Human visual system Essay Example | Topics and Well Written Essays - 1250 words

Human visual system - Essay Example However, for one to see, the human eye has to convert the visible light energy into neural activity, a process that usually takes place in the retina part of the eye (Atchison and Smith 2000, P.11). The retina contains neurons, enabling it to transduce light energy into neural activity. However, the process does not take place in a vacuum, rather with the help of rods and cones found in the retina according to Atchison and Smith (2000, P.11). Rods and cones are photoreceptors that are responsible for the conversion of visible light energy into neural activity (Bernstein et al. 2007, P.45). These photoreceptors usually contain chemicals, which are sensitive to light energy. As such, when light strikes the retina, the chemicals in the rods and cones immediately break apart, generating signals, which are relayed to the brain for interpretation. However, Bernstein (2010, p.91) notes that the process of rebuilding the chemicals broken apart in the rods and cones usually takes some time, w hich explain why a person usually find it hard seeing when entering a dark room when coming from a bright light. Nonetheless, as one continues to stay in the dark, the rods quickly build up the chemicals thereby enabling the person to start seeing things normally. This process of adjusting to darkness overtime is usually referred to as dark adaptation where one becomes approximately 10,000 times more light-sensitive after being in the darkness for quite awhile according to Atchison and Smith (2000, P.12). Cones, on the other hand, contain three light-sensitive chemicals that help in determining the color being seen by an individual. Cones are usually found at the middle of the retina in an area known as the fovea. The fovea is the area where the incoming light is focused. Bernstein (2010, p.91) notes that the density of cones in the fovea differs from one person to another, which explains the differences in visual acuity among different people. What is noted that cones usually works best at high light intensities, where the ability to differentiate colors become active (Bernstein et al. 2007, P.46). For instance, it is possible for one to pick two different socks in a dark room thinking that they resemble each other and only learn later that the socks are actually different in color. From the retina, signals are transferred to the brain, where the information is translated before an individual is able to see something. However, as Bernstein (2010, p.91) points out, the eye does not just transfer the images it focused on the retina directly to the brain as this will make one see blurred pictures. Instead, the visual images are first sharpened by the eye, a function, which hugely depends on the interaction between the rods and cones, found in the retina of the human eye as noted by Atchison and Smith (2000, P.12). Bernstein (2010, p.91) reveals that rays of light usually pass through numerous structures of the retina before striking the cones and rods. Once the rods and cones have been struck, they generate signals that are again relayed back to the surface of retina, thereby allowing the ganglion cells and the bipolar cells to connect enabling the eye to start the process of information analysis. Bipolar cells are part of the neurons capable of sending either positive or negative signals

Linguistics Essay Example | Topics and Well Written Essays - 1250 words

Linguistics - Essay Example Single BMCC student. 4) Jun-ho (Male, 28) – Single City college student 5) Jun-gil (Male, 28) – Married. LaGuardia Student, part time worker at a bar, 6) Hye-jung (Female, 27) – Single Culinary school student Throughout our conversation, we spent most of the time talking about work and family, but also about language. This made sense since we were all Koreans and often had to use English. Also, work and family are two of the most important things for all of us. If we attentively listen to the transcription, Choong-hoon spoke the most. His co-worker, Jun-gil, also spoke often. The reason for such might be because Choong-hoon is the eldest among the men in the party. Although everyone made fun of Jun-gil for only speaking to Choong-hoon, he actually spoke a lot as well. Besides, he probably talks to Choong-hoon a lot since he is just a guest who does not know everybody yet. So, we all wanted to know more about him to help him relax a bit. On the other hand, Hye-jun g, who is the youngest among the women at the party, spoke the least. It might have been because people often made fun of her Korean pronunciation. Since then, she kept quiet for quite a while. In addition, if we listen carefully at the transcription, then it becomes evident that there are some patterns. For instance, people were all polite to Jun-gil, who was not a member of the group before. So they asked him polite questions about his family and job. Between most of the other people, the style of the discussion was a lot more different. Conversations were often filled with jokes, for people were more familiar with each other. Even if this was the case, the polite conversation markers like oh-bba, were sometimes used. Interestingly, they often seemed to be used to making jokes, for they weren’t taken personally. Furthermore, there were some rules for how to interrupt or disagree with someone. Disagreement or interruption usually goes along with the gender of the people pres ent. For instance when, Hye-jung did not speak clearly, another girl said something about it first. Choong-hoon then did say he thought so too, but he did not say it so straight forward as compared to the girl’s comment. Also when Jun-gil was talking about whether he was working during his wife's labor, Jun-ho, another male, is the one who interrupts him. However, there were no fixed rules for bringing up a new topic. It was just done when we had all finished talking about something, but the most notable feature was that Choong-hoon and Jung-yeon, the eldest among the men and women in the party, usually brought up the new topic. Given the aforementioned scenario, let’s take a look at the linguistic principles and concepts in the discourse. First, we’ve learned the various properties of human language in class, and one of them is cultural transmission. Languages are influenced in by their culture; hence these languages are not so easy to understand without a suff icient cultural background. In the discourse, we used the words oh-bba, hyeong and nu-na, because in Korean, unlike in English, there are different ways of saying things like â€Å"you†, depending on how people are related socially, such as the age gaps of people. There are even different verbs for extremely polite situations. In our conversation, Jung-yeon said to Jun-gil, â€Å"It’s really difficult to speak to you in an informal way, even though you are younger than me.† That’s because it was the first time Jun-gil and Jung-yeon met, so