The other day a few friends and I decided to climb mount nittany because he weather was particularly nice out and we had to cross it off of our bucket lists. When we finally got to the top of the mountain we were amazed at the fact that you could have such a perfect view of the campus from this tiny little lookout. As we stood there gazing at the campus trying to figure out where everything was, I realized that I was using a few of my depth cues to help me work out the layout of the town.

I found that a great deal of the depth cues were used. I used aerial perspective to decipher that the mountains in the distance were a bluish color and seemed a bit hazy because the light was scattered by the atmosphere. I used linear perspective to decipher where the roads were close the parallel lines were not converging and in the distance they were converging and forming a vanishing point. I used familiar size with many objects. For instance, I knew how big objects such as Beaver stadium and Thomas were, so I used this as a cue. Also, I used relative height. I could tell that the objects that were highest in my visual field, in this case it was the mountains on the other side of the town, were the farthest away and the objects lower on my visual field, the trees and ground surrounding me, were closest. I used occlusion to tell that the trees, or homes, or whatever was blocking the view of something else, was in front. I also used motion parallax. If a bird flew out of a tree that was just in front of me it seemed to move faster than the cars on the street miles away.

In class, we learned two examples of adaptation. First was when we looked at stripes in one direction for a really long time and when we looked at straight stripes they look like they are tilted. Another example was after we look at the swirling circles for a while and then when we looked at our hands, our skin looks like it was moving. Both of these are due to adaptation because when our visual system is adapted to a certain stimulus thus we see the stimulus when it is not present. The definition of adaptation from Dictionary.com says, “the decrease in response of sensory receptor organs, as those of vision, touch, temperature, olfaction, audition, and pain, to changed, constantly applied, environmental conditions.”
I have had a lot of experience with traveling, especially through airplanes. Every summer and sometimes winter, I fly airplanes back and forth from Taiwan to the states. When the airplane is flying, there is a constant noise coming from the engines. It is very hard to bear at first for how loud of a noise the engines make; however, after I got used to it I feel like it does not bother me anymore. A plane ride back to Taiwan usually takes about 24 hours, including two layovers. Under around 20 hours of listening to the same noise, my ears get somewhat adapted to the noise and thus when I got off the plane I still hear the engine noises in my ear. Sometimes it will last for the whole night until I fall asleep.
Another example is when I ride airplanes or boats and fairies. Whenever the plane is in the air, or when the boat is in the sea, they constantly float up and down. My vision, then, gets adapted to that motion of rising up and down. After getting off the boat or airplane, I feel like my vision does not go back to normal quickly. I still see the objects and everything around me moving up and down. There are times when it was so serious that it was even hard for me to walk straight at first. Both of these examples show adaptations in our vision and hearing. Because I was constantly stimulated by certain stimuli, hearing the noise and seeing the up and down movement, I got used to it. However, when the stimuli are not present, I still see them for a little while before they go away.

Citation
“Adaptation.” Dictionary.com. Dictionary.com, n.d. Web. 29 Apr. 2014.

Everyone has been to an arcade before, or at least has heard about it. Flashing lights, loud noises, popcorn, slushes, and who can forget the games. Usually I like to partake in the driving games or the ones that require a great deal of attention to stop a fast flashing light to stop at the smallest designated spot, but from my last trip to Dave and Buster’s I remember one game; the Whac-a-Mole. It’s not normally my game of choice but my son really wanted to play it. Since it was the harder adult version and he is still pretty small I ended up playing it for him with him just holding the mallet. Just like the other games it was flashing lights galore. My son, who thought he was the actual one playing, directed me to where the moles were so I could hit them. I tried my best to score high so he could have more tickets but like I said it was an adult game with a child directing me.

I didn’t notice until the topic was mentioned in class the trick that was used in the Whac-a-Mole game. They used cues to direct the player’s attention; the holes had lights around them and other places as well on the game. Before starting the game it flashed lights but as soon as I started playing the lights increased, especially to where the moles were popping out of. I know now that the reason why my son had directed me to hit in null places was because if the invalid cues in the game. Cues are defined as a stimulus that might indicate where the leading stimulus may appear. Cues can be valid; correctly directing you to the following stimulus, invalid; wrongly directing you to a following stimulus, or neutral which leads to neither a right nor wrong stimulus. My reaction time was slower due to the invalid cues because I believed that the lights indicated an incoming mole, than if we had not focused on the lights. Whac-a-Mole is filled with invalid and natural cues was designed to direct your attention to a lit hole, giving off the impression that a mole would pop out but really the mole would come out of an unlit hole. Thus making you miss the mole and lose points, all because of theses invalid cues. So the next time you go to an arcade, don’t let the lights get you, direct your attention on the actual game.

In class, we learned how people can be color anomolous based on a lack of one of the three cones. This is part of Young-Heomholtz’s theory that people have S-Cones, M-Cones, and L-Cones. These cones can be excited by certain wavelengths and help in distinguishing color. Without one, color could appear similar, causing difficulty in a world of color. There are some people who are truly colorblind and do not have any of these cones or only have one.

I knew a man who was color anomolous in high school, as colorblindness is more common in men. He had trouble distinguishing between blues and purples. He had told me before that he was colorbling, however, I first understood what he meant when I went to an improv performance for a club he was in at the school. It was called the Purple Monkey Club. When I saw him earlier in the day, he was wearing a blue shirt and I thought nothing of the name of the club having something to do with a type of uniform. Sitting in the audience, I was excited to support my friend and waiting for the group to walk on stage. When the lights when up, it all became clear. Out of the six students on stage, his was the only blue shirt. All of the others were purple. I overheard some laughter in the audience and instantly felt bad that I had not commented on his blue shirt earlier in the day.

I could never understand exactly what he saw with colors, but I got a glimpse of some of the struggles he must forever face. It soon just became a normal part of our friendship, something to joke about. Sometimes it would be a game for him to try and guess different colored outfits. There were times when he looked for my help in situations such as matching a tie to his date’s dress for prom.

This is the first time I was ever exposed to the struggles of those who are colorblind. I will never be able to understand what these people see as I am not colorblind but can only imagine some of the difficulties.  This class has helped me understand these issues even more.

We all experience motion parallax in our everyday lives. It can occur from walking downtown to class, driving to Wal-Mart to get groceries, taking the bus home for a weekend, or even while flying in an airplane on the way to Cancun, Mexico for Spring Break. In all these instances, as we are moving along, the objects/images that are closest to us, the observer, appear to move faster across the visual field than images further away. Essentially, motion parallax provides perceptual cues about difference in distance and motion, and is associated with depth perception. Also, many animals, including humans, have two eyes with overlapping visual fields that use parallax to gain depth perception and this process is known as steropsis.

One of my most recent intriguing cases of experiencing motion parallax happened in the Spring of 2013 as me and five of my best buds at PSU were departing from the BWI Airport on our way to Canucn, Mexico for Spring Break. This was my first time on an airplane that I would actually remember, since I was too young to remember the first time I experienced air flight. Anyway, as we were in take-off mode, the plane began to get faster and faster as it gained speed on the runway. I remember looking out the window and seeing other stand still planes at the airport pass by us in an instant, yet at the same time, the trees far out in the distance seemed to remain in view for most of the runway. This phenomenon was also experienced in the air at an even greater level. As we were flying south towards Mexico, the clouds in the sky passed by the window so quickly, you hardly had a chance to recognize them, yet like the trees on the runway, the ground below remained in view for a very long time. It seemed as if a cloud could pass the window view within a second, but there could be a patch of farmland that would remain in the window view for 20 minutes.

At the time, I didn’t think anything of it because I did not understand the concept of motion parallax. Now that I have an understanding of how it works, the plane ride was more than just a view of the world from a distance, it was a concept in psychological perception.

The Trichromatic Theory by Young-Hemholtz proposed that there are three different types of color receptors that each respond maximally to a different wavelength. The three different cone photoreceptors are the S-cones, M-cones, and L-cones. If one of these sets of cones is absent, it can lead to colorblindness in people. About 8% of the male population and about 0.5% of the female population have some form of color vision deficiency. There are several types of color blind-people. A deuteranope has an absence of M-cones, a protanope has an absence of L-cones, and a tritanope has an absence of S-cones. There are also three types of defects that a person can suffer from. A color-anomalous person has two types of cones that appear so similar they can’t discriminate between the two. A cone monochromat has only one cone type, so this person is truly colorblind. Lastly, a rod monochromat has no cones at all so they are colorblind and are visually impaired in bright light.

My dad suffers from red green color blindness. His parents first identified it when he was a child when the colors in his drawings were incorrect such as coloring an apple green instead of red. His parents first thought he was just doing it to be different, but they eventually figured out he would pink the wrong crayons by accident. He began to read the labels on the crayons instead of looking at the colors. My whole life my dad always got very badly sunburned and he eventually told me it was because he couldn’t tell when he was getting too red so he only ever figured it out before it was too late. Another problem my dad has is when he is barbecuing red meat or chicken on the grill and it is difficult for him to tell if it is cooked well done or raw. He has gotten used to it and now has other ways of figuring it out or he asks one of us for our opinion. Lastly, he sometimes has trouble distinguishing between a tomato that is still green and unripe and a tomato that is red and ready to eat.

Overall, my dad has difficult distinguishing between colors and it is sometimes hard for him to see red, but he is lucky he is not totally colorblind and can’t see color at all. He is color-anomalous and has similar M-cones and L-cones that are hard to distinguish. He has adjusted so well that it’s usually hard to tell he has a problem with it at all.

Normal color vision

Deuteranopia

Source for photo: http://www.colourblindawareness.org/colour-blindness/types-of-colour-blindness/

I decided to write my blog on the concept of apparent motion. Apparent motion is when we perceive motion even though there is no real motion. This was illustrated by a scientist by the name of Sigmund Exner who conducted an experiment where the participants perceived that the two sparks presented to them were actually one spark moving back and forth (Wolfe et al., 2012). However, it was actually two sparks that were just very close together and presented in rapid succession (Wolfe et al., 2012). The neurons in our motion detector system do not need actual motion to fire as evidenced by the perception of the participants in the experiment. Several things in everyday life make use of this concept. One example is TV. I watch TV every day and perceive movement on the television screen even though nothing is actually moving. To make it look like the figures on the screen are moving, there are many frames presented in a very short amount of time. As long as these images are presented at a fast enough pace, the viewer will perceive the illusion of continuous movement (Wolfe et al., 2012). For example, when I was younger I watched Bugs Bunny and he would run away from Elmer. This apparent movement was created with many (an example would be 100 frames a second) drawings presented very very quickly (Wolfe et al., 2012).This is very similar to other things that we see on everyday basis. Another example would be when I went to the movies to the Avengers. When people go to see movies and perceive movement it is very similar to the Bugs Bunny example. The only difference is that still photographs are used instead of drawings (Wolfe et al., 2012). This also the same process used for computers (Wolfe et al., 2012). Overall, apparent motion is a concept that surrounds us everywhere we look even though we may not be aware of it.

My first blog post was written about a disorder I grew up with as a child called strabismus. When a person is diagnosed with strabismus, one eye is turned so that it is receiving a view of the world from an abnormal angle. My current post will be about something that relates to strabismus, called stereoblindness.

Stereoblindness is an inability to make use of binocular disparity as a depth cue. This term is typically used to describe individuals with normal vision in both eyes. Stereoblindness is usually a secondary effect of childhood visual disorders, such as strabismus (like I had). Approximately 3-5% of the population lacks stereoscopic depth perception.

In order to understand stereoblindness, one should be able to understand binocular disparity first. Binocular disparity is the difference between the two retinal images of the same world. Disparity is the basis for a vivid perception of the three-dimensionality of the world that is not available with purely one-eyed vision. Binocular disparity is a depth cue that helps the eyes determine the relative distance of objects in space.

Because I had strabismus as a child, I am considered a person that experiences stereoblindness, someone that is unable to use binocular disparity as a depth cue. I was able to find this out when I was reading about binocular disparity in Chapter 6 in our textbook. There are pictures in the book called stereograms, a diagram or image that gives a three-dimensional representation of a solid object or surface. When viewing these pictures, an individual should be able to cross or uncross their eyes and experience disparity. This is a task that I was repeatedly unable to do, and it is because I had strabismus as a child. This is something that truly interested me, because I didn’t realize that having strabismus as a child could have lasting effects later on in my life. I also found it someone frustrating that I couldn’t look at these pictures and understand them fully. Regardless, I found the topic of stereoblindness to be very interesting to read about.

Below is a picture of binocular disparity: