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.
One of the concepts I especially enjoyed reading about from chapter 4 was contours. I liked learning about contours because I think it’s cool how the visual system goes beyond what information is presented in the environment to form edges around objects to identify what they are. The occasional lack of an edge on an object doesn’t hinder a person’s visual system. Sometimes it may actually be difficult to even see the gap in the edge, because your visual system and then brain fill in the gaps without you even realizing it.
An Italian psychologist, Gaetano Kanizsa, investigated stimuli that were missing edges and how the visual system still perceived the object correctly. Kanizsa is known for his image of the perceived triangle with the three pacman-looking objects. Below is a link to example of illusory contours. Edges that are perceived despite lack of physical evidence for them are called illusory contours. An Illusory contour is a contour that’s perceived, despite a lack of changes from one side of the contour to the other in the image. They were discovered by Friedrich Schumann around 1900.
This concept leads into good continuation, a rule developed by the Gestalt school of thought. The Gestalt law of "good continuation" has been used to describe a variety of phenomena demonstrating the importance of continuity in human perception. Two visible bits of an edge will actually make it easier to perceive a third collinear segment that lies between them, even if that middle segment isn’t visible. Two elements will tend to group together if they seem to lie on the same contour.
I enjoyed spending some time further investigating the concept of contours, and feel that I now have a better understanding of contours and specifically illusory contours.
http://www.google.com/images?sourceid=navclient&aq=f&oq=illusory+contours&ie=UTF-8&rlz=1T4ADFA_enUS426US428&q=illusory+contours&gs_upl=0l0l0l6490lllllllllll0&aqi=g4g-v1&oi=image_result_group&sa=X
http://en.wikipedia.org/wiki/Illusory_contours
http://www.ncbi.nlm.nih.gov/pubmed/8447091
The Kanizsa stuff is really interesting. There is still some research being done on it. My friend is working on a neuroimaging project looking at Kanizsa figures and apparent motion in various areas of visual cortex. Pretty cool stuff.
I chose to do my topical blog on illusory contours because I think they are really cool to look at and I thought it would be a fun topic to learn more about. An illusory contour is when a shape is perceived when there are no boundaries representing that shape. It may appear brighter or luminant. This is the brain’s way of making sense of the information presented to it. It just takes the information that it is seeing and does it’s best to fill in the gaps it is presented with based on past experience. The Kanizsa Triangle is a great example of this. It is basically little packman looking guys arranged in three corners. When perceiving this the brain makes up boundaries to make it look like there is actually a triangle there when really there is not. It sometimes may even look lighter or more luminant than it actually is.
The first site listed has some really cool illusions when looking at them if you lean back and forth the brightness of the middle part changes. I have no idea why or how this works, I know it has something to do with the illusory contour. It is really cool though. Had to put it in my blog. IF you click around on the first website there are some great examples of illusory contour.
If you look at the third link I think this is a really cool example of another way that our mind can play tricks on us. This is a picture done in chalk on a street that is so well done it is hard for my brain not to see it in 3d.
Turns out you can find links of examples of this stuff all day. But what is important is why does our brain do this?? Well it has been predicted that it has something to do with our visual areas V1 and V2 are responsible for these illusions. These areas have the neurons with the most sensitivity to encoding information with the most spatial precision. This is kind of controversial though to my understanding, because a recent experiement done by Mendola found that the Kenzsa triangle image made responses in the lateral occipital region and there was not much response in the V1 and V2 areas. So in short… I it is kind of controversial and not really clear from what I read, why we see the these illusory contours the way we do…. They just know we do.
Terms: Illusory contour, kanizsa triangle, V1, V2, neurons, spatial precision, Mendola, lateral occipital region,
http://perceptualstuff.org/brighttwist.html
http://www.scientificamerican.com/article.cfm?id=the-reality-of-illusory-c&page=2
http://www.youthareawesome.com/photo-day-awesome-3-d-chalk-drawing/
http://repository.cmu.edu/cgi/viewcontent.cgi?article=2098&context=compsci&sei-redir=1&referer=http%3A%2F%2Fwww.google.com%2Fsearch%3Fsource%3Dig%26hl%3Den%26rlz%3D%26q%3Dillusory%2Bcontours%26oq%3DILLUSURY%2BCONTOU%26aq%3D0l%26aqi%3Dg-l4g-lv6%26aql%3D%26gs_sm%3D3%26gs_upl%3D1846l6453l0l7497l15l13l0l0l0l0l180l1703l2.11l13l0#search=%22illusory%20contours%22
The issue continues as to the origin of the Kanizsa illusions. My friend is using apparent motion and various levels of offset of the pac-man inducers to see if you still get a Kanizsa effect and coupling this with activations in areas like LOC and extrastriate cortex. I seem to remember some distinct activation patterns emerging from the study. Pretty cool.
Prosopagnosia is a disorder where the person that has been affected is unable to recognize faces of friends, loved ones, or anyone for that matter. Although these people cannot recognize faces, their ability to be able to recognize objects, colors, or shapes may be left intact. This disorder can also be accompanied by other types of defaults in recognition like place recognition, car recognition, or facial expression recognition. Prosopagnosia dates back to around 1947 where a scientist named Bodamer wrote a landmark paper about two individuals that were displaying such symptoms of the disorder in extensive and precise detail. He coined the term by combining the Greek word for face which is “prosopon” and the medical term for recognition impairment which is “agnosia”.
Symptoms of prosopagnosia are not really set in stone. In summary, they include things such as difficulty recognizing people that have been encountered numerous times, difficulty recognizing people that those affected spend the most time with (mother, father, spouse, siblings etc.), great reliance on non-facial information, and not even being able to follow the plot of a movie or television show. Causes of this disorder are usually a result from an accident, such as head trauma, a stroke, or sometimes even can be caused by degenerative diseases.
There are three different types of prosopagnosia. These are apperceptive, associative, and developmental. Apperceptive prosopagnosia is a disorder of some of the earliest process in the face perception system. This would be considered the worst degree of the three types. Associative prosopagnosia is thought to be an impairment of the links between early face perception and semantic information we hold about people through memory. People with this degree of the disorder may be able to determine if the person’s face is the same or different or derive age and gender, but they may not be able to provide any information about them such as name, occupation, or when they last saw the person. Developmental prosopagnosia or DP is where the disorder is lifelong. It will manifest in early childhood and will not be acquired through brain damage. It is suggested that genetics play a major factor for responsibility of this condition. Something really interesting that has been shown to be true when testing people with prosopagnosia is that sometimes when a person is shown a picture of a friend or loved one, they will not be able to identify who the person is but when they measure of emotional response is taken (such as skin conductance) there tends to be an emotional response to familiar people even though no actual conscious recognition takes place.
TERMS: prosopagnosia, apperceptive prosopagnosia, developmental prosopagnosia, associative prosopagnosia.
http://en.wikipedia.org/wiki/Prosopagnosia
http://www.stereomood.com/activity/studying
http://www.youtube.com/watch?v=vwCrxomPbtY
Definately some great neuropsychological case studies out there on prosopags. I think it would be so difficult and scary to not recognize people who you are supposed to without a doubt know from their face. There are a relatively high number of these people out there. There are also some people who study face processing and recognition that are supposedly prosopagnosics.
This week my topical blog is about the two-streams hypothesis, or the what and where pathways as the book describes. As discussed in earlier chapters, the low and middle level visual processes are generally secluded in the striate cortex and extrastriate cortex. However, to advance into a higher level of visual processing, information is sent to either two different pathways. The separation of types of information associated with the individual pathways is still disputed. However, the pathway leading into the inferior area of the temporal lobe is generally considered as the section of the brain that identifies the objects being perceived (the what pathway); this area is known as the inferior temporal cortex.
One way scientists can make the assumption that the IT cortex is responsible for object recognition and higher level visual processes is that lesions to this area of the brain usually results in visual agnosia, or the failure to recognize objects. Agnosia can be highly specified (facial, animate, or inanimate objects); however, a similarity persists between all cases of agnosia: the patient is able to physically "see" the object, but is not able to recognize what the object is.
However, what interested me the most about the IT cortex was its relationship with memory. The IT cortex (or the final destination for visual stimuli) has a greater connection with the hipppocampus, which is greatly associated with memories, and other limbic system structures. Not only does the IT cortex have connections to the limbic system, but it also has ample connections to the frontal lobe, which is known for its upper level cognitive processes, like decision making.
All of this information clearly points to the IT cortex being a hotbed of higher-level cognitive functioning; thus, representing a sizable chunk of perception and consciousness.
http://www.scholarpedia.org/article/Inferior_temporal_cortex
https://en.wikipedia.org/wiki/Two-streams_hypothesis
http://www.annualreviews.org.proxy.lib.uni.edu/doi/pdf/10.1146/annurev.ne.16.030193.001333
(Miyashita, 1993)
Terms: two-streams hypothesis, striate/extrastriate cortex, inferior temporal cortex, agnosia, limbic system
It is interesting because I believe Kastner's group from Princeton found activation patterns of object based (what) information in the parietal cortex (typically associated with "where" information within the dorsal stream). So, there's clearly a lot of integration in each stream, but the jury is still out on the exact types of information processed within each stream. The memory stuff is interesting, b/c you get a lot of parietal activation when holding things in working memory in an fMRI experiment. The activation builds and asymptotes (levels off) when you reach your individual item capacity limits. Cool huh? They've shown this with ERP/EEG and fMRI activity associated with the posterior parietal cortex.
My topic of interest for chapter four is the illusory contour. This concept fits into the chapter very well because of how we look and see edges. Illusory contours make us believe we see edges when we really don’t. It shows us the tricks illusions play and how we perceive stimuli that our brain lies to us about. Illusory contours are also known as subjective contours. One of the basic examples of an image that was specifically designed to show this illusory contour idea is the Kanizsa triangle. Another illusory contour is the Ehrenstein illusion, which depicts a few black lines shaped to make what looks like a wbhite circle in the middle. These illusions make us believe that if we connect certain parts, or edges together, we visually see a much brighter white color. Structuralists tried to develop sensation and perception ideas that did not quite agree with the illusory contour. However, Gestalt psychology is most notably known for its idea that the whole is greater than the sum of its parts. Further studying on illusory contours shows that neurons in the brain are only extracting the illusory edges of the picture. There is a surface and depth discontinuity in the visual system as well. Early research has shown that V1 and V2 neurons are responsible for the representation of the contour. More recent research suggests that the lateral occipital region may be the cause of responses from the contours when an individual is shown an illusory image, such as the Kanizsa triangle. One of the websites I found to help depict an accurate visual of what an illusory contour looks like is listed below. It is a short video that briefly tricks the brain with an illusory image.
http://en.wikipedia.org/wiki/Illusory_contours
http://repository.cmu.edu/cgi/viewcontent.cgi?article=2098&context=compsci
http://www.youtube.com/watch?v=txbYo_VpNeY
Terms: illusory contours, structuralists, Gestalt, neurons.
Pretty interesting stuff. I made a couple responses to other posts that talk about the illusory contours as well. See those for more feedback.
After reading the chapter I found the topic of prosopagnosia to be interesting. This topic is interesting to me because it is a disorder that many people do not know about, and I believe it should have more attention because it is a serious disorder. Also after watching the video in class this topic was something I wanted to know more about.
Prosopagnosia is a disorder in which people are unable to recognize faces, and there really has not been any successful treatment for the disorder. Usually they are able to recognize other things, but not faces, so they do have the ability to recognize people by other objects. It is a disorder that only effects face recognition. Prosopagnosia is not just a disorder where people forget a face or can’t recognize a certain face; it is when they cannot recognize any faces or the faces they see every day.
Prosopagnosia sometimes happens after someone has been in an accident or something has happened to the brain (the occipital or temporal lobes), but recently they have found that people can be born with the disorder. Because prosopagnosia usually happens because of brain damage it is easy for people who are affected to know they have the disorder. This usually means before they had the brain damage they had the ability to recognize faces. Also when people develop the disease from brain damage the doctors can find that they may have prosopagnosia.
Because prosopagnosia became interesting to me after we watched the video in class, I found a video on YouTube that also discussed prosopagnosia. The video didn’t explain how she developed the disorder, but she did explain what it was like to have the disorder. In the video she took photographs of her mother then tried to recognize the photos with only the faces visible, and she could not tell which was her mother. The only way she could tell which one was her mother was by looking at the clothing. She later discussed that they hardest part of having the disease was not being able to recognize her family, and she felt there was a lost connection between her and her family.
After learning more about the disorder I have appreciated my face recognition ability. I find it hard to believe that people cope so well with this disorder. I could not image not being able to recognize people’s faces that are so close to me.
Terms: prosopagnosia, occipital, temporal lobes, face recognition
http://en.wikipedia.org/wiki/Prosopagnosia
https://www.faceblind.org/research/
http://www.youtube.com/watch?v=vwCrxomPbtY
The interesting thing is that some people have the genetic condition while others typically have suffered damage to an area within the occipitotemporal region of the ventral stream called the fusiform face area within the fusiform gyrus. It's weird to think about what it would be like to never have recognized a face, or on the other hand, being able to recognize a face for part of your life, but then lose that ability.
My topic for this week is camouflage and how it works. The basis of camouflage as we learned from the book is that its job is to persuade the observer from knowing the thing in question is forming their own perceptual group. We also learned that perceptual groups are very important to the way that we see our world. This can easily be seen when looking at the different sets of examples in the book, especially when it comes to facial recognition.
I was amazed at how many animals use camouflage to blend in, animals that I had never thought of such as cheetahs and squid. Many people know about the popular chameleon and the stick bug but some of these animals use their bodies in a really interesting way to throw off their predators. They hide on rocks, near coral, and on trees.
I learned that camouflage has been used by humans for a very long time. This practice was adapted from animals that used camouflage to protect themselves in their natural environments. In fact the military believes so much in camouflage that they are constantly updating to keep up with camouflage technological advances. It’s a good thing the brain plays tricks on us otherwise our military might not be so good at keeping us safe.
I really liked the sentence that I found on one of the webpage’s that said, “hiding in plain sight.” This does a good job of summing up exactly what camouflage allows different species to do. While standing in a bush or sitting in a tree stand while in camo may be good scientists are also trying to figure out how to best move and have camo at your advantage. Some animals can do this such as the mid water squid but humans are getting better as technology advances. An example of effective active camo would be the new drones which are military jets that when in the sky allow light to reflect off of them so that they cannot be seen by the enemy or anyone below. It is obvious as to why this would be a good strategy for defending yourself and creating the perfect setting for sneaker military tactics.
http://science.howstuffworks.com/military-camouflage.htm
http://en.wikipedia.org/wiki/Active_camouflage
http://www.youtube.com/watch?v=uaYbcN7Wa_M
camouflage, perceptual group, facial recognition, and active camouflage.
Pretty interesting feature of the evolutionary process. One species is preyed upon by another species and so the trait of skin/hair that matches the background of the average characteristics of the environment so as to avoid detection from predators by adding more noise to the ambient background.
The Gestalt grouping laws were written because Gestalt psychologists believe that the brain has a way of organizing what it sees in its visual field. This theory states that the brain organizes the patterns into six categories; proximity, similarity, closure, good continuation, common fate and good form. Many of these categories are self-explanatory. They vary from grouping things that are similar and close in form to grouping objects into continual lines. This theory focuses heavily on the organization of perception in the brain, but organization is not the only thing to be considered.
In addition to organizing perceived information, the brain must also be able to separate an object from its background. Once an object is identified, it often becomes easy to establish a background. The brain’s ability to establish objects from the background is an example of Gestalt psychology. This is because Gestalt claims that the whole is different than the sum of its parts. Gestalt psychologists test this theory by creating illusions in which the background and the foreground can be reversed. The brain is able to see two different images depending on which object it chooses to focus on and which object it chooses to have as the background. This is called figure-ground separation.
I chose to focus more in depth on Gestalt principles because I wanted more detail about what the brain is doing with the visual images it is receiving. Gestalt grouping laws fits into the chapter because it explains how the brain organizes perceptions. I decided to go a step further and discuss figure-ground separation, which is another way that the brain processes information.
Terms: Gestalt psychology, Gestalt grouping laws, visual field, proximity, similarity, closure, good continuation, common fate, good form, perception, figure-ground separation.
http://www.sapdesignguild.org/resources/optical_illusions/gestalt_laws.html
http://en.wikipedia.org/wiki/Principles_of_grouping
http://www.sapdesignguild.org/resources/optical_illusions/intro_principles.html#gestalt_laws
I read this paper where they tested the neural response to figure and ground and the effect of an attentional task which took place in the figure. They found different amplitude profiles for the figure based on the attentional task. It was a pretty cool method they used where they flickered each aspect of the stimuli at different frequencies so they could detect the neural response (EEG/ERP based) to the figure and the background during different tasks.
I found prosopagnosia or face blindness to be extremely interesting and I chose to do further research on it. Prosopagnosia is first off defined as the inability to differentiate on face from another. There is a lot more to prosopagnosia than the book explains. The book does not discuss any potential reasons for damage to the temporal lobe it just states that it is there. Diagnosis of face blindness can be a very troublesome task. Many people do not know that there is such a thing as face blindness and individuals are written off as having a cognitive disability. Prosopagnosia affects somewhere around one to two percent of the United States population. In most cases those with prosopagnosia can usually recognize other things, but some may also be blind to many other things such as places, cars, or other objects
There are two types of face blindness on is caused by damage to the temporal love as the book stated, but the other type is congenital. Damage to the temporal love usually comes from having strokes. Due to there being more strokes in males than females face blindness is found in males more than females. A congenital form of prosopagnosia means that an individual had this from birth. The congenital form is where the estimate of 2 percent of the population comes from. Since researchers became aware of congenital face blindness they have begun doing studies on children who have it at places like the University of Minnesota. Minnesota’s main goal is to promote awareness.
As far as treatment for face blindness goes there is currently nothing that addresses this formally. Researchers have t begun to study children, so these studies should give them some ideas on how to help. From what I read it appears that researchers would love more volunteers to be studied.
key terms: prosopagnosia
http://www1.umn.edu/news/features/2010/UR_CONTENT_285211.html
http://prosopagnosiaresearch.org/index/information
http://en.wikipedia.org/wiki/Prosopagnosia
https://www.faceblind.org/research/
Definately an interesting agnosia. Good post.
I decided to do my research on prosopagnosia or ‘face blindness’. After watching the video in class about prosopagnosia, I started wondering if there had been any resent research on prosopagnosia. I just found it interesting because people usually say ‘I so terrible with names’ but there are people who can’t recognize a person’s face. If you forget a name, you can still pick the person whose name you forgot out of a crowd. Faces don’t change a whole lot over short periods of time so for someone to not be able to recognize their own spouse in the grocery story is kind of heart breaking. It completely changes how that person has to look at the world because their ability to identify people has changed while their ability to identify objects has remained intact.
When I first started researching I got the usual ‘what is prosopagnosia?’ answered around three times. But further down on the National Institute of Neurological Disorders and Stroke website it talked about how current research has shown how prosopagnosia has been found in more people who did not have brain damage and even children. This was a big shocker to me because I thought it was centered on adults who had suffered some type of brain trauma. Apparently it can also be linked to children with autism and Asperber’s syndrome. Through the media I was aware of autism because of commercials on TV but I found myself drawing a blank on Asperber’s syndrome. I probably could have guessed that it was a developmental disorder but I didn’t know that it was a more mild form of autism (without delays in communication and cognitive processing). With further research, I was able to find the results from a study that took place in Germany that found that a suspected 2-2.5% of people may have some degree of prosopagnosia. Although it is still a small number, it is much bigger than I thought it would be. I had hoped to find more research but a lot of the case studies I found were giving me the data related to the general population as I had hoped.
http://www.ninds.nih.gov/disorders/prosopagnosia/Prosopagnosia.htm
http://prosopagnosiaresearch.org/index/information
http://www.mychildwithoutlimits.org/?page=autism&gclid=CJyir8jWkq4CFcqf7QodzC2uJA
Terms: prosopagnosia, brain trauma, autism, and Asperber’s syndrome.
I wouldn't say that autistics have prosopagnosia. I would just say they have difficulty attending to faces and particularly the eyes of the face. This can lead them to be less accurate at face recognition but doesn't mean they can't recognize a face.
Illusory contours occur when boundaries are perceived within an environment despite a lack of apparent physical evidence therein. This is an example of the brain attempting to make whatever possible sense it can of ambigious objects within a visual field. Oftentimes, these illusions can produce perceived gradients in luminance levels that do not exists when replaced by their corresponding physical counterparts!
It has been theorized that this phenomenon is caused by cortical sensory neurons called end-stop cells. These structures often are only stimulated by lines in a certain location and of a specific length. When lines in a visual field are longer than that which they are attuned for, these cells have been shown to cease firing. This has been hypothesized to bring about an interpretation similar to that of occluded lines. This implied occlusion is therefore thought to be the source of the illusory contour effect - end-stop cells are essentially signaling a non-existent occlusion within a visual field. Another line of thinking involves what is known as the generic-viewpoint assumption, which states that an observer is not in a special position relative to the scene. This theory implies that tangent discontinuities in the visual field are only necessary precursors to illusory contour perception when the illusory contours appear to be in front of the structures which cause the illusion. They found that illusory contours formed without this initial interposition were much weaker. This model helps to more accurately predict illusions of depth than the simpler end-stop theory, which only accounts for the existence of such illusions.
http://www.cogsci.uci.edu/~ddhoff/Generic.pdf
http://www.scientificamerican.com/article.cfm?id=the-reality-of-illusory-c
http://en.wikipedia.org/wiki/Illusory_contours
Terms: illusory contour, luminance, end-stop cells, occlusion, generic-viewpoint assumption
Great post. I like how you went into the cellular and neural mechanisms from which these illusory perceptions are likely to emerge. Nice work.
I absolutely loved the optical illusions that were discussed in the class and how our eyes play tricks on us, such as accidental viewpoint and gestalt grouping rules which i mentioned in my previous post. The information is gathered by the eye and processed in the brain to form our perception. There are three kinds of optical illusions. The first kind is literal (create objects that are different from the objects that make them), physiological (brightness, color, movement, tilt) and cognitive (unconcious inferences).
Our brain and eyes make us see these opticial illusions because our brain likes to group things together in familiar form. Our brain is constantly comparing itself with what we see and the knowledge of the world. Floaters, the eye condition when you actually see specks of black or white "snowflakes" (most common when older) is an actual form of an optical illusion or a visual perception, which some people think should be the actual name for it. Optical illusions have to deal with your brain playing tricks on you whereas your visual perception is actually your eyes.
This chapter was mostly all about optical illusions and about how our eyes and brain counteract with each other to make us see things that aren't really there. It's very intreging to think about how our brain automatically groups everything together as one and our eyes are really seeing a million tiny pixels but we don't even notice because we are so use to seeing things as a whole or a group of things instead of one individual thing.
http://en.wikipedia.org/wiki/Optical_illusion
http://www.visionrx.com/library/optical_illusion.asp
http://abcnews.go.com/Health/EyeHealth/optical-illusions-eye-brain-agree/story?id=8455573
Terms: accidental viewpoint, gestalt grouping rules, perception, floater
It makes you re-evaluate your perceptions and experiences of the external world. How veridical are our perceptions? I think the illusions make a great case that the brain does a great deal of lying about the actual state of our natural environment.
The topic I decided to further research is Agnosia. Agnosia, according to Wiki, is a loss of ability to recognize objects, persons, sounds, shapes, or smells while the specific sense is not defective nor is there any significant memory loss. This fits into the chapter because it involves the brain as well as the eyes, and involves sensation and perception. The reason I found agnosia so interesting is because I have never even heard of it prior to reading this week’s chapter. Naturally when I get interested about something I didn’t know I have to look into it further.
Agnosia is a rare disorder that is typically triggered when the individual suffers damage to the brain, specifically in the occipital or Parietal lobes. The region that is most susceptible to developing Agnosia. That region is the occipitotemporal border, which is part of the ventral stream. Agnosia is not only limited to just visual system, but is a neurological illness that affects your hearing and smell along with vision. Agnosia can develop from strokes, dementia, a head injury, brain infection, genetics, and other neurological disorders. To date there is no cure for agnosia, but there are various therapies offered to help with the disorder. In the video I found they show the type of therapy they use, as well as seeing how hard it is for a patient suffering from agnosia to determine what the object they are looking at actually is. I just found it to be a very intriguing phenomena. I couldn’t imaging living that way and could just imagine how frustrating it would be.
Terms used- Occipital lobe, parietal lobe, neurological, agnosia, occipitotemporal border, ventral stream, and neurological.
http://en.wikipedia.org/wiki/Agnosia
http://www.ninds.nih.gov/disorders/agnosia/agnosia.htm
http://www.youtube.com/watch?v=rwQpaHQ0hYw
I would go into more specific types of agnosias you read about and found interesting. That way you can start broad with the topic of agnosia and then funnel down to specific brain areas and types/examples of agnosias.
After reading chapter 4, I found the topic of Gestalt psychology to be of interest to me. I wanted to learn about what Gestalt psychology was all about and how it’s applied. Gestalt psychology, as the book defines it, is a school of thought stressing that the perceptual whole could be greater than the apparent sum of the parts. He object we see is like a puzzle piece and the complete construct is the overall perception of each piece. Each piece in Gestalt psychology is a whole in itself. An example would be a tree being a whole object we see and a bunch of trees is a forest which is a completely different object.
The principle of totality is a good way of understanding how we interpret things. It states, the conscious experience must be considered globally, taking into account all the physical and mental aspects of the individual simultaneously, because the nature of the mind demands that each component be considered a part of a system of dynamic relationships. So once again we see something as a whole, but are mind is constantly breaking the image down into smaller parts that make the whole.
There are 4 key principles in Gestalt psychology, emergence, reification, multistability, and invariance. Emergence is the process of complex pattern formation from simpler rules. An example on how emergence works is imagine a picture of a dog by its dog house. We perceive both things in the image as wholes and we are able to determine what they are from their wholes and not the multitude of parts that they are made up of. We notice the image as a whole before its individual parts.
Reification is when the image we perceive contains more explicit information than the sensory stimulus on which it is based on. This is what illusory contours are based on. A lot of the images in our book and in the presentation Dr. MacLin were illusory contours. In the presentation he gave, the picture in which our mind creates lines to form a big triangle when there are really no lines is great example of reification.
Multstability is the tendency of ambiguous perceptual experiences to pop back and forth unstably between two or more alternative interpretations. A good example of this would be a necker cube or the image in which we either see a rabbit or a duck. The main thing is our brain sees different meanings in one picture.
Invariance is the property of perception where by simple geometrical objects are recognized independent of rotation, translation, and scale. What this is basically saying is that no matter how an object is presented towards us, we will be able to instantly recognize it. An example would be see a car upside down, turned to the left, right, etc, we will still be able to determine that the object is a car.
Terms: invariance, multstability, reification, emergence, illusory contour, Gestalt psychology, necker cube.
http://www.gestaltpsychology.org/perception/#more-9
http://psychology.about.com/od/schoolsofthought/f/gestalt_faq.htm
http://en.wikipedia.org/wiki/Gestalt_psychology
I like how you laid out the basic principles of the Gestalt school of thought. This allows you to get a sense of what the topic is all about if you are reading this blog post. Good information and approach.
I really enjoyed learning about the Gestalt principles of perception. Gestalt psychology is so interesting and easy to implement in my life.
I learned more about proximity, similarity, continuity, closure, figure-ground assignment, and surroundedness. I was really interested in the illusory contours, especially after Dr. Maclin's talk last week. It is amazing what our brain makes us see.
Our brains are very picky about what they prefer to look at, and how they perceive everything. In fact, if our brains were not so selective in our perceptions of things we would in turn be very confused.
Figure-ground assignment is a key contender in helping us stay focused on said object. For instance, if I were in the Union talking to a friend around lunch time, it is absolutely crucial that our figure-ground assignment is working properly, or else we would be so confused as to what we are looking at.
It is almost silly to think that my brain is more organized than I am in my daily life. Actually, it's really reassuring! Our brain groups items together to make sense, (similarity/proximity) and we don't think twice about it!
http://www.aber.ac.uk/media/Modules/MC10220/visper07.html
http://www.youtube.com/watch?v=spju-mc9DOI
http://www.youtube.com/watch?v=nxpat5aalSw&feature=related
Automatic from our conscious perspective. Lots of mechanisms making it possible. Pretty interesting.
From this chapter I thought the information on camouflage was interesting. When reading the chapter I thought about how the military has changed from the more blob pattern to the more digital camo. I did not think that the new digital version would be as effective as the old one. The digital camouflage is called Army Combat Uniform or ACU. It has a digital pattern because it allows people to create images in their own mind where as the old camo had pre-disposed figures that were supposed to blend in. The ACU also eliminated the color black from the camo because it is not found in nature and because it appears very dark on night vision goggles.. This camo is used by US military and can be used in urban, desert, and woodland settings. The digital pattern idea came from the US Marines who have a similar design called MARPAT (MARine PATtern.) but have a snowy version and a woodland version. The marines pattern comes from a complex set of highly complex fractal equations. I think that the new camoflague uses similarity very well because the small pixels blend in very well with the surrondings. This eliminates the proximity because items will not be grouped together easily. the equations also gets ride of connectedness and common region that would make spotting a soldier easier.
I chose to search the new version of the army camoflague because it is interesting to see how it works. I also want the best possible camo for our armed forces so I thought it would be a good opportunity to see how well it works.
Terms:similarity,proximity, common region, connectedness
http://en.wikipedia.org/wiki/MARPAT
http://www.slate.com/articles/business_and_tech/design/2004/09/the_us_armys_new_clothes.html
http://www.youtube.com/watch?v=gIV07SuwPPY
In this video you can see how well this man is able to hide using the ACU camo in a snowy/woodland environment.
Topical Blog #5
After reading about different disorder with perception in this chapter, I wanted to further the topic on brain damage and perception. I work with brain injury adults, and my personal experience has shown that perception is a day-to-day struggle for these individuals. When I searched more on this topic, I found out more interesting facts about brain damage and perception that I can use everyday.
1. The first video I found was telling the different types of perception disorders that brain damage individuals can get. Neglect is one of the main ones I found interesting, because the individual with brain damage ignores a part of perceiving. An example of this would be that the individual dresses one side of their body, or only read on the right side of the page. I found that this would be very difficult to live with because it would seem that you are “missing” something. Perceiving both sides of something is crucially important, which I had never taken into account before even after reading the chapter. The brain processes in attention is the main concern in the “neglect” disorder, it does not have to do with vision. An example of this would be a woman or man with this disorder asked to draw a cat, and they only draw one side of the cat. However, they could see the whole picture, but not process the whole picture. Very interesting video!
http://www.youtube.com/watch?v=ADchGO-0kGo
2. The second research I found was from a brain injury program hospital that describes these deficits in patients. When a person has perceptual deficits it causes issues in one or more areas of the brain because of the brain injury. Each brain injury patient is different due to their specific brain trauma. A deficit in depth perception could leave brain injury individuals not about to see how far an object is from the body or spatial relations in knowing the positioning of objects relating to other objects. Another form of brain damage in perception would be not being able to pick an object out from its background. These few examples are everyday visual and mental perceptions. Brain damage causes a struggle for these individuals, and many take advantage of these unconscious processes.
http://www.maryfreebed.com/Rehab-Services/Brain-Injury-Program/About-Brain-Injuries/Sensory-Perception
3. The third research project I found was on the brain damage perception of blind spot. This is when the visual field is damaged. The person may feel blind and not being able to see what they are perceiving. The experiment starts how with a person showing the individual pictures of faces of people being happy or sad. The patients would just stare at the pictures and not say what the face was doing, but they would smile at the happy faces and frown at the sad or frightened faces. The reason the individuals did not see it is because they are blind to the visual fields in front of them. When the visual cortex is not working, the signals to the brain are not as clear to the brain, and the brain damage does not allow the individual to perceive the object normally.
http://www.scientificamerican.com/article.cfm?id=emotional-contagion-blindsight-mimcry-imitation-visual-cortex
These three websites had very interesting information about the different perceptions in brain damaged individuals. The chapter lacked focusing on this topic or personal experiences and experiments. This topical blog has been my favorite so far.
Vocab- visual cortex, visual fields, blind spot, neglect, spatial relations,depth perception
This week, I wanted to focus on illusory contours. I want to dive in a little deeper and know why the mind does these things and maybe even see some more examples!
I really enjoyed going to the Gestalt website. It give great insight into Gestalt psychology and the way we perceive things. What I found different from the books explanation of illusory contours is that these images are seen where there isn't any extra light, different colors, lines or even a texture difference. Everything is solid and the same but our mind plays tricks on us and changes the image in our mind to make us see things that don't exist. I also learned that you sometimes don't just see another object, you can even envision it as brighter or a different size than it really is.
http://gestaltrevision.be/en/what-we-do/overview/39-research-areas/mid-level/93-subjective-contours
Next I looked through the Journal of Neuroscience to see if I could find anymore interesting information about illusory contours. I liked how it explained illusory contours as being the absence of something. I also learned that psychologists still don't fully understand how this works and I can fully understand. I don't know myself how this function works and what makes the brain think up these things.
http://www.jneurosci.org/content/27/20/5269.full
So I didn't go to an actual website for my last entry, but I looked through Google images for examples of illusory contours and I found so many that I liked! They made me super interested in illusory contours and I can tell what all the hype is about. One of my favorites was a bunch of black circles with white lines in them to make you think you are seeing a cube or 3D box when you actually are not.
https://www.google.com/search?q=illusory+contours&client=firefox-a&hs=7CN&rls=org.mozilla:en-US:official&channel=sb&tbm=isch&tbo=u&source=univ&sa=X&ei=GjXAU_2INMWtyATM94DABg&ved=0CCoQsAQ&biw=1280&bih=672