Reading Activity Week #9 (Due Monday)

1A) time to collision
1B) I found this interesting because I play sports not as much as I used to so thinking about the whole keeping eye on the ball gives a new meaning to me. also I hope to use this information when I get the job I want I think it will come in handy.
2A) smooth pursuit.
2B) I liked this concept because we use it so much in our every day lives. we are constantly looking at objects moving about. I do this all the time in my job. and its amazing to learn about how we do it and why. how it all connects to the brain and how we perceive it. it kind of ties into the previous one I liked. because when we are trying to cross the street. we are looking at the moving cars and thinking can i cross without getting hit.
3A) vergance.
3B) the reason this was interesting was simply do to my recent own experiences. with my eye surgery sounds like some of the eye movement i have experienced.
4A) akinetopsia
4B) the only reason this was a part of the chapter I didn't enjoy as much was because I cant pronounce the word. when ever i cant pronounce a word i don't understand it as well or remember it as well. the information about it is interesting but if i had to pick something that didn't sit well with me in the chapter that's what i would have to pick.
5) I think this chapter is very important in understanding sensation and perception. because it talks about movement. Movement is a very important part of our lives. we are always moving and seeing objects move. The thing i think about most is driving. we are always having our eyes dart around looking at different things making sure we don't crash. or looking at something that catches our attention.
6) It relates to the previous chapter because the last one talked about attention. and this chapter is about movement you need to understand your attention before you can understand how we see movement.
7A) collisions
7B) I like to learn more about collisions and how are reaction time comes into play. I think this is a very big thing that we use in our daily lives.
8) I kept relating all the information or daily life and how we use it. movement is what we use everyday.
9) sensation, preception, precive, brain eyes, collisons, movement, vergence, akinetopisa, smooth prusit, time to collions.

1a) What did you find interesting?

I thought apparent motion was interesting. Apparent motion is the illusory impression of smooth motion resulting from the rapid alternation of objects that appear in different locations in rapid succession. An image of something that appears in A’s receptive field, then disappears, and then reappears in B’s receptive field a short time later will drive M to respond just as strongly as if the image had moved smoothly across the two receptive fields. It was first demonstrated by Sigmund Exner in 1875. Exner set up a contraption that would generate electrical sparks separated from each other by a very short distance in a space and a very short period of time. Even though there were two separate sparks, two different perceptual objects-observers swore that they saw a single spark moving from one position to another. This relates to what we see on television. Objects change positions each frame, and when the frames are shown to us at a sufficiently fast speed we perceive these position changes over time as motion.

1b) Why was it interesting to you?

This is interesting to me because in my childhood the Disney commercials would always show how the cartoons were made. They’d show the artist drawing a character on several pages and then flip the pages to show the cartoon moving. Of course this was completely over my head and fascinating when I was little. But even still now it’s interesting to me how our eyes perceive it as a fluent motion.

2a) What did you find interesting?

I also found the correspondence problem to be interesting. Apparent motion works for our motion detection circuit, but there is still a problem. An example of this is with movie diagrams. Movies have two frames that alternate back and forth. The difference between the two frames is that only one object in the movie has shifted diagonally by a short distance. But in other cases, the movie will be perceived horizontally, not diagonally. This relates to the correspondence problem because this is in motion detection, the problem faced by the motion detection system of knowing which feature in frame 2 corresponds to a particular feature in frame 1. Part of the problem is just in general knowing which circles in frame 2 correspond with what circle in frame 1. Our detectors compete to determine our overall perception.

2b) Why was it interesting to you?

This was interesting to me because I never knew we had this type of problem. I always just assumed how we saw movies or these types of slides just worked vertically. I didn’t know our eyes had a problem competing with each other with horizontally and vertically seeing these types of slides.

3a) What did you find interesting?

I also found vergence to be an interesting concept. Vergence is a type of eye movement in which the two eyes move in opposite directions. For example, both eyes turning towards the nose, which is convergence, or both eyes turning away from the nose, which is divergence. There are three types of voluntary eye movements. Convergence, divergence, and saccade. Saccade is the type of eye movement made both voluntarily and involuntary which the eyes rapidly change fixation from one object or location to another. A fast jump of the eye that shifts our fixation point from one spot to another. We can decide to make a saccade deliberately, but whether we’re thinking or not, we will make three or four saccades every second.

3b) Why was it interesting to you?

I thought this was interesting because it talks about the things we don’t even notice our eyes doing voluntarily and involuntarily. I didn’t know there was an actual term for going cross eyed, which would be convergence. I also didn’t know what saccade was or that we do this movement every couple of seconds without realizing it.

4a) What one (1) thing did you find the least interesting?

One thing I found the least interesting was the middle temporal area(MT). This is just simply because I’m not much of a science person and didn’t find this part to be very interesting. The middle temporal area is an area of the brain thought to be important in the perception of motion. Information from the magnocellular neurons feeds into V1 and is then passed on to the middle temporal area of the cortex, and area commonly referred to as MT. This motion-sensitive area may have at least two separate maps located on the lateral surface at the temporal-occipital boundary.

5) What did you read in the chapter that you think will be most useful to in understanding Sensation / Perception?

I think knowing the basics is important to go on. So I think knowing what smooth pursuit is, is important. Smooth pursuit is a type of voluntary eye movement in which the eyes move smoothly to follow a moving object. This keeps the image of an object stationary on the retina while it is in motion.

6) How, in what ways, does this chapter relate (build on) to the previous chapters?

This chapter relates to previous chapters because it talks about motion perception. The previous chapters have talked about spatial vision, perceiving and recognizing objects, and space perception. This chapter builds on that by going over how we view things in motion. The previous chapters were just basics on how we see. But this chapter uses that information and describes how we then see with moving objects.

7a) What topic would you like to learn more about?

I would like to learn more about comparator. Comparator is an area of the visual system that receives one copy of the command issued by the motor system when the eyes move. The other copy goes to the eye muscles. The comparator compares the image motion signal with the eye motion signal and can compensate for the image changes caused by the eye movement. By sending out two copies of each order to move the eyes, the motor system is thought to solve the problem of why an object in motion may appear stationary. The comparator can then compensate for the image changes caused by the eye movement, inhibiting any attempts by other parts of the visual system to interpret the changes as object motion. I want to learn more about this simply because I find the topic interesting.

8) What ideas related to what you were reading (what did you think about) did you have while reading the chapter?

I thought about old Disney commercials I’ve scene and how they actually show how cartoons are made. How the artists draw a few sheets and then flip them together to make it look like the cartoon is moving. This related to his chapter because it talked about apparent motion.

Terms: Apparent motion, illusory impression, rapid alternation, rapid succession, receptive field, Sigmund Exner, perceptual, perceive, motion, correspondence problem, motion detection circuit, detectors, perception, vergence, convergence, divergence, saccade, middle temporal area, neuron, cortex, MT, magocellular, lateral surface, temporal-occipital boundary, smooth pursuit, retina, comparator, image, interpret.

1a) What did you find interesting?
i thought the aperture problem was pretty interesting.
Aperture Problem is the fact that when a moving object is viewed through an aperture, the direction of the motion from the object maybe ambiguous

1b) Why was it interesting to you?
it was interesting to me because our eyes can be very bias about things too as much as our minds could be, depending on how we see things, or what angle we see objects from

2a) What did you find interesting?
Another thing that i was interesting in was the MT, MT is the middle temporal area of the brain thought to be important in the perception of motion.

2b) Why was it interesting to you?
i thought this was pretty interesting because it's actually very important to our central cortex, the fact that it has two different maps that are located in the on the lateral surface at the TO spot, (Temporal occipital) these two locations are also know as the MT or V5, To-1 or To-2.

3a) What did you find interesting?
in this area, i thought First order motion was interesting as well. First order motion is the motion of an object that is defined by changes in luminescence.

3b) Why was it interesting to you?
i thought this was interesting because of the white and gold, or the blue and black dress situation that happened couple of weeks ago, i thought the color changing problem might be because of the changes in luminescence.

4a) What one (1) thing did you find the least interesting? one thing that i found least interesting was the motion aftereffects revisited section

4b) Why wasn't it interesting to you?
i don't think it's because i found it least interesting, i think it's because the examples that were given to explain the section weren't really relatable to me, i didn't find them that helpful, or that interesting.

5) What did you read in the chapter that you think will be most useful to in understanding Sensation / Perception?
i thought how motion objects were explained was very useful, the MT section was helpful mostly because it the center of visual perception, using images and drawings to exemplify things is very visual representation of how sensation and perception can be put into use by everyone in their everyday lives.
6) How, in what ways, does this chapter relate (build on) to the previous chapters?
the last chapter was basically talking about our visual attention , focusing on stimulus, knowing whether or not we can multitask with things, while this chapter is basically talking about the motion of visual perception, the difference in how we perceive things and how fast we do it, also about how there are different levels we go through in order to perceive an image correctly or understanding an object functionally while in motion.

7a) What topic would you like to learn more about?
i thought this chapter had some great topics overall, but if i could pick one i would choose Akinetopsia,which is a rare neuropsychological disorder in which the affected individual has no perception of motion.

7b) Why?
I want to learn more about this topic because it seems rare, interesting, and reading the story of the two patients that weren't able to see motion was very interesting and i can't imagine going through that process everytime i see new objects.

8) What ideas related to what you were reading (what did you think about) did you have while reading the chapter?
while i was reading this chapter, i didn't really think there was such difference in seeing an object and having an aftereffect on it seconds later, but after reading this, i found out that you actually have those things occur, and it makes sense when you see an objection and have images of it later on in our lives about that image, that's mostly how we remember certain things, and also that people with high motion objects memories are the people who have the photographic memory.

TERMS:Akinetopsia, First order motion, Lumninace defined object, temporal cortex, visual fields, V5, aftereffect motion, Aperture, Aperture Problem, Middle temporal Area(MT)

1a) What did you find interesting?
1b) Why was it interesting to you?

The first thing in chapter 8 that I found interesting was the section of the detection of global motion in area MT. This section fused on the middle temporal area or often referred to as the MT. The middle temporal area is an area of the brain thought to be important in the perception of motion. Originally this wasn't very interesting to me and then when I continued my reading it became very interesting to me. The middle temporal area of the cortex is only in nonhuman primates. The human equivalent of MT, has been localized using functional MRI and variously labeled as MT+ or V5. It wasn't recently discovered that this motion-sensitive area may have at least two separate maps located on the lateral surface at the temporal occipital boundary. I found this to be extremely interesting; an area of our brain that has two full maps on it that helps us locate and notice motion.

2a) What did you find interesting?
2b) Why was it interesting to you?

Focus of expansion was the next term I found interesting in chapter 8. The example in the book explains a pilot coming in to land a plane; when she is landing the plane she will always be focusing on one point, the center, or the focus of expansion of the optic array. The focus of expansion is the point in the center of the horizon from which, when were in motion, all points in the perspective image seem to emanate. The focus of expansion is one aspect of optic flow. This is one place in the visual field that will be stationary which helps us determine where things are and where we need to focus on to land. This was interesting to me because we need to have this in our every day lives. One example for me is that I am a runner; I love to run and I often push myself to reach new goals. When running I often focus on an end point and focus on that point to blur out the fact that I am running giving me no choice but to finish strong at that end spot, my focus of expansion.

3a) What did you find interesting?
3b) Why was it interesting to you?
The third thing I found interesting in chapter 8 was the theory of biological motion: the pattern of movement of living beings (humans and animals). I found this interesting because it is the movement of us and how we do things both differently and similarly to other species. Recognized by Gunnar Johansson that there might be something special about the motion of animals and people. There is even evidence that observers can use biological motion to identify whether a set of moving light is attached to a male or female walker.

4a) What one (1) thing did you find the least interesting?
4b) Why wasn't it interesting to you?

One thing I didn't really find interesting mainly because it seems like common sense. A type of voluntary eye movement in which the eyes move smoothly to follow a moving object. I didn't find this interesting because I feel like it seems like common sense. This keeps an image stationary on the retina even when you are in motion. This is actually an interesting term because it is something that we use so often in our every day lives but reading about it felt kind of pointless because it happens so often for us and because it is a voluntary movement that we choose to do; making it seem very much like common sense.

5) What did you read in the chapter that you think will be most useful to in understanding Sensation / Perception?

I thought that all of the terms that had to do with transferring motion. Like interocular transfer which is the transfer of an effect from one eye to the other; or first order motion: the motion of an object that is defined by changes in luminance. Or second order motion: the motion of an object that is defined by changes in contrast or texture, not by luminance. All of these terms seems pretty similar however they all relate to what we are learning in Sensation and Perception very well. The small changes that happen within our eyes to help us notice or recognize something are what give an image its details and diversity. Noticing the small things in an image make you feel a different sensation and have a different perception toward the image.

6) How, in what ways, does this chapter relate (build on) to the previous chapters?

It builds because as we continue through the chapters each chapter builds on something that gives more and more detail to the image that we see when we look at something. explaining each chapter how more in depth we can see and perceive images and how this happens. This chapter focuses a lot on motion and how we can still focus on certain or specific images when we are undergoing motion; this is more complex than the idea of just looking at something while not moving which we would have covered in precious chapters.
7a) What topic would you like to learn more about?
7b) Why?

8) What ideas related to what you were reading (what did you think about) did you have while reading the chapter?

things that relate to the chapters when I am reading them for me are always memories. For some reason whenever I learn about or read about a new term it helps me to try to relate it back to something that happened to me; a memory that I can look back on and say "oh yeah that is why I could do that>" For me learning all of this new information is useless unless I can relate it to something that matters to me in my life; whether past or present or future.

9) Once you are done with your post make list of the terms and terminology you used in your post.
apparent motion, illusion, biological motion, smooth pursuit, interocular transfer, first order motion, second order motion, correspondence problem, sensation, perception.

1a) The first interesting concept from chapter eight that I came across is the idea of apparent motion. This can be explained as the illusory impression of a smooth motion resulting from the rapid alteration of objects that appear in different locations in a rapid succession. This was first represented in 1875 by a machine that generated sparks at different times that made it look like there was only one spark moving when in reality it was two sparks that were set off at different times.

1b) This was interesting to me for a few reasons. First it made me think about these little quarter operated toy machines that you can find at the entrances of many stores like Walmart and Target. The game is set up where there is a light the “moves” around and you must click a button to stop it on a red light in order to win a prize. Now the light is not actually moving, instead it is apparent motion because one light after another goes off making it seem like it is actually moving. This is the same for seeing things on TV. The pictures on the television screen are not actually moving in your own home; instead it sort of tricks us to make your mind believe that it is moving.

2a) The next part that was very interesting to me from this chapter was on first-order motion, which is the motion of an object that is defined by changes in lighting, combined with luminance- defined object which is an object that is delineated by changes in reflective light.

2b) This was interesting because it reminded me of a classroom experiment that I can recall from high school where the teacher turned off all the main lights in a room and used a strobe light to illuminate a small fan. By making the strobe light flicker at different speeds we could actually make it look like the propellers on the fan were spinning backwards (though they weren’t).
3a) The last really interesting part to me was one biological motion which is the pattern of movement of living beings. This goes for both humans and animals alike.

3b) This part got my attention because the example they used was a tennis player, and as a tennis player myself, I was drawn to this example more than normal. It shows how the motion of our bodies work together to make these smooth movements, whether it is just walking or something more vigorous like tennis, it is good to know exactly how and why it works.

4a) One of this least interesting parts of chapter eight was the part on correspondence problems. The book tries to explain it as a problem in motion detection of knowing which feature in frame 2 corresponds with a certain feature in frame one, but I cannot grasp what this means. They then use a few picture to try to show their meaning, but it is very difficult to understand.

4b) This was not interesting to me because I still do not think I quite understand what they are trying to convey. In my opinion the book does a terrible job of explaining this idea so I plan to ask about it in class this coming Thursday. If even Dr. Maclin cannot describe to me what correspondence problems are then I will just try my best to not let it bother me and train myself more on other concept from the book and forget about this one.

5) Everything in this chapter that explains how we see and analyze motion is an important factor to understanding sensations and perceptions. This ranges from the different light pattern to our brain make up. All of the terminologies in this section are very good at explaining these functions.

6) This chapter does a great job of building off of some concepts from chapter three concerning cells in the primary visual cortex and how they selectively respond to motion in a particular direction. It also goes along with attention from chapter seven and how motion actually helps attract or differ our attention.

7a) I would like to know more about smooth pursuit eye movement.

7b) I liked the example they gave in the text concerning this using the pencil and a black dot, and I would like to know more about it what other research is out there on it, and whether or not there can be complications in the brain that could also affect this.

8) Much of what I read I related it back to my cats, I even stopped for a bit to use a laser pointer on them because I was influence by what I read with motion.

9) Terms: Motion, apparent motion, smooth motion, smooth pursuit, first order motion, luminance-defined objects, biological motion, correspondence problems

1a. For first concept from chapter eight that I found interesting was the topic of using motivation information to identify objects, specifically biological motion.
Biological motion is the pattern of movement of living beings such as humans and animals. Researcher Gunnar Johansson pioneered the idea that the specific motion of animals and people are special and can help us identify both the moving object and its actions. Further research into this interesting perceptual experience suggests that we can identify whether a set of moving lights is attached to a male or female walker. It seems that because males have broader shoulders and narrower hips their center of motion is higher and can be identified even when an individual is shown lights moving instead of the human body moving. Additionally, the amount of body sway while walking can also give away a clue as to the gender of an individual. Women were found to sway their hips more frequently than men in the study.
b. I found this topic to be very interesting partially because during my sophomore year I was involved in a psychological study at UNI that involved identifying the gender of a set of dots and lights walking on a computer screen. At the time I was unaware of the exact psychology of the visual system and the physiological experience that contributed to my ability to identify the gender of the walker. I also found it an interesting concept because we perceive motion almost constantly so it is fascinating to learn how the visual system actually perceives the movement around us.
2a. The second topic that I found interesting discussed different types of eye movements that humans experience. Specifically I was interested in reflexive eye movement which can otherwise be known as vestibular eye movement that is an automatic and involuntary movement of the eye. This happens when the eyes move to compensate for head and body movement while still fixated on a particular target. Reflexive eye movement can also occur when the eyes are involuntarily tracking a continually moving object. While this is happening the eyes smoothly move in one direction in pursuit of the moving object and then snap back when it can no longer track the object.
b. I found this interesting as I thought about all of the objects and people that my eyes track every day. Even when I am not consciously following an object my eyes move involuntarily and I never knew the physiological reason behind it until reading this section. I found it fascinating when I took into consideration all of the moving people, including instructors, that my eyes track every day. Without the ability to track movement it would be impossible to function in social settings and would be detrimental to the ability to survive.
3a. The third concept that I found fascinating was the case study of a man who could not see motion. He suffered from a rare neuropsychological disorder known as akinetopsia that results in the inability to perceive motion. The man experiencing this disorder could see that objects or people had changed position but had no perception of the motion that accounted for their new location. Researchers discovered that this horrible disorder resulted because of disruptions to the cortical area of the medial temporal lobe and were occasionally a side effect of prescription antidepressants but could also be caused by trauma such as a stroke or brain surgery. It is possible to regain normal motion perception if a patient is removed from related antidepressants or after full recovery from surgery.
b. I found this interesting because I am always fascinated in deficits of the visual system. It is maladaptive to be unable to perceive motion because it would hinder an individual from tasks such as driving and interacting in social environments. I also found it extremely fascinating that prescription drugs such as antidepressants can cause such a horrible deficit and wondered if they have altered the chemical composition of the drug to decrease that effect in the medial temporal lobe.
4ab. I did not find any part of this chapter to be uninteresting but I found the section of Tau to be a little overwhelming to read because of all of the information. It can be hard to fully comprehend all of the concepts and mathematical terms stuffed into one paragraph.
5. I found the section on biological motion to be the most useful to my understanding of sensation and perception. It is extremely applicable to our daily lives to be able to perceive the motion and actions of other human beings and animals. This ability aids us in survival as well as in social interactions with others. Additionally it provides us with important information for how the visual system works and the specific parts of the brain that are involved with motion perception.
6. This chapter builds on other chapters because it further explores the medial temporal lobe and its function in the visual system. It also addresses vision as low level perceptual phenomena that was previously discussed in chapter three. The authors further discuss the parts of the brain associated with vision and go into further detail about the motion parallax covered in chapter six. This previous knowledge aided in my ability understand the new material that was incorporated.
7ab. I would like to learn more about akinetopsia because I am extremely interested in neuropsychological disorders and their causes as well as treatments that are available.
8. While reading this chapter I thought about deficits that could result in a lack of ability to perceive motion and the causes of them. I also thought about treatment options that are available and the parts of the brain that are associated with the inability to perceive the motion around us.
Terms: biological motion, Gunnar Johansson, perception, motion, reflexive eye movement, vestibular eye movement, akinetopsia, motion parallax, neuropsychological disorder

The first topic that I found interesting was the computation of visual motion. I found this section particularly interesting because the developing of a motion detector is something that has always seemed so complex. Throughout reading this section in the book it made motion detectors and the visual motions seem less complex and easier for me to understand. Looking at the way that motion involves a change in position over time which then involves the object to pass through different receptive fields. Each receptive field is made up of different neurons that respond and eventually take four parts to complete one cycle and create a mechanism that is sensitive to motion.
The second thing that I found interesting was the section on the aperture problem which is closely related to the correspondence problem. This happens when motions is watched through an aperture the direction of motion of a feature or part may be ambiguous. This makes it look different when we look at a image through a aperture. like the figures in 8a,b,and c. The motion component parallel to the line cannot be inferred from the visual input. which means that a variety of contours of different orientations moving at different speeds can cause identical responses in motion sensitive neurons. I found this topic interesting as I looked further into in in reading about the difference of the images. It made me think a lot about how one person can see one item one way but another person might view it completely different.
The third thing that I found interesting was the section over the man who couldn’t see motion. Akinetopsia is a rare neuropsychological disorder which affects those individuals with no perception of motion. I found this interesting when reading about the man who would see images frozen and as soon as the motion ceased the images collapsed into each other. I think this is interesting because I don’t personally know what it would be like to not be able to see or notice the different of frozen objects in your visual perception i feel like it would be something that would be very hard to adapt to.
One thing that I didn’t find interesting was the section about physiology and types of eye movement. I found this section very complex to understand, especially once it went further into the part of the eyes.
The thing that can be taken from this chapter that is important to sensation and perception is the fact that motion is something that we see everyday and to be able to better understand how our eyes obtain motion i think is important and to also know that it is not something that everyone gets the chance to experience.
This chapter continues to build on the eye and how we perceive items at first it talks a lot about how we see items and what our eye goes through but now we are able to learn about motion and what different types of receptors that are used to see.
One thing that I would like to learn more about is akinetopsia, I think it would be interesting to know more about the background of this disorder and what some of the symptoms that are caused by it. I also think that it would be interesting to know more about how one person can live a life affected by this disorder.
while reading this chapter I was thinking about a lot of different things like why we even have senses and who even thought of them. What if we didn’t have any senses but especially those in which we are more dependent on like our ears and eyes. Do you think more people would be likely to develop in a different way and rely on other items? Would those items then become senses?

Terms: visual motion, motion detectors, receptive fields, neurons, aperture, aperture problem, motion component, visual input, motion sensitive neurons, akinetopsia, neuropsychological disorder,

1a) What did you find interesting?
1b) Why was it interesting to you?
The pattern of movement of living beings which are humans or animals is an interesting topic to me. Defining my first sentence presents the term biological motion. We obviously use motion information to guide us as we move through our environment. What engaged me is that actually motion can also help inform us about the nature of objects. In reference to the picture of the tennis player in real time, and then the tennis player in the dark with lights attached, we can identify whether the lights attached resemble a male or female thanks to biological motion. Body sway, center of motion, height of motion all provide cues that allow ourselves to analyze biological motion and understand human action. But oddly enough we seem to do a better job in discriminating biological motion of a human when two humans are acting in sync with each other.

2a) What did you find interesting?
2b) Why was it interesting to you?
I also found that using motion information to navigate wherever was interesting. It was so interesting to me because naturally our vision helps guides us through motion and space. But explaining something that you think is so simple and you body just does automatically is a hard thing to explain in text. That’s like asking someone to explain why the sky is blue. Our vision collects light that interacts with objects in the world in front of the viewer, this is called an optic array. We then move through our environment an experience patterns of optic flow, which is all the changing positions of an image as we move through the world. As we navigate, we seem to zoom in and focus on where we want to end up. This is our focus of expansion, like when we are driving down the road we should hopefully be focused on the road. Explaining how we just go with the flow is easy, explaining how we use that information of motion to navigate is not so easy.

3a) What did you find interesting?
3b) Why was it interesting to you?
Time of collision and tau were very interesting to me. They were interesting to me because I played a lot of sports in high school. The most common coaching advice to a player was, “just keep your eye on the ball.” Good judgement comes into play when a ball is racing at you and it might possibly collide with your body at some time. How does our mind calculate exactly when that ball might hit us, or how do we estimate the time of collision. Optic flow information could signal the time to collision using tau. Tau is the ratio of the retinal image size at any moment to the rate at which the object, or ball is expanding. Tau is an interesting, but it is just one of the different ways our visual information can be used to judge the time of collision.

4a) What one (1) thing did you find the least interesting? 
4b) Why wasn't it interesting to you?
The computation of visual motion was the least interesting topic I found in the chapter. Building a motion detector, and the topic on our motion detection cells seemed hard for me to understand. Creating a mechanism that is sensitive to motion is something I will let electrical engineers tackle unless they have an easier way of explaining it to me so I can comprehend it.

5) What did you read in the chapter that you think will be most useful to in understanding Sensation / Perception?
Fast detection of our own direction of motion is important to our survival. Motion perception provides us with the ability to “go with the flow,” and navigate through our everyday adventures. Motion information helps us identify objects, avoid imminent collision, and overall recognize the movement of animals and people.

6) How, in what ways, does this chapter relate (build on) to the previous chapters?
The previous chapter describes that we pay attention to certain stimuli, but the brain can only process so much attention at one time. This chapter tells us that we will selectively respond or be more attentive towards something with a direction of motion.

7a) What topic would you like to learn more about? 
7b) Why?
I would love to learn more about avoiding imminent collision, sports have always interested me a lot. Understanding how we keep ourselves out of trouble by estimating a time to collision, making split second decisions between life and death, and other estimation sources of visual information used to judge the time of collision interest me quite a bit.

8) What ideas related to what you were reading (what did you think about) did you have while reading the chapter?
I thought about how bad I was in middle school at avoiding imminent collisions and in turn made my parents insurance premiums rise. I also thought about if I was in a dark room analyzing lights attached to an object, person, or animal would I be able to distinguish what it was. I wondered how blind people navigate without the presence of motion information.

9) Once you are done with your post make list of the terms and terminology you used in your post.
Optic array, Optic flow, Focus of expansion, Biological motion, Time to collision, Tau, Motion perception

1. A) I thought that akinetopsia was interesting.
B) I thought this was interesting because I wonder how people perceive things without motion.
2. A) I thought motion aftereffect was interesting.
B) I thought it was interesting learning about motion illusions. I didn't really understand it until the waterfall example.
3. A) I thought reflexive eye movement was interesting.
B) I thought this was interesting because it's something that a person can't help, it's involuntary. I wonder if there is treatment or medication for this.
4. A) I thought the section about the middle temporal area was least interesting.
B) I thought this was least interesting because I don't like learning about areas of the brain and it started getting confusing with the two maps on the lateral surface.
5. I think it will be most useful knowing how we perceive motion in our brains and what kind of problems or illusions we might see.
6. This chapter builds on with how we perceive motion.
7. A) I want to learn more about akinetopsia.
B) I want to learn more about it because it's a rare disorder and I would like to learn how people cope and if there's treatment for it.
8. I was thinking about how I look at things while in motion and how they change while I'm looking at them.
9. Terms: akinetopsia, motion aftereffect, reflexive eye movement, middle temporal area, lateral surface, motion, illusions, perceive.

1. The first concept from chapter eight that I found interesting was apparent motion. According to the book, apparent motion is the illusory impression of smooth motion resulting from the rapid alternation of objects that appear in different locations in rapid succession. We experience apparent motion every time we turn on the television. Cartoon characters are actually just a series of drawings that are put together and at 60 frames per second. Live-action movies and television programs work in the same way. I find this interesting because you never really notice or appreciate all of the work that goes into a movie such as the workings of apparent motion.
2. The next thing I found interesting was the concept called focus of expansion. According to the book, the focus of expansion is the point in the center of the horizon from which, when we’re in motion, all points in the perspective image seem to emanate. The example in the book of the pilot landing her plane really helped me to understand the whole concept. I found this interesting because our vision is what guides through our everyday lives. When I am driving I am always focused on the center of the road to prevent accidents. I never really knew what it was called when we focus all of our attention on one speck in the distance. Although I understand it, I find it really interesting on how all of this works.
3. Another thing that I found interesting from chapter eight was vergence. Vergence is a type of eye movement in which the two eyes move in opposite directions. Convergence and divergence are related to this term: convergence meaning that the two eyes move in towards the nose and divergence meaning that the two eyes move away from the nose. I found this interesting because people used to think that having the ability to go cross eyed was so cool. Some people can go cross eyed but I’ve never seen anyone who can look in two opposite directions such as the term of divergence. I also found this interesting because we don’t always know that the actions we are doing are either involuntary or voluntary. We don’t always know we are doing some things especially when it involves our eyes.
4. One concept from chapter eight that I didn’t find very interesting simply because it wasn’t very easy to understand was the section on correspondence problems. Correspondence problem is the problem faced by the motion detection system of knowing which feature in frame 2 corresponds to a particular feature in frame 1. The book used a couple of pictures to clarify the meaning on this concept but I still had to look over this section a couple times to even grasp a little bit of the meaning. I don’t tend to find things interesting if you don’t fully understand them.
5. I believe the section on biological motion is one of the main concepts one should understand when researching sensation and perception. Being able to perceive the motions of other humans and animals is very important. This ability helps us in our everyday lives such as in social relationships, work, school, and other places. There are so many different concepts present in the idea of biological motion. Just knowing how the visual system works and the parts of the brain involved in it is important and beneficial when trying to understand sensation and perception.
6. Chapter eight builds off of the previous chapters in many ways. Chapter eight was about motion perception and many of these terms related to this correspond with other terms from the previous chapters. Many different terms are described in each new chapter and each of these terms relate to another term. I believe everything in sensation and perception builds off of each other because it is all about us and how our brain and body perceives things.
7. I would like to learn more about the concept of collisions. I think that there is so much to learn about the time to collision because there are so many details associated with it. When I was reading this section I found myself wanting to learn more about it.
8. While reading chapter eight, I was thinking about how we use all of this stuff in our day to day lives without really realizing it. I found this chapter really interesting.
9. Terms: Apparent motion, focus of expansion, vergence, convergence, divergence, correspondence problems, sensation, perception, biological motion, motion perception, collision, time to collision.

I found many topics interesting, a few in particular stuck out. The first was visual search experiments, because these give a more accurate approximation to attention in the real world, than do many other cuing experiments, especially related to reaction time. During one of these visual search experiments, the subject searches for a target in a display full of distractor elements. The target is the goal of the visual search. As humans, we do this in the real world all the time, looking for necessary objects around the house, people we recognize in a crowded place, cars in a parking lot, and so on. The number of items in a display or scene, called a set size, affects the difficulty in finding a desired object. The higher the number of distractions, the harder it is to find the target in a display.

I also found the concept of RSVP and the attentional blink interesting because the timing of the acts of selection, and how the timing can affect accuracy of identifying target stimuli is actually more interesting then it sounds. Rapid serial visual presentation, or RSVP, is an experimental procedure in which a stream of stimuli appear at one location at a rapid rate, usually 8 per second. During this type of experiment, a subject watches a stream of letters that all appear at the same location in space, and they try to find a number in the stream of letters. The variation in the experiment occurs when the speed of the characters presented changes. The goal is to see how fast the stream can move, with the subject still being able to make accurate decisions. This experiment can be done with photographs of various scenes or objects as well as letters and numbers. The task can also be changed to find two digits instead of one in the stream. The first digit called T1 for target 1, and the second digit called T2 for target 2. According to the textbook, the critical variable is the interval between T1 and T2, the surprising result is if T2 appears 200-300 milliseconds after T1, and if T1 is correctly reported, the subject was likely to miss T2. This is called an attentional blink, because your ability to visually attend to the characters in the RSVP sequence were ‘knocked out’ for a short time, despite the subject’s eyes being open. An attentional blink is the difficulty in perceiving and responding to the second of two target stimuli amid a rapid stream of distracting stimuli if the observer has responded to the first target stimulus within 200-500 milliseconds before the second stimulus is presented.

I found visual attention disorders interesting as well. Brain damage that results in complete inattention is close to functional blindness, which is very rare. A visual-field defect is more common. This is when a portion of the visual field with no vision or with abnormal vision, typically resulting from damage to the visual nervous system. If a person loses primary visual cortex in the right hemisphere of the brain, they will be blind on the left side of their visual space. But if the brain damage occurs in the right parietal lobe, that person would have difficulty directing attention to objects on their left side of their visual space. These problems manifest themselves through neglect and extinction. Neglect is the inability to attend to or respond to stimuli in the contralesional visual field-typically on the left field after right parietal damage, and neglect of half the body or half of an object. A contralesional field is the visual field on the opposite side of the brain lesion. Neglect patients usually only see what is to the right of fixation and ignore objects on the left, this can mean eating only food on right side of plate, or shaving only right side of one’s face. Extinction is related to neglect, but it is the inability to perceive a stimulus in the presence of another stimulus, typically in a comparable position in the other visual field. The example used in the book helped me understand this concept better. It said if a neurologist told the patient to focus on her nose, and held a fork in the patient’s “good” (right) visual field, and the patient would be able to identify the fork. Next she would hold a spoon in the “bad” (left) visual field, and the patient would be able to identify the spoon. But if the neurologist held up a fork in one hand and a spoon in the other, the extinction patient would report only the object in the “good”/right field, and the other object would be perceptually “extinguished.”

The concept I found the least interesting to read about in the chapter was change blindness, not because it is not interesting but because it was discussed in another one of Dr. M's classes. Change blindness is the failure to notice a change between two scenes. If the change doesn’t alter the meaning of the scene, quite large changes can pass unnoticed by the observer. In the 1990’s, Rensink and some colleagues created a different picture memory experiment. They allowed participants to observe one picture at a time, and then it would disappear for 80 milliseconds, and then replaced with a similar picture. The participants were supposed to determine what had changed between the two pictures. The two images were shown back and forth with a blank screen in between the two images. This was done until the observer saw the change or the designated time ran out. In Rensink’s experiment, it took participants several seconds to find the change, and some never spotted it at all. They found that if the blank screen is not shown, the changes are more obvious to spot because the participants experience a kind of apparent motion effect that we learned about in chapter 7, when objects move positions, vanishes, or changes color.

The concept of visual search will be the most useful to understanding of sensation and perception, because we are constantly looking for targets in displays with many distracting elements in our daily lives. People are constantly looking for specific targets in scenes and situations full of distractions, like trying to find your car in the parking lot, or looking for friends in the crowds. The number of items in the display or scene can affect the difficulty of this task.

I wouldn't mind more information about visual searches and experiments related to this topic, its what really made the chapter, for me anyway. I would also like more information about limited-capacity parallel processes, because I don’t think I fully understood the concept while I was reading about it in the textbook.

While reading the chapter I kept relating a lot of the information to our daily lives and how we use it.

Terms: visual search, target, attention, distractor, set size, cueing experiments, reaction time, additional blink, RSVP, rapid serial visual presentation, digits, T1, T2, target 1, target 2, visual attention disorders, vision, eye, complete inattention, visual-field defect, visual field, visual nervous system, primary visual cortex, right hemisphere, left hemisphere, visual space, parietal lobe, neglect, extinction, contralesional, fixation, change blindness, limited-capacity parallel processes