Dysgraphia Flashcards
Describe the main model of spelling discussed in class (spelling to dictation)
Is a dual-route model and looks like the inverse of the dual-route model for reading.
- Hear a word e.g., Bat, than dual-route processing (CENTRAL PROCESSES) - basic auditory processing and speech-sound processing
- a - phoneme to grapheme conversion
OR
- b Phonological input lexicon (recognise speech in terms of words) lexical semantics (access words meaning), orthographic output lexicon (access the words written form)
- Abstract letter identities/graphemic buffer
PERIPHERAL PROCESSES:
4a - letter name conversion
4b - letter shape selection (various fonts/forms etc)
What is the ‘lexical route’ in spelling? (Central or peripheral? what components and what does it do?)
Central process.
Required for irregular words (Are not spelled the way they sound), can spell all known words.
Components:
- Phonological input lexicon (recognise speech in terms of words)
- Lexical semantics (access words meaning)
- Orthographic output lexicon (access the words written form)
What is the ‘Sublexical/Non-lexical’ in spelling? (central/peripheral? what components and what does it do?)
Central process
Required for non-words, can spell all REGULAR words (That you spell the way they sound).
Component:
Phoneme to grapehem conversion
What are peripheral processes in spelling?
Once you have the abstract letter identities temporarily stored in the graphemic buffer (arguable the same buffer as in reading!) there are lots of things you can do with them e.g., Allow letters to be output - spoken, written (single letter/word), typed (keypress),
What is ‘Phonological’ dysgraphia?
Impairment to the sub-lexical (sound to letter rules) for spelling.
- Known word spelling (including of known irregular words) is normal [Lexical route is intact]
- Non-word spelling is impaired [can’t ‘decode’ spoken words into the letters required to write them] - nonwords spelling as words e.g., ‘gop’ and ‘gob’
- Writing a letter given a sound is impaired [sound to letter rules are impaired!]
ALSO:
- Difficulty spelling real words that are not know
- Making abnormal errors (non-plausible alternate spellings)
NOTE: Can also occur in the context of phonological dyslexia - may have poor letter-to-sound and poor sound-to-letter. Can be related to poor phonological awareness and working memory (may underly a combination of phonological issues). BUT NOT ALWAYS.
What is ‘Surface dysgraphia?
Impairment to the lexical route for spelling. Can be broken down further as to which module it affects (e.g., phonological input lexicon, lexical semantics, orthographic output lexicon).
BASIC:
- Poor irregular word spelling (often with frequency effect, less common words lost more easily)
- Intact non-word spelling
- phonologicall plausible errors (suggests reliance on intact sound-to-letter rules)
- phonetic spelling style (enough -> inuf)
- homophone confusion (two as ‘to’)
Describe the symptoms of a ‘central’ dysgraphia localised to the orthographic output lexicon.
- Poor irregular word spelling (often with frequency effect, less common words lost more easily)
- Intact non-word spelling
- phonologically plausible errors (suggests reliance on intact sound-to-letter rules)
- semantics intact –> can correctly define words that one spells incorrectly
Describe the theory of ‘obligatory phonological mediation’
What is the evidence against this theory?
The notion that phonology is required in order to produce any orthographic form - even in tasks which would appear to bypass phonology such as written picture naming (See picture, write name) (or silent reading). In written picture naming, the obligatory phonological mediation theory would argue that you must think about how a word would sound in order to write it.
Related to the evolutionary perspective tha thumans learn to speak prior to read or write, thus the latter might therefore be parasitic off the original system.
[evidence against]:
There are cases of people (e.g., PW) who can write (Spell) a word after viewing a picture (e.g., see an onion, and write ‘onion’), but was unable to retrieve the spoken form of the word when looking at the picture.
Describe the symptoms of a ‘central’ dysgraphia localised to the semantic system?
- Semantic errors in spoken and written picture naming (and matching)
- but accurate in spelling to dictation (even irregular words!)
[notion that orthographic input lexicon (written forms), structural/visual representations (picture forms) and phonological input lexicon (spoken form) all use the same semantic system!)]
Do the follow errors prove the existence of a lexical non-semantic route for spelling? (i.e., bypass semantics) What is an alternative explanation?
- Intact non-word and irregular word spelling (spelling to dictation)
- Semantic errors in spoken and written picture naming
- Spelling to dictation better than written picture naming
Not necessarily!
It has been argued that this pattern could also be explained by simultaneous use of both the lexical and non-lexical route.
Spelling to dictation. “I ate a /pear/”
- semantic system is impaired, knows it is a fruit but not which one
- orthographic output offers ‘apple’ ‘pear’ and ‘orange’, how is he reasonable able to select ‘pear’?
- well the sub-lexical route CONTRIBUTES, it derives how it would ‘spell’ the word based on the sound e.g., /p/ /ea/ /r/ - PEAR
- This information feeds back into the orthographic output lexicon and rules out the alternative items (apple, orange) and allows for correct selection of pear.
Making spelling to dictation superior to picture naming (which does not have the ‘prompts’ from the sub-lexical sound-to-letter rules)
What errors might a lesion to the graphemic buffer of the spelling model result in?
- Spelling errors for words and non-words (words in general!)
- Transposition errors (know the right letters, but NOT THE ORDER)
- Errors with correct structural features, e.g., Swapping consonents for consonents and vowels for vowels (within substitution) or word contains germinate (though may have different number).
- More errors in the center of the words (looks like memory! as harder to store letters). Length effects (longer words = more errors)
Are whether a letter is a consonants and Vowels represented in the graphemic buffer?
Yes, this would seem to be the case,
Case CV - errors for words often had the same consonent and vowel structure as the correct word (e.g., metodo –> medoto) [within substitution errors]
He was better on words with simple (CVCVC) than complex (VCCVC) combinations.
This suggests that you hold letters in the graphemic buffer, BUT ALSO the structure of those letters (CVCC etc), and also LETTER PAIRS (i.e., Geminates).
What is represented in the Graphemic buffer in the spelling model?
Can each of these types of information be affected independently?
Letter identities
Geminates
Consonant/vowel status
YES, each type can be affected independently
In a peripheral dysgraphia when there is a dissociation between (poor) written and (intact) oral spelling – what aspects/modules of the process might have gone wrong?
- Allographic Representations - not able to access all of the allographic forms, resulting in specific failures in particular case and/or style e.g., not knowing what the lower case letters look like - NOTE can lose the ability to write lower case letters, but still be able to read them! May also fail to stick to one CasE iN WriTing, difficulty maintaining case.
- Graphomotor programs - Apraxic agraphic, production of malformed letters irregardless of limb used (programs exist at an abstract level) may produce letters which are close in form (substitution errors, though not necessaril ‘true’ substituion, may have tried to write ‘T’ and written ‘I’).
- Graphic codes
- Handwriting
True/False, peripheral dysgraphias affect spelling of both words (including irregular) and non-words.
TRUE
