What I would like you to do is to find a topic from the chapter you read for Monday that you were interested in and search the internet for material on that topic. You might, for example, find people who are doing research on the topic, you might find web pages that discuss the topic, you might find youtube clips that demonstrate something related to the topic, etc. What you find and use is pretty much up to you at this point. But use at least 3 sources.
Once
you have completed your search and explorations, I would like you to
say what your topic is, how exactly it fits into the chapter, and why
you are interested in it. Next, I would like you to take the information
you found related to your topic, integrate/synthesize it, and then
write about it. At the end, please include working URLs for the three
websites.
Once you are done with your post make list of the terms and terminology you used in your post.
Let me know if you have any questions.
For my topical blog I decided to do some more looking into Balint’s Syndrome. This disorder is very uncommon and not completely understood. Essentially, this is a severe impairment of a triad of neuropsychological regions; the inability to perceive the visual field as a whole, difficulty fixating the eyes on a certain area, and the inability to move the hand to a specific object by using vision. This syndrome was named in 1909 by the Austro-Hungarian neurologist Rezso Balint, who was the first person to identify it.
Balint’s syndrome occurs most often with an acute onset as a consequence of two or more strokes at more or less the same place in each hemisphere. The most frequent cause is said to be some sudden and severe hypotension, resulting in bilateral infration of the occipito-parietal region. More progressive symptoms of this disease have been found in degenerative disorders such as Alzheimer’s or other traumatic brain injuries that border the parietal and occipital lobes of the brain. It is cautioned that a lack of awareness of this syndrome may lead to a misdiagnosis and resulting in inadequate or unneeded treatment.
Simultanagnosia is the inability to perceive simultaneous events or objects in one’s visual field. This spatial disorder of visual attention has been referred to as a constriction of the individual’s global gestalt window or their visual window of attention. People with this defective attribute have a hard time retaining attention to a large scene and have a restricted window of fixation. Some studies show that patients with simultanagnosia have an extreme issue with competition between objects, this therefore, makes it difficult to disengage from one object and move onto another.
Ocular apraxia is a another debilitating issue that is associated with Balint’s syndrome. This is the inability to carry out familiar movements when asked to do so. People affected with this are ready and willing to carry out such commands but are unable to physically perform the task. Balint referred to this as the “psychic paralysis of gaze”, the inability to voluntarily guide movements, changing to a new location of visual fixation. The most frequent and disabling deficit of this syndrome is the neglect that manifests itself as a spatial representation and attention on the same side as the lesion. There is no single test or factor that can be used to diagnose apraxia.
Optic ataxia is the inability to guide the hand toward an object using visual information. This is characterized by an impaired bisual control of the direction of arm-reaching to a visual target, accompanied by defective orientation and grip formation. Essentially it takes patients longer to reach for an object and their ability to grasp an object is also impaired.
The cause of Balint’s Syndrome is due to the damage to the top part of the temporal occipital lobes on both sides of the brain. Furthermore, the top part of the parietal lobes on both sides of the brain may also be affected. Since there is the possibility of a lack of awareness of the syndrome, it is important for doctors alike to be aware of the symptoms. The first initial noticing of the issue would be seen by the therapists providing rehabilitation following brain lesions. Any severe disturbance of space representation, spontaneously appearing following bilateral parietal damage, is the only strong suggestion that Balint’s Syndrome could be a possibility.
TERMS: Bilant’s Syndrome, simultanagnosia,
Good post. I like how you tied in the different symptoms of this syndrome and how they all are completely integrated. One symptom makes other functions difficult, all three together makes things really difficult.
Forgot my sources:
http://en.wikipedia.org/wiki/B%C3%A1lint%27s_syndrome
http://www.medscape.com/viewarticle/410860_5
http://www.youtube.com/watch?v=4odhSq46vtU
Neglect syndrome, or spatial neglect, is a condition in which people ignore one side of their visual field. This condition typically develops after damage, such as a stroke or a lesion, to the right parietal lobe. There have been cases of damage to the left side of the brain, but right neglect is very rare. Thus, damage to the right parietal lobe results in neglect of the left visual field, or left neglect. An important aspect to note is that in this condition, there is no damage to the visual system, the damage is only located in the brain. This is why it is defined as an attention deficit, rather than a problem with the visual process. In most cases, neglect only affects present sensation, memory and recall are in full tact, but this varies because most cases of neglect differ from one another.
As I mentioned earlier, individuals with neglect syndrome ignore objects and people one on side of their visual space. More specifically, they have difficulty paying attention to one side of the space. Attention is a selective process in the brain that is draws to novelty stimuli. Thus, neglect patients unaffected by the novelty stimuli in the neglected space. These individuals not only ignore objects and people located in the neglect side, but they also will neglect that half of their own bodies. An example of this would be if a woman with left neglect was applying makeup to her face, she would only apply the makeup to the right side of her face. She is not doing this intentionally but rather she simply does not notice the left side of her face. Another common example is when an individual only eats the food on one side of their plate. What is interesting is that if someone points out the left side of the plate, then they will attend to it and realize that they only ate half of the plate.
There are several ways to test for neglect, but the drawing test is the most common. In a drawing test, the individual with neglect is asked to draw a simple picture. The results of the picture usually indicate clearly that the individual is ignoring on side of space simple because they only draw the part of the picture that was in their visual field. However, these people will typically complete a shape that goes into the ignored field if it is a continuation of the attended field, such as a circle or a line. An example of this is when a person is asked to draw a clock. They will draw a complete circle, but only fill in the numbers on the attended side, indicating that they know that the clock is a circle because their brain fills in that information. An interesting aspect of this test is that when the person conducting the test draws the neglect patient’s attention to the side that they ignored, then they are able to see that they only drew half of the picture and they just did not notice it.
Up until this point, I have been discussing neglect of input, but there are other specific types of neglect. One type is called representation neglect and those with this condition ignore a the left side of memories, dreams and hallucinations. Thus, this is a perceptual neglect and is difficult to test. There is also output neglect, which is when a patient ignores body parts that are on the neglected side of the body. The focus of output neglect is on motor deficits. When the focus is on pre-motor deficits, then this is called pre-motor neglect or directional hypokinesia. Directional hypokinesia is when a patient can move their limbs without a problem in the left side but struggle to move their limbs once they are in the right side of their visual field.
I found this topic relevant because it specifies that the visual system can be functioning perfectly and we still might not be able to see. After researching this condition, I started to appreciate the importance of attention and how it affects every aspect of my day. If I lacked attention then I would not be able to finish writing this paper and I would not succeed in this class.
Terms: neglect, visual field, right parietal lobe, novelty stimuli, representation neglect, output neglect, directional hypokinesia.
http://www.psych.ndsu.nodak.edu/nawrot/Courses/465Projects04/Neglect/Introduction.htm
http://en.wikipedia.org/wiki/Hemispatial_neglect#Treatment
http://emedicine.medscape.com/article/1136474-overview
I think representational neglect is so bizarre. Some of the lesser extreme forms, like extinction are interesting as well.
While reading chapter 8, I found the concept of visual search to be particularly interesting because it is such a huge aspect of our daily lives. Visual search experiments give a more accurate approximation to attention in the real world, than do many other cueing experiments, especially related to reaction time. During these visual search experiments, the subject searches for a target in a display full of distractor elements. The target is the goal of the visual search. As humans we are constantly looking for specific targets in scenes and situations full of distractors, like trying to find your car in the grocery store parking lot, or looking for friends in the crowds at the Iowa State Fair. The number of items in a display or scene, called a set size, affects the difficulty in finding a desired object. The higher the number of distractors, the harder it is to find the target in a display; therefore, the longer amount of time it will take to find the target. For example, the more cars in a parking lot, the more difficult it is to find your car. It is more difficult to find your car in the Disney World parking lot than it is in the McDonald’s parking lot down the street. This is why it’s so hard to find objects in “Where’s Waldo,” “I Spy,” and crossword puzzles.
The scientific study of visual search usually makes use of simple, well-defined search items such as oriented bars or colored letters. There are ways to find targets in scenes full of distracting elements, though. Below is a link to some examples, such as searching for a letter “B” in an image full of “P”s. There are different types of visual search experiments, including feature and conjunction searches.
Feature search is the searching of a target which differs from the distractors by a unique visual feature (color, size, orientation, shape, etc). For example, an O is quickly found in a scene of “X”s, and a red target is found quickly if all the distracters are green. The reaction time results of these experiments are quick because the unique feature “pops out.” Thus, reaction time slopes are usually flat; showing the number of distractors has little effect on reaction time when the target has an easily distinguishing feature (color, size, orientation) that’s different from the distractors.
A conjunction search is the process of searching for a target that’s not defined by one unique visual feature, but a combination of two or more features. For example, the observer searches for an orange square among blue squares and orange triangles. Results tend to be slower than in a feature search because the observer must integrate the information of two visual features to locate the target, instead of one. Reaction time slopes tend to be steep because of the large effect the number of distractors has on reaction time. Researchers, Ashbridge, Walsh, and Cowers, discovered that the right parietal visual cortex is involved in conjunction searches in 1997. In 1995, researchers Corbetta, Schulman, Miezin, and Petersen, found that a part of the superior parietal cortex is activated during spatial attention shifts and visual feature conjunction searches, but not feature searches using positron emission tomography (PET).
Anne Treisman made search asymmetries into an important tool in the study of visual attention. She said, “It was easier to find a target that was defined by the presence of a pre-attentive basic feature than to find a target defined by the absence of that feature.” (1988)This answered my question of what can make it easier, thus make reaction time faster, to find specific targets among distractors I had after reading about visual search in chapter 8 of the textbook. I thought it was interesting to learn that it is easier to find an object with a unique feature, than to find a target that is lacking the feature. I enjoyed learning about the various aspects of visual search, because it is such an important part of our daily lives.
Terms: visual search, attention, cueing experiments, reaction time, distractor, target, set size, feature search, conjunction search, unique visual feature, reaction time slopes, “pop out,” right parietal visual cortex, superior parietal cortex, spatial attention shifts, positron emission tomography, search asymmetries
Sources:
http://en.wikipedia.org/wiki/Visual_search
http://en.wikipedia.org/wiki/File:VisualSearchDistractors.png
http://jn.physiology.org/content/early/2006/02/08/jn.00898.2005.full.pdf
http://www.psy.vanderbilt.edu/faculty/schall/pdfs/newsac.pdf
http://search.bwh.harvard.edu/new/pubs/IntrotoSearchAsym.pdf
Did you read anything from Jeremy Wolfe about Guided Search Theory? This is another take on Treisman's FIT. Also, check out Pylyshyn's Fingers of Instantiation theory about attention. Then of course you have the object file stuff from Khaneman and Treisman. Lots of theories about what is going on in terms of the functional role of attention.
I chose to do my topical blog on Anne Triesman’s feature integration theory because I think there is much more to it than presented in the book. It fits into the chapter because it is a theory of attention. I am interested in it because we talked about it in my cognitive psychology class and I think it would be kind of cool to learn more about it and some of the research that has been done on it.
The feature integration theory is the concept that we have “feature maps” in our head that we use to direct our attention to the most conspicuous area. For the pre-attentive stage in this theory we attend to qualities of the item such as shape, color, orientation and movement to try to identify what we are looking at. The features of color, motion, shape, ect are believed to be process in parallel, or in other words we can process multiple of these things at the same time. However some researchers believe that we can process multiple things at one time but as the number of items we are processing increases the longer it takes for us to process. This is known as the limited capacity parallel process. There is some controversy about the first stage because this all happens so quickly in our minds that it is hard to believe it actually occurs.
The second stage of the feature theory is the attentive stage where our attention is directed to one item or area at a time. We have to integrate the features to be able to perceive the object for what it is. If the object is something that we have seen before this may be less difficult if it is presented in a familiar way.
So basically we see the object, analyze different aspects of it (pre-attentive stage), and then we combine the features and focus our attention (attentive stage) we then perceive the object.
I read through one of her experiments to test this theory and I thought it was very interesting. What she did is she showed her test subjects an image with 2 black numbers and 4 colored shapes for one-fifth of a second. I think that it is cool that she controlled for the after image by placing a random dot screen after the image was presented. An Illusory conjunction occurred in this experiment. 18% of subjects reported seeing shapes made up of features from different stimuli. An illusory conjunction is where people can remember seeing the object but they have trouble remembering specific things about it like color or location of the item. Triesman says that these characteristics are “free floating so they may be incorrectly placed in perception.
Triesman did another really kind of cool experiment to demonstrate how this theory works. She showed people that they were going to see an image of a carrot, lake and a tire before she showed them anything. She then showed them a picture of an orange triangle, a blue circle and a black circle with a hole cut out of it. People did not show any illusory conjunctions this time. This shows that if the objects are familiar to the individuals they are better at perceiving them. Although, prior knowledge may be a factor here as well.
Terms- Anne Triesman, feature integration theory, feature maps, pre-attentive stage, parallel, limited capacity parallel process, attentive stage, attention, after image, illusory conjunction,
http://en.wikipedia.org/wiki/Feature_integration_theory
http://psychologicalresources.blogspot.com/2010/12/feature-integration-theory.html
http://server1.noblenet.org/merrimack/wiki/index.php/*feature_integration_theory
Good points. There is a lot of stuff that is implied from her theory. For example, we can postulate the existence of these so called feature maps, but the bigger issue, is that of the binding problem. How are these features bound together so that we have access to this complete, full, rich, phenomenological experience. Treisman would say attention is the glue binding the features together. I don't know if its that simple, but it is still a very influence model of attention.
Interesting.. I have the 3rd addition to the book so maybe my chapters are moved around a bit. I tried replying to your comment but it wouldn't let me? I read all of your comments by the way and I really enjoy and appreciate all of your feed back! I want to read that book "Island of the color blind" I think it's called. Sounds very interesting! Okay, so this blog will be on Motion Perception and I chose to further research akinetopsia, a very rare neuropsychological disorder in which a person has no perception of motion. I chose this topic because I am one to be very interested in the abnormalities of what we call what's "normal". They talked a little about it in the book. They gave us two examples of individuals who got the disease due to a side effect of an antidepressant drug. (It made me think of the commercials that are promoting a drug and they spend half the commercial talking about the weird side effects. This would be one of those weird side effects, I believe. ha.)
Other research I found on the world wide web was more cases of people who either had a stroke, or had severe "bonks" to the head. People who have akinetopsia no longer see fluid movements and apparent motion does not apply to them. They more see still frames, like snap shots of the moving object as it moves. This makes it difficult to do many simple things like pooring a glass of liquid. The person with the disorder is unable to identify how much the liquid is moving up in the cup so they are not sure when to stop pooring. Or crossing the road. An individual can see and identify the car perfectly, but to them one second they see the car far away, and the next thing they know, the car is right in front of them. This unfortunate disorder makes it impossible for a person to live a normal life. Unfortunately there is no cure or treatment for this disease.
Terms: akinetopsia, apparent motion.
http://www.youtube.com/watch?v=B47Js1MtT4w --Really interesting video!
http://jnnp.bmj.com/content/83/2/229.extract
http://kevinleung.com/archives/akinetopsia/
Right on. Glad you took advantage of some of the info. I think people like the attention stuff better than the motion stuff. I do too. Akinetopsia would be rather dehabilitating though. Imagine not knowing if a car was moving and all of a sudden it is just two feet from you as you are crossing the street. Frightening.
This week I was most interested in picture memory because it is amazing to me that there are such differences between remembering details in pictures versus remembering just scenes. As it stated in the book people can remember thousands of scenes when shown them again but are pretty much stuck on the + or – 7 when it comes to details in pictures. I wanted to know more! This topic fits into chapter 8 because the chapter discusses attention and scene perception. We have to focus on and pay attention to scenes all day long, every single day. This is a crucial part of maintaining consistency in our environment and identifying old and new information. I myself am thankful that every time I walk into the union I remember that I have been there and that I can easily get to chats the coffee shop without having to worry that my brain has completely forgotten this relevant information.
As technology advances I believe that this will become more and more difficult in relation to GPS systems. In the beginning GPS systems in the car made it possible for you to look around and take in the scenery which allowed you to pay more attention to land marks. While this may be true and continue to be important to picture memory I have also started to notice a different happening. When I turn on my GPS I can more naturally let my mind slip away, think about paper topics etc, watch the road, and not pay attention to the scenery at all. This puts very little information in the memory bank of pictures that is formed and in the instance where your GPS dies you are even more lost than you thought possible.
During my exploration I decided to do an online picture memory test. I am notoriously bad at these so I was not surprised when I only remembered 5 of the 15ish pictures. It is so weird that this happens. It seems that you would be able to remember almost all of them. I think it is interesting how you can trick your memory into remembering more if you group things together, this allowed me to remember more pictures on the next try. There was also another game that I did. Related to online games such as these is the issue that they are constantly advertising to older individuals that doing these things will improve your memory. While this may keep the memory functioning better I think it is pretty bold of these websites to preach that this will actually “improve memory,” I am not sure if that is actually possible considering all of the information we know about memory and all of the gaps in the empirical research related to the topic.
If you venture in slightly a different direction with this topic you will come across photographic memory. This feature that people claim to have is something that the media makes quite a fuss about. I myself thought at one point that I had a photographic memory because I could see images in my head. I now know that I was way off. What I learned about photographic or eidetic imagery is that it does not really exist. These people do sometimes remember more details about an image within the first few minutes but this fades after only 2 minutes. The people most likely to have eidetic imagery are small children and this special skill usually lessens after age6. It turns out that photographic memory may be someone what of a myth but on average people in general have a pretty amazing memory for pictures, maybe we should just be happy with what we have.
Terms: picture memory, scene perception, attention, photographic memory, and eidetic imagery.
http://www.msnbc.msn.com/id/6567837/
http://faculty.washington.edu/chudler/puzmatch.html
http://www.psychologytoday.com/articles/200603/the-truth-about-photographic-memory
The + or - 7 items regarding WM capacity is over estimated. The new perspective in the field is that capacity for items that we can briefly maintain (working memory) is about 3 or 4, depending on your individual item capacity (massive individual differences). The other issue becomes, what can we fit into those 3 or 4 slots for a brief period of time. Are they features? Or objects? Conjunctions? Or, can we fit more that 3 or 4 things, but the quality of the WM representation degrades as we add more "stuff" to be maintained.
This week I was most interested in picture memory because it is amazing to me that there are such differences between remembering details in pictures versus remembering just scenes. As it stated in the book people can remember thousands of scenes when shown them again but are pretty much stuck on the + or – 7 when it comes to details in pictures. I wanted to know more! This topic fits into chapter 8 because the chapter discusses attention and scene perception. We have to focus on and pay attention to scenes all day long, every single day. This is a crucial part of maintaining consistency in our environment and identifying old and new information. I myself am thankful that every time I walk into the union I remember that I have been there and that I can easily get to chats the coffee shop without having to worry that my brain has completely forgotten this relevant information.
As technology advances I believe that this will become more and more difficult in relation to GPS systems. In the beginning GPS systems in the car made it possible for you to look around and take in the scenery which allowed you to pay more attention to land marks. While this may be true and continue to be important to picture memory I have also started to notice a different happening. When I turn on my GPS I can more naturally let my mind slip away, think about paper topics etc, watch the road, and not pay attention to the scenery at all. This puts very little information in the memory bank of pictures that is formed and in the instance where your GPS dies you are even more lost than you thought possible.
During my exploration I decided to do an online picture memory test. I am notoriously bad at these so I was not surprised when I only remembered 5 of the 15ish pictures. It is so weird that this happens. It seems that you would be able to remember almost all of them. I think it is interesting how you can trick your memory into remembering more if you group things together, this allowed me to remember more pictures on the next try. There was also another game that I did. Related to online games such as these is the issue that they are constantly advertising to older individuals that doing these things will improve your memory. While this may keep the memory functioning better I think it is pretty bold of these websites to preach that this will actually “improve memory,” I am not sure if that is actually possible considering all of the information we know about memory and all of the gaps in the empirical research related to the topic.
If you venture in slightly a different direction with this topic you will come across photographic memory. This feature that people claim to have is something that the media makes quite a fuss about. I myself thought at one point that I had a photographic memory because I could see images in my head. I now know that I was way off. What I learned about photographic or eidetic imagery is that it does not really exist. These people do sometimes remember more details about an image within the first few minutes but this fades after only 2 minutes. The people most likely to have eidetic imagery are small children and this special skill usually lessens after age6. It turns out that photographic memory may be someone what of a myth but on average people in general have a pretty amazing memory for pictures, maybe we should just be happy with what we have.
Terms: picture memory, scene perception, attention, photographic memory, and eidetic imagery.
http://www.msnbc.msn.com/id/6567837/
http://faculty.washington.edu/chudler/puzmatch.html
http://www.psychologytoday.com/articles/200603/the-truth-about-photographic-memory
After reading chapter 8, I found the information on neglect to be very interesting. The book’s definition of neglect was in visual attention, the inability to attend or to respond to stimuli in the contralesional visual field (typically, neglect of the left field after right parietal damage). Also, neglect of half of the body of half of an object. I found this interesting because we always know what to do when things are working correctly but it’s interesting to learn how things can go wrong and what impacts they can have. I also believe that is how it relates to the class; we have to learn how things work and learn how they also don’t work sometimes.
Neglect usually occurs after a brain injury to the right cerebral hemisphere. Since it’s on the right side your left hand side of space is neglected (contralesional field). An example of what can happen is if someone has a stroke that affects their parietal lobe, their body wants to just completely neglect what the left side sees and the brain only thinks the right side of the visual world exists. Some things that someone with neglect might go through are not eating the left side of their plate of food, having drawings only being half completed, even ignoring that the left part of their body exists in extreme cases.
Neglect is caused by damage to the temporo-parietal junction and posterior parietal cortex. This can cause visual, auditory, proprioceptive, and olfactory domains. It causes a failure of attention to sensory input which is a sign of extinction which some say is a milder form of neglect. A person can also have problems remembering left side information and sometimes only describes the right part of information.
Treatment for neglect can vary from person to person. What doctors want to do is to find ways to bring the patient’s attention toward the left side of the visual field. Either behavioral or drug treatments are used to help with neglect. Behavioral treatments such as prismatic adaptation in which the lens is worn to pull vision to the left, constrained movement of the good limb so that a person is forced to use their left limb. There really isn’t much treatment out there for this kind of disability. Unlike most things in life that can be repaired, it’s a little harder with brain damage.
Terms- neglect, contralesional field, parietal cortex
http://emedicine.medscape.com/article/1136474-overview
http://www.scholarpedia.org/article/Hemineglect#Attempts_to_modulate_or_treat_neglect
http://en.wikipedia.org/wiki/Hemispatial_neglect
Did you read anything about representational neglect? That is pretty interesting as well. I like how you gave a few examples of some of the tasks they have neglect patients do, and how their performance on the tasks change in their functionality after damage.
After reading chapter 8 I became very interested in many of the topics that were discussed. I thought this was one of the best chapters in the book just because it relates so well to the real world. If I would have to pick one topic in chapter 8 that I would like to know more about I would choose Balint's Syndrome. I would like to know more about this disorder/ syndrome because it was only briefly mention in the chapter and it is a disorder that is very rare.
Balint’s Syndrome causes impairments to the visual, sensory and cognitive perceptions. A person with Balint’s Syndrome cannot focus or pay attention to all things that are in their visual field, they also are not able to fixate their eyes on an object, and they are not able to move their body or hand to an object by just looking at it. Balint’s Syndrome has three characteristics which are simultanagnosia, ocular apraxia, and optic ataxia.
Simultanagnosia is one of the characteristic of Balint’s Syndrome; this is when the person cannot perceive an object in their visual field. People with Balint’s Syndrome can see and perceive when one thing is in their visual field, but when it comes to multiple objects they can only focus on one thing. The multiple objects in their visual field are competing for attention and only one object wins, which is why people with Balint’s Syndrome can only perceive one object in their visual field. If there are two objects in the visual field they can only focus on one and it’s like the other is not there at all.
People with Balint’s Syndrome have ocular apraxia because they are unable to change their gaze to something different. So unlike people who have regular or not impaired visual perception people with Balint’s Syndrome cannot saccade their eyes. Their eyes may move but they cannot attend to one object. If the object moves they are unable to follow it with their gaze. This characteristic is usually worse when the person has damage to the right hemisphere of their vision, meaning they have neglect also on the right side of their visual field.
The last characteristic in Balint’s Syndrome is optic ataxia; this is when the person cannot move their hand or body to the object in their visual field. When a person is looking at an object they are unable to reach or grab the object. Because the damage is usually worse in the right hemisphere of the brain this makes it harder for the person to reach and grab with their right hand. They could find the object without looking, but it took them just as long even when they were focused on the object.
The reason that Balint’s Syndrome happens is because there is usually damage to the temporal occipital lobe. From the research that has been done there is usually damage to the right hemisphere of the brain, but people with Balint’s Syndrome usually have damage or lesions to both sides of the brain the right side just tends to be worse. The both sides of the brain that are affected is the area of the brain known as the parietal lobes. Also when Balint’s Syndrome happens it is usually because someone has suffered from more than one stroke in the same place. This is one of the reasons why the syndrome is so rare.
There is not much research on Balint’s Syndrome because it is so rare, and we are learning more and more about it when we find people that do have the syndrome. It is important that many people know about this syndrome because in many cases it can be missed diagnosed or not diagnosed at all. This is especially beneficial for therapists to know about because it usually is visible in a person when they are going through the rehabilitation stages.
Terms: Balint’s Syndrome, simultanagnosia, ocular apraxia, optic ataxia, visual perception, temporal occipital lobe, parietal lobes, neglect, saccade
http://www.medscape.com/viewarticle/410860_5
http://en.wikipedia.org/wiki/B%C3%A1lint's_syndrome
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1737727/pdf/v072p00162.pdf
http://www.medfriendly.com/balintssyndrome.php5
I like how you classified the syndrome and then went into the specific symptoms and their affect not only on cognitive functioning but also perception and attention.
I found that I would like to do some extended research regarding disorders of the visual attention. Like similar posts prior to this reflective writing assignment, I find great interest not in concepts that I come to understand based on my own experience, but those that give an insight to rare cases of a failed visual system, in this case attention disorders. Attention disorders of the visual field relate a great deal within the chapter because it adds a new perspective on how various disorders disrupt visual activity and shows us how the information people with disorders such as neglect and extinction may view things as perceptually normal, when they are in fact missing pieces of overall normal sight. When someone has a defect that is a result of damage to the visual nervous system this is known as a visual-field defect. Someone who has this severe case of impairment is categorized in a rare group. An example of a visual-field defect might include a lesion or loss in the primary visual cortex. When this happens on the right portion of the brain, the individual is suffering visually on the left half, or side, of their visual space. The parietal lobe, a key part of the brain located between the frontal and occipital lobe, is another important factor in the understanding of impairment from one side of the brain that affects the opposite side of the visual field they perceive. The first disorder of visual attention I would like to mention is neglect. Neglect is the inability to respond to stimuli in the contralesional visual field. This means that damage in the right parietal lobe is neglecting visuals of the left field. This might include seeing only half an object or image as well as the body. The contralesional field, I might also mention, is that particular side opposite of the lesion of the brain. My first URL is from a video posted by Dr. Maclin about a patient named Peggy who has fine eyesight, thought half of her visual field is being neglected. Her individual case is due to a stroke that she had experienced in the parietal lobe around ten years prior. Neglect also damages information that we store from memory. When asked to draw a daisy, she was still only able to draw the image leaving out a portion of the left hand side of the picture. This is the same exact thing that happens when attempting to redraw a picture in front of her. Peggy does in fact perceive the drawings to be fully complete, but she is unable to notice this until specifically pointed out to her. Another disorder that is similarly related to neglect in the sensation and perception of attention is characterized by the term extinction. This is the inability to perceive a stimulus to one side of a fixation point in the presence of another stimulus. The book identifies extinction as neglect in a milder form. Here is an example of how distinction and neglect differ. A person with the disorder holds an object of some sort in their hand on their good visual field and can clearly identify the object. Then they hold a new object with their other hand on the bad field (left side) and can still identify the object. Someone with neglect would not be able to determine the left side, while a person with extinction still can as long as each object is independently viewed. When holding both objects, one in each hand simultaneously, a person with extinction only conceptualizes the object in their good visual field (the right side). It might be possible to improve from extinction, though the damaged area of the brain can never be completely healed since there is no allowance for regeneration of the dead brain cells. A study by Dr Vuilleumier identified that out of stimuli, faces were the least likely to be extinct in the contralesional field. Also, there have been indications of the ability to perceive visual contours due to unconscious processing. An illusory contour is a perceived contour that nothing actually changes from one side to the other. The Kanizsa figure is a prime example of the perception of an illusory contour. The last URL shows a short reading of brain injury and shows a visual of where the parietal lobe is located, but also helps to identify the concept of neglect. I learned a lot by viewing these material and other sources on the web. It’s always interesting to learn something new that doesn’t personally affect yourself.
http://www.psychologicalscience.com/perception/2011/03/visual-neglect.html
http://en.wikipedia.org/wiki/Visual_extinction
http://www.neuroskills.com/brain-injury/parietal-lobes.php
Terms: Visual-field defect, parietal lobe, neglect, contralesional field, extinction, illusory contour.
Good points. I like that you referenced a few actual studies that have worked on this topic material.
In this chapter, I chose to look at change blindness. Change blindness is the failure to notice a change between two scenes. If the change does not later the gist, or meaning of the scene, quite large change can pass unnoticed. I was always sort of interesting in those visual search activities like “I Spy” “Where’s Waldo” and finding the target changes in images. So I may have a higher ability to detect change, but it could be average as well, but the fact remains that the topic is of interest to me.
For change blindness to really occur, the scene has to coincide with a visual disruption, much like an eye saccade, or obstruction of the scene or image. This visual perception is more dramatic when the change is unexpected. Like the experiment where two men dressed completely unalike, and exchanged places in mid-speech with a person wanting to be involved in an experiment. This indicates that just because you are looking something, doesn’t necessarily mean that you are actively paying attention to it. Another nice example of this is on one website a man did an experiment and very few people paid attention to the fact that the person they were giving directions to changed from a white man to a black man. Through it all though, when we retrieve memories from the situation the eye and brain play tricks on us once more by giving an impression of richness. This is another phenomenon that is involved with the phenomena of change blindness.
Though much of the research was started in the 1960’s and 1970’s dealing with change blindness, a lot of the assumptions on why have been disproven. In this research there’s been perhaps more findings discussing how it’s now involved in change blindness. Aside from that there’s not much that’s been made sense of in change blindness and there’s plenty of people continuing research on the topic. Then to discuss and research why some people notice the change while the majority does not. There’s still not much answer to any of those questions that are basis of research on perception of change.
Terms: change blindness, attention, perception, saccade, visual search, target
http://nivea.psycho.univ-paris5.fr/ECS/ECS-CB.html
http://psychology.wikia.com/wiki/Change_blindness
http://www.pbs.org/wgbh/nova/body/change-blindness.html
http://www.uxmag.com/articles/change-blindness
I think it would have been cool if you went into inattentional blindness as well to kind of drive home the point that these two phenomena really give us an idea of how much we "miss" despite our personal experience of feeling like we have access to everything in our external world. Good stuff about change blindness though.
After reading the text, I found the information on Balint Syndrome to be interesting. It was named after Rezso Balint who first introduced the condition in 1909. Balint Syndrome is a rare condition in which patients suffer from brain lesions that cause visual-field defects. People with this condition have a hard time perceiving the visual field as a whole (simultagnosia-only seeing one object at a time), difficulty fixatiing their eyes (ocular apraxia), and have a hard time reaching out for objects (optic ataxia). Patients suffering from this have a hard time with normal day to day activities. They have difficulty reading because they can only focus on one letter at a time, they cannot drive safetly, they have trouble putting on their shoes, and they have trouble reaching out for items. In the video clip, you will notice that when the therapist holds out a spoon, the man cannot grab it and when the therapist holds a comb and a spoon, the man can recognize both, but only has the attention for one at a time. He also has more trouble reaching things with his right hand. Having more trouble with the right hand than with the left is a common symptom as well. These symptoms can often be misdiagnoised as blindness, mental retardation, or dementia.
Balint Syndrome can be caused by having multiple strokes in the same area of the brain. People can also get Balint Syndrome from diseases like Alzheimers. Another possible cause is from having major trama to the brain in the parietal, temporal, and occipital lobes in the brain.
There is no treatment of Balint Syndrome, but their are ways to rehabilitate people with this syndrome. One technique teaches patients how to better cope with the syndrome. It helps patients utilize what they know about there vision and it shows them how to change their environment to lessen the effets. Another technique involves trying to restore the parts of the brain that are damaged. In this technique people exercise their brain by doing things such as flash cards, to try and restore what was lost.
I thought this condition was interesting because it is so bizarre. I think that eyesight is my most important sense, and with this condition my sight would be almost useless. I also wonder what constitutes "one object." How would a person suffering from Balint Syndrome be able to recognzize another person because they have so much going on with clothes, hair, glasses,etc. I can't imagine suffering from this and I feel really bad for those that do.
Terms: Balint Syndrome, simultagnosia, parietal lobe, attention, occipital lobe, temporal lobe, visual field defect
http://www.medfriendly.com/balintssyndrome.php5
http://www.youtube.com/watch?v=4odhSq46vtU
http://en.wikipedia.org/wiki/B%C3%A1lint%27s_syndrome
Good points. See above posts for feedback related to Balint's syndrome.
The concept that I chose to do further research on from chapter 8 was neglect. I am amazed at the fact that damage can be done in the brain that actually cause individuals to see things incompletely but not know it. From the videos that I have seen it even amazes the individuals who are doing this when it is finally pointed out to them. It is hard to image how this can be real, but it is and I had to learn more about it.
Neglect is a visual-field defect that in most cases is caused by damage to the right parietal lobe. A common cause of damage to this lobe is a stroke. In my research I found some very interesting data that talks about this but I will discuss that later. Since the damage is done in the right low the visual field that is affected is the left side. What this means is that individuals affected act as if that part of the world is not there. The interesting thing about this is that this may differ depending on the person. If two individuals who were affect by neglect were to view the same scene, say a room full of people they may interpret it differently. One person may completely ignore the entire left side of the room including the people. On the other hand the other individual may see every person and thing in the room but not see the left sides of any of them. It is interesting that there can even be some differences within this disorder. That difference is also a pretty big deal.
The research that I found that talked about neglect was very interesting to me but not that surprising. Research done on stroke rehabilitation states that those who suffer from visual neglect take longer to recover than those who do not. This is the case even when they are treated by specialist. This is not surprising to me because the simple fact that a whole part of their world does not exist is most likely the cause of a lot of set backs in rehab.
There are some treatments being used to help with those who suffer from neglect. The main objectives of treatments are to make the patients attention go to the left. This is a gradual process that seeks to get the patient to see more and more each time. Another common treatment that is used is by giving the patient a prism lens that pulls the patients attention to the left automatically. Treatments have had mixed results however. Neglect is a very interesting topic and something that I believe well never cease to amaze me.
Key terms: Neglect, visual field defect, parietal lobe, contralesional field,
http://en.wikipedia.org/wiki/Hemispatial_neglect
http://stroke.ahajournals.org/content/28/7/1386.full
http://www.youtube.com/watch?v=ymKvS0XsM4w
http://www.hemianopsia.net/visual-neglect/
what were some of the behavioral tasks you read about that they had the neglect patients do? How do they specifically test their deficits? Things like this are good to include as well.
The topic I had expressed an interest of learning more about was simultagnosia. This relates to are chapter because it was a visual condition that was briefly discussed in chapter 8. I found this interesting because it was something I have never heard of before. The condition seemed so odd to me, I felt the need to learn a little bit more about it.
According to wiki simultagnosia is a condition where patients can recognize objects or details in their visual field, but only one at a time. They cannot make out the scene they belong to or make out a whole image out of the details. Simultagnosia, according to wiki was discovered in 1924 by Wolpert to describe a condition where the affected individual could see individual details of a complex scene but failed to grasp the overall meaning of the image. Simultagnosia is one of the three major components of Balint’s syndrome. Simultagnosia can result from strokes, dementia, head injuries, brain infection, heredity, and other neurological disorders.
People with simultagnosia have a restricted spatial window of visual attention and cant see more than one at a time. The way it is diagnosed is they have the patient describe complex visual displays, commonly the Boston Cookie Theft picture is used. Patients that viewed this picture would explain the picture in isolated pieces. For example they would explain seeing a boy, a bench a woman, or individual objects like that, when they were asked to interpret the overall meaning of the picture. There is no cure as of right now for this disorder, but there are various different therapies that have been developed to help improve the condition.
Terms- Simultagnosia, Balint’s syndrome, dementia, and spatial window of visual attention.
http://en.wikipedia.org/wiki/Simultanagnosia
http://brain.oxfordjournals.org/content/114/4/1523.short
http://luria.ucsd.edu/Articles-by-Luria/PDFs/Luria_Disorders.Ocular.Movement.pdf
It would have been cool if you went into the Balint's syndrome and all of the symptoms associated with it. The other symptoms make it incredibly difficult to operate in the world, especially when you have simultanagnosia coupled with these other symptoms.
After reading Chapter 8, I found many topics to be very interesting however there was one that stood out to me particular, Balint syndrome. This disorder was named after neurologist Rezso Balint who first discovered it in 1909. This unfortunate syndrome is a rare condition which impairs neuropsychological impairments. This syndrome affects three things for the patient. It does not allow the patient to perceive the visual field as a whole, otherwise known as simultanagnosia. The patient has difficulties in fixating the eyes, otherwise known as ocular apraxia. The last symptom that affects the patient, is that is doesn’t allow the patient to move their hands to a specific object by using vision, or optic ataxia.
The cause of this terrible disease occurs when an individual that has acute onset of two or more strokes around the same place in each hemisphere making it extremely rare however reportable. Another cause is an individual having sudden and severe hypotension which results in bilateral borderzone infarction in the occipito-parietal region. Balint syndrome has also been found in degenerative diseases such as Alzheimer’s or any other disorders that traumatizes the brain at either the parietal or occipital lobes of the brain. Unfortunately when it comes to treatment of this disease, we are still very unclear with the definite treatment however therapy does help.
I found a very interesting video on you tube. It’s of an elderly man that is asked to grab a spoon. It’s very obvious that he has trouble trying to grab it. He reaches out and closes his hand but it’s very sad to see how confused and disappointed he looks after he was unsuccessful at grabbing the spoon. This disorder has made me extremely thankful for my health. Any one of these diseases that I have researched throughout the semester would be imperative to my every day activities. I never realized how much for granted I take my abilities to sense and perceive the world around me. Without these major functions, I wouldn’t be able to function and live/survive in a society.
Terms: Balint syndrome, neuropsyhological, simultanagnosia, ocular apraxia, optic ataxia, hyptension, bilateral borderzone infarction, occipito-parietal region, parietal, occipital lobe.
http://en.wikipedia.org/wiki/B%C3%A1lint's_syndrome
http://www.youtube.com/watch?v=4odhSq46vtU
http://www.rightdiagnosis.com/b/balints_syndrome/intro.htm
Interesting post. See other comments above for feedback on Balint's syndrome.
The portion of the book that discussed picture memory got me curious, so I decided to devote this week's topical blog to the our short-term memory visual system. Visual short-term memory is the cognitive ability to retain visual information for up to a few seconds after a visual stimulus is no longer in sight. One of the crucial aspects of this ability that we severely take for granted is that fact that our VSTM system is on overdrive…24/7/365. This is due to the fact that saccadic motion is constantly occurring with our eyes, so therefore short-term images must constantly be processed in order to give the impression of a seamless, continuous sweep of our environment whenever we are looking around. One of the studies I examined found that, though many cognitive abilities can be trained or enhanced through repetition and experience, this is not the case with our capacity for visual short-term memory. Participants in their research that were shown repeated visual displays did not display a significant increase in short-term memory ability than when they were shown non-repeated displays. In fact, though this repetition leads to long-term visual memory storage, the researchers even go as far as to say that VLTM representations do not provide much of an increased perceptual advantage beyond that which was originally established in the VSTM system!
A great deal of research in this area has been dedicated to investigating the capacity limits of VSTM. In a typical change-detection task, observers are shown two different arrays that are composed of a number of stimuli. The pair of arrays are separated by a short time interval, and participants are asked to decide if the first and second arrays are identical, or whether one of the two items is different. Much of the research I encountered proposes a theoretical “cap” on the number of objects that can be held in visual memory at one time, typically somewhere around 4 objects total. However, one alternative study suggests that the number of objects that can be held in memory is a function of not only the number of objects, but also their relative visual complexity. Yes, typically the number 4 to 5 holds up, but this all depends on how much visual information there is to be processed for each object. The more information there is for each object, the less amount of potential short-term memory storage to be had.
Digging even deeper into more contemporary research, I discovered a growing body of literature claiming that previous studies do not account for an additional memory capacity that has been termed the intermediate visual store. This system is thought to exist somewhere between iconic memory (immediate visual perception) and short-term memory, with a capacity of around 15 objects. Despite its increased capacity, the intermediate system is described as a weaker version of the VSTM because objects are much more quickly overwritten – often immediately as soon as new visual stimuli fall upon the retina.
http://www.cla.temple.edu/cnl/research/documents/s10.pdf
http://visionlab.harvard.edu/members/patrick/PDF.files/2005%20pdfs/Alvarez%26Cavanagh(2004).pdf
http://www.mendeley.com/research/v4-activity-predicts-the-strength-of-visual-shortterm-memory-representations/
Terms: visual short-term memory, visual long-term memory, saccades, intermediate visual store
First, great post. Second, you've got iconic memory (about 500 ms storage duration) which is incredibly rich and represents the visual scene infront of you. Then you have to have things in VWM and maintain them for transfer to LTM. But, the debate about capacity and what are the units of VWM, is still raging to this day. Alvarez and Cavanagh claim that it is not necessarily just that we have 4 "slots", but that we could represent a lot of information, but that as we add more, the quality or precision of that information degrades. Also, they will argue that complex objects take up more space in VWM (makes sense). BUT, on the other side, you have people like Ed Awh, Ed Vogel, and Steve Luck, who essentially think that its 4 slots, and it doesn't matter how complex an item is, it still takes up 1 slot. So, for this group, bound objects are what are stored in VWM. The thing this group has going for them is neural evidence. The CDA (ERP component) increases as you add items to a memory array, until a person reaches their capacity limit. The amplitude of this neural signal then asymptotes and there is no more of an increase in the signal with more items added to the array. This also happens to correlate with behavioral measures of VWM capacity.
I looked more at change blindness. This fits into the chapter because it looks at attention to detail and how big changes can go unnoticed even when a person has two pictures side by side. I found it interesting because even though the changes were obvious when found, every detail would have to be examined before it could be found. In my old puzzle books I could probably find over 75% of the changes but I usually missed one or two. It would get so frustrating because the pictures would look so much the same and yet it would be completely different.
I was able to find some websites that had different examples using video. With video, I found out the change blindness also works on colors. One of the examples had a picture and one element in the picture changed from green, to red, and then back to green. I was so busy trying to watch other parts of the picture at the same time that I didn’t notice the change until it went back to green but I wasn’t 100% sure that the change had really happened because I caught it so late that I didn’t see a big significance in the different colors. A couple of the examples I had to watch a couple times, and then I gave up and clicked the help button to see what I was supposed to be looking for. Other examples were able to illustrate the blinking of the eye and how because of that split-second black frame was enough to hide the chance in the reflection seen in the lake. Another showed how if you use selective attention to look for changes you will not notice the change happening between the two points of interest. My all-time favorite was the YouTube video (I’m putting it as a separate link so that it is easy to find). It reminded me a lot of the video with the gorilla, except I did even worse on this small ‘test’. I was able to find 1.5 (one for sure and then the other one I knew something was off but I couldn’t put my finger on it for sure) out of the 21 changes that happened. I also love it because I can show it to some of the older girls that I babysit and they will be able to understand it and enjoy it the way I did. I already showed them how to find their blind spot so I need something different to keep them occupied.
http://cognitrn.psych.indiana.edu/CogsciSoftware/ChangeBlindness/
http://nivea.psycho.univ-paris5.fr/#CB
video - http://www.youtube.com/watch?v=ubNF9QNEQLA
Terms: change blindness, attention, selective attention, and blind spot.
See other change blindness posts for comments.
The relationship between attention and memory intrigues me, and since it is related to the chapter this week I researched this topic. The relationship between these two constructs is very interesting in the fact that they are heavily dependent upon one another. Memory is structured upon what you sense, and so attention would heavily influence what becomes retained in your memory. On the other hand, attention is guided by memory and experience. How would you know how to duck in response from an incoming golf ball if your memory didn’t store information about what the situation is and the consequences of you action (or inaction). The relationship is much like M.C. Esher’s work of art of two hands drawing each other into existence.
However, the relationship seems even deeper than that. Attention is very diligent in the maintenance of working memory. As discussed in previous lectures, the brain actually fills in a lot of perception (color in peripheral view is one example). However, the brain would like these representations of reality to be as accurate as possible, and so attention helps maintain these mental assumptions. The result of this is a more accurate and rich perception, which in turn leads to a more accurate and rich memory.
Also, attention acts as a “gate-keeper” for memory. Since constantly memorizing all stimuli would be enormously taxing on the brain, attention selects stimuli in accordance with relevancy; which makes memory much more efficient. The “gate-keeper” selects important stimuli in two stages in the perceptual process; early sensory processing pathways, and post-perceptual processing pathways. According to the research, attention is more selective in the early stages. The research even shows that attention influences even some of the earliest stages in perceptual analysis.
Terms: attention, memory, gate-keeper, early sensory processing pathways, post-perceptual processing pathways, perceptual analysis.
http://www.psy.vanderbilt.edu/students/fougnidl/Fougnie-chap1.pdf
http://www.tandfonline.com/doi/full/10.1080/09297040903559655
http://psychweb.uoregon.edu/~pk_lab/documents/Awh%20Vogel%20Oh%20--%20Interactions%20between%20attention%20and%20working%20memory%20--%20Neuroscience.pdf
https://en.wikipedia.org/wiki/Working_memory
Great sources. These are definitely the leaders in the field of attention and WM and the crossroads between the two. I liked your points about their interaction.
My topic of interest is neglect. Neglect is a deficit in visual attention. Chapter 8 is about attention and scene perception and neglect has a large part in scene perception. When damage is done to the right parietal lobe a person will have an inability to attend or respond to stimuli in the contralesional visual field typically to the left visual field. Visual neglect is a common neurological disorder in which patients fail to attend to, report or represent information appearing in contralesional hemispace, despite intact sensory processing and visual acuity. Hemispatial neglect is a common result of stroke, particularly after right-hemisphere brain damage (RHD), with reported incidence over 80% following lesions to the right middle cerebral artery. Hemispatial neglect can be debilitating in everyday life. For example, after a right-hemisphere lesion, neglect patients may fail to notice objects on the left of a scene, words on the left of a page or food on the left of a plate. In the laboratory, these patients show an ipsilesional spatial bias in many simple paper-and-pencil tests; they deviate towards the right when asked to bisect a horizontal line at its midpoint and omit to copy or draw features on the left of a figure while preserving the corresponding features on the right. I am interested in this topic because I did not realize how common this inability was and how it could impact peoples life.
Some researchers have reported that different degrees of impairment are associated with different visually guided movements. Neglect patients who showed a strong rightward bias when pointing to the judged center of a rod but showed little neglect when a grasp response was used. This advantage for grasp over pointing responses occurred only when performance was guided by on-line visual feedback. While this possibility seems counterintuitive, one must keep in mind the fact that perceptual representations are not only utilized for object perception but also for “perceptual–motor” tasks like pointing. The pointing tasks described earlier require patients to “show” the experimenter the middle of the rod— a very perceptual concept. Hemispatial neglect may, therefore, disrupt perceptual representations while sparing the visual motor networks guiding grasping. While some neglect patients may be able to successfully pick up an object they have difficulty perceiving in its entirety, it does not mean that they are picking up the object in the same way that an intact individual would.
Article: http://www.cnbc.cmu.edu/~behrmann/dlpapers/Marotta.pdf
Video/ Human: http://www.youtube.com/watch?v=ymKvS0XsM4w&feature=related
Video/ Animal: http://www.youtube.com/watch?v=hHo-y7WJIlU
Good points, I like how you mentioned some of the tasks they use to test neglect patients.
After reading this chapter I did not understand the Aperture problem. Because of this, I wanted to further my knowledge on this subject and search about this issue.
1. The first examples I found explain in pictures and words what exactly the Aperture problem encounters. The aperture problem occurs when we view a motion from an object but the motion is coming from a different fraction of our visual field. The motion of an object cannot be detected correctly because it is coming from multiple patterns. A suggestion to solve this aperture problem is to intersect the constraints by finding the intersection of all possible motions and then detect the global motion. The motion can be detected when we find a common middle point of the movement and understand the direction of the
moving object.
http://fourier.eng.hmc.edu/e180/lectures/motion/node11.html
2. The second article I found explains from the book Measurement of Visual Motion about the aperture problem in detail. As stated in the above article, the aperture problem can not detect TRUE movement of the object of view. The motion detector is sensitive and can only detect the motion if it is perpendicular to the edge of the object. It can be hard to detect motion if is parallel. The motions deliver a signal to the brain that consists of the pattern of the motion being observed, however, if the object is moving in different patterns it is unable to detect and deliver a TRUE motion reading.
http://www.bcp.psych.ualberta.ca/~mike/Pearl_Street/Dictionary/contents/A/aperture.html
3. The third website I found gives a demo of the constraints in motion interpretation. I found this to be very interesting and the most useful out of the three websites I found due to the fact I can chose different movements to understand the motion in the aperture. This example shows that the edges of the circle are physically moving upward and the edge motion is consistent with the other motions. When the edge is diagonally it is known as the aperture problem because the motion measurement does not specify the direction of motion.
http://web.mit.edu/persci/demos/Motion&Form/demos/one-square/one-square.html
vocab- constraints, motion interpretation, aperture problem, true movement, detector, patterns, visual field
For my blog post this week, I chose to focus on change blindness. This concept was super interesting to me because it's a phenomenon I have experienced my whole life but never made a connection to!
So I didn't even know what I was in store for with this website but it turned out to be a test of my abilities to beat change blindness in myself. This website had a series of pictures in which you would watch the picture flicker back and forth and you have to see what is different between the two pictures. You are also being timed for your reaction time. I honestly thought it would be a lot easier but I kept getting stumped because your eyes can only focus on one area at a time between flashes. It took me a lot longer than I thought it would. I really liked being able to experience this phenomena first hand through these pictures!
http://www.gocognitive.net/demo/change-blindness
I used this website because the article was written by one of the psychologists who is known for his research on change blindness: J. Kevin O'Regan. No, I had not heard of him before, but he popped up in a bunch of the articles I searched. I really like how he pointed out that change blindness is much different than inattentional blindness. When I first learned about change blindness, I thought that it could occur when you are distracted by something else, but that is what inattentional blindness is. Change blindness is when something gets in the way like a pause, blink of the eye or a blank screen. Your mind isn't distracted, it is covered up. O'Regan pointed out that if you take away the black space, your eyes would be able to notice the change right away. But since that blockage is there, your mind is more slow to react. I really think that this helps me relate to my own test. Most of the differences were obvious, but they took me forever to find!
http://nivea.psycho.univ-paris5.fr/#CB
I found that this article was also written by O'Regan, but this is from the Encyclopedia of Cognitive Science so it isn't just O'Regan's findings, which I thought helped give different insight than the previous article. I really liked how this article pointed out that this phenomena of change blindness occurs during and eye movement. This happens within a second of each other where these significant changes occur and our eyes are blind to them because of the disruption. That is crazy how fast a change can be, but we don't even notice. I feel like I notice this at stop lights. I will be looking at the light and all of the sudden it's green and I didn't notice for a second. It's funny how significant time is in our vision. I also like the point that was made about how when one of these phenomena occur, your mind is able to notice that a change occurred, where it occurred, but not what the change was. Its awesome that our minds can notice something so insignificant but not be able to distinguish what the change is.
http://nivea.psycho.univ-paris5.fr/ECS/ECS-CB.html