Types of dyslexia and dysorthography

Three types of dyslexia-dysorthographia are recognized in people with a learning disability.
These types involve either decoding by the assembly (letter-sound), decoding by addressing (or lexical, therefore photographic recognition of the word), or both routes.

1) Phonological dyslexia and dysorthography

Dyslexia or so-called phonological dysorthography, affects the assembly decoding pathway. That is to say, a person will have difficulty accurately converting sequences of letters or syllables while respecting their phonetics; we then speak of difficulties with grapheme-phoneme correspondence, where the written word is not the one that is read or pronounced by the person. The individual will, therefore, make errors in the sequence of letters by reversing letters or syllables, by adding or omitting some of them, etc. This is especially true for rare or new words. Often, these individuals will then prioritize the overall recognition of words by trying to remember and recognize their form in writing or guessing them from the first letters when reading.

2) Dyslexia and surface dysorthography

These learning disorders will in turn affect the decoding pathway by addressing or visual recognition of words. Although each word has its form, this is not recognized or is poorly recognized by dyslexics or surface dysorthographics. The words are then sometimes guessed, but these individuals will, above all, present a slow, laborious, and syllabic reading since they will then rely heavily on the grapheme-phoneme conversion to read the words one syllable at a time; for example, the words sir and heart will not be recognized visually and therefore read as they are: “mon-si-heure” and “co-heure”. Dysorthographic people, for their part, will often write words by sound in a similar way, without remembering their true form or configuration; for example, they might write “famme” or “feble” rather than femme and weak.

3) Mixed dyslexia and dysorthography

This is the most severe variant, which affects both the assembly and addressing decoding pathways, therefore, both the grapheme-phoneme correspondence and the visual recognition of the shape of words.