Ακίνδυνοι Γλωσσοδέτες

Most authors working in the field of reading acquisition and especially dyslexia come from English speaking countries. Therefore most studies are conducted with English speaking people and concern English language acquisition or English dyslexics. Only a few studies are conducted in other countries and even less have focussed on cross-national differences.

The reported incidence numbers of dyslexia are mainly based upon estimates. The incidence of dyslexia in the USA and Great Britain is estimated at about 10 % (Satz et al. 1978 quoted by Klicpera and Gasteiger-Klicpera 1995; Busse 1997). German studies report fewer incidences of 5 to 7 % (Valtin 1989 quoted by Wolf et al. 1994). In Italy only about 3 % of people are dyslexic (1,34 to 5,04 % range) (Morchio, Ott and Persenti 1989 quoted by Wolf et al. 1994). Finally, a Japanese study reports the lowest incidence of dyslexia of just 1 % (Macita 1968 quoted by Witruk 1994).

On the one hand, Wolf et al. (1994) emphasize that these ranges of incidence do not necessarily support the hypothesis of the influence of language or orthographic systems on reading acquisition. On the other hand, Lindgren 1985 (quoted by Witruk 1994) could empirically verify this hypothesis.

Επίσης

Landerl et al. (1997) could show that the degree of orthographic consistency has impact on dyslexia. They assumed that the higher the degree of inconsistency is the higher are the demands on phonological processing and the higher is the degree of dyslexia. They compared English and German dyslexics on several tasks, including reading words of high and low frequency, reading non-words, and a spoonerism task, which is a language and age independent dyslexia test. They could show evidence for their hypothesis that English dyslexic children “…suffer from much more severe impairments in reading than the German dyslexic children.” (Landerl et al. 1997: 328). The kind of reading errors indicates that the difficulties are due to the opaque phoneme-grapheme correspondence in English. Therefore the findings support the theory of phonological decoding deficits in dyslexic children (Landerl et al. 1997).

The differences between English and German dyslexics show that the orthographic system, especially the irregularity of phoneme-grapheme correspondence has an impact on reading acquisition and dyslexia.

Εξάλλου

The low incidence of dyslexia in China and Japan (Macita 1968 quoted by Witruk 1994) led to the hypothesis that learning to read logographic languages is easier for people who have phonological deficits like dyslexics are supposed to have.

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Moreover, reading Chinese seems to be an activity that is more dominated by the right hemisphere than reading alphabetic languages. The latter have a left hemisphere advantage (Hoosain 1991 quoted by Jackson et al. 1994). According to Davis (2001), the main deficit of dyslexic people is their main chance because they are right-hemisphere dominated. That means on the one hand, they are more creative and good at complex visual stimuli, and on the other hand, they have severe visual perception problems with symbols and therefore their difficulties to read alphabetic systems. It could be that this right-hemisphere dominance of Chinese reading activity contributes to the little incidence of dyslexia in China.

However, the study of Jackson et al. (1994) concludes that the large differences in the language systems of Chinese and English do not have such a big effect on the reading acquisition one might think. The major differences between Chinese and English reading are found for words of low frequency (Jackson et al. 1994). Unfortunately, Jackson et al. (1994) did not examine dyslexic but normal readers, therefore the conclusion whether Chinese might be easier for the dyslexic reader cannot be given.

The mentioned findings in this chapter suggest that reading Chinese might be easier for dyslexic people, but only in the case that their dyslexia is due to deficits in phonological processing and not due to deficits in visual processing. However, there is empirical evidence that the difference between reading a logographic language (such as Chinese) and an alphabetic language (such as English) is much smaller than the scientists originally believed.

Δια ταύτα

Most dyslexic people have their main deficits in phonological processing
(auditive dyslexia). They have huge problems to learn the phoneme-grapheme correspondence in a language. Therefore irregularity in this correspondence (orthographic inconsistency) makes their difficulties worse. In addition to that, the hypothesis that logographic language systems are easier to learn for dyslexics with phonological deficits can not be verified. It remains uncertain whether they might profit from logographic language system like Chinese. Certainly, dyslexics with (additional) deficits in visual processing or working memory have more problems to learn a visually complex logographic system than people with auditive dyslexia only.

For these reasons, it is clear that dyslexic people should choose their second language carefully. The learning of orthographically consistent languages as Italian or Spanish should be more appropriate for dyslexics than the learning of the orthographic inconsistent English language. In addition to that, the dyslexic should feel more comfortable if she or he learns a second language that is based on familiar letters than a language that is based on a distinct alphabetic system.

The Impact of Linguistic Factors on Dyslexia - Implications for Foreign Language Learning, Jeannette Dietz

Ένα άλλο περισσότερο πλούσιο απ' ότι φαίνεται, αλλά σε πολλά σημεία δύσκολο για κάποιον σαν εμένα που δεν σκαμπάζει ιδιαίτερα από γλωσσολογία: Phonology, reading development, and dyslexia: A cross-linguistic perspective, της Usha Goswami. Περιέχει και στοιχεία από έρευνες στην Ελλάδα.

These studies generally report high levels of phonemic awareness for children learning to read consistent orthographies within the first year of instruction, and lower levels of phonemic awareness for children learning to read inconsistent orthographies. Comparing studies of children tested during first grade, representative performance levels are 100% correct for Greek children (Harris & Giannouli, 1999; Porpodas, 1999), 97% correct for Italian children (Cossu et al., 1988), 94% correct for Turkish children (Durgunoglu & Oney, 1999), 92% correct for German children (Wimmer et al., 1991), and 83% correct for Norwegian children (Hoien et al., 1995). Phonemic awareness is thus close to ceiling in most orthographies during the first year of being taught to read. In contrast, performance levels for children learning less consistent orthographies such as French and English are less impressive. In a study of French children, Demont and Gombert (1996) reported 61% success in a phoneme counting task at the end of first grade. Perfetti, Beck, Bell, & Hughes (1987) reported 65% correct responding by American English children at the end of second grade.

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The most striking finding from the study was that the children who were acquiring reading in orthographically consistent languages were close to ceiling in both word and nonword reading by the middle of first grade (see table I). The only languages to deviate from this pattern were Portuguese (73% correct), Danish (71% correct), French (79% correct), and English (34% correct). Almost identical patterns by language were found for nonword reading, also shown in table I.

Εν κατακλείδι

According to this cross-linguistic analysis, a deficit in phonemic awareness is not really a cause of dyslexic children's reading problems. Rather, it arises from a preexisting problem with phonological representation, which impedes learning about letters and learning about phonemes. Although dyslexic children learning to read consistent orthographies like Greek and German do acquire highly accurate phonemic awareness and grapheme-phoneme recoding skills, because of their persisting phonological problems, these processes are never as efficient as in their typically developing peers. Consequently, even in consistent orthographies, children with dyslexia are much slower in any task involving phonological processing, including reading. Dyslexic children who are learning to read inconsistent orthographies like English are even worse off. English dyslexic children show a persisting deficit at the phoneme level, perhaps even when they are adults, and so are characterised by both speed and accuracy deficits in phonological tasks. These persisting deficits must be due, in part, to the inconsistent nature of the orthography that they need to learn to read.