Theories Explaining The Cause Of Dyslexia Psychology Essay

Theories Explaining The Cause Of Dyslexia Psychology Essay According to this hypothesis dyslexia is caused due to the impairment of the phonological module which disrupts the ability to sequence the written word into its phonetic constituents[ D. Shankweiler et al,1995]. Reading is a complex process that involves two steps: decoding and comprehension[P.B. Gough,1986]. The process of comprehension requires higher order cognitive abilities like intelligence, vocabulary[D.L. Share,1995] which are left unaffected in dyslexia[Shaywitz SE,2001]. Decoding involves the conversion of graphemes to phonemes. As a result the written word is not decoded properly which makes the individual difficult to comprehend it. Support for this hypothesis comes from an fmri study conducted by Georgiewa[P. Georgiewa,2002] in which both the dyslexic and control subjects were asked to read silently the given linguistic stimuli. There was a significant activation of Inferior frontal gyrus(IFG) in the control subjects[P. Georgiewa,2002]. In the dyslexic subjects there wa s activation in 3 areas in addition to significant activation in the Brocas area. The hyper activation of Brocas area in dyslexics when compared to the controls could possibly be due to increased effort in phonological decoding. Recent anatomical evidence shows that there is a significant underactivation in Wernickes area, angular gyrus and striate cortex and overactivation in the Inferior frontal Gyrus in dyslexics when performing a phonological task[Shaywitz SE,1998]. Critics of this hypothesis argue that it doesnt account for symptoms not related to phonological decoding. Another criticism of this theory is that these phonological skills can be recovered on extensive training. This hypothesis states that the symptoms in dyslexia are causes due to the impairment of the magnocellular pathway of the Lateral Geniculate nucleus(LGN)[ Livingstone M,1991]. In their post mortem study of 5 dyslexic brains, Galaburda and their colleagues found that the M cells of the LGN were 20% smaller than that in normal people. The LGN is a six layered structure with the layers 1 and 2 known as magnocellular layer and the layers 3,4,5,6 known as the paarvocellular layer[Carlson,2007]. The Magnocellular layer is known as the faster processing pathway as they respond faster and responsible for contrast sensitivity at low spatial frequencies and low luminance levels[XuX, IchidaJM 2001, WIESELT,. N. D. H. HUBEL1. 1966].As this functional segregation of the LGN is maintained upto the cortical association areas,(posterior parietal cortex)this M-layer defect could cause impairments in reading[M. Kinsbournen 1962, Morris, R.K 1991, Olson 1991]. The theory is supported by the fact that the flicker fusion rate in dyslexics is low at conditions operated by the magnocellular layer[W.J. Lovegrove,1980].Since the major target of M cells is the Cerebellum there are possibilities where this defect in specific line of M-layer could account for the motor symptom defects in dyslexics[John Stein and Vincent Walsh,1997].The Magnocellular hypothesis has some criticisms. There is evidence against the theory that dyslexics perform worse not only in low spatial frequencies and luminance but also on high frequencies and luminance levels[Skottun, B. C, 2000]. THE DOUBLE DEFICIT HYPOTHESIS(DDH) According to this hypothesis the reading impairment caused in dyslexia is due to two deficits which are phonological and rapid naming and both are different[Wolf, M,1999]. Rapid naming deficit is a deficit in which the subjects have problem in naming different classes of stimuli when presented visually. A typical test which assesses rapid naming is Rapid Automatized naming(RAN)[ Denckla MB,1974]. According to Wolf[Wolf, M,1999], Dyslexics perform poorly on RAN. Support for this theory also comes from other researchers like Tallal, Temple[Temple 2000] who argue that dyslexic children process sounds very slowly than normal people. But Critics say that the task of rapid naming is also phonological since naming is done by spelling and producing sounds and so it involves the Brains phonological system. THE AUTOMATISATION DEFICIT HYPOTHESIS(ADH) Automatization is a process by which the process of acquisition of skill becomes finer and refined so that the skill can be performed easily. This hypothesis states that the dyslexics perform badly in any task that requires skill automatization[Nicolson,1990]. For example dyslexic children perform poorly in balancing task and the performance is poor only when they are not allowed to compensate for it consciously[Nicolson R.I and Angela J. Fawcett(1995)]. A normal child would automatize the process of hearing phonemes in a word after some period, which is difficult for dyslexic children. THE CEREBELLAR DEFICIT HYPOTHESIS(CDH) The poor performance of dyslexics on tasks that require motor skill automatization(balance task) raises a possibility that Cerebellum might the involved in Dyslexia since cerebellum is primarily involved in motor learning[J.F. Stein and M. Glickstein, 1992] and error based learning. This theory states that Dyslexia is characterised by cerebellar impairment[Nicolson, 2001]. Almost 80% of the cases of Dyslexia is characterised by Cerebellar impairment. If the cerebellum is impaired in Dyslexia then the dyslexic patients should show classic cerebellar syndromes like dystonia and ataxia[R.S. Dow and G. Moruzzi, 1958]. It was found that the performance of the dyslexics were worse than the control subjects on all the cerebellar tests[A.J. Fawcett  et al., 1996]. Direct evidence for the involvement of cerebellum in dyslexia is based on the experimental paradigm of a PET study conducted by Jenkins[I.H. Jenkins  et al, 1994]. In their study the subjects were made to learn a sequence of ke y presses by trial and error and using auditory feedback. It was found that the Cerebellum was active when the subjects learned new sequence and when the subjects were performing a prelearned sequence. The dyslexics showed less cerebellar activation (ipsilateral) both during learning of new sequence and performance of a prelearned sequence[Nicolson, 2001].One important question to answer is how cerebellar impairment could cause specific cognitive deficits in Dyslexia. The answer would be Cerebellar impairment causes problem in the childs articulatory speed which leads to reduced working memory which in turn causes language acquisition problems[S.A. Gathercole  et al, 1992]. A recent study on the morphology of Cerebellum correlates cerebellar symmetry with the degree of phonological deficit in dyslexics[Rae C,2002] indicating that there is a connection between cerebellum and phonological deficit. A lot of neuroimaging studies say that the Cerebellum is involved in language processi ng tasks[J.E. Desmond and J.A. Fiez 1998, S.G. Kim, K. Ugurbil and P.L. Strick 1994].Also abnormalities in the fronto cerebellar network is related to double deficit in dyslexics[Mark A. Eckert and Christiana M. Leonard 2003].Given all these evidences it becomes clear that cerebellum is involved in Dyslexia. But the Cerebellar deficit hypothesis also has some unanswered questions. The Cerebellum is a large structure receiving inputs from a lot of regions of the brain and so the primary impairment might be located somewhere else in the brain causing a disruption of Cerebellar processing[T. Zeffiro and G. Eden,2001].Recent research also suggests that the actual impairment might be located in the perisylvian neocortical regions[Eden, G.F. and Zeffiro, T.A. 1998, Klingberg, T. et al. 2000], which sends and receives projections from the Cerebellum. CONCLUSION Dyslexia is characterised by a wide range of symptoms and so it highly possible that the underlying defects are in multiple brain systems. Given the role of Cerebellum in Language and motor tasks, it is quite clear that cerebellum is involved in dyslexia. That said one cannot deny the PDH and MDH. Many problems in dyslexia are phonological which is in accord with the PDH. The MDH accounts for rapid processing deficits. Also Anatomical evidences described above shows that there is sufficient underactivation in the angular gyrus, Wernickes area and the magnocellular layer and the striate and extra striate cortices in dyslexics which account for the phonological and rapid processing deficits. One way of unifying these three theories is by using the fact that the Cerebellum is connected with many parts of the brain [J.D. Schmahmann and D.N. Pandya 1997, H.C. Leiner, A.L. Leiner and R. Dow 1993]. Thus I conclude by stating that Dyslexia is an impairment of multiple Brain systems.

Evolution of Goaltending in the NHL Essay -- essays research papers

Today, the term hockey describes differing games in various parts of the world, but specifically in North America it refers to as ice hockey. In its origin, hockey is one of the oldest games played. The earliest mention of the sport of hockey dates back to 1572, when it was on a list of prohibited games. Hockey's birthplace is believed to be in Asia and authorities credit Persia with having devised it about 2000 BC. People who perfected the game of polo must have known "hockey on the ground" before "hockey on horseback". Certainly though ice hockey originated in Canada. Two theories have surfaced as to who really came up with ice hockey. The first credits English soldiers serving with the Royal Canadian Rifles at Kingston, Ontario. They improvised the game at the rear of their barracks at Tete du Pont, on the iced up harbor on Christmas day in 1855. After sweeping the snow from the ice, the soldiers tied "runners" to their boats and, with borrowed hockey sticks, played a match with an old lacrosse ball. The other theory gives not soldier's credit, but students credit. It tells that G.F. Robertson, of Mcgill University in Montreal first thought of ice hockey. On a visit to Britain in 1879, he had watched a field hockey match and had greatly been intrigued by it. Himself being a skilled ice skater, he wondered if it was at all possible to combine the two sports into one, thereby creating something new and exciting. On his return home, he discussed the idea with a friend and together they worked out a synthesis of hockey and skating, adding for good measure a few football rules. Enjoyment of the game proved so great that from an initial experimental venture, it soon graduated at their college to an invigorating sport of tremendous speed, leading eventually to the formation of the McGill University Hockey Club. The first theory is the one believed to be the right one but no one knows for certain the originator of the game. We do know that the term "Ice Hockey" was the earliest recorded in a game that took place in Montreal. As the Canadians love and knowledge for the game of ice hockey grew, so did the sport. After various problems between teams playing with different rules, McGill University stepped in to set up the rules, thus making ice hockey a sport. The most popular ice hockey league in the world is the National ... ...the goalies in the NHL have always had to evolve along with the game. The position of goaltending has greatly evolved since the formation of the NHL and even before the NHL started. The formation of the NHL in 1917 opened doors for players to show off their skills to the world and make a living, especially the goalies. The equipment that goalies use have evolve to be much lighter, more comfortable, and more aerodynamic since the start of the NHL and will keep enhancing in time. The physical and mental abilities of goaltenders today is much more sharper, stronger, and quicker than what they were in years in the past. The style of play of goalies these days has evolved greatly from the base styles that were set by some of the great goalies in the past. Also, the rule changes that the NHL has set forced goalies to evolve their game to fit the new rules and make the most out of what situations are presented to them. These are all the aspects of the position that have evolved throughout the years in the NHL. Goaltenders today are the most conditioned, sharpest, quickest, and most important piece of a professional hockey team and has all evolved from what goalies in the past have done.

The Billingual Instructors for Bilingual Educations

The amount of non-English-speaking minorities in the United States is continuously increasing. Be that as it may, there are people in today†s society that feel that English should be the only language spoken. It is for that reason bilingual education may be eliminated from many public schools. Low academic outcomes from students also contribute to possible abolition of bilingual education. If schools don†t obtain better methods to ease the transition from one language to another, bilingual education will be faulty and seen as useless. In turn, many students will be denied the chance for an equal education. American students have learned the language easily because it has been incorporated into everyday events from an extremely early age. An adolescent has had at least 5 years to learn English vocabulary, and continues learning through high school. Many bilingual programs have students on slower learning tracks where they barley learn English and from which they may never emerge. However, society wants bilingual students to learn English and learn it quickly. By eliminating bilingual education, society is telling the student to learn English, but not giving him a place to learn it. The student is not given an adequate chance, which results in bilingual persons having poor reading, writing and speaking skills. Bilingual students can keep up academically with their English-speaking peers if they are taught at least partly in their native languages while learning English. There are many ways that bilingual education can be improved. By hiring bilingual teachers that communicate clearly when giving directions and accurately describing tasks will help ease the transition from a native language to English. If new information was introduced by using strategies such as thoroughly explaining, outlining, and demonstrating, comprehension of instructional tasks may be maintained. Promoting student involvement, communicating expectations of students', and explaining success in completing instructional tasks would give students motivation so they feel at ease. A new language is difficult; approaching bilingual students with methods such as these could improve their learning. An effective way to have positive student outcome is to value and respect students' languages and cultures. This value and respect needs to go further than the food and holiday celebrations that may be the only recognition of cultures in many schools. Teachers should involve themselves by learning about students' experiences in native countries and communities in the United States, while encouraging and supporting the development of the English language. These actions and attitudes show a student she is valued and respected; this, in turn, supports a more comfortable atmosphere for her. Furthermore, it builds self-esteem and improves academic achievement by incorporating the students' cultures into classroom instruction. Building lessons from things in students' experience and backgrounds promote more active engagement and increased learning. The will always be a need for bilingual education. There are many ways in which schools, teachers, parents as well as the student herself can improve. Answers to all of the questions posed by bilingual educators may not be available, but ideas about features of effective bilingual schooling are available. People involved in schooling need to work together to set realistic goals and strategies to promote success of bilingual education.

Concord Bookshop Paper - 716 Words

Concord Bookshop Paper Karen Jackson HCS/587 November 8, 2010 Laura Rainey Concord Bookshop Paper Organizational change can derive from small changes to large changes that can affect a business. The Concord Bookshop went through changes as many other companies are faced in today’s recession, fierce competition, innovative technology, and restructuring needs. The important factors a company needs to concentrate include implementing successful interventions to stay in business, increase finances, and motivating employees to change their behaviors. If certain phases of an organizational change do not take place, this could lead to failure. In this paper, I will describe three processes not completed or implemented at the†¦show more content†¦In the Concord Bookshop, the board told staff, â€Å"We’re going to do it our way and if you don’t like it, each of you will have to make up your mind as to how to proceed.† Any employee would not be pleased with this response just as the Concord Bookshop staff was not pleased with the response from the board. Processes for Change Organizational change process is composed of three stages. The first stage is unfreezing that is used to create motivation of change. This is creating some anxiety in an individual without using a defense mechanism when stress or threat is increased. According to Spector (2010), to unfreeze, â€Å"We must accept disconfirming and connect it to something we care about.† This process was not implemented by the Concord Bookshop as previously mentioned of board deciding to do things their way and not include the staff in the change process. The second process for change is moving. Schein (2002) stated moving is allowing â€Å"members of the group to change from one set of behavior to another,† such as new job responsibilities, new roles, and new job skills. The third process of change is refreezing. Refreezing occurs when the person or group gain new behavior patterns. Schein (2002) supports ideas of refreezing to secure change by remaining in the same group that has changed. The change is temporary if the changes are made to theShow MoreRelatedConcord Bookshop Paper816 Words   |  4 PagesConcord Bookshop Paper Concord Bookshop Paper Organizational change has many concepts from wide changes to small changes that can affect a company. Introducing a new person into the company, changing mission statement, restructuring, and even adding stock options are examples of organizational changes. According to Spector it is important to understand, analyze the dynamic of change, and requirements of effective change implementation. Successful changes requires management to explore many driversRead MoreConcord Bookshop678 Words   |  3 PagesConcord Bookshop Introduction As the world is changing with Technology, many companies are finding themselves struggling to stay afloat in competitive market. Whenever new business strategy is introduced in a company, a change has to take place. The way changes are introduced and implemented, determines the success of the change. Before change is introduced, there must be need for change and after implementation of change; there is expectationRead MoreThe Phases of Organizational Change Essay807 Words   |  4 Pagesthe Concord Bookshop, a bookstore that is in the process of implementing new changes. Spector (2010), states that â€Å"for the Concord Bookshop, the increasing penetration of online booksellers into the store’s market space triggered the requirement for strategic renewal† (p.18). Kurt Lewin developed a change model to assist organizations such as the Concord Bookshop with changes. There are three steps in Lewin’s model and they are: Unfreezing, Transitioning or Moving, and Refr eezing. This paper will