Go to the following site and read this article: http://www-psychology.concordia.ca/fac/deAlmeida/PSYC352/Pages/Treisman-1986-Features.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 article looks at how meaningful wholes proceed parts and properties. Certain aspects of visual processing seem to be accomplished simultaneously and automatically. Other aspects of visual processing seem to depend on focused attention and are done serially or one at a time. An example would be behavioral, like visual adaptation occurs separately for different properties of a scene, like looking at a waterfall for awhile and then looking at the bank it will seem like it’s moving in the opposite direction. It shows the after-affect of the adaptation process. Segregating figure from ground can be done with seeing the boundaries between regions. For example, line orientations are important features in early visual processing but certain arrangements of conjunctions of lines are not. The example in the article is an L and a T, one doesn’t “pop out” because the lines are the same way, but a T and an angled T pop out because of the line orientation. When making errors, they reflect genuine exchanges of properties instead of simply misperceptions.
Another part of the article looked at the simple difference between a Q and an O. When the person had the extra line in the Q, the search time was independent of the number of distracters. This meant that the Q popped out of the display. The Weber law is brought up for accounting for the findings about quantitative features. That is, the ability to distinguish differences in intensity grows more acute with decreasing background intensity. Illusory conjunctions are not induced by prior knowledge and expectations. This means that illusory conjunctions seem to arise at a stage of visual processing that happens after semantic access to knowledge of familiar objects.
2.This article is saying that to separate an object from its surroundings, you see the boundaries between the regions. This is shown by the line orientation example. Detecting an object is easier when the object is unique, just like how the Q is compared to the O. Another way of detecting an object was with decreasing background intensity.
3.I liked how the article had pictures to show what it was talking about. I liked how it showed the L and T example because I could actually see that one region stuck out more than another. I understood what it was talking about because of the pictures. I also liked this article because it was a lot easier to understand than other articles. It used its experiments and examples to explain what it was trying to say and that helps a lot with understanding the material.
4. I think this is an important classic in history because it was another way of explaining how we detect objects and why certain objects are more noticeable then others. Like with the different regions being more “bright” then others, making them pop out more.
5.My textbook talks about the difference threshold, which is the smallest difference between two stimuli that a person can just detect. Also known as the just noticeable difference, has shown that the JND is larger for larger standard stimuli. This ratio ends up being constant. This has been shown to be true for most senses, as long as the stimulus intensity is not too close to the threshold.
6.Visual adaptation, Weber law, illusory conjunctions, difference threshold, just noticeable difference
1) This article focuses on how our brain processes visual stimuli consciously and unconsciously. Differing aspects of stimuli make it easier for our brain to process the stimuli, such as boundaries that pop out to us like T’s and sideways T’s. O’s and V’s also pop out to our visual system because of the distinct differences in shape. Closed boundaries are easily perceived by our eyes as well, and because of this we have a tendency to close objects even if no line is present. For instance Q’s pop out to us more so than O’s. These all occur in the preattentive stage of vision. In class we have discussed this “bottom up” technique of vision. The article also experiments with how our expectations effect what we see. We are less likely to detect things in the wrong color if told they will be in colors we would expect. Our expectations shape what we see in that we construct everything we see. It’s easier for our brains to construct what we expect to see rather than bend the rules and create something we have not experienced.
2) Our eye detects objects by breaking it down into components. Curvature and orientation are 2 features that the eye looks to when breaking objects down. The article discusses that while we see objects as a whole, our eyes place more importance on some characteristics. Our eyes can focus pick out differences and similarities in objects easily.
3) I found it interesting how many different aspects of vision the article covered. It covered how our vision perceives colors, lines, and borders. It also covered how our mind organizes some information without our knowledge and then organizes other details consciously. I think it’s very interesting how our brain can function so efficiently without any focus from the conscious mind. I also found the point the article made about how our brains can adapt to the object changing shapes easily. I had never thought about how we have no trouble identifying a flying bird as the same as a bird sitting in a tree. Even when the shape of an object changes, our brain can easily associate a differing shape with the same object. I had never thought about this concept before. If our brain struggled with identifying objects should they change shape, our lives would be much more difficult. Identifying a human moving would become unrecognizable, and facial expressions would also be difficult to comprehend if we didn’t understand it was the same person.
4) I believe this article is important because it breaks down the aspects the brain views as important when taking in stimuli. What we focus on consciously is not necessarily what is important to our brain when recognizing an object. Consciously we may focus on colors, but unconsciously shapes and orientation may be more important. This article focuses on the cues we concentrate on in making our visual determinations of an object. This is important because we can better understand how our brain works, and help to make it more efficient. We can also understand deficits in visual perceptions better, and help to cure these.
5) My textbook discusses the laws of perceptual organization. This is similar to what the article discusses because our brain uses rules to simplify stimuli. Our brain likes to sort and organize everything in our environment. We use rules for vision as well as stereotypes to sort information about people. Our brain tries to be as efficient as possible. Some of the rules discussed in my textbook are the rule of similarities, proximity, and familiarity.
Terms: curvature, orientation, visual stimuli, rule of similarity, proximity
1.) Treisman’s idea throughout the article is getting the readers to understand that our visual systems look at things as a whole and the process done to break it down whether consciously or unconsciously. This can be done by distinguishing between curvatures and line orientations. Also, the article mentioned that our visual systems understand tilted and curved lines, but not vertical or straightness. The second part of the article was focused on understanding that the visual system can determine what the target is, but gives it the wrong location. Research has found that the presence or absence of an illusion can have an impact on the time that it takes to find the objects with all the surrounding distractions. Another key point was the Hypothetical Model. This was a good illustration of how we perceive objects. First, there is a stimulus, and then it depends on the color, orientation, size, and distance, and depending on all those factors gets transmitted to another location to determine the location.
2.) The article gives us the understanding that in order to understand the images that we may be looking at we have to distinguish the different pieces of the picture. In order to do that, we must interpret where the boundaries. Some examples used in the article was the process of distinguishing between the objects in the picture by breaking them down by their orientation and their curves. One example was the use of “O” and “V”. We can see the boundaries between the two letters because our visual system can break down the orientation and the curvatures in the image.
The pictures in the article were interesting in explaining how the eye detects shapes and objects. The article stated that boundaries between objects pop out more or become more obvious when there are letters or objects going in different directions versus the same way. When the eye sees an image that has straight lines and curvatures it is also obvious where the line and curves are separate. Also, boundaries between different colors are more obvious to see. The article stated also that our visual system can interpret certain things regardless of the location of these objects.
3.) It was interesting to know and to continually learn about all the processes that play a part in our visual system. The pictures and illustrations were also interesting when talking about breaking the image down by finding the boundaries between the curvatures and the line orientations.
4.) This plays an important role in the history of perception because being able to understand all the pieces that go into our understanding of what we see. Anything that has to do with breaking down to better understand the world around us is important.
5.) My book talked a lot about the idea of Conjunction Searching. This is the idea of searching for target which is defined by a particular combination of features, each of which is also possessed by distracters. The book talks about research done which involves the observer to scan a collection of letters in order to find a particular target letter. Researchers were testing how long it took for the observers to find the target letter in the arranged 50 six letter lines. The observers began using techniques which helped their speed, but the researchers were noticing that when the target letter was an angular letter (W, Z, X) or rounder letters (O, Q, C) they were struggling more. They came to the conclusion that when a search target is different from all the other distracters by a particular feature they don’t have (ex-angled lines) this was known as a Feature Search. Whereas the only way to detect the target is to see the similar combination of features was known as a Conjunction Search.
6.) Conjunction Search, Feature Search, curvatures, boundaries, line orientation, Hypothetical Model
1) She starts off the article talking about how we perceive different objects and how we place them into our mind. Saying that we have all of these built up ideas and beliefs about how certain things are supposed to look and stand. She goes on to say that we have a distinction between two levels of processing, saying that visual processing seems to happen simultaneously. She says that people have a scheme for how certain things are supposed to look, that the visual system begins by coding a certain number of simple and useful properties in what people would call maps. Basically saying that we all look at everything a certain way its just that its complex. That everything we see is a part of the puzzle and eventually its all put on top of each other so that we are able to actually identify the object that we were looking at. She also talks about the way we see different objects or letters that some are more visual or pop out at us, and that some of the things we see are subconscious not even fully being aware that we are noticing things.
2) The article talks about how we see everything as a map and it is stacked up on top of each other. Saying that we take in every bit of information piece by piece and the final product is what is relayed to the eye. We will pick up certain colors and shapes because that is what we are used to seeing or how we want to categorize things. That is the first thing we do when we walk into an unfamiliar place we scan the room trying to find out what we recognize and can categorize piece by piece.
3) I thought the article was interesting on how she explained how we see everything. She talked about the importance of colors, shapes, and lines. But the way she referred it to as a map and we pick out each piece by piece which is eventually one piece combined. Also with how our brain is able to pick apart different shapes or sizes and we are not even fully aware of what is going on. It was an easy way to understand what she was trying to get across and still be able to keep up with the material.
4) I thought this article was important because of the depth it covers. She talks about so many different aspects from color, shapes, sizes, lines, and boarders. She goes on to talk about how our mind arranges different parts of the vision and will only send certain parts for us to see. She also talked about the importance of the subconscious and conscious mind and how that affects us. She went into a lot of detail about how we pick up different colors and how we arrange different schemes in our brain.
5) I seen above that someone talked about perceptual organization so I thought that would fit, however when I was looking through my textbook I came across a term called likelihood principle. The likelihood principle says we will perceive the object that is most likely to be the cause of our sensory stimulation. Basically saying that we will construct what we are used to or what we have seen in the past. Talking about how we organize different sets of data to be matched up with what we are used to. That is why optical illusions and camouflage are so important because it tricks our mind into not seeing things that are there. This principle is basically saying that we will perceive what ever is most likely to be in that spot at that given time, that is why camouflage is so important because if something is not supposed to be there we will overlook it with ease. I think this principle is also important in placing things in our memory and mind that we are used to seeing or dealing with, it just shows the importance of how we "map" out different visuals.
6) Camouflage, perceptual organization, likelihood principle, visual processing, categorize, and subconscious.
1) This article talks about how our brain processes vision in the conscious and unconscious. It states that we see boundaries for example T’s and V’s. We like to see boundaries that have an ending such as Q’s and often our brain will lie to us and create an ending or a boundary such as the Pac man triangle example. The article also talks about our expectations and how they affect what we see. People who were told what color they should expect to see would almost always see that. It is easier to construct what we expect to see rather than create something we have never experienced before.
2) The eye sees things in different components. The article talks about when we see things as a whole our eyes place more importance on certain things such as boundaries. Our eyes can pick out small details easily because of our complicated visual system.
3) I thought the article did a good job of covering many things about vision including colors, lines, and borders. I liked when it talked about the conscious and unconscious because it is unbelievable that our minds can function so efficiently without us even being aware of it.
4) I think this is another important window into the visual system. It tries to breakdown what we focus on when looking at an object and this is very important to our understanding of the visual system. It also gives us an idea of what we prefer to see when we look at things and how our expectations can play into what we actually see.
5) The text talks about laws of perceptual organization which goes hand in hand with the article because it talks about how we like to organize what we see and put our environment into categories. We use rules for this organization such as proximity and similarity.
6) Visual Stimuli, Proximity, Similarity,Perceptual organization, Visual System
1. This article was about how we are able to recognize things under certain situations. The Gestalt theory was emphasized in the beginning because we can more easily interpret a whole picture effortlessly and how this whole picture is what we see; we don’t just see a bunch of parts that make up the picture. The article gave many examples of how our brain perceives things and what things it perceives easier than others. One example that it gave was how a certain object (in this case a bike) could be picked out of a picture when the picture was of a natural setting rather than a bunch of parts of a picture. This goes along with the whole being different from the sum of its parts and also shows that the whole may be easier to interpret. The article also gave a few examples using letters and how sometimes certain letters (like Qs when compared to Os) stand out because they are unique and how other letters stick out because they lack closure (like Cs when compared to Os) or how some stick out because they have different line curvature (like Os and Vs). Also it gives the example that line orientation is also important in the example with the straight up and down Ts and the slanted Ts.
2. This relates to how our eye detects shapes and objects because we see them automatically and unconsciously for the most part. Sometimes we are able to tell figures apart because they just stand out to us, whether because they are colored differently than the rest of the figure, because they have different line shapes, like in the Q and O example, proximity, or because it is in its natural setting rather than a jumbled up picture. How we expect things to look also influences how we detect them.
3. I thought this article was interesting because even though I knew what they had found in regard to the time it took to distinguish an O from a group of Qs and a Q from a group of Os from their studies, I felt that I was exactly the same way. It was harder for me to pick out the O in the group of Qs because it was missing something and I had to look the picture over for longer, but when looking at the group of with a lot of Os, the Q stuck out because of its added line. I thought it was also interesting that any figure that has something added to it (like the Q compared to the O has the line going through it that the O does not) is not necessarily easier to distinguish from a group. This was shown in the O and C example, where the O was harder to tell apart from a group of Cs, even though it had more to it than the C. I wish that the examples that were meant to be in color were, or could be distinguished from each other by their shade because I think that would have helped clarify those experiments for me.
4. I think that this is an important article in the history of perception because it covers many different topics pertaining to the eye. A lot of the visual processing that our brain does happens without us even realizing it, and when we notice certain stimuli, it is a subconscious process, partly because of its own properties and partly because of the properties of its surroundings. Also it points out when our brain makes mistakes interpreting these things, that it is actually how the brain saw it and how properties were altered or switched from one thing to another and not just that it made a mistake.
5. My textbook talks about a few of the principles that the article used. One was how we use ‘natural constraints’, which are the basic, regular, properties of the environment. In a natural environment, there are abrupt changes when an object is introduced as well as shadows and other lines that help us pick out that object from the background. Another principle that my text talked about in relation to this article was the pop-out boundaries method of differentiating two objects. If the two areas contain different features (like the Q with a extra line added to the O from the article) or have different values of the same feature (in my text it gave the example of + signs and L shapes) then your brain immediately recognizes the boundary that pops out between these two.
6. Terms: Gestalt theory, Proximity, Subconscious Processes, Line Orientation, Closure, Line Curvature, Natural Constraints, Pop out Boundaries
1) This article helps us understand that our visual system looks at all parts as a whole, whether we consciously know it or not. It discusses who the effort to trace what happens to sensory data suggests that this is processed in different specialized areas. One area consists with the orientation of lines and edges, another is color, and the third is with movement. Experiments on visual search tasks were explored on the effect of exchanging the target and the distracters. The subjects were to find a target by stating that it lacks a feature in all the distracters. An example they used were the letters O and Q. The difference between the target and the distracters is that one is a circle, and the other is a circle intersected by a line segment. In another study, subjects were shown a set of three colored objects flanked on each side by a digit. Then they showed them a pointer, then a random checker board in order to wipe out any visual persistence from the initial display. They were then to name the 2 digits, and then which object the pointer designated. The sequence was too short for the subjects to focus on all three objects. Subjects made many mistakes in associating colors with shapes when they expected pairings of colors and shapes. They made fewer mistakes when they were expecting pictures and familiar objects.
2) The article states that when we see things as a whole, our focus more on boundaries than the object as a whole. We are able to depict those small details from our complicated visual system.
When we see an image that has straight lines and curved lines, it is obvious where the line and curves are separate or intersect. Boundaries that are different colors are easier to see. We notice and pick up information on colors and shapes because that is what we are used to seeing and it helps use place things into categories.
3) It is amazing how much information there is on our visual system. It seems like it never stops. The article was very helpful with the pictures and examples it gave. It’s interesting to find out that we break images down based on the boundaries of the objects and the orientation of lines and curvatures.
4) This plays an important role in the history of perception because it goes into detail about many things such as color, shapes, lines, orientation, and sizes. It is referred to as a ‘map’ because we pick out little pieces of information unconsciously.
5) My book talks about the gestalt theory (I think I have mentioned this 4 times so far in my blog posts). Going more into detail, color helps with perceptual organization, which is the process by which small elements become grouped perceptually into larger objects. This can also be done by the lightness of objects (achromatic colors).
6) Perceptual organization, visual system, achromatic, line orientation, boundaries, line curvature, gestalt theory
1. This article talked about how aftereffects, boundaries, distracters, and expectations effect how we perceive images. This article relates to what we have been talking about image construction. Aftereffects are when something is carried over form one image to another. My example is after I play Guitar Hero to long and then look away from the TV the motion of the notes moving carries over and it looks like the wall is moving. Boundaries are explained in an example in the text of the letter T shown in rows next to the letter T that is tilted. We see a boundary between the letters when really they are next to each other. Distracters are what I found to be most interesting. When looking at a bunch of circle some closed and one opened the closed circles are a distracter from the open one. They draw your attention away from the different one. Expectations were also mentioned in the reading. When we expect to see a certain thing and are shown something completely different we perceive it slower and differently because it wasn’t expected.
2. This article relates to how the eyes detect shapes because this article discussed things that get in the way or help to determine images. The very beginning of the article talked about three stages to seeing an image. First we see lines, dots, edges, and colors. Second we see the surface and volume. Then thirdly we see the identification of the object. We recall the name and what it is from our memory.
3. I found distracters to be the most interesting part. When I think of the examples they gave in this reading I relate it to an I Spy book. In the book you are told to find a specific object or multiple objects and it’s in a mess of other distracter objects. The objects might not be related at all but they are there to distract you from what you are looking for. Not only are distracters an important aspect but when there is an absence of something it’s a distracter as well as when there are multiple like in the I Spy books. In the real world camouflage could be considered a distracter.
4. I think this is a good article because it talks about different aspects of perception from an expectation point of view. Aftereffects are what we were seeing, boundaries are imaginary lines we put in place, and distracters are a distraction from what we want to see.
5. The text gives the example of an aftereffect with a waterfall example. When you look at a waterfall for some time and then look at a hill it appears that the hill is moving. The text also discusses induced movement. This is where you are sitting in your car and the car next to you begins to move and you feel you are the one moving and they are sitting still. Normally the larger image or car is inducing the perception of movement.
6. Aftereffects, boundaries, distracters, expectations, perception, object construction, induced movement, and identification.
1) This article is about conscious and subconscious stimuli that our visual system picks up on. There are things that are easy for our visual system to pick up on which would be the conscious stimuli, this stimuli has distinct shapes that stick out to our visual system and makes it easier to process, for example, closed boundaries are easily processed like O’s. This article also talks about wholes and parts. We see things that are whole easier than we see things that are parts. This goes with Gestalt approach that we have discussed in class, which states, that we see things as wholes, and will place parts together in order to make them whole. This article also states that what we expect to see changes what we actually see. We know this because of the examples we have seen in class. An example you gave to us was the video of the kids playing ball in white T-shirts when we are told to focus on the kids in the white t-shirts we don’t see the monkey in the room, but when you focus on the kids in the dark shirt you can spot the monkey. The article describes these things as illusory conjunctions which are influenced by what we expect and what we already know.
2) This article relates to how the eye detects shapes and objects, because it describes subconscious stimuli and conscious stimuli. Things that we can detect easier than other things and how what we see might differ because of what we expect to see, or previous knowledge about a stimulus. Depending on what we know about the specific stimuli it can change things such as color and size and parts of the whole. This article focuses on how we detect and decipher stimulus.
3) What I found most interesting about this article was when they talked about how our visual system organizes what we see constantly and it does this without us knowing that we are actually processing information. Our visual system is almost like a book, it has a lot of knowledge about stimulus that it has already seen, and that it knows things about and it uses its knowledge and the curvatures lines and colors to help us decipher what we see. Not all dogs look alike, some are big, some are small, and they are all different colors. Yet, we still recognize dogs even if it is a breed we have never seen before; we will recognize it as a dog. We don’t do this consciously we do this without even knowing we are processing information.
4) This article plays an important part in Sensation and Perception history, because it emphasizes how we visualize things and that process. There are subconscious processes that our visual systems go through that we aren’t aware of and that help us recognize objects.
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, and how we process visual stimulus.
6) Terms: Curvatures, gestalt approach, conscious stimuli, subconscious stimuli.
1) The article by Treisman was aimed to get the reader to understand how our visual system processes information and how construction of objects work. I also feel the article conveys that whole objects can be broken down into parts in order for our visual system to process the information. Our visual systems have two levels of processing that work automatically/simultaneously at a very high speed. Through a series of visual identification experiments, our researchers explain and provide evidence on how our visual systems work. The researchers concluded that our visual processing starts with coding of information about what we are looking at. Whatever we look at has characteristics that our brain processes and stores for reference like a file cabinet. Past experience of seeing objects allows the associations of objects to coded and stored. After the information is stored in our brains, the specific information needed is retrieved and is compared to what we are looking at so our visual construction can start breaking down the whole object into parts. Our systems have rules of construction such as, separating ground from figure, color/shade and identifying lines/ gaps. The mentioned rules (and others) help us recognize, identify and pick out the smaller parts of the whole. Our attention dictates what specific information is needed to construct/retrieve all information about what we are looking at. The author compared attention to a moving spotlight that highlights objects. During attention/focus of an object our brains pull all information associated so we can recognize and interact with the environment the object is in. Depending on the object’s importance in the environment, our conscious awareness dictates how we react to that object. If inconsistencies/illusions occur, our old “files” are changed based on the new experience and the replacement of information is continuous.
2)The article mentioned that our visual systems process information in states of conscious and subconscious. Depending on our own past experiences/expectations we interpret objects through the eye just like we process the information. Our eye breaks down what we see into small parts that are recorded, analyzed and replaced (as necessary) just like how our brains process information. The first part of the article talked about how our eyes start the identification process. The first part identifies the object’s shallow characteristics; such as color, shape and lines. The second part identifies medium characteristics; such as texture, depth and size. The last part would identify the deep information; such as what the object is, if it can harm us and all past experiences with the object. Just as the article speculated how we process the information; our eyes see in the same way.
3)What I found interesting about this article was how they explained the speeds of identification in the experiments. I started to think about the order, preference and speed of how I can pick out aspects of objects. I spent about 20min looking around my room at objects and pictures and paid attention to the order and speed of my recognition. I was delighted to realize that I jumped from colors, shades and lines to the size and depth of objects in my room. The recognition of the objects happened so instantly I did not realize it until I stopped spacing off and proceeded to finish this assignment. I also liked how the article broke down the technical findings into common references; I found the article easier to understand.
4)The article gave a lot of information on the visual system that was credible and easy to understand. I feel it also gives a good understanding and explanation of the conscious and unconscious processes we all take for granted. The model the author provided at the end of the article gave a good visual on how we recognize and identify objects in our visual world.
5) The text mentioned the rules we use to construct and recognize objects in our environment. Like the article the text referred to the categorical recognition as a way we process our visual information.
1) In this article Treisman discusses how our minds do not automatically detect colors, edges, movements, or distances. We automatically recognize objects in an organized and coherent framework. The purpose of this article is to show that meaningful wholes seem to precede parts and properties. Meaningful wholes in the visual world depend on complex processes. We automatically process objects from scenes into assembled objects. Treisman talks about how aspects of processing are focused on attention and are done one at a time. Our minds are able to look at objects and automatically recognize and categorize these objects, especially when using past experiences with seeing these objects. Our minds automatically pick out small pieces of objects and automatically put these pieces together to form an object without having to tell it to. It is an automatic response. Our minds use information already processed to do this. The information is already there, it is just retrieved from our minds.
2.) This article discusses how this recognition is both conscious and subconscious. When something is already stored in our mind, it is not necessary for us to take any effort to remember what something is. We automatically retrieve certain information such as recognizing certain objects based on our past experiences. Our eyes recognize shapes, sizes, colors, depths and distances automatically. When all this information is recognized and interpreted our puts it all together and identifies the object.
3) I found the beginning of this article the most interesting. How Treisman uses going to a brand new city for an example of object recognition like the Gestault Approach. She says even though it is a brand new place and we may have never seen anything in it before, our minds are able to use past experiences in order to recognize the ojbects such as buildings. Our mind first recognizes shapes, colors, textures, and distances and then puts all this information together in order to recognize the objects. We recognize objects by subconsciously breaking it down in to smaller pieces in order to get the full picture.
4)I think this is important for the history of visual perception because this concept is never changing. It is a constant concept which never will change. Our visual intelligence and visual perception will always work this way and our minds will continue to break things into smaller pieces before it recognizes the full object. I think this will never change.
5)Terms: Gestault Approach, depth, visual recognition, depth perception, textures, visual processing
1) The article was about how we code for properties when assessing a visual scene. The article illustrated how features such as line curvature, differences in shape and color act as signals for interpretation. As shown by the Q and O differentiation task, comprehension of these features is influenced by our attention and selection. According to this article, we have “object files” where we store the coding necessary to interpret visual stimuli. These files create a recognition network, and new visual information creates a new file.
2) The present article relates to how the eye detects shapes and objects through the explanations of the model for our visual system. This model is similar (if incomplete) to the rules that make complex vision a universal phenomenon (the model in this article reminds me of a mind map – and in essence is a mind map of the author’s current understanding of the visual system). As stated above, the article describes how we go about the process of comprehending incoming visual input, and the factors that influence our interpretations.
3) Some things I found interesting about this article include the visual illustrations and corresponding description of the concepts in the study. The model was also interesting because it represents an attempt to understand the concepts that are incorporated into the rules of our Hoffman Visual Intelligence reader.
4) This article shows the development of our understanding of the minds way of categorizing and structuring visual information according to certain heuristics. The terms used in the classics article are different, but the concepts are similar to what we have been learning, and what we have been learning represents the most current understanding of the visual sense. Therefore; this article represents an important contribution to current-day understanding at the time.
5) The textbook I have talks about Gestalt Laws of Perceptual Organization. These rules “specify how we organize small parts into wholes” (Goldstein, 2007). We simplify things as much as possible, according to the law of simplicity, and then we group similar things together with the law of simplicity. We group things together when they are moving in the same direction according to the law of meaningfulness or familiarity, and their nearness influences these groupings.
6) Coding for properties, presence of features signal, attention and selection, object file, perceptual organization, law of simplicity, law of similarity, meaningfulness or familiarity.
1) The article is about how we process various features and combine them during object recognition. Treisman here demonstrates the famous ‘pop-out’ effect of visual psychology. Treisman manipulated different features of basic shapes and letters in order to find out which features were more easily recognized as unique. In one experiment she had a screen with a bunch of ‘Q’s’ and on ‘O’, and measured how long it took them to find the 1 odd ‘O’ in the set. She also tested the opposite by placing 1 ‘Q’ amidst a sea of ‘O’s’. She found that when searching for a ‘Q’ participants took the same amount of time to find it regardless of how many O’s were present. However, when searching for an O the more Q’s there were the longer it took them to find the O. This mean’s that the line segment of a Q causes it to ‘pop-out’ from the rest of the images but the lack of the line does not pop-out. Following along with this idea she did another of other experiments to find out what features ‘pop-out’. Amongst them were color, size, contrast, tilt, curvature, and line ends.
What she found was that ‘Building blocks of vision appear to be simple properties that characterize local elements….but not the relations among them” (p 119). This coincides with what we have been learning all semester, not surprising since it’s a classic. Visual processing takes place in stages which become more complex and require more cognitive effort the higher up you go. We are programmed to ‘see’ certain basic features of our environment almost automatically, a kind of pre-processing. Changes like those Treisman found to pop-out are often good indicators of danger. A new color, incredibly large or small items, contrast, tilt (is that tree branch very sturdy?), and certainly line ends (a cliff face perhaps?) are all good things to be able to recognize without much cognitive effort.
2) One important set of experiments she performed examined higher level recognition when several features were combined. They originally tested this by placing an odd item on a screen and asking the participant to locate where the object was. With basic feature changes they saw the item but could not always tell where it was. They new, for example, that one of the items was red, but were not exactly sure where on the screen they had seen it. Evidence for what she had already proved. However, when she instead changed just how the features were combined recognition of the item and its location were dependant on one another. For example, a blue O or a red X amongst red O’s and blue X’s. In this way O’s, X’s, and the colors red and blue are the same, but how they are combined is changed.
So how does the eye detect shapes and objects? First, we are programmed to see certain basic features. We then use prior knowledge, contextual cues, and our own attention to scan the visual scene and combine other features to get a full picture of what’s in front of us.
3) One experiment was particularly interesting to me because it so well explains a large part of what she’s doing here. They showed an elongated orange triangle, a filled in blue ellipse, and a black ring to various spectators followed by a mask with an arrow indicating what item they were supposed to report about. When the items were referred to as a carrot, a lake, and a tire (familiar objects) they made far fewer mistakes in reporting the color than if they referred to as a triangle, elipse, and a ring. One idea is that if you flash a blue carrot, orange lake, and black tire then ask for information about the carrot, they should be more likely to use prior information and miscall the carrot as orange when one of the other items was orange, than when neither of the other two items was orange. This was not the case however, which indicated that these “illusory conjunctions” take place during a stage of processing not linked with prior knowledge.
4) The pop-out effect is a very important phenomena in visual psychology. It is a great way to really demonstrate that some aspects of vision happen automatically, yet that even these automatic visual cues are governed by strict rules. As she mentions in the opening paragraph it seems that ’meaningful wholes precedes recognition of parts and properties’. Although this seems to be the case it is not to say that complex processes do not lie behind this feeling. This is a classic because it points out such an important aspect of visual psychology. Just because something appears simple, passive, effortless, and automatic, does not mean that it is.
5) The text explains that attention is important in vision to help ’bind’ all of the features we recognize (color, shape, size, etc.) into a cohesive world. Without this binding we may see the world as does someone with total visual agnosia, a complete inability to put together all the various parts of the visual world. Teisman and Gelade (1980) helped develop the “Feature Integration Theory” which states that feature recognition happens during a preattentive phase (they pop-out) and then during the later focused attention stage the features are ’bound’ together.
In the research article we read a lot about ’illusory conjunctions’ which is what happens when features from two different objects are switched. E.g. a red circle and green triangle are identified as a green circle and a red triangle. This indicates that feature recognition has happened, but attention was not sufficient to bind them all together.
Another important tool put forth in this article and discussed in the text is the idea of conjunctive searches. A conjunctive search is a search which requires you to find more than one feature in an object to distinguish it from the rest. Imagine all vertical green lines with one horizontal green (or any other color) line, and being asked to find the horizontal green line. Only one feature, namely horizontalness, needs to be found to distinguish the object. However imagine a combination of horizontal red lines and vertical green lines. Now when finding a horizontal green line you must search for two features; a conjunctive search.
6) features, pop-out effect, pre-processing, illusory conjunctions, the binding problem, feature integration theory, preattentive phase, focused attention stage, conjunctive search.