in the reader. For example, the reader mentions edges as an important depiction in separating figures and spatial changes, but the text elaborates on this idea even further. The text discusses the first and second order of contours to explain ways in which we are able to perceptually organize our visual field. I found it very easy to find comparisons between the reader and text; however, the text expanded more broadly on topics addressed in the reader throughout four different chapters versus one. In the text, one chapter discussed the visual system and anatomy of the eye, another chapter discussed the effects of brightness and color, object and scene which involved problems of the visual scene perception and 3-D vision was discussed in another chapter and as mentioned previously, a different chapter addressed the perception of patterns and edges.
3.After thinking about the material covered between the reader and the text I believe one concept I will remember for a longer period of time is the orientation of specific cells in the visual system. While the reader only mentioned three types of cells, simple, complex, and hypercomplex, the text elaborated on the interaction of these excitatory and inhibitory responses by giving an example of the Hermann grid. The Hermann grid was interesting because although it was only a regular arrangement of black squares with white interspaces, it had gray smudges on the intersections between the black squares; however, when you focus on the gray smudges they disappeared. Something I believe I will forget sooner is probably the explanation in the reader for subjective surfaces because it focused more on anatomy and physiology versus theories and concepts.
4.Subjective surfaces, subjective contours, rods, cones, retina, Kanizsa’s triangles, Ehrenstein’s disks, symmetry, contour perception, visual acuity, spatial frequency analysis, contour interactions, feature extraction, perceptual organization, visual field, simple cells, complex cells, hypercomplex cells, excitatory responses, inhibitory responses and Hermann grid
1.Chapter 3 talked about our perception of things that are not physically there. In one of the pictures it showed three circles and they were shaped around a triangle. The author never intended us to see make the object out to be a triangle, but that is what we intentionally or unintentionally do. Also we percieve objects to be darker in some areas than others by lines that give off that efffect, when really that is just our perception of the picture. One of the pictures that I found interesting is the ones with a rectangle with two squares inside, one black and one white. Inside those squares were two circles of the exact same color. He then asked which circle was darker. Being that the circle on the right is inside of the black square we percieve that one to be darker because of the black background.
2. In the book the author talked about Constructive Theories. He defined Constructive Theories as how we percieve things combine a number of different factors to "Construct" the final perception. I think that Constructive theories relate to the images in the books because there are a lot of things to see in the particular images and then to interpret what you are seeing would be using the theory cooperatively.
3. From the readings that I did in the two books I found that the most interesting pieces were in the reader. The pictures were very enlightening and gives us a good idea of what our mind does unintentionally to understand what we are actually looking at. Our vision system tries to make sense out of what we are seeing and the process of that happeneing is very interesting to read about.
4.Constructive Theories, perception
1) Chapter three in Visual Intelligence was mainly focused on constructing objects. The specific issue dealt with the invisible surface that glows. Hoffman gave examples of illusions like the magic square and rules like, if three or more curves intersect at a common point in an image, interpret them as intersecting at a common point in space. This chapter pretty much explained how we are able to complete and construct objects in our world. This chapter also explained how we construct images that are behind other objects. Later in the chapter the author discusses the structure of the eye and how information is processed through the eye. The last part of the chapter talks about how information from the eye is transferred and processed in the visual cortex.
2) After searching through the text I only found sections on the structure of the eye and transfer of information to the visual cortex. The text went in to more detail about rods and cones, saying that the rods of the eye are for seeing dark objects. The cones are for seeing colored objects. Another aspect the book talks about is darkness sensitivity. The text said that the eye gets more sensitive to light the longer time spent in darkness. I was surprised that the reader did not go into a little more detail about how the eye actually works and how the brain gets to process the information.
3) The information that I will remember will probably be the structure of the eye, as a result of having to learn this material on numerous occasions. I will remember the most of the illusions from the reader especially the magic triangle. I don’t have a reason why I will remember them I just think they are cool to look at and ponder about.
4) Rods, Cones, construction, visual cortex, darkness sensitivity.
1) VI is trying to demonstrate that we construct all the visual images we see according to rules. Sometimes these rules are too strict and we can become confused by what we see, or have tricks played on us. Although most people probably accept the basic premise that are eyes ‘create’ basic visual tricks as when it appears to us that one line is longer than another when we know it is not, VI is also trying to convince us that literally every single dot, line, color, etc., everything we see is constructed. This at times seems almost too unbelievable a claim to even understand let alone be convinced by it; yet Hoffman’s method is to continuously explicate more and more specific, specialized rules that we follow when constructing visual sensations.
The absolute best example I can give of this, and which I think best explains his view that every nanometer of our visual scene is constructed rather than ‘seen as is’ is on the bottom of pg. 67. He has briefly outlined the purpose of and relationship between rods and cones. Cones help us see color and also produce clear images and are focused around the fovea, we have only 7 million of these; whereas cones produce black and white images, found outside the fovea, and are less focused and more important in detecting motion and number approximately 120 million. These rods and cones are very much like pixels on a computer screen. As cells they are discrete, not continuous, there must be gaps, tiny as they might be, where cell walls touch. As a result our brains must construct the fluid images we see as a result of the pixilated scene located at the back of our retina’s.
2) The biggest difference here between the reader and the text is that my text explains much more about the relationship between rods and cones and how they transmit impulses to the other types of neurons in the retina. Analogizing rods and cones to pixels makes clear the discrete (as opposed to continuous) nature of our visual field. To continue that along the text explains why rods produce less clarity than do our cones. Basically there are about 15-20 times the number of rods as there are cones. Rods and cones send signals to bipolar cells which link to ganglion cells of which there are approximately 1 million. Some quick math shows that there are many more rods connected to any particular ganglion cell than there are cones (i.e. there is greater convergence amongst rods than cones). Even more so considering that cones are clustered at the fovea. Since ganglion cells have a particular threshold which needs to be met before they will fire it is obvious that a smaller amount of light is necessary per rod than per cone to reach this threshold.
This explains sensitivity but not clarity. Again the text does a brilliant job with easily explaining why we see this difference. For ease of reference imagine that 10 rods connect to 1 ganglion whereas each cone is connected to 1 ganglion. If the ganglion requires 5 unites of energy to fire through the previous example we know that luminance of only 2 would produce 20 units for the rod-ganglion, but only 2 unites for the cone-ganglions. So a minimum of 5 units is necessary before the cones will pick up on the image. The book explains that if two lights where shown close together the greater convergence on the part of the rods would make them less able to notice the gaps. Whether the input is coming from rods 1 and 2, 1 and 5, or 1 and 10 makes little difference as all rods communicate with the same ganglion. However with the cones a gap becomes immediately recognizable since each cone connects to a different ganglion. Greater convergence equals more sensitivity but less clarity, lesser convergence equals less sensitivity but more clarity. Freakin’ awesome.
3) Things that will fade more quickly I imagine are the various names of cells, in particular remembering the link between bipolar and ganglion cells, versus amacrine and horizontal cells. In VI I’ve started a document that lists all the bold/italicized rules and fundamentals because I’ll never remember these. There’s simply too many to really keep them straight. It would be nice to be able to be given an image, and then list the rules which account for why you see it as you do, this will not happen for me I believe.
Things I will remember I think are the properties and the eye, the relationship between rods and cones, as well as the underlying similarity between all the rules in VI. Namely, that we interpret 2d images as their 3d counterpart based on the ‘rule of generic images’.
4) Rods, cones, fovea, discrete, continuous, neurons, retina, bipolar cells, ganglion cells, amacrine cells, horizontal cells