Subtypes of developmental dyslexia in transparent orthographies: a comment on Lachmann and Van Leeuwen (2008).
Lachmann and Van Leeuwen (2008) proposed two diagnostic subtypes of developmental dyslexia in a language with transparent orthography (German). The classification was based on reading time, rather than reading errors, for lists of words and nonwords. The two subtypes were "frequent-word reading impaired" (FWRI) and "nonword reading impaired" (NWRI). Notably, FWRI were very slow in reading high-frequency words but as fast as controls in reading nonwords; ca. one-third of these children showed this "reversed lexicality effect" in a particularly marked fashion (i.e., read nonwords two to three times faster than high-frequency words). Since Italian is a highly transparent language, we applied this classification to 87 third- and sixth-grade dyslexics from various previously published studies. Some children showed a marked lexicality effect, while others showed small or no difference between word and nonword reading speed. However, regardless of stimulus length, grade and presence/absence of a previous language delay, no child showed a marked reversed lexicality effect; more generally, no child could be classified as FWRI. These findings indicate that the search for subtypes of developmental dyslexia in transparent orthographies still constitutes an open question.
Spinelli
Donatella
D
Department of Education Sciences in Sport and Physical Activity, University "Foro Italico", Rome, Italy. donatella.spinelli@iusm.it
Brizzolara
Daniela
D
De Luca
Maria
M
Gasperini
Filippo
F
Martelli
Marialuisa
M
Zoccolotti
Pierluigi
P
D004410:Dyslexia / Q000145:classification* / Q000175:diagnosis*; D006801:Humans; D007802:Language; D011932:Reading; D013997:Time Factors; D014706:Verbal Learning