Please read chapter 3. 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
Chapter 3
1a) What did you find interesting?
Herman Snellen, a Dutch eye doctor invented or introduced the Snellen chart to study visual acuity in 1862. He constructed a set of block letters which the letter as a whole was five times larger as the strokes that formed the letter. By doing this he then defined visual acuity as follows:
(distance at which a person can just identify the letters) over (distance at which a person with “normal” vision can just identify the letters
1b) Why was it interesting to you?
Once I began reading about visual acuity, I then remember my optometrist saying I had great vision and that I had better than 20/20. So when reading about the Snellen chart, I wanted to see if there was something about the standard and if someone could infact have better vision than 20/20. Our text book did infact say that “20/20 is often considered the gold standard, most healthy adults have an acuity level closer to 20/15”, (pg. 59) putting me right up there with the best. And honestly after reading the first part of Chapter 3, that was the first really interesting thing that caught my eye, (no pun intended).
2a) What did you find interesting?
(Honestly, that I’ve been massaging my striate cortex for years.) What I mean is, if you put one hand at the back of your head, about an inch or two above the top of your neck, you would be able to feel a small bump known as the “inion”. The receiving area for LGN (lateral geniculate nuclei) inputs in the cerebral cortex lies below the inion. This is also known as the primal visual cortex, area 17, or striate cortex.
2b) Why was it interesting to you?
After reading about the certain part of my head/body, I correlated a relationship between doing lots of reading (pressure on my eyes and brain), my headaches and when someone massages that part or I do it myself, I find relief. The striate cortex consists of six major layers that are being rubbed/massaged. Some of the six layers even have sub layers. There is a whole vast of things going on inside this certain part of the visual process. A major and complex transformation of visual information takes place in the striate cortex.
3a) What did you find interesting?
Visual Crowding - this deleterious effect of clutter on peripheral object recognition.
3b) Why was it interesting to you?
Because visual crowding occurs in natural scenes and the difference in our vision when this occurs wasn’t something that I was truly aware of. Especially how objects that can easily identified in isolation seem indistinct and jumbled in clutter.
4a) What one (1) thing did you find the least interesting?
Cytochrome oxidase (CO) - An enzyme used to reveal the regular array of “CO blobs,” which are spaced about 0.5 millimeter apart in the primary visual cortex.
4b) Why wasn't it interesting to you?
It was very complicated and difficult to understand. That whole section was extremely biological and began using so much comparisons between columns and hypercolumns and adding mathematical computations, it was giving me a headache. For example on pages 73-74, It starting bringing in the fovea and the different degrees of a portion of what someone could see and then asking about the different angles and so forth bringing us to the point of CO, thus not very interesting, TO ME …
5) What did you read in the chapter that you think will be most useful to in understanding Sensation / Perception?
“The primary visual cortex is organized into thousands of tiny computers, each responsible for determining the orientation, width, color, and other characteristics of the stripes in one small portion of the visual field.” (pg. 83) Also, “The human visual cortex contains pattern analyzers that are specific to spatial frequency and orientation”, (pg. 80). Knowing how the human/primary visual works and affects all other aspects of the eye is extremely important in dissecting eachs responsibilities.
6) How, in what ways, does this chapter relate (build on) to the previous chapters?
Definitely continues on the previous chapter as it continues to describe what is happening further inside the cells, neurons, cones, rods, etc.
7a) What topic would you like to learn more about?
Primary Visual Cortex (V1), aka Striate Cortex, area 17. And about the Spatial Vision and the development aspects of it.
7b) Why?
Once I began reading about the V1/Striate cortex/area 17, I began fascinated with the subject and its processes, I just went ahead and started reading on my own. So much is happening during or to the V1 that is was very interesting.
8) What ideas related to what you were reading (what did you think about) did you have while reading the chapter?
Honestly, about headaches and migraines and how I think this chapter defines some of the underlying layers of how our eyes and visual processing can have relationships to our health and feelings.
Terminology: Snellen chart, Herman Snellen, eye, visual acuity, sensation, perception, primary visual cortex (V1), Striate cortex, Area 17, LGN, lateral geniculate nuclei, vision, visual crowding, peripheral, recognition, cells, neurons, cones, rods, Cytochrome oxidase (CO), enzyme, spatial vision, spatial frequency.
1a) The first thing that I found interesting was the section about how doctors decide what your visual acuity is. I didn’t realize that it evolved from having the letters change position in relation to the person, to having the letter change their shape with the person remaining stationary (20 ft away). It is interesting to me that they don’t mention why 20 was chosen. It seems so random; unless studies were done and that was the average a person could see most of the letters at. This was interesting to me because it is something that everyone has experience with bur rarely knows what it is or how it is determined.
2a)I found the discussion on the LGN or lateral geniculate nucleus to be the next interesting thing. Mainly the area discussing the Konicocellular cells, and how they are layered in order to do different jobs in the processing of visual information. Previous to reading this I assumed that visual perception was pretty straight forward. But, like our brain our eyes like to mix things up and relay information from one eye to the other and vice versa before mental processing. This process of sending information to specific places within the visual nervous system was called topographical mapping. Which I also found interesting because I only knew topography to relate to geological mapping of the earth, and would have never applied the word to something like the visual system.
3a) The final thing that I found interesting was the tilt aftereffect. The idea is that our visual system has different neurons, and each is responsible for perceiving visual stimuli at a different angle. When one set gets tired and is presented with a stimuli of the opposite or neutral angle, the stimuli will actually begin to tilt due to he exhausted neurons. This was also a part of the discussion on adaptation, meaning our eyes and visual field adapt depending on the stimuli so that we have “better” vision. I guess I found this section interesting because it explained what most people would just call an optical illusion. I’ve done a lot of those, and grew up with a book of them, but never really had one explained to me.
4a) To be honest, I found most of this chapter difficult to swallow. The discussion about contrast sensitivity, aliasing, sine wave grating and spacial frequency left me a little confused. Could have been because I read this chapter at a bad time, but I felt like it was heavily saturated with math jargon, and I don’t comprehend it a lot. I got the basic concepts from the chapter, but I wouldn’t say I could recap it all and feel confident about what was coming out of my mouth, no matter how many times I would read the chapter.
5) I think the most useful part will probably be the discussions on things like visual acuity, and the striate cortex, as well as the discussion on adaptation. Especially since the discussion on human perception doesn’t officially begin until halfway through the chapter, as most of it discussed studies on cats and monkeys previously in the chapter. But, I think knowing where the visual interpretations occur in the brain and in the eyes is the most important part.
6) The anatomy of the eye is still important in this chapter, although less so. It also mentioned sine waves when discussing sine wave gratings. This chapter just further emphasis the functioning of the visual system as opposed to it’s anatomy and basic functioning.
7a) If there was anything in this chapter I would want to know more about I would choose amblyopia. I like disorders and abnormal functioning of anything, so I would be interested in learning more about developmental and under stimulated vision during early years, and how it further effects vision. I don’t know a lot about cataracts or visual disorders.
8) When reading the part about the baby studies I wondered why we didn’t have a device like baby goggles to track their visual paths. It seemed a little archaic to be looking through a peephole at babies and their parents. Other than that i was just thinking about the optical illusions I have done previously.
9) visual acuity, lateral geniculate nucleus, topographical mapping, Konicocellular cells, tilt aftereffect, adaptation, contrast sensitivity, aliasing, sine wave grating, spacial frequency, striate cortex, amblyopia
1ab. One of the first things that really popped out to me in this chapter was the page on eye doctors and visual acuity. We know that in our society we consider 20/20 vision as being good, but what I did not know was that most healthy young adults actually have 20/15 vision which is even better. I was drawn to this part mostly because I do not have good vision and I am required to wear glasses or contacts in order to read/drive.
2ab. Another interesting aspect of this reading was the discussion on contrast sensitivity function (CSF) which as we read we know that is a function describing how the sensitivity to contrast as defined by the reciprocal of the contrast threshold depends on the spatial frequency or size of the stimulus. When first reading this part I was a bit confused as to what they were talking about but then I notice the figure they placed with it that did a great job of explaining the CSF. So I guess you could say that I was interested in this topic more because I was totally confused as to what they were talking about.
3ab. A third item that I found interesting was when talking about visual crowding. Visual crowding we know it the deleterious effect of clutter on peripheral object recognition. The interesting part I found was with the example the book gave. It was a picture of a street with many signs and some children and etc. What happens when you look at the far away bulls eye in the picture is that you no longer can see one of the children. This is because that child, even though it is exactly the same as the other one, is put in between to objects with similar color, thus making it harder to distinguish with our peripheral vision. Crowding impairs the ability to recognize objects, but it does not make them disappear.
4ab One of the least interesting parts of this chapter was the description of the different layers of the lateral geniculate nuclei (LGN). The book states that there is an LGN on both hemispheres and it is made up of 6 different layers. The bottom two are bigger and called the magnocellular layers and the top four are called parvocellular layers. It t6hen describes differences between the different layers along with what kind of ganglion cells connect to them. This was just a hard read and I did not enjoy this part because it was very dry and boring.
5. The most helpful areas to understanding perception and sensations from this chapter I believe came from topography and magnification. With topography we can start to understand that we map out what we see in the world both with the visual cortex and geniculate nucleus, and with magnification the images we see are scaled from different parts of our visual field. These two working together begins our understanding of how we recognize different things and people.
6. This chapter relates back to the previous chapter mostly because we are still talking about the eye and visual stimulus, only now instead of just focusing on the parts of the eye, we are focusing on the areas of the brain too.
7ab. After reading this chapter I would like to know what kind of things can go wrong with topography. This is because of something professor Maclin said in class last time and that was the way we recognize faces of people differs from how we recognizes faces of animals and now I am curious about that topic.
8. The only thing I really thought about outside of the reading was if this is also similar to how animals see things or how their brains differ in this area. This thought mostly came about because both of my cats have been bothering me while I have been typing this out so that may have influenced it a bit.
Terms: contrast sensitivity function, visual crowding, peripheral vision, lateral geniculate nuclei, magnocellular layers, parvocellular layers, ganglion cells, topography, magnification, visual cortex, geniculate nucleus, sensation, and perception
1a) What did you find interesting?
I thought the very last part of the chapter was pretty interesting. "The Girl who almost couldn't see stripes"
1b) Why was it interesting to you?
I thought it was interesting because i wrote about cataracts last week, and mentioned that my mom had them at a young age and that increased her chances of having them simply because she is from a third world country which they stated that fact as well.
2a) What did you find interesting?
Another interesting thing in this chapter was "The Development of spatial vision". i thought it was very interesting.
2b) Why was it interesting to you?
This was very interesting due to the fact that Hubel and wiesel did a research on it, and also compared the developing of a human infant and also compared it to cat's and monkeys. the results weren't the same but they weren't also as different as you'd think.
3a) What did you find interesting?
Another item that i thought was as interesting was the simple and the complex cells section.
3b) Why was it interesting to you?
this was interesting because it was talking about how both of our eyes work differently, how we can identify edge detector and see stripes as well, those work differently, just as if you're looking at something, if you cover one eye, you have a different vision of whatever the item is.
4a) What one (1) thing did you find the least interesting?
something that i found least interesting would have to be the retinal ganglion cells and stripes
4b) Why wasn't it interesting to you?
i thought this was informative but yet it was sort of uninteresting, i think if they would've explained it a different way, i would've found it more interesting.
5) What did you read in the chapter that you think will be most useful to in understanding Sensation / Perception?
i think the one thing that i think will help me understand perception and sensation is the baby visual system developmental process.
6) How, in what ways, does this chapter relate (build on) to the previous chapters?
this chapter is a lot more like chapter two in many ways, but mostly it is because the way they're explaining the visual system, the different parts of it, last chapter had chug of information about the visual system, but in this chapter, it actually breaks down into small pieces.
7a) What topic would you like to learn more about?
i would like to learn more about infant visual system, human infants and monkey's infants as well.
7b) Why? because i want to know how we develop that particular area, if our younghood has something to do with how we see things in adulthood, if our visual system is different or the same from a monkey, if it is then how different is it.
8) What ideas related to what you were reading (what did you think about) did you have while reading the chapter?
this made me thought of ceaser from the planet apes, how he was treated as a human child and he was different from some of the apes that were treated differently, he showed intellectual differences, speech, etc.
TERMS: Visual System, Visual cortex, ganglion cells, infant, Lateral Geniculated.
1. A) I found the term and definition of cycle interesting.
B) I found this interesting because I have never heard of it before and it provided me a visual to better understand in Figure 3.2.
2. A) I found the information in the section A Visit to the Eye Doctor interesting.
B. I found this interesting because it could actually be useful to know when I am at the eye doctor so I can better understand and know what's going on.
3. A) I found visual crowding interesting.
B. I found this interesting because I liked the examples that were shown in Figure 3.17 especially the one pertaining to driving.
4. A) I found topographical mapping least interesting.
B) I found this least interesting because I didn't really understand the definition and I do not think that they described it enough.
5. I think that knowing the different parts and what they do in Figure 3.1 will be most useful in understanding Sensation and Perception.
6. I think that this chapter is more in depth and has more definitions about perception.
7. A) I would like to learn more about topographical mapping.
B) I would like to learn more about this because I do not really understand it.
8. While reading through the chapter I was thinking about they eye doctor and how things in this chapter pertained to going there.
9. Terms: Cycle, Visual Crowding, Topographical Mapping, Perception
1. The first thing I found interesting was cortical magnification. This is a term that refers to the amount brain space is used to focus on a specific point in one’s visual field. When an object, such as a face, is “imaged” on or around the fovea, parts of the face nearer to the fovea take up more of the striate cortex. In contrast, parts of the face imaged further from the fovea take up less of the striate cortex. I find this interesting because it seems a little cartoonish to imagine an image on your brain, which is distorted based on which section you focus on. Focusing on a 1 inch point in your visual field would make that part take up a much larger section of the striate cortex. It does make sense, however. You need more brain-power to see in greater detail, which takes a considerable amount more work than blankly staring off into the distance.
2. The second topic I found interesting was columns and hypercolumns. I think it is absolutely fascinating that the neurons in the striate cortex are so organized. Neurons organize themselves first into columns of other similarly stimulated neurons of one eye, and then into hypercolumns of similarly stimulated columns, but for the other eye. The simple fact that that happens is amazing to me.
3. The last topic I found interesting was the girl with cataracts and her resulting amblyopia, or lazy eye. I found this interesting because I find the process of development in any area quite neat. It is strange to me that if a living thing doesn’t use particular neurons enough during the “critical period,” then those neurons won’t ever serve much use. If her cataracts hadn’t been addressed in time, then the amblyopia would never have really been fixed.
4. In all honestly, I couldn’t pay proper attention too much before the Striate Cortex section of the chapter. It all seemed mathematical and dull to me. I understand the lure behind that area; the concept of understanding the process behind seeing patterns and such is interesting. However, the actual content held little interest for me.
5) I believe that understanding the terminology and overlying concepts of spatial vision is most useful in understanding sensation and perception. If you understand those, you have a basic idea that you can build upon in order to understand areas you may have more interest in.
6) This builds on chapter 2 similarly to how chapter 2 (vision) built upon the very basics of chapter 1. Chapter 3 offers a more focused view of a part of vision that chapter 2 prepared us for. For example, you must first study mammals in general before focusing on a dog, which is a very specific mammal. From that point, you can study certain breeds of dog, then a single dog, and so on.
7. I want to learn more about amblyopia. This is because while I was reading this section I thought a great deal of my brother who has amblyopia. I never really thought much about it until recently, when it affects his ability to enlist in the military. In his case, his amblyopia is permanent because of his refusal to wear the eye patch. Now, he gets by okay without it. In fact, he is an amazing shot with any type of gun you give him. He has learned to compensate the terrible vision in his one eye to the point he has sniper-like skills. He is even a better shot than my dad, who has been sharpening his skills for the Air-Force for 21 years. Despite this, the amblyopia could still keep him from enlisting. Now, I would like to know what else could be done, or if my brothers skill with aim is typical.
Terms: cortical magnification; visual field; fovea; striate cortex; columns; hypercolumns; neurons; amblyopia; critical period; retina
Chapter 3:
1a) What did you find interesting?
1b) Why was it interesting to you?
I found spatial frequency to be an interesting topic. The idea of seeing something differently depending on where you are seeing it from is fascinating to me. I always have wondered if others see what we see. Spatial frequency is defined as the number of grating cycles in a given unit of space.
2a) What did you find interesting?
2b) Why was it interesting to you?
I find the idea of topographical mapping to be interesting. How the book explains that each LGN layer contains a highly organized map of a complete half of the visual field, is extremely interesting to me and is a topic I would enjoy learning more about. This ordered mapping of the world onto the visual nervous system is known as topographical mapping and it provides us with a neural basis for knowing where thing are in space.
3a) What did you find interesting?
3b) Why was it interesting to you?
Visual crowding, the deleterious effect of clutter on peripheral object recognition is also interesting to me. Visual crowding is known as a problem in the periphery. Objects that can be easily identified in isolation seem indistinct and jumbled in clutter. I find this interesting because I can think of many examples of this actually happening to me. When I am driving or looking at a crowd of people it often becomes too much of a blur for me to truly focus on something as I normally would.
4a) What one (1) thing did you find the least interesting?
4b) Why wasn't it interesting to you?
One thing that I don't really find interesting throughout this chapter is all of the boring term and definitions. I feel like I learn better from the chapters who have a lot of examples and learning points; not chapters that state a bunch of terms and their biological definitions that seem way to complicated to relate to myself.
5) What did you read in the chapter that you think will be most useful to in understanding Sensation / Perception?
I believe that I could learn a lot from visual crowding and other such peripheral complications. This helps us to understand why we sometimes experience something one way and other times we experience it some other way completely different based mainly on how we are literally seeing it. How far away something is, what else is around it, how focused we are; all of these things effect how we actually perceive what we are seeing which can change the sensation we receive when seeing this particular thing.
6) How, in what ways, does this chapter relate (build on) to the previous chapters?
this chapter is mainly building off of the first part of any sensation or perception; or at least the most basic one. We must see something (or interpret it with some sort of sense) in or to feel the sensation we receive from it. Building from actually seeing it we can go on to how we perceive and feel about this.
7a) What topic would you like to learn more about?
7b) Why?
I thought the idea of visual crowding was pretty interesting, I also would like to learn more about both strabismus and anisometropia. I find any type of condition that can affect us and change the way we see the world to be interesting. Having knowledge on these subjects can never hurt; it can only help you be more prepared and knowledgeable about ourselves and our bodies.
8) What ideas related to what you were reading (what did you think about) did you have while reading the chapter?
This type of reading and the examples given with the chapter always make me appreciate what I do have; it makes me think of all of the people who have developed the conditions described in the examples and what they go through. Because of this I like to understand the conditions more; understand how other people perceive the world around them due to conditions they can't often help or change.
9) Once you are done with your post make list of the terms and terminology you used in your post.
Terms: contrast sensitivity function, visual crowding, peripheral vision, lateral geniculate nuclei, ganglion cells, topography, magnification, visual cortex, geniculate nucleus, sensation, perception, strabismus, anisometropia.
1. I thought it was interesting to be able to do a fast but not terribly accurate visual acuity test. I took off my glasses to do the test, I thought I was prepared for the bad results but I was still very shocked at how bad my vision is. I could barely make out the orientation of the line at less than half a meter away from the textbook. It was also interesting to be able to calculate my resolution acuity on my own. I found this interesting because for the longest time of my life I couldn’t understand how eye doctors come up with the numbers, and decided that I needed new prescription for glasses. I used to ask eye doctors what those numbers meant, they usually said “it meant that your vision is getting worse.” It is nice to know where the numbers come from and what they actually mean. With that said, doctors should educate their patients more effectively.
2. I also found the paragraphs about striate cortex interesting. Figure 3.14 helped me understand the text better. It was interesting to see how the visual field of both eyes crosses and everything flip horizontally and vertically when the image reaches the striate cortex. The journey an image has to go through before reaching the striate cortex is also fascinating, and contrary to the common beliefs that the images we see directly gets delivered to our brain in a straight line. Lastly, I didn’t know that information is scaled from different parts of the field and receive different treatment – objects closer to the fovea gets more attention from the striate cortex and objects further away from the fovea gets significantly less portion of the striate cortex. It was interesting learning about cortical magnification, because although I knew the images closer to the fovea is clearer than the peripheral vision, but I always thought it was because I don’t pay attention to the peripheral vision, not because the cortical representation of the fovea is greatly magnified compared to the cortical representation of peripheral vision.
3. I found the story of Jane interesting because it showed the importance of early detection and treatment, as well as how fast our brain can adapt to new information. Within a month of inserting the artificial lens, Jane’s left eye had begun to catch up with the acuity in her right eye. And what’s more fascinating is that there are cases that shown improvement shortly after corrective measures have been taken, showing us the capability of the brain’s plasticity.
4. I found the section about the lateral geniculate nucleus less interesting because I had a harder time understanding the concept, and it made the following sections more difficult to grasp. But as I did some research on google and had a better idea of what it was, this chapter became easier to understand. Most of this chapter is very heavy and requires more effort than the previous ones. I had to search a lot of concepts online for easier definitions. This chapter is definitely the hardest so far.
5. I think topography and magnification are important, but I am not so sure how important they are. We’ve only been discussing mostly biological (boring) concepts so far, so I am not quite sure which part is the most important part in understanding S&P. I think topography and magnification are important because they help us perceive what we perceive – if the brain is the judge then they are the prosecutor, they decide what to send to the brain through a series of filtering.
6. This chapter explains the visual system in more details than the previous chapter. It uses what we’ve learned in the previous chapter to explain more concepts in more details, and breaks each concepts into smaller pieces and provides more information on how the visual system works together. This chapter shows us that we don’t just see what we see. The images we see are actually being filtered and passed on from one part of the system to the other.
7. I would like to learn more about the different abnormalities of the visual system that can cause impaired visual as a result, as well as the treatments available to repair the damage. It would also be interesting to learn about any viruses that attack the visual system, and with treatment one can regain their vision. I watch the TV show House and there is one episode where this virus makes people blind but the brain thinks it can still see, so the person thinks they can still see but they are actually blind. I think I will do some research on that.
8. I thought about what I wrote for question 7, the virus that attacks the brain and the visual system, leaving the person blind but thinks they can still see, as a result nothing they “see” is accurate.
9. visual system, topography, magnification, lateral geniculate nucleus, acuity, peripheral, striate cortex, fovea
1a) Tilt altereffect
1b) The tilt altereffect is the perception of tilt in a pattern based on its orientation. I thought that this was interesting because I have always enjoyed optical illusions. I find it fascinating that the brain tricks itself into seeing something that is actually not there or not occurring.
2a) Amblyopia
2b) Also known as “lazy eye,” Amblyopia is a disorder that occurs when there is a reduction of spatial vision in a healthy eye. The story of the “girl who almost couldn’t see stripes” was interesting to me but I especially found this and strabismus to be the two things that stood out most to me. I’ve never really known what “lazy eye” really was until I read this story. Jane was born with a dense cataract on one of her eyes making it very difficult for her vision to properly develop. Because the first several years (three to eight) of a human’s life are so important to this development she developed Amblyopia.
3a) Strabismus
3b) As I said earlier, I also found this interesting from the story at the end of the chapter. Jane’s amblyopia was caused by congenital cataracts but that is not the only thing that can cause that disorder. Strabismus is a condition where one eye is misaligned and, therefore, sees the world from a different angle than it should. The author talks about previous historical treatment options such as a patch over the eye. However, now there has been more research to actually teach the eye to go back into place. I found this interesting because I like applying what I have just read in the chapter to real life examples out in the world.
4a) “Oh say can you see”
4b) This chapter was really hard for me to get into. I really didn’t enjoy reading about the technicality of all the individual parts of what is happening in the brain when presented with an optical illusion.
5) I think the reading about the Striate Cortex will be the most helpful to me in later readings in this class. The information about the primary visual cortex was helpful in explaining what part of the brain receives visual information.
6) It relates to the previous chapters by talking more in depth about what we see when we process visual information. Chapter two had started on this topic, but this chapter began digging in a little deeper.
7a) Amblyopia
7b) I would like to learn more about this disorder and understand it a little better.
8) While reading the end story, I thought about our discussion in class over cataracts and what that does to one’s vision.
9) Tilt altereffect, perception, orientation, amblyopia, spatial vision, strabismus, vision, congenital cataracts, misaligned, optical illusion
I thought the concept of acuity was interesting. Eye doctors measure acuity in terms of 20/20. Where vision scientists talk about the smallest visul angle of a cycle of the grating that we can perceive. Visual angle is the angle that is formed by lines going from top to bottom of a cycle. There is a measuring process that can be used to find the visual angle of a resolution acuity.
I thought this was interesting because I’ve always heard of 20/20 vision being perfect, but I never knew that this was a measure of something called acuity. I’ve always been told by the eye doctor that I have terrible eye sight and lost by 20/20 vision forever ago. So for me it was interesting to get to learn more about why this actually happens, and what exactly “20/20” means.
I also found LGN/lateral geniculate nucleus to be interesting. The axons of retinal ganglion cells synapses in the two LGN’s. There are two bottom layers called magnocellular layers and top four layers called parvocellular layers that create the LGN. Both have different functions. Konicocellular cells are layered in order to do different jobs in processing visual information.
I thought this was all interesting because it shows how much our eyes go through in the process of receiving information. The left eye, which is also called the contralateral eye receives the information of layers 1,4, and 6 while the right eye, also known as the ipsilateral eye, receives information from the layers of 2, 3, and 5. This is just so interesting to me how we receive information from both of our eyes and yet we still end up seeing one image.
The last thing I found interesting was tilt aftereffect. Our visual system has different neurons that each perceive visual stimuli at a different angle. When our eye is tired and is presented with a stimuli that is opposite of a neutral angle, the stimuli will begin to tilt due to exhaustion.
This was really interesting to me because even when I’m dead tired exhausted, I’m not sure if I’ve ever realized that it could actually effect the image I’m seeing. I’ve always just assumed that my eyes probably need a break, but it wouldn’t effect to the degree that a stimuli would actually tilt.
To me this chapter was just not my type of reading. I’m more of about learning how we perceive different things thinking wise, not visually. So this chapter was extremely hard for me to understand and keep up with. A lot of topics like columns and hypercolumns were hard for me to grasp.
I think the most useful part would probably be about visual acuity, the striate cortex, and visual crowding. I think learning about how we perceive things visually is hard to understand, but important. These three different subjects all had to do with how we perceive things differently.
I think this chapter built on the last chapter pretty well. It followed pretty well on the last chapter since it was the anatomy of the eye. This chapter more so explained how the eye interprets things and functions.
One thing I would like to learn more on is visual crowding. I thought this concept was interesting. I’ve always wondered if we can have too much stimuli going on to the point where we can only focus on one object. Visual crowding somewhat explained this phenomenon and I’d like to learn more about it.
During this chapter I generally thought a lot about my own eyesight, and how this chapter explains how my eyes operate with bad eye sight. It explained why I don’t have 20/20 vision. It was hard to understand a lot of it, but I think from what I could get out of it I was able to relate to some of my eye problems and why my eyes are the way they are.
Terms: Acuity, cycle, visual angle, LGN, lateral geniculate nucleus, konicocellular, axons, retinal ganglion cells, synapses, magnocellular layers, parvocellular layers, contralateral eye, ipsilateral eye, tilt aftereffect, neurons, stimuli, visual system, columns, hypercolumns, adaptation, striate cortex, visual crowding, adaptation.
1. The first thing I found to be interesting was the concept right at the beginning of chapter 3 about visual acuity. I found this interesting because I always thought 20/20 vision was the best vision one could have. After reading the section about vision acuity and looking over the Snellen chart. I never knew where they constructed the idea of calling it 20/20 vision. I found it kind of cool that the reason they call it 20/20 vision (or 20/30, 20/10, or 20/15) is because that is the distance one stands away from the chart with the letters on it and then taking the size of the letters into consideration as well. I also found it interesting that the book said that most healthy young adults have “better” vision than 20/20 such as 20/15 vision. Who knew that was a thing? I sure didn’t!
2. Another thing that I found to be interesting in chapter 3 was the section about visual crowding. Our eyes do a ton of work to see both in high resolution and low resolution. Our visual system has actually evolved into seeing high resolution in the center and low resolution in our periphery. (pg. 67) When using our peripherals, visual acuity goes bad but an even bigger obstacle than this is the cluttering of objects in our peripherals known as visual crowding. I find this interesting because I always thought my peripheral vision was really good but I never actually noticed how crowded things were. Compared to my center vision, I never noticed a change in my peripherals so I was surprised when the book said “objects that can be easily identified in isolation seem indistinct and jumbled in clutter.” (pg. 67) On top of this, crowding has an effect on the ability to recognize and respond appropriately. In other words, crowding has a lot more effect on than just the eye.
3. A third concept that I found interesting was the condition of amblyopia. Reading about Jane’s experience was very interesting to me. When one is born with a dense cataract, sometimes it might not be easily noticeable. I find it interesting that there is a critical period in one’s life to have their eyes fixed. In a human’s life between 3 and 8 years, it is critical to make sure that the visual development is on track. During this period, cortical neurons are being wired to the eye and it is critical that it is done right. If this condition is left untreated then this is where amblyopia comes in place. Amblyopia is known as a lazy eye. If one tries to correct this visual problem later in life, chances are it will not be beneficial.
4. I actually found this chapter kind of overwhelming and confusing. I did not understand a lot of the sections because it all seemed to kind of jumble up together and I did not know what connected with what. All of the talk about the cells and neurons in this chapter almost put me to sleep. The amount of cells and neurons our body contains is almost unimaginable yet they all have a purpose. Although this idea may be cool or interesting to some people, I find the study of different cells and different neurons to be boring and too informative. They are complicated and I think this chapter spent too much time explaining these concepts.
5. I think that the concepts of our visual cortex and visual acuity are very useful when trying to understand sensation and perception. Knowing and understanding our vision is key when understanding sensation and perception because these two concepts are all about the individual and what they sense and perceive. Our visual cortex is made up of so many different things that allow humans to see. Understanding our abilities and different setbacks is all about sensation and perception and I do not think that you can be fully aware of our surroundings and our vision without knowing the abilities our eyes have.
6. Chapter 3 builds off a lot of what was discussed in chapter 2 because we are continuing to talk about the eyes and our visual system. Chapter 2 goes further into detail about other concepts deeper in the eye and other concepts in different places of the eye. Chapter 2 was a little more basic functioning and now in chapter 3 we are learning different functions of the eye further into detail.
7. After reading about an infant’s visual system, I have become more curious about the subject and would like to know more. Babies cannot talk so we do not know what they are thinking or what they are seeing of their surroundings. My brother and sister-in-law recently had a baby girl and my family and I always talk about how her vision continues to grow throughout her aging. We are all interested in what she can see such as colors and shapes and how far of a distance that she can see. The book touches base about this concept but I would love to learn more.
8. When reading about the inion, all I could think about was how good it feels to get neck massages. After reading this section on the striate cortex and the inion, I understand why it feels so good to rub that bump.
9. Terms: Visual acuity, Snellen chart, visual crowding, visual system, visual acuity, visual cortex, peripherals, crowding, amblyopia, cataract, cortical neurons, cells, neurons, sensation, perception, striate cortex, inion.
what is one thing you found interesting in this chapter?
One thing I found interesting was the Lateral Geniculate Nucleus I found this interesting because of the fact that it is really such a complex situation. The LGN is a structure in the midbrain that acts as the relay station with information on the way from the retina to the cortex. The LGN is a 6 layer structure, and these layers on the bottom are naturally larger than those in the top layer. The bottom two layers are the magnocellular layer and the top four are parvocellular layers. The magnocellular receives input and the Parvocellular layers process the information. As if this wasn’t enough information there is more splitting that goes on between the magnocellular layers and the parvocellular layers called the koniocellular cells. I found this particularly interesting because there are so many parts to something that looks to be so simple.
2) what is one thing you found interesting in this chapter?
The second thing that I found interesting was cortical magnification. This refers to the amount of brain space that is used to focus on a specific point in one’s visual field. When a object is “imaged” on or around the fovea, the object further from the fovea takes up less of the striate cortex. I found found this interesting because as we think about our brain we don’t often think about all the different things that it has to do at one time. There are still so many things that we don’t even know that our brain is doing and that it has been doing since before we were even born.
3) what is one thing you found interesting in this chapter?
Another thing that I found interesting was the section with simple and complex cells. I thought that this was interesting because it looks at how both eyes look and work differently. How we are able to identify edge detector and see different stripes as well . I found this interesting that even if you were just to look out in front of you and look at an object and then cover one eye you may not see the exact same object as before.
4) What is one thing you found least interesting in this chapter?
The main thing that I found to be least interesting was all of the definitions and terms. I found it very hard to just read and enjoy the chapter without having to look up each and every definition. I found that the more time I looked up the words the more I was less interested in looking at the chapter.
5) What is one thing that you read in this chapter that you think will be most useful to understanding sensation/perception?
I think that something that I will find helpful in understanding sensation and perception better will be to better understand the visual development process and how it differs in children.
6) How, in what ways does this chapter relate to the previous chapters?
This chapter is a lot like chapter two as they continue to go on about explaining the visual system and this continues to break the visual system down into many different chunks.
7) what would topic would you like to learn more about ?
I would personally like to look further into the tilt aftereffect. I personally think that the general concept is something that is interesting but I would further Like to look into the different parts related to vision.
8) what is something you were thinking about that relates to the reading.
One thing that i thought about was how long did it take someone to study the human eye, how did it all start, what made them want to study the eye?
Parvocellular layers, magnocellular layer, koniocellular cells,retina, cortex, Lateral Geniculate Nucleus. foveal, striate cortex, cortical magnification, simple and complex cells, tillt aftereffect. visual system
1A&B) It’s interesting that lower frequency gratings elicit weaker responses than do gratings with higher frequency. This is because part of the large bright bar falls on the inhibitory surround, limiting the ON retinal ganglion cells’ response. I find this interesting because it seems completely intuitive – shouldn’t large bold stripes be easier to see? When the frequency is just right, the cell’s measured response depends on the phase of the sinusoidal wave. We have plenty of ganglion cells which pass on information to the brain, and together they construct a striped image.
2A&B) I think the most interesting part of the chapter was learning about the path of neural signals to the cortex and how visual information is decoded in the visual cortex, telling us about the size, shape, orientation, color and movement of an object in the visual field. “From spots to stripes” it’s amazing to see how we can ever manage to see a clear picture, given all images start out as a collection of dots like stars in the sky.
3A&B) The multiple-spatial-frequency model of vision demonstrates how the eyes perform something similar to Fourier analysis automatically. Pattern analyzers detect different frequencies in a single image. Individual frequencies are actually individual sinusoidal waves combined in one picture, but the receptors in our eyes filter differing frequencies into groups of high and low frequencies. This is useful when looking at a scene. If we wish to notice only broad qualities of the scene, low frequency channels are relied on. Comparatively, fine details utilize high frequency channels to pick up on visual minutiae. This model shows how our eyes can recognize and sort different types of information in various situation depending on what we want to focus on.
4A) I kind of wish this book had devoted a whole chapter to vision problems, or perhaps disorders related to sensory input altogether, rather than sprinkling them here and there at the end of the chapter. The approach the authors took makes them difficult to keep straight as they have minute differences in some cases, and I’m less interested to learn about these if I know I’ll have trouble remembering them.
5) In this class, I think the neural input portions of the chapter will be most useful. Of course we need to know all about the mechanical operations of the eye, the methods of collecting visual information. But to really understand perception, we next need to know how this information is transmitted to and processed by the visual cortex.
6) This chapter builds on chapter 2 by explaining the next step in the visual process. In chapter 2 we learned that rods and cones detect separate aspects of the visual field by perceiving contrast and color. Now we are getting into the path of information to the brain, such as how different frequencies vary the response in the ON retinal ganglion cells, and how the visual cortex perceives this collective picture of responses.
7) I’d like to learn more about some of the differences in peripheral vision. Sometimes it’s difficult to follow what the chapter is describing regarding the periphery of the visual field.
8) Related to Question 7, I was wondering how the periphery is studied in the lab. It must difficult to isolate one’s vision, and it could be difficult to control the validity of testing due to biases that may be present in the test subjects.
9) Terms Used: frequency, grating, inhibitory surround, ON retinal ganglion cell, phase, sinusoidal wave, neural signal, visual cortex, multiple-spatial-frequency model of vision, pattern analyzers, frequency channels, rods, cones, periphery
I'm sorry I noticed a typo here - that should say counterintuitive in the first paragraph. As in, you might assume larger bars are easier to see
1a. The first concept in chapter three that I found interesting was the section on the development of the visual span. When research on the visual system was first becoming popular, William James hypothesized that infants were surrounded by confusion and an inability to see objects around them because their visual systems had not developed yet. Further research has suggested that James' hypothesis is incorrect. Although it is hard to assess vision in an infant it is now thought that the visual system is fairly developed at birth. Researchers use methods such as the one created by Robert Fantz to determine visual acuity in infants. Fantz discovered that if an infant is confronted with two different scenes differing in complexity, he or she will always choose to look at the more complex scene. The second popular method used to assess infant vision is visually evoked electrical potentials. Researchers measure electrical signals from the brain evoked by visual stimuli by attaching electrodes to the scalp to measure the changes in electrical activity as different visual stimuli are shown. As a result of its ability to measure an entire contrast sensitivity function in as little as ten seconds, this technique has been deemed one of the most successful yet.
b. This section interested me because it focused on the visual system of infants. I have often wondered if the ability of an infant to see a stimulus is the same as mine. It is interesting research into what parts of the visual cortex we are born with and what develops over time with neural migration and aggregation.
2a. The second section I found interesting covered the importance of normal visual development in children and the consequences of not intervening when abnormal visual experiences occur. A child must experience normal visual experiences for normal visual development to take place. Deficits in the visual system such as congenital cataracts do not allow the the retina to form clear patterns and thus results in form deprivation as well as an inability of the eyes to view the same images at the same time. Researchers Hubel and Wiesel found that monocular form deprivation resulted in massive changes in cortical physiology that caused permanent loss of spacial vision. This research and others like it found strong evidence to suggest that there is a critical period of early visual development when normal binocular visual stimulation is required for normal cortical development. For humans this critical period takes place between three and eight years of age. During this important time of plasticity, the visual development of cortical neurons is still being wired up to their specific location in each eye. If one eye is not receiving normal stimulation it is possible for an abnormal visual experience to occur. As a result the neurons that are destined to respond to that eye do not properly connect and start an abnormal wiring process that cannot be reversed after the critical period has ended.
b. I was interested in this section because I think critical periods are fascinating and informative to the general population. As with language, the visuals system has a critical period of development and the knowledge of this allows doctors and parents to make sure that children are developing at a healthy and normal rate. It also allows doctors and parents to intervene quickly if a child is off track so that the issue or deficit does not become permanent.
3a. Another section I found interesting discussed the consequences of leaving visual disturbances untreated. If congenital cataracts are left untreated during the critical period the misplaced cortical connections cannot ever be repaired. This results in amblyopia, a developmental disorder with reduced spatial vision in the eye because of an abnormal early visual experience, otherwise known as a lazy eye. As a result of the cortical connections being altered during the critical period it is not possible to receive treatment later in life, but recent studies have shown that receiving treatment during the critical period allows the cortical connections to begin to form normally within hours of the repair. Two other common disorders an cause abnormal cortical development. Strabismus occurs when there is a misalignment of the two eyes resulting in one eye that is turned and receiving a view of the world from an abnormal angle. Anisometropia occurs when the two eyes have a very different refractive errors (one is farsighted and the other is nearsighted). Both of the disorders depend on therapies such as perceptual learning to lead their patients to recovery of their normal visuals systems.
4ab. I did not find any of the reading to be uninteresting but I found the section on retinal ganglion cells and stripes to be dry and full of terms that are hard to grasp. I find it difficult to learn sufficiently from what the book says because it is hard to read and does not give effective examples. I would feel more comfortable splitting up all of the terms and addressing them separately to ensure my comprehension.
5. I think that reading about the lateral geniculate nucleus and the striate cortex will be very helpful in my understanding of Sensation and Perception. It gives information on important parts of the brain associated with the visual system and explains how they work together to allow us to perceive stimuli. Each region of the brain associated with vision holds a special function and allows me to apply these terms and parts of the brain to what I experience on a daily basis as I view stimuli around me.
6. This chapter built heavily on chapter two because it continued into greater detail of the visual system and how we perceive the stimuli around us. It covered the structures of the visual system in depth and reviewed the parts of the eye that influence what we see and our perception.
7ab. I would like to learn more about the critical period of normal visual development and visual deficits that effect development and vision of an individual for the rest of their lives. I think it is interesting and important information to learn about. It can be applied to our own lives and the new lives entering this world every minute. I enjoy furthering my knowledge when it is applicable to the real world and when it entails deficits of the human body.
8. I thought about the various different disorders not mentioned in this chapter that could cause abnormal visual development during the critical period. I am interested to learn about more and if they are able to be discovered and treated.
Terms: visual system, visual span, William James, Robert Fantz, visual acuity, visually evoked electrical potentials, electrodes, stimuli, visual cortex, migration, critical period, plasticity, cortical neurons, cortical development, amblyopia, strabismus, anisometropia, lateral geniculate nucleus, striate cortex, ganglion cells
1. I found the section on visual crowding interesting. For me it was interesting how when looking at the bulls eye the child on the left was not as easy to see immediately because of all of the signs in that same area. However when I changed my gaze then I was able to see the child. It seemed like it is the brains way of helping to keep focus. We can turn our eyes so that we then can focus in on those other things but it keeps us from getting overloaded.
2. The section about spatial frequency channel was interesting in how we use different levels to recognize different things. The low frequency would be for more general issues like how many or perhaps color. The high frequency would be to detect emotion on faces or more details. It was really fascinating how when squinting my eyes I was able to see the photo of Lincoln a little more clearly.
3. Of course the somewhat odd abnormalities like the section on amblyopia are interesting as they show just how one small thing being not right can mean huge consequences for sight. We have all known the child that wears a patch over his or her eye under glasses. I have even heard the term lazy eye, but I really never knew exactly how this occurred. During early development if one eye is not getting the normal stimulation, which in the case in the text was due to cataracts from birth then the other takes over. If corrected early the weaker eye can recover but if treated too late then treatment may have little to no effects.
4. Once again I can’t say that anything was really not interesting just overwhelming. For me this came at the very beginning of the chapter with the topic of visual acuity. This is about the perceiving the smallest spatial detail. I probably would call it my least favorite because I had to read the section several times and I still am not sure that I came away truly grasping the concept. Perhaps I will choose this topic to do further research for Wednesday’s post.
5. I think that the parts that talk about spatial frequency, and cycles per degree really pertain a lot to understanding sensation and perception. This topic tells us how we see things like lines in regards to space, color and angle. Again this topic is quite a lot to take in, but it has to do with how our vision adjusts and perceives shapes and colors.
6. Each chapter is building on how we sense the world around us, how different functions work together. Chapter three really builds on the aspects of eye function and vision that were begun in chapter two.
7. Acuity is something I would like to learn more about, simply because it is important to understanding much about how we perceive visually. It is a difficult topic and perhaps by looking further into it I can grasp the concepts from the text a little clearer.
8. First I felt very overwhelmed. I had to really take some time looking at this and the last chapter. But as I read I kept thinking about how many different things go into simple every day visual occurrences. Things I don’t think twice about, like how I may not notice things peripherally when I am focused ahead, or the colors and spaces of the stripes on someone’s shirt. It’s crazy how one small part of our senses has so many little parts to it.
Terms: visual crowding, focus, spatial frequency channels, low frequency, high frequency, amblyopia, cataracts, visual acuity, spatial detail, perception, sensation, peripheral vision
1. One thing I found interesting was the idea optometrists use different terms then the terms used by vision scientists to describe the same concept: 20/20 vision. 20/20 vision the best a person can have but most adults do just fine with 20/15 vision. Vision scientists study the size of the cycle and its relationship with the acuity. A cycle is the repetition of a pair of dark and bright bars. A cycle is measured by the visual angle (the angle subtended by an object at the retina. The Visual angle can be different from person to person because each person’s acuity is likely to be different. Herman Snellen is the mastermind of the equation used to identify why only some people have a hard time reading certain sizes of letters, which is another key part of reading: distance that person in question can identify letter divided by the distance that a person with normal vision can identify the letter. I thought it was interesting because I figured eye doctors need to learn this in school but have found a better way to measure the acuity.
2. Another thing I found interesting was how important contrast is when reading anything. Contrast is defined as the difference between an object and the background, aka the difference between the lighter and darker colors of an object. This is where spatial frequency comes into play as that is the main reason eyes can see the contrast in the image they are looking at. Spatial frequency is the number of grating cycles (the grating within a sinusoidal luminance profile – an image) in a given unit of space. Grating cycles are only visible because the eye is capable of seeing different cycles per degree as they the pairs that make up the contrast in pictures. I thought this was interesting because contrast is only seen when enough grating cycles are present, and if there are not enough grating cycles in the pictures contrast sensitivity function will not work and the difference will be invisible.
3. The third thing I found interesting was the role the inion plays in a person’s ability to see well. The inion is located on the outside of the area where the cerebral cortex receives the LGN inputs from the magnocellular axons. This area has several different names: primary visual cortex, area 17, and striate cortex. No matter what it is called, the inion has two important jobs: interpreting topography and magnification when necessary. The Topography function of the inion is important because it applies to reading how steep a hill, or stair steps for another common example, are to reading a person’s emotional state by using their eyebrows as a measure. Magnification is another important job the inion does. This process works by taking the images of objects in front of the fovea and dedicating a large portion of the striate cortex to understanding where they are in relation to the person who is seeing them(all while ignoring the nose which is always in the way). While most of the striate cortex is busy with objects in the foreground, the objects on the left and right of the vision field (aka Peripheral Vision) are monitored by a much smaller portion of the striate cortex. This system works well for us, but visual crowding is a common issue as the brain assumes that the objects in the peripheral vision are less of a threat, and therefore less important, but that is not always the case. I found this interesting because it is really cool how much processing our brain and eyes do unconsciously that didn’t know about before.
4. I didn’t find part about columns and Hypercolumns interesting because I find it hard to pay attention to ideas that are related to needles going into eyes.
5. I think the part about the inion relates most to me because I know the part of my brain processes most of the information about the visual field that I have trouble with, depth perception.
6. This chapter takes the information in the previous chapter about the basic eye structures/ differences in functions and expands on them in more detail.
7. I would like to learn about people who get concussions cause they hit the inion of their skull because that is where I hit my head when I got a conclusion in high school, and has slightly impacted my vision ever since.
8. see answers from 5 and 7.
9. optometrists , 20/20 vision, cycle, acuity, measured, visual angle, subtended , object , retina, Herman Snellen , identify, contrast, difference, lighter, darker colors , background,, spatial frequency , grating cycles , image, sinusoidal luminance profile , unit of space, visible, cycles per degree , contrast sensitivity function , invisible, inion, cerebral cortex receives , LGN inputs , magnocellular axons, primary, visual cortex, area 17, striate cortex, topography, magnification , fovea, foreground, Peripheral Vision, visual crowding , columns, Hypercolumns and depth perception.
Aliasing was interesting. Aliasing is the misperception of grating due to under sampling. The Diagram in the book demonstrated that if the photoreceptors overlapped on the stripes that the result will be greyer but if they did not overlap you would be able to perceive the stripes. I found this interesting because it made me think about what else we can’t see.
I also thought the section on 20/20 vision was interesting, it’s a little different from what I thought, it pertains to the Snellen test. The Snellen test is that vision chart they use in schools, and eye doctor’s offices to test a person’s vision. The top half of the fraction/chart is the distance at which a person can identify the letters, the bottom half of the fraction/chart is the distance at which a person with “normal’ vision can identify the letters. So the number on top is usually the one that changes to fit your particular eye sight. I understood the chart, but just learning about how it works, and the actual name for it was interesting.
Another thing I found interesting in the book was when people are asleep even if their eyes are open, they actually do not process and visual input. I found this interesting because I’ve seen movies and heard about people sleeping with their eyes open. It is a bit weird, I always wonder if they could see what was going on, or if any visual information was being processed. This chapter made sense of my question. I had to look a few things up but it mentions, in the book, how the Lateral geniculate nucleus is part of the thalamus. When you go to sleep the thalamus sleeps shuts down, so the information will go through your retinas and to your LGN but not any further.
One thing I didn’t find that interesting was the simple vs complex cells. A simple cell is a cortical neuron with clearly defined excitatory and inhibitory regions. A complex cell is a neuron whose receptive field characteristics cannot be easily predicted by mapping with spots of light. I didn’t find this interesting at all, not the biggest fan of biology.
The thing in the chapter I think is going to be most useful in understanding sensation and perception is the part of the chapter that went through how an image is processed and passed along from the retina to that striate cortex. This is something I would like to learn more about.
Terms: Aliasing, photoreceptors, Snellen test, Lateral geniculate nucleus (LGN), thalamus, retina, simple cell, complex vell, striate cortex
I found the idea of selective adaptation to be pretty interesting. I found it interesting, because as I have stated before, I am always fascinated by the ability for our brains to be "tricked" by optical illusions regardless of our awareness of the illusion. An example of this is the tilt aftereffect. This is when one looks at a series of tilted lines for a period of time and then looks at a series of straight lines only to find them to appear tilted as well. What was especially interesting about this to me was that the example in the book showed that brain tended towards more of an equilibrium rather than copying the tilt between the pictures. I would have expected the straight lines to appear to be tilted the same direction as the actual tilted lines.
Another thing I found interesting was visual crowding. I have always been impressed with the brain's ability to tune out so much of the competing visual stimuli that it is constantly bombarded with. By somewhat blending visual stimuli together in a clustered situation, not only is the brain able to focus only on what needs focusing on, it still retains the stimuli to an extent that one may still recognize a stimuli that requires a greater deal of attention. I cannot imagine how overwhelming the world would be if the brain was not able to do this.
The third thing I found interesting was the testing at eye doctors. This was interesting to me, because I never knew what the numbers (20/20, 20/30, etc.) actually meant. I also thought it was intriguing that even though we tend to label 20/20 as perfect vision, it is technically only the average. These numbers are gathered through the Snellen test, which I did not know the name of even though I'm sure everyone has taken the test at least once in their lives.
The one thing I found least interesting was, again, the discussion of anatomical/physiological structures. While this of course is of vast importance to the understanding of the psychological processes I am interested in and studying, I have never been able to make myself interested in learning about it.
Unfortunately for me and my personal interests/disinterests, the anatomical/physiological discussions will probably be most useful for me in understanding sensation/perception. One cannot truly learn how and why people are affected by their environment if one does not study the physiological reactions to said environment.
This chapter builds on previous chapters by going into more detail about how eyes work and communicate with the brain. It was very similar to chapter 2, it just went into more detail about processes that were not previously discussed.
I would like to learn more about visual crowding. Specifically, I want to know if people like soldiers or detectives can learn to somewhat overcome the blending of peripheral stimuli. We have all seen movies where the special ops agent or the detective are aware of every little detail in the room. Are they just looking around more, consciously paying more attention to their peripheral areas of vision, or have they found a way to work around visual crowding all together?
While reading this chapter, I thought mostly about how complex our visual systems are. We are constantly bombarded with a ridiculous amount of visual stimuli and are somehow able to deal with it all. I am in constant awe of how efficient and amazing the human brain is.
Terms: Selective Adaptation, Tilt Aftereffect, Visual Crowding, Snellen Test, 20/20, Peripheral Vision, Visual Stimuli
1a) What did you find interesting? 1b) Why was it interesting to you?
I found interesting the way our brain combines with the outputs from the brains computer which then produces a relevant representation of our vision. The processing path of an image processes from the eyeball to the brain. The neurons in the cerebral cortex translate the image by the ganglion cells into the beginning forms of patterns and forms. The cortex contains a lot of microcomputers that determine the orientation, width, color, and etc. This process was so interesting to me because so many variables go into our visual field. Producing and interpreting the image is a comprehensive process that ceases to amaze me. Being able to see and explain what I see is a gift that I take for granted but haven’t really being able to understand so in depth like this.
2a) What did you find interesting? 2b) Why was it interesting to you?
I also found that selective adaptation was interesting. An adaption is a reduction in response caused by prior or continuing stimulation. Does the human visual system include neurons selective for orientation, line width, direction of motion, and much more? Methods of approaching this learning about the brains process had been difficult but devised as adaptation. It is a noninvasive way of probing the brain and figuring out what we need. This topic was interesting to me because it is just like a conditioned action which was previously learned in other courses. I honestly believe that whatever the person or scientist gives the learner or tester can be conditioned to get the result on what he or she wants the outcome to be.
3a) What did you find interesting? 3b) Why was it interesting to you?
Another topic I found interesting was the development of spatial vision in infants. Over the past decades we have foubd that that visual system was not very defined at the infant stage. Nowadays we have witnessed that infants actually understand and see a lot more than we think. With cooperation of babies to stare at certain stimuli, preferential looking can be examined. But attaching electrodes, a ground and a reference point on an infants head have further developed our educational developments of scientifically examined the infants images of a nonverbal infant. This was interesting to me because my best friend just had a baby and as I was holding her certain questions came to mind. Will she remember me? Does she know what I look like? What can she see? After this chapter I am able to realize that there is a high possibility that she may remember me because her image that she sees is a lot better than I had ever thought.
4a) What one (1) thing did you find the least interesting? 4b) Why wasn't it interesting to you?
The girl who almost could see stripes was not interesting to me as much. We elaborated on the topic of cataracts a lot during class due to student information. I previously knew cataracts could be treated if caught at the early stage.
5) What did you read in the chapter that you think will be most useful to in understanding Sensation / Perception?
Sensation and perception can be hard to break down and overwhelming at times. But the most useful thing to understand is the way our brain breaks down the path of image processing. Each microcomputer in your brain produces a coherent representation of the image at hand.
6) How, in what ways, does this chapter relate (build on) to the previous chapters?
The previous chapter provided education on the basics of vision. This chapter builds on the past chapter by taking what we learned in chapter 2 a step farther. Understanding spatial vision and how we form the spots to strips, and the complex pathway of image processing is the main topic in chapter 3.
7a) What topic would you like to learn more about? 7b) Why?
I would like to learn more about adaptation. Just like conditioning, I would like to read examples and studies done by scholars that relate to adapting our vision to a certain outcome projected by the observer. This is very interesting to me because I think our minds and body, and also our vision, can be conditioned or adapted to achieve a certain goal even if its not deliberate of the examined being.
8) What ideas related to what you were reading (what did you think about) did you have while reading the chapter?
Some ideas that came to mind when reading this chapter were: do animals like dogs and cats see the same images as us? I know they have different spatial variances and see limited colors but what is so different? I also thought about my best friends baby when the chapter discussed how much babies can see when they are in the infant stage.
9) Once you are done with your post make list of the terms and terminology you used in your post.
Adaptation, spatial frequency, cortex, spatial vision
1a & b) The first part of this chapter was probably the most intriguing. I like how the author gets us involved in the reading. The visual resolution acuity test was a neat exercise to do. Measuring how far my eyes were from the book after walking backwards til I couldn't see the orientation of the lines. The next step was to walk towards the book, stopping when I could see which grating includes stripes or horizontal lines and again measuring. Although this test isn't as accurate as one performed in the doctors office, it did give me insight as to how much interpretation our eyes do. To achieve the visual angle of my resolution acuity, was done by dividing some previous data collected, averaging 1st and 2nd measurements. It was interesting to reading that this resolution acuity represents a fundament limit of spatial vision.
2a & b) The second item in this chapter I found interesting was the determination of our vision from the doctors office. I didn't know exactly what the number/number meant when see this on my prescriptions. 20/20 = good vision; 20/30 = need glasses; 20/10 = read the smallest letters on the eye chart. This method of visual acuity was developed in 1862 by an eye doctor Herman Snellen. I would not have guessed the eye exam to go back in history that far. Snellen created a set of block letters for which the letter as a whole was five times as large as the strokes that formed the letter. He then defined visual acuity as (distance at which a person can just identify the letters)/(distance at which a person with "normal" vision can just identify the letters) I also found it interesting that most young adults have 20/10 vison.
3a & b) The last item I found interesting in this chapter was the development of spatial vision. It was interesting to read how over many decades of studying infants, the research found was that babies visual system was more than just "buzzing confusion". In early as the 1960's Robert Fantz noticed that if he gave a baby a complex scene with many contours vs. a gray scene, the baby was more than likely to look at the complex scene. This gave way to a method of used by researchers preferential looking. In more recent years, technology has paved the road for helping us achieve this in babies at scientific look. Using VEP's (Visually Evoked Electrical Potentials) electrical signals from the brain that are evoked by visual stimuli, by attaching electrodes to the scalp and measuring the changes in electrical activity that are elicted by the changing visual stimulus. This technique can be done in as little as 10 seconds for a non-verbal infant.
4a &b) Honestly, I found most of this chapter difficult to comprehend. The discussion about spatial frequency, contrast sensitivity, aliasing, sine wave grating left me a very overwhelmed. I felt like it was heavily saturated with math concepts and graphs. The graphs got particularily confusing because if I don't understand the reading, I feel like an idiot when you show me a picture and I don't understand it. I got the basic information from the chapter, but I would under no circumstances feel comfortable to discuss any of the items in this chapter, no matter how many times I read the chapter.
5) I believe knowing the structures of the Lateral Geniculate Nucleus will be a key component to understand. Knowing the distinctions in each of the layers will show us that the visual system splits input from the image into different types of information. The organizations of the retinal inputs to the LGN provides important insights into how our visual world is mapped to the brain. The internal structures and cells as a whole, I believe will help me understand Sensation and Perception better.
6) This chapter explains our visual system in more detail than the previous chapter. It uses some important structures we’ve learned in the previous chapter to explain new structures in more detail. It breaks each concept into smaller pieces and provides more information on how the visual system works together. It shows that there are many components that are bound together, pieced throughout our brain and visual system and back together, almost like a circuit.
7a & b) I would like to know more about the infants visual system. I think it's very interesting the stages that infants, toddlers, and young adults go through. I would like to know more about the research methods performed in previous decades. Looking at past research methods fascinate me on how much innovativeness people had without today's technological advancements.
8) I was thinking about all the research studies, the raw information they got at the time of these findings and related them back to incorporate the brain and its structures. Even using the VEP's is a major research method used on infants that was not present in the early part of the century. I was also thinking about how these scientists came to the conclusion to gather these tests in these fashions.
9) Terms: visual resolution acuity, grating, resolution, spatial frequency, contrast sensitivity, aliasing, sine wave grating, Herman Snellen, preferential looking, Lateral Geniculate Nucleus, VEP's (Visually Evoked Electrical Potentials
1. Spatial Development- I found this interesting because infant development is the direction i'm planning on going in after graduation. I think its awesome to learn about how we develop from in the womb till adulthood. Development of the eyes and spatial skills is something I have not learned so much about.
2.Topographical Mapping. This is interesting because it explains how we see where things are. In the book is says how we see things in space. If I'm taking it in correctly I think it means it shows us how to bring everything we are seeing together in our brains making sense of where things are .
3.Visual Crowding. This is interesting because it talks about our peripheral vision. Its weird how the less things around us, the easier we can tell whats around us. If theres too much it just clumps all together and makes no sense to our peripheral vision.
4. The primary visual cortex stuff bored me. It goes into a lot of the stuff we learned in bio psych which is yes of course important and cool, but its something I did not care to read about again.
5. I think the parts about visual acuity are pretty important to continue the understanding perception. It explains deeper into spatial frequencies and how we are seeing things and the visual angles.
6. This chapter just goes more in depth about our visual field and how we see things .
7. While reading I was just curious to learn more about how we bring the things were seeing together into our brain to recognize them .
8. I would like to learn more about the topographical mapping to learn more about how we bring everything together as one.
topographical mapping, visual acuity, visual angles, depth, spatial development, visual crowding, spatial frequencies
1a) One thing that interested me was visual crowding.
1b) Visual crowding is the deleterious effect of clutter on peripherial object recgonition. I found this topic to be quite interesting because I didn't realize crowded objects seemed jumbled to the brain. I thought it was cool that our brains were able to pick out individual objects when they are cluttered.
2a) The second thing I found interesting in the chapter was the tilt affect
2b) The tilt affect was the illusion of tilt because the brain adapts to the pattern that is fitted closely together. I enjoy looking at these types of images, so learning about how our brain interprets illusions and tilts them was quite interesting to me. I didn't know that the visual system countered neurons for spacial frequency.
3a) The last thing I found quite interesting in the chapter was contrast threshold.
3b) The reason why I found this so interesting was because it shows the contrast between light and dark.
4a) I found the one thing to be least interesting was the part of the book about selective adaptation.
4b) I found this part quite hard to follow because it was very wordy and had many parts to the concept.
5) I found the optical illusion part of the book to be the most useful to the understanding of the course. This is becasue it talked about perception of how the brain interprets tilt and crowding. It also gives good hindsight to sensation of the brain.
6) This chapter relates to other chapters in the way your eyes work with your brain in order to perceive and decipher what you are seeing.
7a) I would like to learn more about tilt shift.
7b) The reason I would like to learn more about this topic is because, I would like to fully understand what makes your brain adapt to optical illusions and creates different pictures than what is perceived.
8) I really thought about the brain and how it looks at things, and the point of view it has when our eyes focus on things such as pictures. I also thought about crowding and how that works and how our eyes help work with the brain in order to see things correctly.
Terms: perception, tilt adaptation, optical illusions, brain, eyes, point of view, crowding, contrast threshold, decipher