Please read the following article:
http://www.uni.edu/~maclino/sp/pdfs/Julesz_1965.pdf
After reading the article please discuss:
1) What was the article about and how does it relate to the material we discussed so far in class?
2) How does the article relate to how the eye detects shapes and objects?
3) What did you find interesting about this article?
4) Why do you think makes it an important classic in the history of perception?
5) What does your text say about the material covered in the article?
6) Make a list of the terms and concepts you used in this post.
Let me know if you have any questions,
--Dr. M
1) This study attempts to remove familiarity cues in visual perception, and see how perception of objects is changed. The study generated random dots in differing colors, and also in differing shades of grey. If the same dots are changed to a different color, but left in the same pattern it changes the texture of the image. The spatial separation also creates depth when we view an image, and so 2 images can be the same but viewed differently. This relates to class because we have been learning about how our brain constructs what we see. Our brain takes the stimuli in from our visual senses, and then constructs the image.
2) I think the article focuses on how our eye is pulled towards clusters of objects. Depth perception by our visual system is based on many different cues. Monocular vision isn’t required for depth perception. Our eyes and brain also make sense of these images in a very short time. It doesn’t need a lot of time to study the image, but this process happens automatically. It’s believed that depth perception happens in the central nervous system after the image from the left and right retinas are transferred to a common nerve path.
3) I didn’t find this article very interesting at all. I prefer research articles which are broken up into an introduction, participants, methods, results, and discussion section. It organizes the article more clearly, and makes looking for particular information easier. I did find it interesting how quickly our eyes perceive depth and patterns. This all happens literally within milliseconds of viewing an object. Our brain is a professional at making sense of the world we see.
4) I think that this article is a classic because it attempts to make sense of how we see depth and texture when we view the world. It tries to see how our eyes view patterns and what cues it uses to distinguish textures and depth. I referenced my textbook to fully understand the point Julesz was trying to make, but even my textbook referenced him and his work on texture segregation. Apparently he was the first to explore how we view things in groups based on textures, and what cues change how we view textures.
5) My textbook discusses texture segregation which is done when there is a perceptual separation of fields with different perceived textures. Texture segregation occurs because the components have different orientations, or if the components have different line crossings. It is believed that this happens at a preattentive stage of processing. Textons or primitives for object perception and texture segregation must be present or texture segregation will not occur.
Terms: depth, texture, central nervous system, retina, texture segregation, textons
1. This article was about how the eye can detect differences in visual patterns without cues. The paper starts with the example of a picture of colorful dots. It then talks about how those colors are perceived. It then shows the patterns without color in different shades. This topic relates to our class because we have been discussing object construction, color construction, and cues. This paper discusses pattern construction.
2. This article relates to how the eye detects shapes when it explains discrimination. The paper discusses ease of discrimination, spontaneous discrimination and nonspontaneous discrimination as well as cluster identification and noise. Ease of discrimination is where the eye determines if there are recognized clusters. Spontaneous discrimination is when the eye determines a pattern that is less likely to be seen. The paper shows some images to better understand. Nonspontaneous discrimination is explained through the example of a picture of seven letter words. The left half is actual words and the right half is clusters of seven letters. From a distance the entire picture looks like words. The eye sees it as a pattern and not different words unless you look specifically at one of the seven letter clusters. Noise was also mentioned in this article. When you think of the word noise you think of sound. In this case noise means distraction. When looking at a specific area the surrounding imagery is noise.
3. Honestly I thought this article was full of jargon and hard to follow. I like to read the articles that are broken into methods, results etc. They are easier to follow and look through all of the other information that's presented. In this article I did understand that the eye puts together patterns just like it constructs images and colors. I think the best example was the image of the seven letter word. When I was looking at the article I really thought it was all word. I then zoomed in and saw my eyes were wrong.
4. I think this is an important article because it does give examples of how the eye sees patterns. The other examples we have read about the eye and brain constructing images and colors didn’t talk about patterns. This article does a thorough job of explaining that. It’s just a bit hard to understand the first time through.
5. My text talks about spontaneous looking preferences in infants. In an experiment visual stimuli was presented to an infant and the researchers looked to see what stimuli the infant would look at. They found that infants rather look at objects with contours rather than a gray field. The child was intrigued with the patterns and didn’t care to look at the plain colored stimuli. They also found that when a familiar stimulus and a novel stimulus are presented the infant will look at the novel stimulus.
6. Visual patterns, cues, perceived, object construction, color construction, discrimination, spontaneous discrimination, nonspontaneous discrimination, clusters, noise, spontaneous looking, and stimuli.
1.This article looks at concerns that Gestalt theories have wondered about. One problem looked at is why under certain conditions an outline drawing is seen as a whole and in other conditions it is seen as different parts. The author used random dot patterns that were generated by a computer to prove her perception points. Texture discrimination is mentioned saying that the discrimination of the colored dots depends on the way the colors are paired. Ease of discrimination within patterns of different brightness depends on whether they form clusters. The article also mentions clusters and how our visual system when presented with complex patterns whenever possible detects clusters and evaluates only a few of their simple properties. The example it gives is an image with seven letter words, the left side made up of words in the English dictionary and the half had scrambled words. The non words would form clusters that could not be discriminated spontaneously from the English words.
The second half of the article also used random dot patterns that were generated by a computer. When looking at the patterns, someone would get a sensation of depth when the two patterns were viewed stereoscopically. This relates to our talk about camouflage in class; it proves that a camouflaged object can be perceived in depth even when the camouflage is perfect.
2.First, the camouflage example says that we detect objects with our sense of depth perception. Depth perception has to occur at some point in the central nervous system after the images have been projected onto the retinas. Also, the random dot pairs don’t contain recognizable shapes, some similar patterns can be perceived in the two fields and these might serve as the basis for fusion.
3.I thought the stereoscopic images were interesting because if the images are viewed with a prism held in front of one eye then it makes the image have depth with a part seen floating above the background. I also thought it was neat how it shows to make a prism and that it allows us to be able to see these stereoscopic images on our own.
4.I think this is important because it helps explain the Gestalt effect. We can perceive simple lines and curves as detailed images. It also explains how our brain interprets these images into something much more complex; especially with the use of depth perception.
5.My textbook presents information from Bela Julesz who proposed that the primitives for object perception are units called textons. He shows their existence by presenting displays, which create texture segregation. Texture segregation is the perceptual separation of fields with different textures. It occurs because the components have different orientations. The preattentive stage of vision happens rapidly and automatically, so texture formation happens almost instantaneously.
6.Textons, texture segregation, preattentive stage, texture discrimination, stereoscopically, camouflage, central nervous system, retina
1) The study showed images of random dots in different colors, shades, and textures. If the same dots transition to a different color from one side to the next (left in the same pattern) it changes the texture seen in the image. The author questions how certain conditions can make a unified whole, but in others are individual parts. This topic relates to our class because we have been discussing object construction, color construction, and cues.This relates to class because we have been learning about how our brain constructs what we see. Our brain takes the stimuli in from our visual senses, and then constructs the image. This study stresses a lot about the Gestalt theory.
2)This article focuses on how our eye is geared towards clusters within objects and colors. There are many different cues within our depth perception. It discusses how the eye detects shapes and colors through spontaneous discrimination and non-spontaneous discrimination. Spontaneous discrimination is described by an illustration in the paper; there are 2 fields of pattern, both contain black, gray, and white dots with equal first order, or overall probability. If viewed from a distance both images seem uniformly grey, in close range, it is easy to distinguish between the two. Non-spontaneous discrimination is defined in an example with letters. This can be successful only by someone who knows the difference between english worlds and random sequences of letters. In this demonstration, discrimination requires a particular kind of pattern recognition.
3) I felt distorted and confused reading this article. There was good information, but it was clustered in with many examples and no 'real' definitions. It was hard for me to define spontaneous/nonspontaneous discrimination because of the examples used. It made sense with the images, but when trying to define it, I could only give the examples. I wish this was setup like a research article (lit review, method, experiment, results, discussion). I am not sure how they would go about this, but it seems like it would have been easier for me to understand.
4) This article expanded the thought of the Gestalt Principles. It went into depth with depth perception between colors, shapes, and shades. When I learned about the Gestalt Principles in history and systems of psych, it only dealt with the object alone, nothing to do with color or shade.
5) My text discusses how disparity creates stereopsis, which shows that we perceive depth when two slightly displaced views are presented to the left and the right eyes (ie: 3-D glasses). The text mentions Julesz and random-dot patterns, and showed that subjects can perceive depth in displays that contain no depth information other than disparity. The Correspondence Problem asks "how does the visual system match the parts of the images in the left and right eyes that correspond to one another?" A possible answer is that the visual system may match the images on the left and right retinas on the bases of the specific features of the objects.
6) Depth, spontaneous discrimination, nonspontaneous discrimination, object construction, color construction, shade perception, retina, texture, cues, visual patterns, random-dot stereogram
.This article looks at concerns that Gestalt theories have wondered about. One thing was why an outline drawing is seen as a whole sometimes and in parts at others. The author used random dot patterns that were generated by a computer to prove her perception points. It talks about texture discrimination saying that discrimination of the colored dots depends on the way the colors are paired and whether or not they form clusters. It also talks about when we see complex patterns we try to detect clusters and evaluate only a few of their simple properties. The example it gives is an image with seven letter words, the left side made up of words found in the dictionary and the half had scrambled words. The non words would form clusters that could not be discriminated regular words.
The next part of the article also used random dot patterns. When looking at the patterns, someone would see depth when the two patterns were viewed stereoscopically. This relates to camouflage because it proves that a camouflaged object can be perceived in depth even when the camouflage is perfect.
2)This article talks mostly about how the eye is geared towards clusters within objects and colors. It talks about how the eye detects shapes and colors through spontaneous discrimination and non-spontaneous discrimination. Spontaneous discrimination is an illustration in the paper; there are 2 fields of pattern, both contain black, gray, and white dots equally. If you see it from a distance both images seem grey, in close range, it is easy to see the difference between the two. Non-spontaneous discrimination is talked about in an example with letters. In this one discrimination requires a particular kind of pattern recognition.
3) I didn't find this to be as interesting as I hoped. I thought it was really confusing and unorganized in a way. If it had been set up more like a research article and had more experimental exampkes that were easier to understand than these it would have been better.
4)I think it is important to the Gestalt theories. It explains how we see objects and colors and how we organize things with our vision.
5)The Correspondence Problem is mentioned in the text in relation to this idea. It also mentions Julesz and random-dot patterns, and showed that subjects can perceive depth in displays that contain no depth information other than disparity. It also says that disparity create stereopis which causes us to see two slightly different pictures with each eye to create the one that our brain says we see.
6)Camouflage, Stereopis, Correspondence Problem, Gestalt Theories, Discriminative Stimulus, Non Discriminative Stimulus, Depth
1) The Bela Julesz (1965) article was about texture discrimination. The author writes that he/she hopes to contribute to the Gestaltian experiments in a new way, using computers to alter the images in order to see id subjects can discriminate between parts. The author uses colored dots, varied patterns, and letter which are either random or form words.
I think perhaps, that this article best relates to visual construction as it relates to figure and ground heuristics (that it is unlikely that two adjacent objects would have the same contours and line up perfectly), the theory of unconscious inference (unconscious assumptions that we make about the environment) and perhaps the content of this article relates to how motion helps us to discriminate parts – where using our “optic array” movement allows us to distinguish and differentiate objects as we move about in our environment (E.B. Goldstein, 2007).
2) As we have learned, the visual system is an expert constructor, and is able to rapidly detect differences between visual inputs. The article relates to discovering how we do this, and the researcher seems to be attempting to learn the threshold for just noticeable differences in ways that the existing research had not yet touched upon.
3) I really struggled to read through this article and construct important meaning from it. I am not sure if it the way the author presents the material, or if it because the verbiage and concepts, as presented, are so far over my head that my mind was tuning out. The most I can say, with all due respect, is “pretty colors” - which is more a comment on my comprehension than on the material itself.
4) I think that this article may be important to the history of perception because it allows really intelligent, well-educated people to understand the research that shows how we differentiate between color, shade, and texture – and then explain it to the rest of us. I apologize, as I really did feel inadequate for understanding this one, but I would love to learn more about what this article means in a class discussion in the future, if possible.
5) Gestalt, unconscious inference, optic array, figure and ground, motion construction.
1) This article is about our visual mechanisms. Julesz did this study in hopes to dissociate the primitive mechanisms of perception from the more complex ones that depend on lifelong learned habits of recognition, and to figure out the extent to which one can perceive differences in visual patterns when all familiar cues are removed. He asked two questions that have puzzled Gestalt theorists for years: 1) can two unfamiliar objects connected n space be discriminated solely by differences in their surface texture? 2) Can two unfamiliar objects with identical surface texture be discriminated solely on the basis of their separation in space? He was looking at texture and at the separation of space to understand the complex and simple terms of how we decipher objects and why we either put them together as a whole or break them into parts. This article relates to the things we have been discussing in class. We have looked at Gestalt approach, camouflage, and constructing visual perceptions and this has to do with all three of these things. Gestalt approach emphasize that we perceive objects as well organized “wholes” rather than separated, isolated parts, and this article was trying to get to the bottom of why our visual system does this. Gestalt theory also goes along with camouflage and how we view things as parts, camouflage is almost like the dot examples they used in this study.
2) I think this article has an emphasis on depth perception and how our visual system picks up depth perception by lots of different cues. The process to how our eyes detect depth and images is amazing we don’t even realize that our visual system is processing this because it all happens so fast. We think that what we see is somewhat concrete, but we construct what we see. This article focuses on how we construct what we see and what visual cues we pick up on and use to construct what we see, and if those visual cues enhance what we see our don’t see.
3) This article was a little hard to read, but the underlying concepts of this article were very interesting. The thing that stood out to me and what I found extremely interesting was the goal of this study, to find out how to separate complex mechanisms from our primitive mechanisms and what these cues are that cause us to see what we see.
4) I think this is a very important article in the history of sensation and perception, because it explains how our brain and visual system interpret images and how things can be interpreted differently by just changing one small thing about the image. This article focuses more on a Gestalt Approach which is very interesting in helping explain and comprehend more about Gestalt Approach.
5) The book talks about the Gestalt Approach according to the text, emphasizes that we perceive objects as well organized “wholes” rather than separated, isolated parts. This goes along perfectly with the article and the goal of the study trying to understand why we see what we see. My text also talks about Bela Julesz which states that Julesz fixed the problem with stereoscopic pictures that they often incorporate pictorial depth cues in addition to binocular disparity by developing random dot stereograms in which neither of the images made any sense when viewed alone. So, no pictorial distance cues are present in the random dot stereogram which showed only stereoposis can explain the apparent depth that emerges when the two images are fused together.
6) Terms: Gestalt Approach, stereoscopic, pictorial depth cues, camouflage, visual perception, visual cues, primitive mechanisms, complex mechanisms.
1) The article starts off talking about how we perceive differences in visual patterns when all familiar cues are removed. He was trying to look at the differences our eyes had when looking at an outline of an object compared to when it was filled in. The article goes on to talk about the importance that certain colors have on each other when trying to make a match for camouflage. It talks about the different types of discrimination that camouflage can have and how it can play tricks on your eye. The way that it relates to the material in class is how our eye can lie to us and tries to show us things that are not there a lot of the time. It goes back to the argument you presented in your lecture last week talking about a short women in the background compared to a giant in the front. Our eye will naturally try to make up the difference and tell us what is going on when really it isn't the truth. The article that we had to read talks about the importance that different types of shade, color, and even patterns make on the human eye. The article talks about the importance the dots of each part of camouflage make and how we will perceive some things to be farther back when in reality the are not.
2) This article talks about the importance of our eye and how we try to place everything where we think it should be. Camouflage plays an important role because it is able to mess with our depth perception and we are not able to see things that are really there. Our eyes and brain are very good about predicting where something might be based off of past events. For example last week when we only saw the front of a chair and the back was covered up by a wall, we were all able to tell what it was and what the back of the chair actually looked like with out ever even seeing it. Above someone talked about where we actually develop depth perception in the brain and its important because it is supposedly suppose to happen in the central nervous system. Its here after images are sent that you are able to tell how far away a certain object is, even though in some instances we are trying to make up for what really isnt there.
3) What I got out of the article was how important different dots and shades of dots can be to a persons eye. Just by having a certain pattern you will not be able to see what is actually going on, along with the different shades that you put above or below the pattern of dots is just as important. In the article it talks about how you can hide some colors based off the color that is in the background, which is why understanding this is so important to people that are wearing camouflage. I would have never thought that there was this much importance on camouflage but it is very important to the people that are wearing it.
4) This article is very important to how we see and perceive different objects. Camouflage has been around for years and been an important role in winning different battles that we have had to fight. Its important in so many ways from wars to trying to hunt and feed your family. This one concept has helped provide food for people that are hungry and comfort for people that are wearing it. Its all about perception and whether we see what is really going on, and this one concept is something that we have been taking advantage of for years.
5) I think a major way that my reader related the material to this article was talking about the importance of movement and perceiving movement. The first thing it talks about is how movement attracts our attention, this is way camouflage has been so important for so many year because we are trying to hide from people or animals that we don't want to see us. It goes on to talk about how movement helps us build how large the object is that is moving and also helps us tell the difference from the ground and the thing that is moving telling us how far away it really is. Perception and movement are very important because of all the things you are able to tell from one simple movement by a person or animal. My reader talks a lot about the information that you are able to obtain just by seeing something move. That is way camouflage is so important to so many different animals and humans.
6) Depth perception, perceive, visual patters, cues, nervous system
1.This article was about the Gestalt theory and how our brain constructs depth perception, and methods used to study visual discrimination. To discriminate visual textures and depth, the object does not need to have a form and people can perceive an object's depth and texture without even realizing that they are doing this. To demonstrate this, the author of the article came up with a few different random dot displays. In some of these examples, our brain can easily distinguish that the samples are different, based on the amount of a certain color of hue, clusters of similar dots, frequency of dots, sharpness... Also, if you viewed some of these random dot samples with a prism, you would see part of the image being in front of the rest. Depth perception is discussed at happening after the image hits each of the retinas and meets back together in a neural pathway. I also thought that it was interesting that at times we can perceive depth ambiguously and images on a 2D surface can appear as having depth, or we can also see them as not having depth.
2. This article relates to how the eye sees shapes and objects in terms of depth and texture and how we perceive them by patterns and clusters that we see. When we look at things we either discriminate two things or we group them together. I’m really glad that it had the pictures to explain what the article was trying to convey because just by reading the article, I would have been really lost.
3. I thought one image that the author gave that was titled ‘Effect of Noise’ was very interesting. In the image on the left, my brain was able to make sense of it, and I could see a pattern. The image on the right was the same, but instead of having just a thin solid grey line on every fifth horizontal and vertical row, the grey was replaced by random black or white dots. After this was done, the image didn’t even appear to really have a pattern anymore. This emphasizes the need for similarity in the pattern, proximity, and the grid pattern that the speaker today touched on a little bit. Having the grids makes the pattern so much easier to make sense of. Also, the example with the 7 letter word/letter clusters I thought was interesting because it was kind of the opposite of a lot of the other examples that were given. Instead of at first glance seeing that the images were different and then later realizing that they were in fact pretty similar this example looked pretty consistent with itself until you looked very closely at it and then realized that on one half there were English words and on the other half was nonsense
4. This is an important article in the history of perception because it changed what was known about depth perception at the time. Prior to this article, the knowledge on depth perception was that the individual needed to be able to recognize familiar shapes and also to distinguish the texture. By using just random dot samples, there was no familiarity in the image, by depth and texture were still able to be identified. Also, this article does a pretty good job on emphasizing Gestalt theory and some of its principles, like similarity, proximity, and seeing things as a whole rather than just its parts and vice versa.
5. My text actually talked about the random-dot stereograms and it said basically what the article said but in a little easier way to understand. According to the text, these stereoscopic images of random dot samples showed that people can perceive depth when there is actually no depth information available except for disparity. Disparity can be created when a section of the sample is shifted. When our retinas receive this information, we perceive that the image has depth. The text also goes into how this information is transported from our retinas to our brain. Once the retinas receive this information, it is responded to by the binocular depth cells (aka disparity detectors) which are stimulated and give the brain the perception of depth.
6.Terms: Gestalt theory, depth perception, visual discrimination, texture, retina, binocular depth cells
1.) The article related to a lot of the topics that we have been reading about in class. One was the topic of camouflage and how the eye may or may not see these differences. The article also talks about Gestalt Theory as well as brightness and texture and how important that comes into play when looking at am image. When it comes to texture, the image may look the same, but when placed side by side and magnetized, the two images are a lot different than what we may think. The article also discussed the idea that objects that are separated allow us to see depth within the image. An example the author uses in the article that I thought was very interesting and something that most people can relate to. He talked about if you needed to replace a section of wallpaper, but the store did not have the original style, but a similar one. You may not be able to tell much of a difference, but if one were to sit down and study the two prints, they would see lots of differences. This example relates to another topic covered in the article. The author talks about clusters and how when we see them our visual system tries to break down the parts, but can only interpret a few of what makes up the cluster, therefore we are not seeing all the details that make up the entire image.
2.) Spontaneous Discrimination is occurs when there is almost two sized dots in one image. Nonspontaneous Discrimination is when the image has the same texture and granules. IN the article you can see the left half of the image actually having words and the other half having letters put together, but when you look at the whole image it looks like words throughout the whole image. Cluster Identification involves an image full of clusters. When you break the clusters down you begin to see that the clusters are in fact very different. The article also discusses the effect of noise in images. Images that show patterns have little details that are different from the rest of the image. The example in the article was that the image was full of patterns of an S shape, but every fifth line had a gray line running through the image.
3.) The most interesting thing about this reading was the pictures and how there are these almost invisible details running through the picture. The eye does not catch the little things that make up what some pictures are all about. But other than that, I didn’t really like it. The thing that I didn’t like about this article particularly was the fact that there was nothing clear cut and full of information. I don’t think that the article broke down any of the terms either. But I did like the pictures. A couple of the clusters that showed noise in the patterns were very interesting to look at. I never thought to look closely at clusters throughout images. I always just thought that the image was the exact same throughout.
4.) This topics covered in this article make a good point for perception. There may not be people out there, like myself that knew that these images were not universally the same when broken down. The images and examples used in this particular article may not necessarily be important or life changing, but there may be certain things in the world that this may in fact be important and useful and perhaps life changing.
5.) In my text I decided to focus on the Law of Similarity. This Law is determined with the amount of brightness, color, or shape revolving the object or image. The Law of Similarity maintains the similar objects tend to be grouped together. This Law relates the clusters in the article. The similar objects stay together. In the clusters the similar objects are staying together. One example in the article talked about the cluster with the “S” going throughout the image and then every fifth line had a gray line running through the image. This would support the Law of Similarity.
6.) Gestalt Theory, depth perception, clusters, texture, brightness, camouflage, noise, Law of Similarity, Spontaneous Discrimination, Nonspontaneous Discrimination
1. This article was basically looking at the Gestalt Principles and seeing how visual texture discrimination and depth perception relate to them. In looking at the primitive mechanisms of perception, habits of recognition come into play. This ties into the different rules the reader gives us to construct objects. At the beginning, Julesz talks about different approaches that have been taken to study these theories. One approach was to add visual “noise” by presenting the stimuli for a limited time or impairing the typical conditions of viewing. Another one was to impoverish or degrade images presented to the subject. Julesz was basically interested tin twp particular things and he had two questions she wanted to answer in his research. She wondered why is it that under certain conditions, an outline drawing can be unified as a whole. Also why in other conditions, is it seen to have two or more parts? The questions she asked would be the foundation of her research. Can to unfamiliar objects connected in space be discriminated solely by difference in their surface texture? Julesz used the example that you had to get some wallpaper and you realized that you couldn’t get the exact same kind. If the pattern was nonreprestational and irregular, there might be a chance that you could in fact get a new pattern, not being discriminated from the old one when they were lying side by side. Can two unfamiliar objects with identical surface textures be discriminated solely by their separation in space? An example of this is flying at a height of thousands of feet; an observer can easily be tricked by camouflage. In answering these questions, Julesz put together a series of random dot patterns to distinguish if they were able to be discriminated. First, she wanted to test texture and depth discrimination. In random fields of colored dots, the pairing of the components is contingent on each other. Also they are created by lights that have equal subjective brightness. In observing texture and depth discrimination, objects really don’t require a form also people have the tendency to perceive different objects depth and texture without being cognizant of it. The examples show different form of discrimination one being spontaneous discrimination. This occurs even when the average field has the same tonal quality as the larger field due to the fact that the granularity of the two fields is different. In looking at the examples given, the random dot patterns were sometimes easier to construct that the examples had differences, due to the fact they had particular colors of hue, clusters that were similar, and the frequency of dots. If you look at some of the random dot samples with a prism, you construct that one part of the image is in front of the other. This leads into the depth perception segment of the article. The process used to analyze Depth perception was said to be similar to an optical range finder, in which corresponding separate images are identified first then brought into alignment. Being the last step, it needs to measure through the displacement amount and through trigonometry. These depth perception phenomena can be summed up in two points. One is that depth perception occurs at some point in the central nervous system after the images on the left/right retinas have been shown into the common neural pathway. I found the ambiguous depth effect to be quite intriguing. The figure was displayed as if we would see double vision because they lie in front or behind the eyes position of convergence, but in fact that’s not the case. The random-dot stereoscopic images didn’t contain recognizable images before actual perception in depth. This would make it impossible to perceive double images before or after fusion
2. Well this article relates in a number of ways as to how the eye detects objects and shapes. The first one I thought of was discrimination because the eye is constantly deciphering different clusters and seeing if it can recognize them. Spontaneous discrimination is determining objects and patterns that are less likely to be seen. In non spontaneous discrimination was illustrated by the figure that flipped the seven letter word. It appears to me that on the left hand side they appear to be words and on the right side they were clusters. This causes us to discriminate because we are trying to select out what the object, being the words in which we are consistently ruling out possibilities. Our eye constructs it as patterns unless we take into account the seven letter word. Also I think the eye detects objects by clustering them. Another way is by depth perception because it detects based on the left and right retinal image which sends the images to the correct neural pathways. Our brains and eyes can make snap judgments within milliseconds in which this happens unconsciously. Camouflages cause use to detect objects using depth perception as well. But the random dot patterns utilized the attributes of constructing shapes.
3.I found this article to be interesting mainly because of the curiosity that I had due to some of the things the author was saying. I liked how the illustrations really brought out the information in the text. The only thing is I wish the illustrations were on the same page as the information that I needed to get. My favorite illustration was the ambiguous depth effect because it showed exactly what I needed to see to construct the right interpretation of it. Sometime pictures say things that have a meaning, but they are totally different from the construction you came up with. I also enjoyed reading the information on the AutoMAPS. This was a computer program that compares left and right fields point by point and also subtract the brightness of each counterpoint.
4. It makes it a classic in perception because it outlines a lot of Gestalt theories in which our basic understanding of what perception really is derives from such principles. Most of our visual intelligence information and rules we use in constructing an object piggy back off of what Gestalt initially brought to the table. I don’t know if this has an effect but judging by the structure and the layout of the article it seems to be a little older which might make it a classic as well!!
5. The text pointed out some of the neurological pathways the left and right retinal images go down in analyzing the depth perception. In haptic perception, there were also some geometric properties that had to do with the recognition of objects. This ties into how Julesz mentioned how they had to do some small trigonometry to calculate some depth perception issues. It elaborated a lot on seeing and recognizing objects. It used terms like proximity similarity texture segmentation, symmetry and many others. Proximity- tendency for two features to group together will increase as distance decreases. Similarity- tendency of two features to group together will increase as similarity increases. Symmetry was defined as a rule for figure-ground assignments stating the symmetrical features are more likely to be viewed as figure.
6. Visual texture discrimination, depth perception, Visual noise, camouflage, depth discrimination, retinas, stereoscopic images, spontaneous discrimination, clusters, AutoMAPS, Gestalt, haptic perception, proximity, similarity, texture segmentation, symmetry.
1) This article discusses gestalt theories, how the eye perceives things, and how we do not necessarily need certain cues to detect differences in things such as patterns. The study that was done was focused around different random dot patterns created with different colors of dots. The study shows that when darker dots are near each other we see them as a cluster, but the opposite when lighter dots are formed together. It also discusses spontaeous discrimination. Also, the atticle talks about how breaking up an identical pattern just slightly, you can notice the difference between the two. Depth perception is also mentioned in the article and how our eyes will perceive things differently depending on how the depth is perceived.
2) The article focuses on how our eyes see depth. It also shows how our eyes tend to cluster similar things together depending on color or texture and ignore other things depending on color and texture. Our eyes also construct shapes by pairing parts of an object or pattern together, even if it's not necessarily suppose to create that shape.
3) I really didn't think that the article was all that interesting. If I had to chose something it would be the pictures shown of the different random dot examples. They better explained what the study was about and the point the article was try to get across.
4) This article is important because it discusses and breaks down the Gestalt theories. It talks about breaking down an image and realizing that they are almost the same besides minor details or rearranging. it's important because this method can be used in different situations in the real world.
5) My textbook also talks about gestalt theories and depth perception. The Gestalt laws are discussed and how perception is affect by these. The book also gives different photo examples of these laws.The text discusses how we connect cues with depth. We see the world in three dimensions and there are three cues that help us do this. The three cues are oculomotor (deal with position of our eyes and tension in our eye muscles),monocular ( cues from one eye), and binocular (cues from two eyes).
6) Gestalt, depth perception, spontaneous discrimination, patterns
1) The article was about how we perceive texture and depth, specifically in the absence of more common visual cues like familiarity of the object, and standard color and border cues. He mentions two research questions that were at the center of his research. 1- can two unfamiliar objects connected in space be distinguished solely by their differences in surface texture, and 2- can two unfamiliar objects with the same surface texture be distinguished solely by their differences in space. He relates these questions to real life by having you imagine that you need to try and match a new type of wall-paper to an existing one (the old one having gone out of business, e.g.) and also that you are an airplane pilot trying to locate a military outpost that has camouflage netting strung across the roof’s of the buildings. These two research questions and the real-life examples demonstrate how this material relates to our current work.
Much of sensation and perception is about figuring out what rules our brains use to construct our perception out of our sensations. In this article Julez is trying to do that regarding texture and depth. Our ‘perceptual intelligence’ is so seamless that it is often very difficult to find out what the rules are, and it takes sophisticated research techniques like the ones Julez uses here to find out what’s really going on (or better, that something IS ‘going on’).
2) So far we’ve learned a number of rules for how our visual intelligence constructs lines, part boundaries, and then whole objects. Julez is very interested in studying sort automatic or ‘spontaneous’ discriminations in the perception of texture. I assume this is what we now refer to as the ‘pop-out’ effect. He was interested in this because this shows a sort ‘preprocessing’ of information that underlies other more complex cognitive tasks inherent in visual perception.
In VI we’ve read about a number of basic rules of visual perception most importantly being the rule of generic views, and that we assume sensations in 2D to be identical to their 3D counterpart. In this article we see a few of the primitive rules which no doubt helped Hoffman in writing VI. For example, he demonstrated the phenomena of cluster identification and various effects of ‘noise’ on textures. In essence Julez demonstrated that several of the more common gestalt principles are at work even in unfamiliar and seemingly random visual scenes, which helps to better explain what is going on when we construct the images. A small change in distribution of color or hue can create a huge change in how the overall image is perceived even if probability distributions remain the same. Hoffman repeatedly made reference to the fact that a ‘photometer’ would not recognize a difference but we do; here a photometer might recognize the same overall brightness or consistency yet we see distinct patterns.
3) Although I think I just barely understood them, the stereoscopic experiments were the most interesting to me. He mentions that his research helped to demonstrate that one common hypothesis regarding binocular vision was ‘demolished’. That idea is that since our eyes are separated each eye sees a slightly different view of what’s in front of us, so we have to sort of fuse or add these two images together to get a 3D image. He mentions that this makes depth perception even more mysterious than before, since we can recognize depth even with incredibly brief exposure times such that our eyes do not have time to move and thus create these ‘fused’ images. In the end he gives ideas for a possible computer system that would be able to detect these stereoscopic disruptions that would obviously be useful for detecting camouflaged objects.
4)- One demarcation of a ‘classic’ work is its range of applicability. The work Julez has done here is able to account for a wide variety of phenomena. He mentions over and over that his work demonstrates an underlying mechanism in our visual system, and that connectivity detection is even more fundamental than recognition of form. Similar to this feature, a classic should also bring together a lot of previous research and focus it down creating a more parsimonious theory or explanation. Here Julez basically ‘creates’ the ideas of cluster identification, connectivity detection, and a much better understanding of stereoscopic image construction.
5) The text does a much better job of explaining Julez’s research in my opinion. I get now that Julez was using a machine to present one picture to the left eye and one to the right, the fact that these stereoscopic images helped to create the ‘floating square’ demonstrates that this binocular disparity alone creates the impression of depth. This fact led to the development of the ‘correspondance problem’, given that the left and right visual fields have differing images how does the brain create a correspondence between them? The common answer to this problems is the one which Julez claimed to help “demolish.” Without Julez’s experiments the answer would be obvious, there are all sorts of visual cues which help us add the two pictures together, mostly involving the common gestalt principles; e.g. when an object is occluded in one visual scene we know what should be there (because we recognize the object as a window, car, etc.) so we construct the occluding object to be in front of the occluded object. Julez demonstrated the same effect however in the absence of any common visual cues with random assortments of dots.
6) texture, depth, spontaneous discrimination, pop-out effect, photometer, stereoscopic, cluster identification, connectivity detection, correspondence problem