Aphasia; an impairment of language function Essay Example

Aphasia; an impairment of language function Essay Example Aphasia; an impairment of language function Essay Aphasia; an impairment of language function Essay The ability to comprehend words processed non-auditory, suggests that the entrap semantic representation of words is intact, but the auditory lexicon input is detached from previous semantic knowledge. This results in a patients ability to process speech sounds, and reproduce them both orally and to dictation but have no comprehension of the words meaning. Laptop and Funnel (1981 ) argued this selective impairment to be of great theoretical significance because it indicates that there must be separate processes for written language and phonological encoding, otherwise written comprehension would be just as impaired as auditory comprehension, in all asses of aphasia. This essay will explore a case study of abstract word meaning deafness, firstly by describing how the case study was conducted and what pattern of results was found. The text will then evaluate whether the findings reliably imply a separate proves for phonological input and written abstract word processing through orthographic analysis, therefore providing evidence for Patterson Shells (1987) argument for auditory and visual processes in their lexical processing model. Finally this discussion will weigh the strength of the experiments findings and claimed implications, against issues of method, alternative implications and additional research to form a developed conclusion on how far abstract word meaning deafness can reliably illuminate functions of healthy language. Franklin S, Howard D, Patterson K (1994) ran extensive tests over a two year period on a patient that exhibited damaged auditory comprehension of abstract but not concrete words to test how the patients performance could reflect Patterson Shells 1987 processing model of lexical organization, by identifying a specific phonological semantic processing fault. The patient (DRY) suffered a stroke aged 54 causing a left middle coverall infract, Drys hearing and IQ was undamaged and was found to be normal. The patient underwent TV0 years speech therapy three times a week before the experimenters began a through 2 yearlong examination of Drys impairment. Franklin et el ran multiple tests aiming to establish the patients impairment at an auditory- semantic level. Key experiments tested auditory lexical decisions by getting ORB to match words with pictures. Analysis Of ORBs errors indicated whether e was making phonological errors (such as selecting a picture of an iron for the word lion,) or semantic errors (such as selecting a picture of a cat for the word lion. Further tests were conducted to test auditory, written, and speed( sound interpretation abilities of semantic proves through word repetition AR written dictation. The experimenters established DRY had an impaired auditory understanding of abstract words (such as love) but not concrete words, (e. G. Chair) with a full comprehension of all types of written words. The as shown in Drys ability to match abstract words with pictures, suggesting access to semantic lexical information was intact through the visual proves. However DRY made semantic errors when the same words were presented through auditory information. The lower the instability and more abstractness of the word resulted in more semantic errors. Furthermore the lack of phonological errors in correct auditory lexical decisions implies the impairment of comprehension is semantic rather that phonological. Word frequency and familiarity had no significant effect on correct phonological 01 mantic decisions. This pattern of impairment of auditory semantic comprehension and preserved phonological abilitys and written word comprehension matches the symptoms of pure word meaning deafness specified in the introduction. However the patient Was unable to write or repeat non-words indicating an impairment of the process of speech sound! Which would not be expected in a perfect case of abstract word meaning deafness as full phonological encoding should be completely intact with only) semantic comprehension impaired. That said the majority of these findings purport an abstract word meaning deafness diagnosis providing evidence FCC a word meaning deficit. This condition establishes an argument for separate; auditory and written systems within models of language, thus supporting Patterson Shells 1987 processing model of lexical information. This model defines the process of auditory comprehension of words in a three part system. There is an initial auditory analysis of speech sounds, which the provides access to correct word forms in auditory input, allowing aces to word meaning within the cognitive system. The model identifies an process for written word comprehension begging in orthographic rather that auditory analysis. Franklin et al argues Drys pattern of impairment could BC explained in terms of damage to the second stage of auditory input, consequently denying access to word meaning through the auditory process ± but allowing access to the same words meaning through the preserved written word process. Conversely Drabs inability to reproduce non words could indicate an issue with the early phonological encoding that the experiments tests were too insensitive to find. This would suggest a potential overlap between phonological and semantic encoding, disproving Patterson et alls model. The experimenters counterbalance this argument bi suggesting that this impairment is a separate deficit resulting from the stroke which could be reasonably expected as stoke induced aphasia patients often suffer multiple language deficits. Caber, Tare A. -Z. K. Parsons, Fay Augusta Vides 2011) However although this suggestion could be consider viable HTH F-rankling et al accepts no empirical evidence can be offered to prove the explanation of the patients inability to process speech sound within the context of Patterson model, and consequently the theory requires further case studies of word meaning deafness to provide a reasonable argument fool word meaning deafness. Supporting evidence can be found in Hall and Riddances (1997) case study of an aphasia patient (K) with impaired auditor) comprehension with intact written comprehension mimics Drys pattern of symptoms and supports Franklins findings. Unlike DRY the patient was able to repeat and correctly write both real and non-words regardless of impression, demonstrating an isolated impairment of auditory semantic aces. These findings strengthen Freidmans argument for DRY having a separate language deficit which would account for his inability to reproduce non words. However due to the rare nature of word deafness research into this field is not large enough to be conclusive as external variables could be skewing the results. One potential issue in methodology is the assumption 0 full patient motivation when recording the results. DRY underwent extensive amounts Of language tests which would be hugely demanding on a covering aphasia patient. Most of the failed comprehension tests were responded to by dont know, stating he cant hear the word. But the experimenter acknowledges it is unlikely his comprehension is all or nothing. This contradiction between the experimenters expectation and the patients direct reports indicate that DRY s results may not completely reflect his abilitys as he could have lacked the motivation to try and access more difficult processing information. Nevertheless the study was incredibly thorough, a very detailed analysis of Drabs abilitys in over fifteen different sets in over two years is likely to accommodate for most i ssues of low motivation, as the pattern of abilitys was established across a great wealth ii texts. Furthermore this experiment was one of the first language studies not to only focus on the correct or incorrect answer but test how difficult DRY found responding by tests of word fluency in comparison with a healthy control group, thus proving a far more accurate representation of the patients impairment than previous research. As the study was began two years after the stroke occurred it would have been of interest to complete a allow up study 5-10 years later to review what impairments have been recovered.