Acquired dyslexia Flashcards
(35 cards)
How might aphasia affect reading and writing?
- some degree of impairment in reading and writing, in addition to difficulties in spoken language
- acquired dyslexia and agraphia
- small number have impairment spectific to this - pure dyslexia/agraphia
- imp to consider prior literacy levels
What is necessary for skilled reading?
rapid decoding of orthographic information at word, sentence and text level
What are the different levels of reading and processing?
- Text processing
- Sentence processing
- Single word processing
What does text processing require?
- Rapid processing of visual information
- Holding of earlier information in memory whilst simultaneously decoding more of text
- Constantly updating interpretation of text
Why might text processing be difficult?
Complex, skilled reading requires accurate and timely interplay of visual, linguistic, and cognitive processes
What are the possible sentence level reading behaviours in aphasia?
- slow processing/reading time
- Repeated re-reading
- A more ‘interactive’ reading strategy - 🡩 use of sentence context (Huck et al., 2017)
- Reduced accuracy of reading comprehension
- Difficulty ‘parsing’ the sentence – chunking a sentence into structurally salient units or thematic roles
What is the serial stage model for reading single words?
- perceptual level
- word recognition
- word comp
what is the Patterson and Shewell (1987) model of single word reading?
- written word
- orthographic analysis
- orthographic input lexicon
- semantic system
What are the psycholinguistic variables impacting single word reading?
- frequency
-imageability - length
Describe how the perceptual level/orthographic analysis works
- banks of visual feature detectors operating in parallel
- Detector system fires when input matches their specification (e.g. a vertical line detector)
-Combinations of features correspond to letters - Identify letter & word position
- Word not recognised and meaning not activated at this point
How is perceptual level assessed?
- form perception tests (recognition of graphemes)
- basic level is matching of forms
- abstract categorical level - different surface form but same category (e.g. palpa 18 and 19)
someone with impairment at the perceptual level will do what?
make misperception errors
Describe word recognition/orthographic input lexicon (OIL)
- Stores of written words reader has encountered before and remembered
- forms not meaning
- frequency effect
- associations between words with similar perceptual features: organised into form-based cohorts (sat – mat – pat – rat)
How is OIL assessed?
- written lexical decision tests e.g. is ‘flud’ a word or a non-word? (e.g. PALPA 24 & 25)
- can manipulate legality, frequency, length, imageability
What might you see if OIL impaired?
- Low scores on tests of lexical decision
- Mis-recognitions of forms e.g. symphony – sympathy
- Low Frequency forms not recognised
- Low scores on word comprehension tests
- Homophone errors
- in some cases a pattern of letter-by-letter reading
Describe word comp/semantic system
- central system for all comp and retreival
- Conceptual knowledge builds up over time through multi-modal experiences of a concept
- impairment results in multimodal disruption
- Associative links within semantic system develop between representations based on co-occurrence in the real world and in language (sheep – goats, but not sheep – coffee)
- imageability imp variable
What are the two types if damage to semantic sytem?
- activation from OIL
- damage to semantic system
How can discriminate between two types if damage to semantic system?
comparing reading performance to other modalities
What can damage to semantic system show as?
- mis-comp/semantic errors
- low imageability words more vulnerable to damage
How to assess semantic processing?
- Written word to picture matching with semantic distracters (e.g., PALPA 47/48)
- Odd one out
- Synonym judgement
- reading aloud
what are the dual reading routes?
1 - lexical route
2 - sublexical route (grapheme -> phoneme)
What is the lexical reading route?
Follows the three stages
- orthographic analysis
- OIL
- semantic system
What is the sublexical processing reading route?
- Knowledge of links between graphemes and phonemes
- new data can be transcoded to see if it matches a known form
- every word is non-word when first encountered
- non-words can only be read by Grapheme-Phoneme route
- computationally demanding
- if reading aloud, may be able to access semantics through auditory route
How to assess grapheme-phoneme route?
- reading aloud non words and irregular words
- correct production relies on following regular spell sound correspondance
- will observe regularisation errors
- length effects may be observed
