The Communicative Behaviours of Aphasics - Essay Example

RUNNING HEAD: The Communicative Behaviours of Aphasics The Role of the Brain in the Acquisition, Production and Understanding of Language Based on the Communicative Behaviours of Aphasics [Name] [Professor/Class] [University] [Date] The Role of the Brain in the Acquisition, Production and Understanding of Language Based on the Communicative Behaviours of Aphasics Oral and written forms of communication are two of the most essential requirements to be able to survive in society. Language is crucial in being able to successfully communicate as it is the medium in which people are able to commune with each other in order to go about his or her everyday businesses. The world today without language will be chaotic as words are used in easing conflict, reaching an agreement and a compromise, and expressing thoughts and feelings. As Abraham Lincoln (1863, quoted in Caplan 1995) once said in his Gettysburg Address, “Language is an indispensable part of human culture, without which jurisprudence, commerce, science and other human endeavors could not exist in the forms we know them.” Because of this significance of language in individual and societal lives, many researchers and scientists have studied it and the various language disorders in order to better understand the processes that inhibit or stimulate and reinforce its use. The brain is central to the scientific study of language as it is in the brain that language has evolved from mere monkey utterances into words and then coherent phrases and sentences (Deacon 1997). The increasing occurrences of language disorders have also made the brain the focus of language studies in order to ascertain what can be done—if there is indeed something that can be done—to correct or cure these illnesses that debilitate the afflicted from functioning normally in society. This paper will focus on a specific language disorder called Aphasia, as it is through the research and study of language disorders that most findings about the brain, in relation to language, are grounded on (Chudler 2007). Through the discussion of the ins and outs of this type of language disorder, the author aims to present an exposition of the role of the brain in the acquisition, production and understanding of language. For the clarification of the objective of this paper, it is important to note that the acquisition of language will pertain to the different regions in the brain that are designated to be language areas; the production of language concerns Brocas Aphasia research; and understanding is explained through Wernickes Aphasia. Language and the Brain The complex structure of the brain and the vast range of its functions have long been a source of interest that has spawned an evolution of theories and scientific facts. Due to this, what is dubbed as “the mysteries of the brain” can no longer be characterized as wholly mysterious—the neuroscientists have shed light into the various workings of the brain through the study of various language disorders, the specific areas that were damaged and the corresponding symptoms of the disorder (Miller & Tallal 2006). Hence, the areas of the brain responsible for language have been delineated and ascertained over years of neuroscience research with specified areas attributed to the articulation and comprehension of language. This section will provide an overview of the role of the brain in language acquisition. Theory of Nativism The proponents of this theory believe that through the course of a child’s growing up years, he or she is able to acquire language naturally (Onda & Matsuishi 2003). This means that individuals are born with the capability to learn language—fluency is enhanced through this innate ability of individuals to acquire language. Chomsky (cited in Onda & Matsuishi 2003) further explains that the brain inherently has areas in the brain specifically tasked to learn language called the “language acquisition facility.” This view posits that there is a universal grammar that humans are innately equipped with at birth and that this is a prerequisite in language acquisition (Chomsky cited in Onda & Matsuishi 2003). This view is a simplistic one, which has been strengthened and weakened by many studies, depending on the nature of the research and methodology. The following sections will discuss the more complex and specific discourses on language in the brain and the corresponding functions that characterize the different language areas. Lateralization In order to fully understand the brain’s function in language acquisition, it is imperative to provide a rundown of how the brain works. Lateralization is the division of the brain through the location of its capabilities into the right and left hemisphere (Boeree 2004). The left hemisphere is responsible for language, math, logic, and reasoning, while the right hemisphere is where music, facial recognition, visual imagery, and spatial abilitie are centered (Buckley 2002). A function is said to be lateralised when one side of the brain (the left or the right) exercises more control over this particular function than the other side (“The Brain from Top to Bottom” n.d.). Contralateralization, on the other hand, pertains to the fact that the left side is dominant for right-handed people and vise versa (Buckley 2002). This division of the brain is dependent on the “handedness” of an individual (Boeree 2004). Language is proven to be centered in specific areas in the left hemisphere (Boeree 2004). “While this holds true for 97% of right-handed people, about 19% of left-handed people have their language areas in the right hemisphere and as many as 68% of them have some language abilities in both the left and the right hemispheres” (Boeree 2004). However, it has been found that the left hemisphere is anatomically and naturally inclined towards language processes (“The Brain from Top to Bottom” n.d.). The WADA Test developed in the 1960s, which put to sleep either of the two sides of the brain, ascertained this as it was found that when the left hemisphere was put to sleep, the individual could not speak (Chudler 2007). However, when the right hemisphere was sleeping, the person was able to articulately answer the questions placed before him or her (Chudler 2007). Localization of the Brain The localization of the brain specifies and differentiates the various regions of the brain into areas specific to their functions. In 1836, Paul Broca studied the brain of a man whom he dubbed as “Tan” (for this was the only word he spoke) and discovered that the left frontal cortex was damaged, preventing Tan from speaking understandable words and putting his thoughts into writing, yet not impairing his ability to understand (Chudler 2007). Broca examined eight other patients with the same symptoms and the same lesions to the left frontal cortex (“The Brain from Top to Bottom” n.d.). More than a decade later, in 1876, Karl Wernicke learned that when the posterior part of the temporal lobe is damaged, it impaired the individual’s ability to understand language (Chudler 2007). Although the person can pronounce words correctly, he or she has lost the ability to form coherent sentences (Chudler 2007). These language-specific areas in the brain were then later named after the two neuroscientists. The Broca’s Area came to be known as the region in the brain that is responsible for language production or “language outputs,” while the Wernicke’s Area is linked with “language inputs” or the processes of speech and language comprehension (“The Brain from Top to Bottom” n.d.). In order for a person to speak coherently, the thought is passed on to the Wernicke’s area, where it is understood, and then transmitted to the Broca’s area, where the words are formed to translate it into coherent speech (Chudler 2007). Finally the information is sent to the motor cortex, where the muscles are controlled and moved in order to produce coherent speech (Chudler 2007). The motor cortex is the area responsible for the movement and control of the skeletal muscles (Marieb 2004). This allows individuals to move the facial muscles and the jaws in order to be able to produce words and speak. The angular gyrus is the region where reading abilities are located (Buckley 2002). The diagram below illustrates the main areas of speech and language as located in the brain. Source: Boeree 2004 Modularity of the Brain Terrence Deacon (1997), a renowned figure in the field of Neuroscience, has delved deeply into the evolution of language in the brain and has attempted to challenge the more widely accepted localization of the brain by stating that it is an act of “misplaced concreteness.” Instead, Deacon (1997) proposes to distinguish how language functions are plotted along the different brain functions. This view is in accordance with modularity as the latter is concerned with the structural design of the brain as the different functions, like linguistic ones, are located in various “modules” (Crain n.d.). Furthermore, Deacon (1997) differentiates language functions into semantic and syntactic, the right and the left hemispheres respectively, and holds that “there is a progression from parts of words, to words and phrases to verbal short-term memory” and that a precise “language/grammar organ” in the brain does not exist. This is because the brain, together with language, has evolved over time. This progression, he asserts are characterized as slow and takes a long time to develop if one considers the evolutionary approach from animal talk to human language and the development of the brain from Neanderthals to modern man, while the progression is much faster when taking into consideration the localized regions of Broca’s and Wernocke’s areas, for instance. Hence, the evolutionary progression is more characteristic of modules acting out the different language functions in the brain, rather than being localized. This capability of the brain to evolve negates the nativistic view as it alludes to the fact that the brain has grown and developed in parallel to the advancement of language from the era of the apes to man as we know it today. This is done through the process of natural selection, which supposes that favorable traits that are genetic become more widespread throughout generations of reproduction, while unfavorable traits become more infrequent and rarer as they finally come to be extinct (Deacon 1997). This means that the universal grammar popularized by Chomsky is not applicable as humans evolved from monkeys and the brain of humans was therefore just developed through time through the process of displacement, which is the analogous counterpart of natural selection as applied to the workings of the brain (Deacon 1997). Deacon (1997) further insisted that the lateralization of the brain is a mere separation of the functions of the brain. This does not make the left hemisphere the language center in that the right hemisphere “is critical for the large-scale semantic processing of language, not word meaning so much as the larger symbolic constructions that words and sentences contribute to: complex ideas, descriptions, narratives and arguments.” He came to this conclusion by stating his experiments and studies that show that damage to the right hemisphere debilitate individuals to grasp the entirety of an issue (for instance, the person is not able to get the point of a joke) or to be able to identify the misplaced and omitted elements (Deacon 1997). This again is in acordance to the evolving characteristic of the brain, its functions, and the location of its functions. Aphasia As mentioned previously, much of the segregation of the different parts of the brain into language functions are due to the studies conducted on individuals who suffer from language disorders. Aphasia is one of the more common language disorders, which is defined as “an abmormal neurologic condition in which language function is disordered or absent because of an injury to certain areas of the cerebral cortex” (Allen et al. 2002). Hence, it is an acquired disorder, wherein the more common cause is a stroke, and it should not be confused with developmental and inborn language disorders (Xiong 1999 and Jacobs 2005). A.H. Raskins (quoted in Xiong 1999) explains his experience with Aphasia through a stroke in the following statement: “My most valuable tool is words, the words I can now use only with difficulty. My voice is debilitated - mute, a prisoner of a communication system damaged by a stroke that has robbed me of language.” In 1999, of the 400, 000 cases of stroke patients in the United States, 80, 000 were giagnosed with Aphasia (Xiong 1999). As of April 2007, the number of Aphasics in the United Kingdom is 221, 583, while Americans uffering from this condition rose to a staggering 1,079,615 (WrongDiagnosis.com 2007). Aphasia can either be receptive (what is understood) or expressive (what is said), depending on what part of the left hemisphere was damaged (American Speech-Language-Hearing Association 2007). There are also cases wherein the repetetive speech is impaired due to the damage on the part of the brain that connects the Broca’s and Wernicke’s area, the arcuate fasciculus (Buckley 2002). The most severe form of Aphasia is Global Aphasia, wherein a massive damage has occurred in the left hemisphere, which has erased the individual’s capacity for all forms of language expression and reception (Buckley 2002). This section will tackle Broca’s Aphasia and Wernicke’s Aphasia as they relate to language production and understanding, respectively. Broca’s Aphasia Because the Broca’s area is responsible for the production of language outputs, a lesion in this region is tantamount to the impairment of expressive language. Because the Wernicke’s area is not damaged, the patient is still able to understand speech and read relatively well (Buckley 2002). Individuals suffering from expressive aphasia have the following impairments brought about by the condition (Buckley 2002): Speech output is severely reduced, limited mainly to short utterances of a few words. Vocabulary access is limited. Lack of syntax and diminished morphology. Formation of sounds is often laborious and clumsy. May understand speech relatively well and be able to read, but be limited in writing. An example of an expressive Aphasic’s attempt to form a coherent sentence is this: “Cinderella ... poor ... um dopted her ... scrubbed floor, um, tidy ... poor, um ... dopted ... Si-sisters and mother ... ball. Ball, prince um, shoe….” (Buckley 2002). However, because the syntactic capability is diminished, there are some minor misunderstandings that can occur in understanding sentences where there are two similar nouns, the role of the two are interchanged (Buckley 2002). Take for example the following sentence: The girl kissed the boy. An expressive will not know the difference between the girl and the boy, specifically, which one is doing the kissing. Why is the comprehension of language debilitated, albeit slightly, when the Broca’s area was the only one that was damaged and not the Wernicke’s area? Deacon (1997) answered this by stating that: Human language has effectively colonized an alien brain in the course of the last two million years. Evolution makes do with what it has at hand. The structures which language recruited to its new tasks came to serve under protest, so to speak. They were previously adapted for neural calculations in different realms and just happened to exhibit enough overlap with the demands of language processing so as to make "retraining" and "reorganization" minimally costly in terms of some as yet unknown evolutionary accounting. Many of the structural peculiarities of language, its quasi-universals, and the way that it is organized within the brain no doubt reflect this preexisting scaffolding. Simply put, this means that there are certain areas of the brain whose functions have evolved over time to include others in the progression of linguistic integration. Wernicke’s Aphasia Damage to the Wernicke’s area of the brain, as it is responsible for the comprehension of language, results to the individual’s having a hard time understanding spoken words (Buckley 2002). Because the receptive factor of language is damaged heavily, expressive language also suffers in that people who suffer from this type of Aphasia speak what is known as a “word salad”—a string of nonsense words (Buckley 2002). An example of a word salad is when a speaker asks the question of “What kind of work have you done?” a receptive Aphasic may answer in the following way: “We, the kids, all of us, and I, we were working for a long time in the... You know... its the kind of space, I mean place rear to the spedawn...” (Buckley 2002). Receptive Aphasics normally exhibit these types of characteristics (Buckley 2002): inability to grasp the meaning of spoken words easy production of connected speech normally-intoned stream of grammatical markers, pronouns, prepositions, articles, and auxiliaries difficulty in recalling correct content words, especially nouns (anomia) words may be meaningless neologisms (paraphasia) reading and writing are often severely impaired Wernicke’s Aphasia is thought to be more serious than Broca’s as the latter can still largely understand what is being said and think clearly having major problems expressing themselves, while the former cannot understand spoken language at all, and thus is mostly unable to successfully communicate. On the other hand, Broca’s patients are said to be more despondent and miserable as they are fully aware that their speech cannot be understood by the people around them as they can understand whatever is being said to him. It is indeed very frustrating to be able to understand and the subsequent desire to be able to reply appropriately and be understood. In contrast, because Wernicke’s patients cannot understand what the people around them are saying, they are “often blissfully unaware that nothing they say makes any sense at all” due to the fact that their “higher-level thinking processes are often as haphazard as their language is” (Buckley 2002). Conclusion With the presented facts and theories regarding the function of the brain when it comes to language acquisition, production and comprehension, it can be said that the brain is an extremely complex organ that has the capacity to evolve and adapt to the language needs of the individual. With the right stimulation, language proficiency is an easy thing to acquire as the brain has developed, and is still continually developing, the functions specific to the needs of the individual. For instance, some functions characteristic to the right hemisphere, like syntax, have been known to overlap into the left hemisphere due to the capability of the brain to evolve (Deacon 1997). It can be said, therefore, that the areas in the brain responsible for language has become innate—although it was not once like that—through evolution. However, even with the capacity of the brain to evolve, it has not yet perfected itself and damage to a specific region, particularly the Broca’s and Wernicke’s areas, still present problems as manifested in the various forms of aphasia. Because the brain, especially the left hemisphere, is where language is made possible to an individual, it is most vulnerable and lesions brought about mainly by cerebrovascular accidents can cause an individual to lose his full capacity for language. Hence, it can be said that the brain is language’s foremost ally and foe—for this is where language can burgeon and thrive, but at the same time, this is where the capacity for language can be greatly diminished and even lost. References Allen, M.A. et al. (2002). Mosby’s pocket dictionary of medicine, nursing, and allied health (4th ed.). Missouri: Mosby. American Speech-Language-Hearing Association (2007). Aphasia. Retrieved May 7, 2007 from http://www.asha.org/public/speech/disorders/Aphasia_info.htm Boeree, C. G. (2004). Speech and the Brain. Retrieved May 7, 2007 from http://webspace.ship.edu/cgboer/speechbrain.html Caplan, D. (1995). Language and the Brain. The Harvard Mahoney Neuroscience Institute Letter. Volume 4, Issue 4. Crain, S. (n.d.). Language and Brain. Retrieved May 7, 2007 from http://psikoloji.fisek.com.tr/psycholinguistics/Crain.html Buckley, E. (2002). Language in the Brain. Retrieved May 7, 2007 from http://www.gazzaro.it/g/Language%20in%20the%20brain.htm Chudler, E. (2007). “Oh Say Can You Say” Brain and Language. Retrieved May 7, 2007 from http://faculty.washington.edu/chudler/lang.html Deacon, T. (1997). The Symbolic Species: The Co-Evolution of Language and the Brain. London: W. W. Norton & Co. Jacobs, D. H. (2005). Aphasia. Retrieved May 7, 2007 from http://www.emedicine.com/NEURO/topic437.htm Marieb, E. N. (2004). Essentials of Human Anatomy and Physiology 7th Edition. San Francisco, CA: Pearson Education, Inc. Miller, S. & Tallal, P. A. (2003). Addressing Literacy through Neuroscience: With the Brain Now Viewed as a Continuously Modifiable Plastic Organ, Educators Have Real Opportunities to Influence Students Experience-Dependent Learning. School Administrator. Volume 63, Issue 11, December. Onda, Y. & Matsuishi, T. (2003). Language and Brain-Reading Kuniyoshi Sakais Language and Brain Science. Journal of Disability and Medico-Pedagogy. Vol. 8, pp. 1-5. “The Brain from Top to Bottom” (n.d.). Broca’s Area, Wernicke’s Area, and Other Language- Processing Areas in the Brain. Retrieved May 7, 2007 from http://thebrain.mcgill.ca/flash/d/d_10/d_10_cr/d_10_cr_lan/d_10_cr_lan.html WrongDiagnosis.com (2007). Statistics by Country for Aphasia. Retrieved May 7, 2007 from http://www.wrongdiagnosis.com/a/aphasia/stats-country.htm Xiong, J. (1999). Aphasia: A Language Disorder. Retrieved May 7, 2007 from http://serendip.brynmawr.edu/bb/neuro/neuro99/web1/Xiong.html Read More