Developmental surface and phonological dyslexia in both Greek and English

Area of Science:

• Neuroscience
• Developmental Psychology
• Linguistics

Background:

• Surface dyslexia typically involves inaccurate word reading due to atypical spelling-sound correspondences in languages like English and French.
• Previous research suggested surface dyslexia might occur in Greek, a language with a transparent orthography for reading, but less so for spelling.
• Greek surface dyslexia was hypothesized to manifest as slow reading of familiar words and spelling inaccuracies with atypical sound-spelling correspondences.

Purpose of the Study:

• To investigate the existence and characteristics of developmental surface dyslexia in Greek.
• To examine the reading and spelling performance of Greek adults with suspected surface dyslexia in both Greek and English.
• To explore the relationship between surface dyslexia in Greek and English and its implications for computational models of reading.

Main Methods:

• Case study of seven adult individuals exhibiting slow reading and impaired spelling accuracy consistent with Greek surface dyslexia criteria.
• Assessment of reading accuracy for words with atypical grapheme-phoneme correspondences in English (second language).
• Analysis of co-occurrences between impaired spelling of words with atypical phoneme-grapheme correspondences in both English and Greek.

Main Results:

• Seven adult cases met the criteria for Greek surface dyslexia, showing slow reading and spelling impairments.
• These individuals demonstrated severely impaired accuracy when reading English words with atypical grapheme-phoneme correspondences.
• A significant co-occurrence was found between impaired spelling of atypical phoneme-grapheme correspondences in both English and Greek.

Conclusions:

• Developmental surface dyslexia genuinely exists in Greek, characterized by slow reading of real words and impaired spelling.
• The findings support the hypothesis that slow reading in transparent orthographies reflects underlying lexical or semantic route impairments.
• Evidence suggests shared neurophysiological substrates for lexical/semantic and phonological reading/spelling pathways in both Greek and English.