Posner & Petersen Essay Example for Free

Posner Petersen Essay With the advent of technology and the increasing complexity of the human machine interface, the demands on the attentional capacity of human operators in these evolving systems is very high. Broadbent (1958) was the first to propose a theory on attention; he argued that we have severe limitation on our ability to pay attention to more than one event. According to him the source of this limitation is an internal filter that accepts one message and rejects others. The view that our attention is limited comes from the presence of the cocktail party problem and air traffic controllers which are essentially attention-switching problems. Thus in our technologically advance world, where everything is a sensory experience, it is apparent that the stimulus overload in our sensory modalities may lead to diminished performance. The importance of attention to performance has been widely accepted, it is a necessary component in mental processing (Posner Petersen, 1990). In controlled laboratory experiments on dichotic listening (Cherry, 1953) which is more widely known as shadowing found that listeners could report much of what was presented to the attended ear but little if anything about the contents of the message in the unattended channel. We use our attention to choose and increase the processing of stimuli that are most significant at each moment. Directing attention to a stimulus leads to lower perceptual thresholds, faster reaction times and increased discrimination accuracy (Rorden Driver, 2001). However, the study of attention remains to be a challenge for most researchers due to its ambiguity and the difficulty in measuring it. Neurological and cognitive explanations of attention have abounded in recent years and have afforded us with a better way of understanding attention (Posner Petersen, 1990). Posner (1980) in his article devised a theory of understanding attention that gave us a deeper understanding of the human spatial attentional process in the perceptual domain. He proposed that understanding the mechanisms of orienting; detecting, locus of control and covert and overt orienting can be used in explaining how spatial attention functions. The most important of which is his differentiation of locus of control which are external and central controls, or for purposes of this study it is referred to as exogenous and endogenous processing. Exogenous processing refers to events controlling the orienting of attention outside the mechanisms or more specifically stimulus driven responses. For example when a stimulus draws the attention of the mechanism to a particular area in space the detection of other target events in that area become more likely. Meanwhile, endogenous processing is where the central mechanism alone directs the allocation of attention to a particular are in space through such means as instruction or probability of target events occurring in the appropriate area of space. Likewise, Posner also distinctly categorized orienting into overt and covert orienting. He said that being able to distinguish covert form overt orienting one must first be able to measure covert orienting without using overt head and eye movements. Previous studies on attention had focused on vision rather than other senses. The numerous studies on visual attention had based their assumptions on the localization of visual receptors and eye movement. Recently, the paradigms used to measure visual attention have also been applied to auditory attention. Researchers Spence and Driver (1994) had demonstrated in their experiments that the cuing paradigm can also be applied to auditory attention. They found that covert orienting does occur in human auditory system and that it influence localizations in the exogenous tasks and both localization and pitch discrimination in the endogenous tasks. Given the limited theories and scientific experiments on auditory attention it is of importance to replicate the said study to validate their findings and possibly explore new findings. However, in the present study, 3-dimensional audio is used to generate cues as opposed to the free-field cues used in the original experiments. Using 3-dimensional audio as opposed to free-field sound has been found to be more effective in controlling for front-back confusion, wherein the sound is identified as coming from an incorrect hemifield and given that high occurrence of this confusion can lead to localization errors thus the choice of using 3-dimensional audio (Parker, et. al. , 2004). However, early researches using 3-dimensional audio as compared to free-field sound have generated dubious results, like in a study where virtual and free-field sound was compared in terms of cues associated with movement of the head found that the front-back confusion rate for virtual sound have been double to that of the free-field (Wightman Kistler, 1989). Upon exclusion of front-back errors in the analysis, the localization errors were still greater for virtual sound. The conflicting results of auditory studies have led researcher Martin, McAnnaly and Senova (2001) to devise a system that would enable the use of virtual audio by ensuring that its quality is equivalent to that of free-field sound with respect to front-back confusion and localization errors. In contrast, it was found that non-individualized 3-dimensional audio is associated with an increase in front-back confusion, poor localization acuity and poor externalization (Begault Wenzekm 1993; Moller, et. al. , 1996, Wenzer, et. al. , 1993). Parker et al (2004) investigated the effectiveness of using virtual 3-D audio in a high workload flight simulation task. They supplemented the head-down displays with high-fidelity 3-D audio, and found that when the virtual 3-D audio was presented visual acquisition time was quicker. Furthermore they found with the virtual 3-D audio presented perceived workload was reduced and situational awareness was improved. Flanagan et al (1998) also used virtual 3-D audio in an experiment which compared an unaided search with visual and auditory search cues for targets outside the visual field. In the experiment they used both virtual audio (via headphones) and virtual visual cues (via helmet mounted display), and found that both the visual and auditory cues were effective in reducing search times for the targets. The present study would therefore make use of the system developed by Martin, McAnally and Senova (2004) to administer 3-dimensional sound using Spence and Driver (1994) experimental conditions. In order to gain a better understanding of the intricacies of the variables in this study and of how important the study of attention is, a review of the pertinent variables is presented. 1. 1 Attention System The attention system is difficult to explore, in cognition the various perceptual properties can be related to concrete perceptual systems like how perceptual illusions can be explained by the limitations of our optical system. While in the study of attention system one has to deal with it as a totally cognitive event without any physical substrate to refer to. In order to explore the properties of attention, the various components of the inner workings and cognitive processes need to be isolated; in the study of cognition, researchers can control the amount of input that the perceptual modalities process and even the physical and neurological structures of attention can be identified. Posner (1980) in his article devised a theory of understanding attention that gave us a deeper understanding of the human spatial attentional process in the perceptual domain. He proposed that understanding the mechanisms of orienting; detecting, locus of control and covert and overt orienting can be used in explaining how spatial attention functions. Orienting refers to the aligning of attention with a source of sensory input or an internal semantic structure stored in memory. Orienting can happen in an overt or covert manner. Detecting refers to the level with which the nervous system is made aware of a stimulus. It may be in a verbal or manual form. A very important distinction in the study of spatial attention is the locus of control. Posner (1980) define the process of control as either being external or central control of the orienting of attention. Other terms such as automatic vs. non-automatic and exogenous and endogenous have also been used to describe this process. Overt orienting refers to the observed head and eye movements when an organism attends to a stimulus, covert orienting refers to bodily processes that can be achieved only by the central mechanism and can be measured by experimental methods. Spatial attention has been related to overt movements of eyes, body, head and etc. but the relationship between movement and attention has been entirely unclear. A number of theories governing the degree of dependence of the attentional systems to eye movements have been postulated along the years. The common system says that attention movements are fixed to the movement of the eyes. However, the behavioral evidence suggests that attention can be shifted with the eyes fixed, this findings and together with results showing enhancement of evoked potentials (Eason, Harter White, 1969; Von Vorrhis Hillyard, 1977) and the firing rates of single cells (Bushnell, et. al. , 1978), have eliminated the idea that attention and eye movements are identical systems. The efference theory (Wurtz Mohler, 1976) proposed that attention shifts were programs for the movement of the eyes. Klein (1979) said â€Å"when attention to a particular location is desired , the observer prepares to make an eye movement to that location; the oculomotor readiness, via as yet unknown feedforward pathways , has the effect of enhancing processing in or from sensory pathways dealing with information from the target location†. In his experiments, Klein (1979) found that there are clearly conditions under which one gets no relationship between spatial attention shifts and eye movement latencies. Functional relation theory (Remington, 1978) found that under simpler testing conditions like those conducted by Klein (1979), a relationship between eye movement and spatial attention is present. He found that there is a strong tendency for attention to shift to the target position for an eye movement prior to the eye leaving the fixation point. He also found that just before and after the stimulus presentation that detection was high at both the peripheral targets. In general, the results suggest that the relationship between eye movements and attention is not as close as either a complete dependence or efference view. Klein’s findings that eye movements does not influence latencies of shifts of attention and Posner’s results showing that attention movements is in the opposite direction to eye movement programs, debunk the popular notion that attention can be measured through overt bodily movements. Nevertheless, the two orienting systems are not completely independent; it has been observed that attention can focus on the target prior to an eye movement even when detection signals are more probable for fixation. Posner (1980) concluded that eye movements have a functional relationship with the spatial attentional system. It seems that eye movements are programmed by an initial movement of attention to the new eye position well before the eyes actually begin to move. This presupposes the idea that even without moving, we are already using our attention system to process the target object. Further, Remington (1978) compared peripheral and central cues for eye movements in order to determine their relationship to shifts of attention. When he used a peripheral cue he found improved sensitivity in the vicinity of peripheral target after the cue and well before eye movement. When a central arrow was used to cue movement, there was no evidence of any change in sensitivity in the direction of the target until after the eye movement began. Thus, eye movement is not a reliable measure of attention shifts and in the same way overt attention cannot reliably demonstrate the mechanisms of attention, hence we turn our attention to covert attention. 1. 2 Covert Attention Posner (1980) emphasized that the study of spatial attention should focus on covert attention for it gives a better picture of how attentional systems work than overt attention which can be subjected to external influences. Overt attention is manifested through external movements and more often than not the person is aware of that behavior, hence results on overt attention may be due to various factors not related to attention. In studying covert spatial attention, Posner (1980) said that it is important to keep in mind the functions of orienting, detecting and the distinction between external and central control. Orienting is the ability of the individual to shift attention around the visual field; detecting is when the individual becomes conscious of the stimuli, external and central control identifies the process by which the individual is attending to the stimuli and overt and covert attention is the ways in which the individual process the stimuli. Thus, even before attention is directed to a target, the individual can orient his/her sensory receptors to focus on the stimuli, and when the attention has been oriented, the individual can now detect the stimulus and depending on the context with which the stimulus is presented may attend to the stimuli exogenously or endogenously. Based on Posner’s influential work, it can be deduced that the study of covert attention is more important and scientifically worthwhile than overt attention, hence the number of models used to explain and study covert attention. The three models used to study the covert spatial distribution of attention has been used in experiments on visual attention but since few researches focused on auditory tasks it is presented here as it can possibly used to explain other sensory modalities. The first model says that attention can only be directed to one visual field (Kinsbourne, 1993). This in essence means that we can only attend to one thing at a time; hence we can only see one movie at one time. However, the model is too simplistic to fully define visual attention. The human vision can accurately build a spatial model of the external environment and relevant objects will compete for selection with other objects. On the other hand, this model may be used in the study of auditory domains because its spatial distribution is lesser. Sound is composed of waves that travel in the air, it is quite dispersed and thus to attend to a sound cue is much faster than attending to a visual stimuli. Moreover, as we perceived it sound does not occupy a physical space much like objects, letters, and colors etc. that are used as visual stimuli. The second model states that attention can be divided in a graded manner with the maximum performance at the focus of attention, which gradually deteriorates, with the increasing displacement of the focus. This means that the quality of our attention to a target is at the most accurate if it is within our central focus and that our perception of the target deteriorates a sit moves further away. This model is much more suited in the study of auditory performance since it takes into account the graded allocation of attention with respect to sound and distance. It is interesting to explore at what point our attention to an auditory stimuli would decrease and to which it is strongest.

State Universities Should Lower Tuition Essay -- State Colleges Should

What to do after graduation? This is a question many high school students ask themselves as they near the end of their senior year. Most students will want to go on to higher education and continue their studies to receive a degree in something they are passionate about. Unfortunately, some of these students don't have enough money or receive enough financial aid to attend the schools they dream of; and most of the ones that do, graduate with a huge debt due caused by student loans. Over recent years, state universities, whether public or private, have been raising their tuition rates and fees. Because of this increase, fewer and fewer students are enrolling in universities to further their education, and the number of students dropping out of college is rising as well (McClure 12). State universities should lower their tuition rates and fees in order to allow more students the opportunity to go on to higher education after high school. The transition from high school to college is hard enough with all the coursework. But now, students have to worry about constantly rising prices in their schools. A main obstacle students face while in college is being able to pay for their classes and books. That is why many students seek to obtain part time jobs. However, a part-time student’s salary is not enough to cover the expensive books and high tuition. This leads to students obtaining full time jobs, multiple part time jobs, or the most common of them all, student loans. Erin Sandonato is a perfect example. She graduated from a public high school in Georgia and had good enough grades to have scholarships pay for her education. However, when she transferred to a university outside of Georgia she no longer had any aid and h... ...08. Web. 19 Nov 2009. Dannenberg, Michael. "The Truth About Tuition." American Prospect, September 2009. Web. 15 Nov 2009. Duke, Alan; Martin, Augie; Morrison, Greg; Lamanivong, Lynn. â€Å"Protests of tuition increase continue on California campuses.† cnn.com. CNN, 20 November 2009. Web. 27 Nov 2009. â€Å"Federal Pell Grant Program.† ed.gov. U.S. Department of Education, n.d. Web. 27 Nov 2009. McClure, Ann. "Conclusion: college is expensive: annual trend reports put the spotlight on pricing and student aid." find.galegroup.com. General OneFile, December 2008. Web. 15 Nov 2009. Price, Tom. "Rising College Costs." library.cqpress.com. CQ Researcher, 5 December 2003. Web. 22 Nov 2009. Riley, Anjanette. "Tuition increase will provide $55 million to Arizona universities." find.galegroup.com. General OneFile, 5 December 2008. Web. 17 Nov 2009.

Bank of China †Survey of products and services provided Essay

Personal Banking. In the personal banking segment one of the principal products and services include deposit products. The Bank of China provides a variety of deposit products including foreign currency deposits. It has also included multifunctional debit card which can assist financial planning. (Deposits, 2006). It has also got a facility for deposit collections at different places which facilitate those with transferable jobs or changing residences frequently to follow up their deposits without any geographical constraints (Deposits, 2006). Deposit Certificates are being issued by the Bank for people’s needs for studying abroad, visiting relatives or for domestic requirements. (Deposits, 2006). The bank also provides facilities for payment of fees, providing pay to employees, stock fund transfer service and handling of securities trading services. (Deposits, 2006). In addition Personal Checks are provided for high value account holders for making large purchases which are beyond the credit card limits allotted. (Personal Check, 2006). In the loans segment, Bank of China is providing a variety of loans to its personal customers. The primary loans include educational loans which can be commercial or state. The latter are at discounted interests by the central financial authorities in China, while commercial loans are for financing tuition and other fees which is supported privately. (Loans, 2006). Auto loans include financing for purchase of cars. In addition there are travel loans to facilitate in board as well as out board travel which however has to be only through approved travel company services as per bank norms. (Loans, 2006). There are petty consumer credit loans which are provided for facilitating normal consumption needs of customers such as labor service and fee payments. (Loans, 2006). For such purposes the client is required to be credit worthy. A normal service provided by the Bank is renting of safe deposit box. (Loans, 2006). Another important service provided by the bank is that of Bancassurance, which involves a tie up with the insurance companies, providing the client a full range of services to include insurance, premiums on policy and preservation at a savings outlet in BOC. (Bancassurance, 2006). Corporate Banking. In the corporate banking sector, the Bank of China has a strong presence with a global profile. Its experience and expertise is seen to be of particular benefit to the Chinese businessman seeking to do business globally. (Corporate, 2006) The bank claims to provide unique services based on its ability to assess market sensitivity. The various corporate services provided by the bank include financing for trade, risk controls, protection of risk of debt and is extending even further to management of ledger and collection. (Corporate, 2006). In the loans segment the various types of loans include providing working capital to the companies, for financing projects, real estate businesses, fixed assets and loans on foreign currency. (Corporate, 2006) Business is provided finance in various forms of credit such as a normal credit line, credit for export buyers, finance lease guarantees, credit for export sellers, accounts receivable purchases and labor service contracts. (Corporate, 2006). For international businesses, the services provided include both inward and outward remittance, collection of letters of credit for both imports and exports, bill discounting, packing loan and guarantees for businesses and shipping. (Corporate, 2006). The investment banking services include a financial advisory service, cash management, loan trusts and agent bank business. The bank has also developed extensive e banking services to include i-banking, telephone banking and mobile phone banking. These services are seen to be highly effective in providing the corporate a variety of mediums of interaction on the World Wide Web. (Corporate, 2006). In the segment of foreign exchange and settlement, it is the lead bank in China and hence enjoys considerable leverage in the Chinese banking industry. This caters for individual and personal foreign exchange needs. (Forex, 2006). It has also facilities for forward transactions in foreign exchange Global business facilities include same day facility of funds transfer with the GLOBAL NICS programme in place which enables transactions across 581 overseas branches in 26 countries and regions on a single computer network. (Global, 2006). Linked to SWIFT communications, it enables a safe and speedy transaction for business persons. This is particularly significant with the extensive network of the Bank within China comprising of over 12,000 branches. It also facilitates international clients to transfer money within China speedily. (Global, 2006). Overseas Presence. The Banks overseas presence has been consistently growing after the China Development Finance Company (HK) was established in 1979, followed by Bank of China Groups Securities Limited in 1983, Bank of China International UK Ltd 1996 and Bank of China International in Hong Kong in 1998. (BOCI, 2006). The subsequent entry of BOCI into mainland has provided it added opportunity to establish close links with stable Chinese corporations to include China National Petroleum Corporation, State Development & Investment Corporation, China General Technology (Group) Holdings Limited and so on. (BOCI, 2006) This enables strengthening of the financial link of the Bank providing it greater stability in the international as well as national banking domains. (BOCI, 2006). Banking Facilitation. The BOC is also an agent bank for a large number of other banks providing them the services of consignment banking to manage loans between borrowers and the agent bank. The consignment banks include China Import and Export Bank and the State Development Bank. (Agent, 2006). This provides the client bank the advantage of drawing upon the experience, expertise and network of a larger bank with an international presence as the BOC. A relatively high quality of service is said to be provided to the agent bank by BOC. Generally a tripartite agreement is signed between the BOC, the client bank and the borrower. (Agent, 2006).

What to Do if Youre Charged With Plagiarism in College

Plagiarism—the act of passing off someone elses work as your own, no matter where you found it—is pretty common on college campuses. If one of your professors or an administrator realizes what youve done, you may be charged with plagiarism and put through some kind of campus judicial system. Figure out the Process Do you have a hearing? Are you supposed to write a letter explaining your side of the story? Does your professor simply want to see you? Or could you be placed on academic probation? Figure out what youre supposed to do and by when -- and then make sure it gets done. Make Sure You Understand the Charges You may have received a strongly worded letter accusing you of plagiarism, and yet youre not totally clear on what exactly it is youre being accused of. Talk with whoever sent you the letter or your professor about the specifics of your case. Either way, make sure you are crystal clear on what youre being charged with and what your options are. Understand the Consequences In your mind, you may have been up late, writing your paper, and absentmindedly cut and pasted something from your research that you forgot to cite. In your professors mind, however, you may have not taken the assignment very seriously, showed disrespect to him or her and your fellow classmates, and acted in a way that is unacceptable at the college level. What is not very serious to you may indeed be very serious to someone else. Make sure you understand what the consequence are, therefore, before you are unpleasantly surprised at how your sticky situation just got a lot worse. Respect and Participate in the Process You may not think the plagiarism charge is a big deal, so you toss the letter aside and forget about it. Unfortunately, however, plagiarism charges can be serious business. Respect and participate in the process so that you can explain your situation and reach a resolution. Figure Out What Youve Learned so It Doesnt Happen Again Plagiarism charges in college can be dealt with lightly (essay rewrite) or severely (expulsion). Consequently, learn from your mistake so that you can prevent getting yourself into a similar situation again. Having a misunderstanding about plagiarism, after all, can only happen once. The next time you receive a letter, folks are much less likely to be understanding since youve already been through the system. Learn what you can and move forward toward your ultimate goal: your diploma (earned by you and your own work, of course!).