Developmental dyslexia in different languages: language-specific or universal?

Area of Science:

• Cognitive Psychology
• Developmental Psychology
• Linguistics

Background:

• Most developmental dyslexia research originates from English-speaking nations.
• English presents greater reading complexity due to irregular spelling-to-sound correspondences compared to other European orthographies.
• This linguistic difference necessitates investigating dyslexia's generalizability across diverse orthographies.

Purpose of the Study:

• To determine if core findings on developmental dyslexia in English generalize to German, an orthography with more regular spelling-to-sound correspondences.
• To compare reading process marker effects in German- and English-speaking children with dyslexia.
• To identify cross-orthographic similarities and differences in dyslexic reading mechanisms.

Main Methods:

• A comparative study involving 149 German- and English-speaking children.
• Investigation of theoretically significant marker effects within the reading process.
• Analysis of reading speed, nonword reading accuracy, and phonological decoding efficiency.

Main Results:

• Dyslexic readers in both German and English exhibit significant similarities in deficits.
• Common findings include reduced reading speed, a pronounced nonword reading deficit, and slow, serial phonological decoding.
• These deficits were comparable across orthographies and persisted even in younger children at similar reading levels.
• While both groups utilized larger orthographic units, English dyslexics showed less efficient integration for grapheme-phoneme decoding.

Conclusions:

• The core cognitive and linguistic deficits associated with developmental dyslexia are largely consistent across different orthographies, such as English and German.
• Phonological decoding appears to be a fundamental challenge in dyslexia, irrespective of the regularity of the spelling-to-sound system.
• While orthographic processing abilities exist, their effective utilization in decoding differs, potentially impacting reading acquisition in languages like English.