Developmental surface and phonological dyslexia in both Greek and English

Abstract

The hallmark of developmental surface dyslexia in English and French is inaccurate reading of words with atypical spelling-sound correspondences. According to Douklias, Masterson and Hanley (2009), surface dyslexia can also be observed in Greek (a transparent orthography for reading that does not contain words of this kind). Their findings suggested that surface dyslexia in Greek can be characterized by slow reading of familiar words, and by inaccurate spelling of words with atypical sound-spelling correspondences (Greek is less transparent for spelling than for reading). In this study, we report seven adult cases whose slow reading and impaired spelling accuracy satisfied these criteria for Greek surface dyslexia. When asked to read words with atypical grapheme-phoneme correspondences in English (their second language), their accuracy was severely impaired. A co-occurrence was also observed between impaired spelling of words with atypical phoneme-grapheme correspondences in English and Greek. These co-occurrences provide strong evidence that surface dyslexia genuinely exists in Greek and that slow reading of real words in Greek reflects the same underlying impairment as that which produces inaccurate reading of atypical words in English. Two further individuals were observed with impaired reading and spelling of nonwords in both languages, consistent with developmental phonological dyslexia. Neither of the phonological dyslexics read words slowly. In terms of computational models of reading aloud, these findings suggest that slow reading by dyslexics in transparent orthographies is the consequence of a developmental impairment of the lexical (Coltheart, Rastle, Perry, Langdon, & Zeigler, 2001; Perry, Ziegler, & Zorzi, 2010) or semantic reading route (Plaut, McClelland, Seidenberg, & Patterson, 1996). This outcome provides evidence that the neurophysiological substrate(s) that support the lexical/semantic and the phonological pathways that are involved in reading and spelling are the same in both Greek and English.