4 - 7 - Oral language impairment, Childbirth A Global Perspective
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Within this dys-constellationwe are now going totalk about the co-occurrence of dyslexiawith oral language difficulties.First of all ... a distinctionshould be made between oral languagedifficulties at the level of production,and at the level of perception.For production, in his publication,in his latest book,the French neurologist Michel Habib,considers that about half of the dyslexiclearners display a history of delaysin the acquisition of spoken language.Now, when this concerns pronunciation,usually a fewmonths of visiting the Speech andLanguage Therapist will do.However, conversely, when this concernsthe acquisition of the syntax,the vocabulary and the grammar ...the possibility of underlying dyslexiais greater - this was for production.Now let's move to the perceptionof spoken language.Categorical perception studies haverepeatedly shown that representations ofphonemes are 'fuzzier', less well definedin dyslexics compared to non-dyslexics.This may be related tothe fact that learners, ...dyslexic learners, are oversensitive towhat is called allophonic variation.For example, the 'a' in 'bar', 'cap' and 'mat',note 'a' in those three wordsis not exactly the same, but we,or non-dyslexic learners, have learned toignore those small variations whichare not relevant for the meaning.However, dyslexic learners dohear those small variations, andthat's the reason why they build truepresentations of phonemes which are not asaccurate as the ones innon-dyslexic readers.Other studies say that'snot exactly the case,there is a controversy herewhich is not solved yet.Some studies suggest that the phonologicalrepresentation in dyslexics are intact,but the problem is accessingthose representations.Studies by Ramus anda team of Leuven, Belgium,Boets, have shown and suggest that thephrenological representations are intact.as speech is also a fast signal;another group, Tallal andcollaborators have suggested thatdyslexic learners havedifficulties in identifying fast,temporal changes which occur in speech.Furthermore, as Jenny has already told you,Heikki Lyytinen andhis colleagues ... have interviewed over 200 families andhave classified new borns as at risk fordyslexia versus not at risk fordyslexia, depending onthe familial risk for dyslexia,which is often hereditary as we said in,in the definition.They show that a test administeredonly six months after birthwas a good predictor of future dyslexia ornot.You need to know that in Finnishthere is ... a distinction betweenthe short consonant (as in) 'at ta',and the long consonant 'as in) 'at' -'sss, ta',- let's redo that.You should know that in Finnish thereis a distinction between the shortconsonant (as in) 'atta', andthe long consonant (as in) 'a ta'.And ... not only are the children at risk fordyslexia who became dyslexic later onneeded more time to makethe distinction between these ...the two consonant, the short one, and thelong one, but also the electrical activityof the brain was different compared tothe children not at risk for dyslexia.So, linking to productive languageand vocabulary, the study also foundthat the children who were late talkers -that these children were late talkers.They started talking at around two,2.5, two years, two years and a half,and also have genetic risk in combinationwith a strong risk factor for dyslexia, sothose children had difficulties perceivinga consonant contrast at six months,and ... ... they were also late talkers.Evoked potential, which is a techniqueconsisting in measuring the electricactivity of the brain, through electrodes ... put on the head measures ...... measured whenlearners are five years old,robustly predicts eventual risk fordyslexia - this was shown by Giroud andcollaborators.Finally, functional magnetic resonancestudies show that before learning to readand write, the density of the greysubstance is rarified in the temporalregion, which (is) the region where readingoccur, and that this region (is) lessactivated in children proving to bedyslexic compared to non-dyslexic.There is a sort of continuum betweendifficulties in oral language development,called specific language impairment orSLI, and dyslexia.Most children with SLI willdevelop dyslexia afterwards,will display subsequentreading difficulties.In fact, we can say,to put it simply, that SLI isoften co-occurring with dyslexia,and that it's a sort of 'stronger' form ofdyslexia which start with difficultieswith the oral language first and thensubsequently with the written language.These two conditions shouldbe seen as complementary, andthere is also geneticoverlap between the two.Researches usually makea distinction between three type ofspecific language impairments:... receptive forcomprehension, expressive forproduction, and mixed.But be aware that these categories areshould not be taken ... straightforwardly- these are generalization and even kidswith the ... predominantlyexpressive profile are likely to havesome symptoms of receptive issues as well.Severe forms of specific languageimpairment can lead to silence sometimes.And specific language impairmentacquired by adults who (had) acquiredoral language normally andthen have lost this ability,is called Dysphasia in the US andAlexia in Europe.
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