1) Discuss what your text has to say about change blindness (or a closely related topic).
2) Search the Internet and follow your interests as they relate to change blindness.
Discuss the sites you visited, the information you found, and how it relates to Sensation & Perception. Make sure you integrate the information from the sites (Do not discuss the individual sites).
3) Provided a breif overview of the talk I presented in class last week on how the brain lies
4) Discuss how changeblindness relates to the talk I gave
1.My textbook doesn’t mention change blindness; however it does talk about motion agnosia which is a movement perception. It is caused by damage in an area of the brain that may correspond to the area identified with movement in the monkey: the MT cortex. In the textbook a woman describes eye problems that she was having. She had a loss of movement vision; she had difficulty in pouring drinks because the fluid appeared to be frozen. She didn’t know when to stop pouring because she wasn’t able to see the fluid rise in the cup. She also had problems with dialogue because she couldn’t see the face movement. That problem leads me to mention prospagnosia, an inability to identify faces. People with this disorder have trouble recognizing people that they have known for years. It is usually associated with damage to the temporal lobe, from the location of monkey face selective neurons in the IT cortex.
2.In the experiment, two completely different looking people with different colored shirts are the confederate. People walked up and were given a consent form to sign from one of the confederates, he would duck down and the other confederate would pop up. 75% of the time the participants didn’t notice that the guy had changed. This is what they called change blindness; where people miss large changes to their visual world that would appear to be obvious when aware it’s going to happen. This phenomenon that is at times striking that even experts on vision and attention have had a difficult time believing the results of change detection experiment. Experiments already done have demonstrated what is already known about change that occurs during saccades. This change blindness could be explained by failing to detect change during saccades because as our eyes are rapidly moving over the visual field, change is occurring over the entire retina. These changes in our current visual field may serve to mask the change in the scene.
http://boingboing.net/2009/12/14/change-blindness-exp.html
http://mixingmemory.blogspot.com/2005/01/i-didnt-even-notice-that-you-had-new.html
3.How the Brain Lies lecture discussed different visual illusions and perceptual attention. It first started off with the physiology of our vision. The cones detect color, fine details, and bright lights. The rods are the gray scale, detect movement, and are the blurry area. There is a chunk of spot missing called a blind spot in the rods. We have two visual systems: bright and dim light and our vision can go from one to another. The visual illusions part of lecture gave a few examples of illusions like images that look like they’re moving when it’s actually an image that is not moving. The perceptual attention part of the lecture took a good amount of time looking at faces and how we detect what race someone is. When someone is doing a line up and trying to find the person who was guilty, the people who picked the line up would chose people that they thought could have been guilty. Someone’s face that has been plastered on television for weeks could be in that line up and could be selected as being guilty because that face has been seen a lot. This means that our memory is reconstructive and we will think that a certain person is guilty because we have seen them at some point in our life.
4.Change blindness could be seen as our brain lying to us because something is obviously happening right in front of us, but since we aren’t paying attention to it, our brain makes it seem like it never happened. Even when told what happened, we still can’t remember it because our brain makes us think that it never happened because we didn’t catch it happening visually.
1. My textbook describes change blindness as the inability to detect unattended changes that are occurring in changing environments. We tend to be aware of our environment in general, but might not pay attention to the details in that environment. Experiments have been done that support this idea, including one done by Levin and Simons in 1997. In their study, a video was shown to each subject of two women talking, and the participants were instructed to pay close attention. In the video a few different small changes were made in different frames, such as a plate being a different color than in previous frame and the women in the video having their arms in a different position than before. With the ten people who participated in this study, only one mentioned anything about noticing changes.
2. http://www.youtube.com/watch?v=mAnKvo-fPs0
I found this clip on YouTube that demonstrates change blindness. This was an experiment done at Harvard by Daniel Simons, the same psychologist who helped run the change blindness experiment that was mentioned in my text. In this experiment, people went up to a counter for an experiment that they were going to participate in and talked to a man who was instructing them what they were going to have to do. At one point, this man ducked under the counter to grab something and crawled away and another man, who did not bear resemblance to the first man, took his place and stood up and started talking to the participant. They found that later, when asking the participant if they had noticed anything unusual about this encounter, 75% said that they did not. Simons says that it is still unsure why some people are able to notice these differences and some are not, but he speculates that it might be just a coincidence. The people who do notice differences just happen to be paying attention to a certain detail about the person, such as the shirt color, hair, or whatever and then notice when it has changed, but for the majority of people, they just happen to be paying attention to something else at that point.
http://www.youtube.com/watch?v=ubNF9QNEQLA
I also found another clip that tests your change blindness. Just thought it was kind of fun to watch and to try and see how many of the things I could notice.
3. The brain lies to you in many different ways. We can perceive things that aren’t there as being there, like in a few of the illusions that we have seen throughout our classes, like the glowing triangle and neon worm, and we can perceive that things that actually are there, aren’t, like in our recent lecture on camouflage. Things can get lost in our blindspot, and we might not even be aware that they are there. We are able to test and prove that we have blindspots by closing one eye and moving toward a picture with two figures. At some one of the figures will disappear. Another way it lies to us is by not being fully aware of all the details that might be present in our environment. This is called change or inattentional blindness and it can be demonstrated by the video clip where you are told to pay attention to how many times the basketball is passed between team members and you are so focused paying attention to that that you don’t even notice other things entering the scene, like in this case, a gorilla.
4. This relates to the how the brain lies to you lecture and other talks that we have had in class because we like to think that we are very aware people and that if we are in a situation, that we are picking up on every detail, but this is not the case. Our brain can’t pick up on every detail at once and a lot of the time we just pick what we feel in the most important stimuli in the situation and focus our attention on that.
1) My book describes change blindness as the phenomenon that occurs when a person is viewing a large scene fails to detect large changes that occur in the very scene they are viewing. This typically has to coincide with some visual disruption such as eye movement or obstruction of the scene for change blindness to occur. This is due to the brain’s tendency to ignore major changes, and focus on certain stimuli. Most people feel very strongly they would notice any changes in the environment. They trust strongly in their visual system and overestimate their visual abilities. The visual system can be misled however resulting in change blindness.
2) http://www.youtube.com/watch?v=8tqd5EnTg-Y
I searched for sleight of hand tricks on the internet. These relate to change blindness because many magic tricks happen right in front of our face. We focus in on one movement the magician is doing, and completely ignore other movements. Magic tricks use our brains tendency to miss some movements in order to make things “magically” happen. Our confidence in our visual senses make us believe that there is no way we missed obvious movements by the magician. What’s so interesting about magic tricks is that we as the audience are often time focusing in as hard as we can to the stimuli convinced we will solve the trick. Even when we are working hard to focus on movements, our brain lacks the ability to pick up on it.
http://www.ritacarter.co.uk/page16.htm
The second website I found explains how our inattention blindness is exploited by magicians. Magicians realize that if they focus the audience’s attention elsewhere, it leaves openings for other movements in the less focused on areas. All of this occurs right in front of our eyes. The website also discusses that change blindness has serious implications for drivers and pilots. Focusing on certain stimuli can be dangerous because we miss dangerous cues in other areas. Our brain only has a certain amount of attentional ability to provide to our environment, and this leaves openings for us to miss movements.
3) How the Brain Lies to You focused on how our brain misperceives stimuli presented to it through our visual system. Visual intelligence and organizational rules our brain follows to make sense of the stimuli may not always be correct. The cues our brain focuses on when making sense of visual stimuli can be manipulated to give us false impressions of characteristics of what we are viewing. The eye is composed of rods and cones. The rods focus on movement, grayscale, and function best in dim lighting. The cones are best for perceiving color and fine perceptions.
I also enjoyed the part of the lecture which discussed how priming effects can effect which race we perceive a person to be. Examples of these were provided in mixing two different politicians faces, and having the audience stare at the person’s portrait and then viewing the mixed face. The mixed face looking remarkably different from the first face shown due to the priming that took place. This may be to blame for misidentification during police lineups. Seeing a suspect’s photo on television can prime the jury or population’s perceptions.
4) Change blindness can be seen as our brain lying to us because we misperceive the stimuli being presented to us. Our brain focuses in on different visual cues to analyze and make determinations about objects in our environment. It does this based on “rules” that is has developed over time. Sometimes the rules we view by however are incorrect and lead us to misperceive the environment. Change blindness is an example of how our brain can focus in on particular images, and miss some stimuli completely in the process. It’s also an example of how we overestimate our visual abilities, and believe that what we saw is exactly what happened.
1. My text doesn’t cover change blindness directly but I found some information on blindsight. I have learned about blind spots before but never blindsight. Blindsight is when patients with a damaged striate cortex report seeing things in there blind areas. When a light is shown in their blind area they report seeing multiple spots of light even though it’s in their blind area. Not only do they report seeing the light they can determine where it is and locate it. They still can’t see images etc but can determine the lights location. Studies have determined that this is due to extra-striate cortical areas.
2. I went online and found two videos that are examples of change blindness. You mentioned them in class last week and I wanted to find them to see for myself. The first video is the experiment where the guy ducks under the counter and another guy pops up in his place and the majority of participants don’t notice the difference. The second video is with the basketballs and the moon walking gorilla in the background. These videos relate to change blindness because our eyes are focused on a certain aspect of the situation and not on the gorilla or the guy handing us the papers. In the first video the participants’ attention is focused on filling out her personal information on a sheet of paper. When she hands it back her attention is then focused on the new set of papers and the directions on where to go next. In reality she more focused on directions than on who is giving them to her. When I watched the gorilla video for the first time and counted the times the ball was passed. I was focused on the ball and not the background of the video. My brain filled in the blind spots and in a sense lied to me. Change blindness relates to sensation and perception because change blindness is how the brain tells us we are seeing things. Our brain constructs the missing piece of the puzzle that is from our blind spots and tells us what we are seeing even if it is wrong.
http://boingboing.net/2009/12/14/change-blindness-exp.html
http://www.youtube.com/watch?v=Ahg6qcgoay4
3. In your talk you gave last week you talked about how the brain fills in the areas we don’t see whether it is due to peripherals or our blind spots. The eye sends the message to the brain and the brain constructs the image and fills in the missing area. So in a way the brain lies to us. We really couldn’t see a certain part of the image but our brain tells us we saw the whole thing. You gave the example of a witness to a crime testifying that they saw the criminal out of the side of their eye. They said they could identify the person but in reality our peripheral vision is the brain lying to us because the rods in our eyes don’t have the acuity of cones so our vision isn’t accurate. In a lineup the person wouldn’t be able to pick them out unless they had a distinct characteristic that was remembered, such as a tattoo etc. You also talked about how after looking at a picture of a certain person for a certain amount of time it can change how we see the next person. (The Kerry Bush example) One of my favorite examples is the gorilla/basketball video that I mentioned earlier but we couldn’t see in class.
4. Change blindness relates to what you lectured on last week because change blindness is our brain lying to us. With the videos I talked about our brain is focusing on a certain aspect of the video. In the first one the participant fills out the paper and looks more at the paper than the first guy. Then when the guy changes her brain tells her it’s the same guy. In the video with the gorilla our attention is focused on counting the times the ball is passed not on the other team or things happening in the background. Our brain tells us there’s nothing there. It fills that space with a constructed image or idea.
1.) The book I have didn’t talk about change blindness, but it did cover a lot of information about blind spots. A blind spot in relation to our visual system is when there is no visual response to light striking a portion of the retina. This response to the light in the retina is required in order to process the visual information from the brain to the eye. The axons of the retina ganglion cells gather together to leave the eye through the retina. So you can see why this poses a problem. When there is no response to the light there is no information passed to the brain, therefore that information is not making sense to us. We then can’t react to what we are seeing and that can cause some problems.
2.) Change Blindness occurs when a person fails to identify large changes in a particular scene. This usually can result from a disruption in eye movement or for a brief moment we are obscured from that image or scene. According to some readings I did online change blindness can occur when differences in our expectations of a certain scene happen and this causes us to miss part of what we are watching. Our memories, concepts, creativity levels, and belief systems are challenged by what we are watching and therefore we are missing it or distorting the image of what is really happened. One example that I think fits this description well is the idea of watching someone get murdered or if a person gets raped. They tend not to focus in on what is really happened because they don’t want it to happen. Or perhaps it is against their personal morals, so they may refuse to believe that it is happening. Another example that is key to the idea of change blindness is car accidents. People aren’t focused into the surroundings around them and therefore run a stop sign.
3.) The discussion done in class the other day covered a lot of topics dealing with how the brain lies to us. You mentioned that it was physiology and the brain fills in gaps of things that we might not have seen, but this is needed in order to make sense out of what we have just seen. It was also talked about that through visual illusions the brain begins to see things that are not really there. The brain also sees things move when in fact they never did. Cones detect color, fine perception, reading, and is seen best in brighter lights. Rods are used to detect motion. It was interesting to hear that the world that we regularly see is in fact blurry. We have to look around and focus objects in to understand what we are looking at and then the brain fills in what we didn’t see. It was also mentioned that each person has two visual systems. One is used for bright lights and the other is used for dim lights. This is used during the different times throughout the day (nighttime, daytime). You also talked about memory and how is it reconstructive. Memory is also more like a puzzle and as much as we would like to think, it doesn’t play like a movie.
4.) Change Blindness relates to a lot of the material we covered in class. Our brain fills in the pieces of what we didn’t see. Change Blindness is when we don’t see a large part of a scene. These two ideas relate because we may not have seen a large part of what happened, but we reconstruct that missing section with what we think may have happened. An example of this would be if a person got in a car accident. That person probably won’t remember what happened right after they got hit, but they have a pretty good idea. Therefore they tend to make up the story of what they think may have happened. They smacked their head on the steering wheel and that is why they have a headache.
1) My text starts out by defining change blindness which is the difficulty in detecting changes in scenes. The importance of attention in determining change blindness is demonstrated by the fact that when Rensnik added a cue indicating which part of a scene had been changes, participants detected the changes much more quickly. Change blindness also occurs in scene changes in a film. Not only does change blindness show the importance of attention for perception, but also because it is a counter intuitive result. Even though people feel that they would detect the obvious changes, they fail to do so when tested as well. David Levin coined the term change blindness blindness. It describes the face that people are blind to the fact that change blindness will occur. The text states that one reason people think they would see the changes might be that from past experiences they know that abrupt changes rarely occur in real life, and when they do occur, they are usually noticed. Changes in real life are often expressed with motion, which catches our attention. But in change blindness experiments, the change signal is removed by presenting a blank field between the two almost-identical stimuli. Hence attention is not directed to the change, and we miss it. One of the paradoxes of vision is that although you can't make out the details of objects that are far off to the side of where you are looking, the overall picture appears to be sharp and focused. This observation can lead the impression that the visual system creates a clear representation of the whole scene, but the results of the experiments show that this isn't true.
2) http://www.cogsci.uci.edu/~ddhoff/cb.html
This website gives a demonstration of what the participants in a change blindness study would be shown. It threw me off at first because I was confused why a picture was flashing, but then I realized it was suppose to be flashing. It says it takes most people a long time to find the change. I could not find it and gave up because the flashing was giving me a headache. If you find it, let me know :P
http://www.youtube.com/watch?v=38XO7ac9eSs
This video is an interactive experiment done by Harvard University. It demonstrates experimenter #1 handing a consent form to the subject. After the subject signs it, the experimenter bends down to put it away, as he is down, experimenter #2 crawls behind the counter to take the place of experimenter #1. This is to show how much attention is used by the subject, if they notice the experimenters looked different from the first appearance and the second appearance after putting the paper away. In this study, 75% did not notice the switch of experimenters. It is funny because you can see the two people who knew the person changed because they laughed when the second experimenter handed them a packet to take with them in the next room.
3) The discussion you gave in class had to do with how the brain lies to us. It is physiological rather than all psychological and the brain tends to fill in gaps of things that we might have missed, but this is needed in order to make what we saw a as a whole rather than parts. In visual illusions, the brain begins to see things that technically not there. Each individual has two visual systems; one for bright lights and the other for dim lights. This is used during different times of day (nighttime, daytime). I hate driving at night because my dim light visual system sucks. Memory is reconstructive; it puts together puzzle pieces and fills in the gaps, unlike a movie where each change is provided by a different shot. I liked when you talked about after looking at a picture of a specific person for a certain amount of time, it can change how we see the next person (Bush to Kerry example).
4) Change blindness relates to your talk because it relates to how the brain lies to us. It isn't necessarily the brain is lying, but if we happen to not focus on a specific thing (that happens to be the one to change in an experiment), then we do not notice the change. That large gap is filled in with, for example, a random experimenter wearing the same clothes in that video I posted. The first thing the subjects probably noticed was the color and pattern of shirt he was wearing. If the subjects had noticed the hair color for example instead of the shirt, then they would have noticed the change in experimenters.
1) My text says that we are surprisingly slow at detecting changes to successive views of scenes. We must attend to and encode each object of the scene to notice changes. Some objects are paid more attention to than others and the ones that are not given such attention do not stay in our memory. We must process the scene to notice changes.
2) http://www.uxmag.com/design/change-blindness
http://www.ritacarter.co.uk/page16.htm
Some changes that we might see as obvious can be easily missed such as a change of clothes in a person we are in contact with. We may not even notice if a person behind a counter, who is helping us, bends down to get something and a different person stands up to help us. We may not even notice if a person we are giving directions to changes. Things like gender and race can go unnoticed.
Something else that is interesting and almost everyone can relate to is driving and change blindness. Almost all of us have been in the situation where we are about to pull out from an intersection and we think we have looked every direction and seen everything but then when we pull out, we hear a car horn because we just cut in front of someone. This didn't happen because we weren't paying attention. This just happened because we weren't giving our attention to the right area.
3) The lecture on how our brains lie talked about how we create a full story from the small image we see. When we are looking at something, we can't really see the surrounding environment but that full picture comes from what we have already seen or what we think we are seeing. In order to see the whole picture we would have to be looking from side to side constantly. Part of the lecture that was very interesting to me was the part that talked about witness testimony. By now we realize how wrong our visual system can be. If we see someone out of the corner of our eye they may not look how we think they look. Also, Otto's example of his car in the Disney World parking lot was interesting. Light can change the way we see color and the way we recognize something. Something that may relate more closely to change blindness is the Bush-Kerry pictures. One was Bush, one was Kerry and the middle one was a mixture. It was weird how when we looked at the actual picture of Kerry or Bush for an amount of time, the middle picture looked like the other one.
4) Change blindness relates to the talk because they both demonstrate how much can change in our visual environment without us recognizing it or how another factor like light can change how we see things. If we can go without noticing a change in race of a person, how can we be so sure about identifying someone in a criminal case? Can you ever be sure about what you are seeing? Change blindness and the lecture would suggest that we cannot.
1. Change blindness was described as the failure to notice change between two scenes. If the change doesn’t alter the gist, or meaning, of the scene, big changes can remain unnoticed. It talked about a picture memory experiment done by Rensink. He showed observers one picture at a time. They would look at the picture for a while then it would disappear for 80 ms and would be replaced with a similar image. The participants’ job was to determine what had changed in the picture. The picture would go back in forth with a brief interval between them until the observer figured it out or until the time ran out. It took the participants several seconds to figure the changes out some don’t didn’t get them at all. If the removed the blank screen between the objects the change was obvious because they experienced a form of apparent motion. This ties into environment issues to because we may in fact be aware of our environment, but miss key changes in it which cause us to misconceive things. An example might be if your describing the scene of a crime and the location you might experience some change blindness which could led you to miss certain parts out of the crime scene. Another famous example was the Simon and Charbis 1999 experiment with the gorilla. They had the participant count how many times the ball had been passed from the white shirt team. As a result of that, most of them missed the gorilla that walked in between them. This pointed out that our eyes only see only one thing at a time which is the current object of attention. Another reason why we miss things is because our attention constitutes a bottleneck between or visual world and our conscious world. If the particular stimulus doesn’t make it to the bottleneck we our effectively blind to it. Change blindness can have a serious effect on a person if they aren’t cognizant of it. Some people are so adamant about what they see that is would anger them if they are made aware of change blindness. When Zach performed that magic trick on me, it made me upset that I didn’t pick up on the change blindness.
2. http://www.youtube.com/watch?v=aKVj2mssYxA&feature=channel
I found a clip on youtube with Chris Angel doing some magic or some change of blindness stuff. He had a bottle and a cap and some way shape or form he managed to slam the cap inside of the bottle without the cap being bent. This had me stunned because it happen so fast that I didn’t even get to see the trick he used. This showed a good example of change in blindness because it happens so quick that we missed the actual change. The trick tricked your perception on the object because we know that a cap can’t really fit inside a bottle without being bent because it goes on top of it ,but this changed our perception of the bottle to maybe think that it’s some form of trick bottle or something. Also it violates some of the laws we use in our visual intelligence.
http://www.youtube.com/watch?v=bTO1SuM2Qi0
Another video I found showed some pick pocketing techniques which have a lot to do with change blindness. He pulled a couple guys from the street and acted like he was talking to them when he was in fact pick pocketing them as he was speaking to them. The video shows the various pick pockets with a red circle around each one. He did this to make people aware of different changes in blindness and to display the various changes. This perception has something to do with touch and visual perception. The average eye would be able to see him taking something out of their pocket because of how fast it happens. With touches that feel normal, it makes it hard to realize that something has be taken or something has gone strong because it blends with the ordinary.
3. In the talk you gave about the brain lying to you, I learned a lot because you pointed out the little things that happen which causes you to alter your visual intelligence. One example you showed was the rabbit duck example which displayed how we reconstruct things according to how we perceive them. Also this example shows how the brain borrows and steals from other source which causes it to be less accurate. We have certain blind spots in our cones and rods which also play a part in misconstruction. One of the biggest things that play a part in our brain lying to us was light. The example you used was the one about how your car became a different color at night which made it difficult for you to find it. This plays a role in how we perceive most things especially clothing. All these things play apart in eyewitness testimony because these factors are what causes our visual intelligence to be impaired.
4. These relate to change blindness because it makes us unaware if the change in scenery. As different events happening such as a car accident, people perceive different things due to our different constructions. Lighting plays a part in that because someone might have been wearing sunglasses which could alter the colors you see. The accident could have taken place in the dark which would cause different perceptions. Also time in which you looked at the accident would play apart in misconstruction. You might have turned your head for a quick second in which it would cause your brain to reconstruct the incident like a puzzle.
1. Change blindness was described as the failure to notice change between two scenes. If the change doesn’t alter the gist, or meaning, of the scene, big changes can remain unnoticed. It talked about a picture memory experiment done by Rensink. He showed observers one picture at a time. They would look at the picture for a while then it would disappear for 80 ms and would be replaced with a similar image. The participants’ job was to determine what had changed in the picture. The picture would go back in forth with a brief interval between them until the observer figured it out or until the time ran out. It took the participants several seconds to figure the changes out some don’t didn’t get them at all. If the removed the blank screen between the objects the change was obvious because they experienced a form of apparent motion. This ties into environment issues to because we may in fact be aware of our environment, but miss key changes in it which cause us to misconceive things. An example might be if your describing the scene of a crime and the location you might experience some change blindness which could led you to miss certain parts out of the crime scene. Another famous example was the Simon and Charbis 1999 experiment with the gorilla. They had the participant count how many times the ball had been passed from the white shirt team. As a result of that, most of them missed the gorilla that walked in between them. This pointed out that our eyes only see only one thing at a time which is the current object of attention. Another reason why we miss things is because our attention constitutes a bottleneck between or visual world and our conscious world. If the particular stimulus doesn’t make it to the bottleneck we our effectively blind to it. Change blindness can have a serious effect on a person if they aren’t cognizant of it. Some people are so adamant about what they see that is would anger them if they are made aware of change blindness. When Zach performed that magic trick on me, it made me upset that I didn’t pick up on the change blindness.
2. http://www.youtube.com/watch?v=aKVj2mssYxA&feature=channel
I found a clip on youtube with Chris Angel doing some magic or some change of blindness stuff. He had a bottle and a cap and some way shape or form he managed to slam the cap inside of the bottle without the cap being bent. This had me stunned because it happen so fast that I didn’t even get to see the trick he used. This showed a good example of change in blindness because it happens so quick that we missed the actual change. The trick tricked your perception on the object because we know that a cap can’t really fit inside a bottle without being bent because it goes on top of it ,but this changed our perception of the bottle to maybe think that it’s some form of trick bottle or something. Also it violates some of the laws we use in our visual intelligence.
http://www.youtube.com/watch?v=bTO1SuM2Qi0
Another video I found showed some pick pocketing techniques which have a lot to do with change blindness. He pulled a couple guys from the street and acted like he was talking to them when he was in fact pick pocketing them as he was speaking to them. The video shows the various pick pockets with a red circle around each one. He did this to make people aware of different changes in blindness and to display the various changes. This perception has something to do with touch and visual perception. The average eye would be able to see him taking something out of their pocket because of how fast it happens. With touches that feel normal, it makes it hard to realize that something has be taken or something has gone strong because it blends with the ordinary.
3. In the talk you gave about the brain lying to you, I learned a lot because you pointed out the little things that happen which causes you to alter your visual intelligence. One example you showed was the rabbit duck example which displayed how we reconstruct things according to how we perceive them. Also this example shows how the brain borrows and steals from other source which causes it to be less accurate. We have certain blind spots in our cones and rods which also play a part in misconstruction. One of the biggest things that play a part in our brain lying to us was light. The example you used was the one about how your car became a different color at night which made it difficult for you to find it. This plays a role in how we perceive most things especially clothing. All these things play apart in eyewitness testimony because these factors are what causes our visual intelligence to be impaired.
4. These relate to change blindness because it makes us unaware if the change in scenery. As different events happening such as a car accident, people perceive different things due to our different constructions. Lighting plays a part in that because someone might have been wearing sunglasses which could alter the colors you see. The accident could have taken place in the dark which would cause different perceptions. Also time in which you looked at the accident would play apart in misconstruction. You might have turned your head for a quick second in which it would cause your brain to reconstruct the incident like a puzzle.
1) My book doesn't talk about color blindness but I found a lot of information on color deficiency. Color deficiency is basically the same thing, its the inability to perceive some colors that people with normal color vision can perceive. The text starts off talking about the first famous case which was a 19th century chemist names John Dalton. They used to actually refer to color deficiency as Daltonism. There are three major types of color deficiency; monochromat, dichromat, and anomalous trichromat. They all refer to the amount of wavelengths a person will need to see different shades of certain colors. By classifying them into three different categories it takes an objective way to look at how different people will see colors. The last major thing that they talked about in the chapter was color vision test, which are called Ishihara plates. Its a way of people taking different test to see if they are color blind or how bad they will be affected by it.
2) The first site I went to was wikipedia just to figure out the definition of change blindness. Change blindness is the phenomenon that occurs when a person viewing a visual scene apparently fails to detect large changes in the scene. It also goes on to say that for it to occur something needs to change in the scene, for example you need your eyes to saccade across an image or a scene. The next site I found did a lot of the same type of things that you did in class, showing two different people and trying to see if they are able to keep up with the large changes.
http://boingboing.net/2009/12/14/change-blindness-exp.html
It was a larger scale experiment that switched out people in the middle of the experiment and the participants never even noticed. Its a lot like how you were able to make George Bush and I think John Kerry look a like. The information is directly relevant to sensation and perception on the fact that we overlook so many different things that are right in front of us. Again the experiment one man in a yellow shirt handed the people their surveys and a blue man switched spots with them and they never even noticed.
3) What you demonstrated in class was a smaller version of change blindness. You tried to get two different people to look like the same person if you looked at a spot long enough. It was a way to show that our eyes can basically fake us out into thinking something isn't there or is there when it is not. It was a quick way to show how our eye adjust to different things and that some things that are right in front of us are completely false. Im assuming this is all very important for the courtroom and talking to people who witnessed different crimes. It just shows how things can change right in front of our eyes and we would never even know the difference.
4) Change blindness and your talk are almost the exact same thing. Your talk was just on a smaller scale showing us how two different people can look a like if you look long enough. And change blindness is when something dramatic and large that is right in front of you can change and you wont even notice because your eye is lying to you. The link up above shows a perfect experiment about how we are not seeing the things that are right in front of us. Its funny cause I think change blindness could also be something that is solved by people being more aware of what is going on, a lot of the times people are trying to get through their days and dont even pick up on some of the dramatic things that are right in front of them.
1) The text talks about change blindness as the inablility to detect unattended changes that are occurring in changing environments. This means that sometimes we may be oblivious to the details in the environment because we tend to see the big picture just like in the concept of camouflage. The book talks about Levin and Simons doing an experiment in which they show a video of two women talking to the subjects. They were told that they must pay close attention. They made slight changes in the background of the video however the subjects barely noticed the changes because they were so focused on the women.
2) http://www.youtube.com/watch?v=mAnKvo-fPs0
This is a video of a change blindness experiment. The subjects were told to to go up to this counter and sign a consent form to be in the study. There was a guy behind the counter who issued the form and after they signed it he bent down to put it away and another guy stood up. They were wearing the same type of shirts but they were different colors and they were different looking people. Most of the subjects didn’t even notice the change. The ones who did were analyzed and the researchers were unsure if it was just a coincidence that they noticed or if these people just pay more attention to detail and possibly have a different brain pattern.
3) The lecture on how the brain lies to us was about the visual system and the cones which detect color , details, and lights. The rods which detect movement and they have a blind spot on them. The lecture said that we can go between bright and dim lights easily. You spoke briefly of visual illusions and then we spent a lot of time talking about face recognition. It was said that in a line up of criminals we were going to pick the one who we thought would most likely be guilty not who actually was. We also use different features to detect the race of a face. It says that the memory is reconstructive and we are more likely to pick out someone that we have seen before multiple times than someone that we have never seen or only saw for a second.
4) I think change blindness definitely relates to the lecture it could be closely tied with the fact that our memories are reconstructive. In the video the people are not really looking closely at the two men so their brains have convinced them that they are the same person because they only briefly glanced at them. Even though their vision might see two different people their memory have convinced them otherwise.
Change Blindness is described in my text as a phenomenon that occurs when a person viewing a visual scene apparently fails to detect large changes in the scene. If the image changes the viewer may experience change blindness and when there is a visual disruption change blindness can occur. This happens because of the brains visual process seeing what it wants to see or what it expects to see, and ignoring major changes that may occur.
2) http://www.cogsci.uci.edu/~ddhoff/cb.html This website gives an example of change blindness. The image constantly switches back and forth between two images. The two images only have one thing different in each picture. It is very hard to see the change if you aren’t looking in the right place. This suggests that we can focus on one thing at a time when looking at an image. Change blindness is basically a failure to notice change between two images and this is an example of not noticing change, because the two images appear to be the same. http://cognitrn.psych.indiana.edu/CogsciSoftware/ChangeBlindness/index.html This website is made by Indiana University and discusses change blindness. It asks the questions what are we really aware of when we look out into our world? Because of Change blindness we are starting to wonder what we are actually missing from our day to day visual experiences. A number of studies on change blindness have posed the idea that instead of storing complete knowledge about the world in our memory, we use the world as an external memory source. There are many examples on this website that are awesome. I suggest you try them out for yourself. This is a great website that deals with change blindness, because it explains and shows example of change blindness and how studies are helping us understand more about this.
3) In class you talked about how the brain lies to us. We see our visual system as something that is concrete and something that doesn’t lie to us and doesn’t change. We don’t see it as things that our visual system makes up or interprets in the ways that may be wrong or different from others. Your lecture discussed how the brain interprets stimuli that are present to our visual systems, and our interpretations are not always correct. You discussed how our eye is structured and the parts of the eye which was a helpful refresher since we learned that in the beginning of the course. My favorite part of the lecture was the George Bush and John Kerry. It was amazing the more you look at George Bush the more the look alike in the middle looked like John Kerry and vice versa. I loved how you brought examples in that were interesting and would allow us to become more involved and more interested in how the brain lies to us. Our brain can only focus on one stimuli and this allows for things that we may think we see to sneak by us.
4) Change blindness relates to our visual system not picking up on a major change in an image or in the environment around us. This relates to our brain lying to us, because when we think we would see something such as a monkey running across a room and then we miss it because of change blindness this is our brain “lying to us”. We definitely rely heavily on the things we see, and don’t think that we will see things that aren’t there or miss big changes, but it definitely happens, and our visual systems miss more than we know.
1)My textbook doesn't discuss change blindness it only discusses blindness. It is a common conception that a person who is blind lives in a world of total darkness or formless diffuse light. While this description is true for some blind people, many people who are classified as legally blind do have some vision, and many can read with the aid of a strong magnifying glass. According to the definition accepted in most states, a person is considered legally blind if, after correction with glasses or contact lenses, he or she has a visual acuity of 20/200 or less int he better eye. A visual acuity of 20/20 means that a person can see at 20 feet what a person with normal vision can see at 20 feet. However, a person with an acuity of 20/200 needs to be at a distance of 20 feet to see what a person with normal vision can see from a distance of 200 feet. When we define blindness in terms of visual acuity, we are evaluating a person's abilitity to see with his or her fovea.
2) Change blindness is a phenomenon in visual perception where apparently large changes within a visual scene are undetected by the viewer. Typically for change blindness to occur, the change in the scene has to coincide with some visual disruption such as an eye movement or a brief obscuration of the observed scene or image. When change blindness was first explored systematically by George McConkie and his colleagues in the late 1970s, the phenomenon was largely limited to the study of changes introduced to words and text during eye movements
http://psychology.wikia.com/wiki/Change_blindness
I found a youtube video that explains change blindness. The person in the video talks about how we often miss large changes in our world from one change to the next. We often do not realize large changes that take place that would appear to be obvious unless somebody know's that these large changes are going to take place. In this video and experiement was conducted to demonstratue how a majority of the population does not notice large changes. An interesting question is brought up in this youtube video. Why do some people notice these obvious changes when others do not notice these changes? This question intrigues me and I am not curious to know further research on this topic.
http://psychology.wikia.com/wiki/Change_blindness
3) You started out by talking about the physiology of the eye. You mentioned that everything goes through our eye upside down (this is what started your presentation on how the brain lies). You talked about how we have two visual systems (shades of gray, dim lights, and bright lights, colors). You talked a lot about how the breain fills in the gaps. How although we may not remember the exact events our memory some how pieces together parts of the event which in turn leads us to the conclusion of all the pieces that took place in that event. You talked about how the brain processes what we see from adaptations, what we think we want to see etc. Lastly, you emphasized how our memory is reconstructive and that the brains job is to put the pieces back together.
4) Change blindness is the brain not recalling a majorly obvious change. In your talk you discussed our our memory/brain is suppose to fill in the gaps however; our brain does not recall change blindness. How is our brain/memory suppose to fill in the gaps if our brain cannot even recognize a major obvious change that occurred right in front of us?
1. my text touches briefly on change blindness, explaining that it occurs in details that our eyes miss. It is demonstrated in pictures that came from 4 frames of a short video. Throughout the frames, items such as the clothes characters are wearing or colors of objects in the video changed but the first go round, only 1 out of 10 people watching it could pick up on this. Even when they were told there would be things wrong and were shown the video again, many didnt catch the changed objects.
2. Staying on this same note, I decided to visit http://www.moviemistakes.com/best.php and check out some mistakes that were made in big time movies and weren't caught. This has always been something that is fun to go back and check out, plus I know that in Hollywood there are some people who have the job of watching for these mistakes and making sure things stay the same throughout so it shows that even when you make a career or stopping these mistakes, you aren't always able to do so because of the tricks or change blindness that occur in our brain. Seems like it would be a pretty easy job, but seeing how many mistakes have been over looked and are overlooked by the average person until someone exposes it, I'm sure it is quite difficult!
3. In the lecture "How the Brain Lies to You" we started with some basics of the eye and how it works, setting up what it is in the eyes that contribute to these misconceptions and lies. There was discussion about how witnesses in court can hardly ever be certain of what they are saying because lighting, timing, or emotions at the time of a crime can cause the lies to begin. For a good portion of the lecture and my favorite part, we looked at face morphing and how seeing certain images can lead us to trick ourselves into thinking we see someone. (Thinking a mixture of George Bush and John Kerry really was John Kerry). The memory is like a puzzle, filling in missing parts as it does with some optical illusions..we connect the dots to make a shape. Our brains job is to create the pieces we forget.
4. Change blindness is sort of missing out on those details that we could make up later on when/if asked about them. A great example was the video we were told about with 6 people running around. A gorilla steps on screen at one point but people that watch the video wont even notice that a large majority of the time. Is it that we see only what we want to see or does our brain really only allow us to see so much at one time?
1. Change blindness occurs in a visual scene where the viewer fails to take notice of a large change. Many explorations have been done on the change blindness study. It notes that change blindness often occurs during eye movement. It is said that visual short term memory may be a problem in this phenomena. It may be possible that some of the information seen is not even being stored at all.
2. I found this fantastic article from the New York Times on change blindness. The author claims to have been at a symposium and a professor speaking talked about change blindness. The professor says there are two type of vision in this phenomena. These two classes are bottom-up and top-down. Basically bottom-up looks for anything vivid. We could say a red, flashing light, or a wild hand waving in the air. Top-down is more focused on our keen eyesight. The article gives a reference of a black suitcase on the carousel at the airport. There are a thousand black suitcases, but using top-down vision we can found our personal case with its 3 unique scuffs and broken wheel.
This article really illuminated the significance of change blindness to me. While the obvious change is staring at us in the face, we are unable to see it. At what point does our brain give attentiveness to minute details in visual stimulation. The professor in this piece goes on to explain that we would need a superhuman brain to absorb and sort everything we see. Like we've been talking about in class, the professor says we strip down the scene with things that we recognize or are familiar with. We use our bottom-up class to pick out important objects, and then our top-down class to analyze the details of those objects.
3. This article relates a lot to the talk that was given in class. Even with these obvious changes in scenery, our brain does not decipher them. The brain must pick out whats important, focus on them, and tell the body how to react to it. The brain most certainly lies to us when we think about change blindness.
When thinking about how the brain lies I thought of those nudey touch-play machines inside of nightclubs and restaurants. Change blindness can be used to explain why we find the "Photo Hunt" game challenging. The first picture is right in front of us, we identify the large objects first but half of the time the change isn't in them. This is how the game works, it plays on the fact that our brain needs to recognize important objects first, thus it puts minute changes all around that are hard to detect (heavy intoxication probably does not help either)
4. Change blindness is a perfect adaption in seeing how the brain works and does not work. In essence, our own brain can lie to us. This can make us see things that are presumably there, but really not. It can make us view colors oddly depending on the angle we see them at, and make us think somebody was an Asian when they were really an Indian.
Oops, here is the link to my article.
http://www.nytimes.com/2008/04/01/science/01angi.html
1. According to Wolfe, Change blindness is the failure to notice change between two images that are shown in sequence. If a brief time synapse is not placed between the images, changes may go unnoticed due to an apparent motion effect.
2. I found a video of an experiment on change blindness in which a man (confederate) is working at a counter handing out forms. Unsuspecting participants in the experiment approach the counter and request a form, fill it out, and hand it back to the man. He tells the participant that he must file the paper in the correct file, then disappears from view behind the counter. A few seconds later, a very dissimilar looking confederate pops up from behind the counter and directs the participant where to go. Strangely enough, 75% participants do not notice that the man has apparently morphed into a different person right in front of them! The reason for this is because our brain would be overloaded if it tried to memorize every detail of every object. Therefore, our brain chooses to pay attention to key aspects of a scene, concentrating on one element as the rest falls into the background of our memory. Researchers are unsure why some people notice the change while others do not. They believe it's possible that individual differences may account for the 25% who noticed the change, and that these people may be naturally better able to detect change. It is also suggested that those who notice the change may have coincidently been looked at whatever stimuli underwent the change and were therefore more able to notice any such changes.
3. In the lecture "How the brain lies to you," we saw many examples of how we might remember a scene differently when trying to recall it from memory. What we think we may remember depends heavily on past experiences and what we may expect to see. The brain constantly fills in gaps where the memory may have lapses, and therefore when remembering an event, we construct what we want to see or what we expect to have seen and we do not construct what we may not expect to have seen. We gained insight into why key witness testimonies cannot always be reliable; memory is reconstructive and subject to emotions, lighting, past experiences, and other variables.
4. An example from the lecture relating directly to change blindness was one in which the face of one man could be interpreted as three different races, depending on the adjectives used to describe him. Another example featured a morphed image of John Kerry and George Bush. The morphed image would appear to look more like one man or the other, depending on the presentation of a 'primer' image for 60 seconds beforehand. These examples account nicely for why 75% of the participants did not notice the experimenter change in the experiment mentioned beforehand (see 1.). Our brain is not able to notice subtle changes due to the necessity of focusing on larger or salient details of any scene, which is why small changes, although easy to see for those who may expect them, are nearly impossible to notice when only viewing any scene for a brief period of time.
Forgot to include the link:
http://www.youtube.com/watch?v=mAnKvo-fPs0
1.) My text refers change blindness as the inability to detect unattended changes that are occuring in changing environments. Change Blindness was demonstrated by Daniel Levin and Daniel Simons by creating an experiment where subjects viewed a video of a brief conversation between two women. There are four pictures that show the changes that take place when the camera angle changes. There were some small changes such as a woman's scarf disappearing, and plates changing from the color red to the color white. There were ten people that participated in this study and only one out of the ten people noticed any kind of change.
2.) I found a video on youtube that has an example of change blindness and demonstrates an experiment. In the experiment, a subject comes up to a counter and takes a consent form from experimenter 1 and fills it out, then she gives it back to him, experimenter 1 ducks under the counter and puts the consent form away and experimenter two comes up from the counter and gives the subject a packet of information and tells them where to go. 75 percent of the subjects didn't notice a thing. I was laughing the whole time and could not believe how many subjects didn't notice that there were two different people. Great example of change blindness!
http://www.youtube.com/watch?v=mAnKvo-fPs0
3.) The lecture in class about "how the brain lies" started out by showing parts of the eye and brain and how they function. You showed us examples such as the rabbit-duck and asked us what we saw and after you explained that it could be a rabbit or a duck is when I could see both, but I could only see the rabbit it first. You talked about different things that the brain "sees". The Brain "sees" things that aren't always there, things move when they really don't, the brain "sees" things different sizes than they really are, and different colors. This information stuck with me because I talked about it in my mind map and I felt that I was very comfortable discussing it.
4.) Change blindness relates to the lecture about "how the brain lies" because something could be happening right in front of us, but if we are not focused on it our brain acts as if it never happened. Just like in the youtube video, the subjects weren't focused on the men so they didn't notice that there were actually two people and not just one. And unlike the video, our brain can play tricks on us and think that we can see things when nothing is really there at all.
1) My Goldstein textbook defines change blindness as “difficulty detecting changes in a scene”, and “change detection” as a stimulus that is not perceived even when a person is looking directly at it. My text describes the “Gorilla” video in detail to illustrate how inattentional blindness occurs. According to the text, change blindness shows us the necessity of attention for perception to occur. In the real world, changes are often accompanied by motion, which offers us a cue that change is about to occur – so being able to pay attention is cued by other things so that we can focus our attention more efficiently. This is why we can be tricked into not noticing. One more interesting thing that my textbook describes is a coin termed by Levin called “change blindness blindness” – that is when people are blind to the fact that change blindness will occur. (This is important in discussing how the talk on we were given in class showed what happens in line-ups because awareness of this matters! See more on this below).
2) For my internet divergence, I found a cute video clip on youtube that dealt with change blindness using a “whodunit” skit similar to the game clue. While the viewing audience was focusing on details about the mystery of which person was the killer among three possible suspects. The scene was being changed even as the camera rolled without a pause – the background furniture, décor, flowers, and even the dead guy were all changed out as the camera panned the detective questioning each of the suspects. I thought I was paying attention, but apparently I wasn’t because I did not notice any of these changes taking place. I was paying attention to the wrong thing!
3) The talk presented in class on how the brain lies to us demonstrated how our brain function using heuristics and rules on order to construct reality. Our brain fills in the gaps for our vision. Sensory illusions were shown to illustrate how our brain is able to see things that aren’t there by filling in the gaps. We do not usually realize that we may be missing important details based on our perceptual attention. The anatomy of our visual system was used to help explain factors such as the importance of lighting conditions to visual interpretation – the rods functioning for low light, and the cones for brighter light. With this knowledge of the visual system we learned about change blindness. We talked about the “Gorilla” video which demonstrated how we don’t necessarily notice important parts of a scene. And then we moved onto learning about the components of, and the flaws within, eyewitness testimony. Our existing expectations and our exposure to information can influence our memory of an event without us being aware. A line-up is not effective unless very specific precautions are taken to ensure that we do not fall on our schemas to select a possible perpetrator out of a line-up.
4) Change blindness is very relevant to the “How the Brain Lies to Us” talk given in class. We need to understand this phenomenon of the visual system in order to overcome some of the usefully efficient yet faulty ways that our brain functions, particularly important in certain situations, such as when society puts a person on trial with life-changing consequences based on eyewitness testimony. This part of the talk is very relevant to what the textbook refers to as “change blindness blindness” because if the just system does not recognize this factor in our perceptions as it relates to eyewitness testimony, then we will not be able to render the best uses of justice within the legal system.
1) My text describes change blindness as when someone can not detect changes in what they are viewing. The most common reason for this error is a visual disruption within the visual system. People often are too confident in their own visual systems and it leads to the brain not recognizing a change in their view.
2)http://www.cogsci.uci.edu/~ddhoff/cb.html
This site had a picture that was flashing every two seconds and something different was between the two pictures. The site then proceeded to explain that when you find the difference between the two pictures you always notice the change every time you view the picture. This example of change blindness helps provide evidence that we can only identify changes in the visual experience we are paying attention to.
3) N/A
4)N/A
Change blindness is a phenomena in which we are incapable of noticing differences from one scene to the next. Research has shown that remarkably large changes can be made to a particular scene and yet we are still incapable of detecting the change. The phenomena is important because of what it demonstrates about the relationship between attention and perception. The text also discusses the counter-intuitive nature of this phenomena and refers to this as “change blindness blindness.” Most people cannot detect these changes, yet when shown a particular change claim that they would be able to detect it. Our vision sort of lies to us because even though it seems like our entire visual scene is clear it is actually fuzzy and out of focus.
2) Perhaps the greatest internet video depicting change blindness (other than the world famous ape-basketball video) is the following. http://www.quirkology.com/USA/Video_ColourChangingTrick.shtml Even if you know that certain things change throughout the video it is almost impossible to detect which ones, just like the text says. In fact I’ve seen the video several times and sometimes forget all the changes and am fooled again.
Most of the sites I visited contained videos and descriptions of just how much change can take place yet we still won’t notice it. Many of the experiments involve someone interacting with a research assistant, either to get directions, or follow some basic instructions, and at some point during the exchange the spectator and research assistant are blocked off from one another either by construction workers walking by with a large piece of wood, or ducking down behind a counter to pick up a pen, etc., and at this point another research assistant is switched in. The question is how dramatic can the change be, and still have the spectator not realize a switch has been made. In one clip mentalist Derren Brown switches himself, a short, white, Englishman with a suit, for a tall black man in a t-shirt.
Naturally a lot is going on here. First, we sort of assume that whenever we see something we view it in it’s entirety and with equal clarity. If this were the case we would notice any changes which occur. If however, we only see a small amount and our brains fill in the rest based on how it ‘probably is’ much could be changed without our recognizing it, and this is what happens. This explains why things like clothing, basic facial features, and the like can be switched without our knowledge, we don’t attend to ‘eye color’ in particular so we wouldn’t notice that change. But the question becomes what are we attending to then. If it’s not hair color, clothing, facial features, and perhaps not even gender or race, what are we attending to? One answer is that we are attending to the cognitive task at hand. In most examples people are doing something else like thinking about directions to a different location, or paying attention to directions regarding how to fill out a form, etc. And the more engaged in this task they are the more change seems to be able to take place without our knowing it.
Top down vs. bottom up processing was also discussed in a number of sites. Top down processing involves processing from basic contextual and schemata related information down to more specific details. Bottom-up processing is the exact opposite, often called data-driven processing wherein we process based on cues from the stimulus alone rather than by relying on previous information and contextual cues.
http://www.uxmag.com/design/change-blindness
http://www.theness.com/neurologicablog/?p=2061
3) It’s been over a year since I remember sitting in on this talk so I’ll give my impressions as best I can remember. The brain ‘lies’ to us in numerous ways by making our visual field a complete and orderly whole. First discussed were the physical characteristics of the eye. Rods are more numerous, are clustered around the peripheral area of the retina and predominantly detect movement and are in black and white. Cones are fewer in number, clustered around the fovea of the retina, predominantly detect fine details and color vision. Furthermore they all come together at the fovea, located at the back of our retina which creates a blind spot in our vision. Rather than see in this way, which would be very confusing our brain fills in the gaps; what we sense is not what we perceive.
Then a number of basic illusions (e.g. muller/lyer) were discussed to show again that our brain ‘does something’ with the raw data we take in. It constructs the perception based on previous information, contextual information, and common sense. A number of these ideas are further demonstrated with facial recognition demonstrating racial blindness and the cross race effect.
4) Change blindness is proof that the brain lies to us, and that we do not see the world as it really is, but instead we see the most likely and probable scene in front of us. If we perceived directly what we sense it would probably take to much computing power. Instead our brains take a short-cut, since there is a large amount of similarity in our visual world from one moment to the next, and even one year to the next, there is little need to constantly be analyzing every nanometer of visible space in front of us. A small amount (which we are attending to) is ’good enough’ to get by and recognize the ’important’ changes when they happen. Better to focus on this area and lie about everything else and spend other cognitive resources elsewhere. Though this is good enough for survival, it results in strange phenomena like change blindness.