Dyslexia Flashcards
(13 cards)
DSM-V dyslexia
Specific learning disorder with impairment in reading. Problems with fluent word reading, poor decoding, and poor spelling.
Dyslexia biology
Large number of genes. Higher concordance between MZ than DZ twins. Chromosome 15 linked.
Dyslexia in the brain
Structural atypicalities. Perisylvanian regions (Broca’s and Wernicke’s areas/left hemisphere).
Phonological deficit hypothesis
Dyslexic children have difficulty processing sound structure of spoken language (phonology). Leads to difficulty on any task that depends on phonological skills (including reading and spelling). Reciprocal influences (less reading -> worse reading).
Marshall et al. (2001) phonological awareness in dyslexic children for phoneme deletion and rhyme oddity
Dyslexic group had lower scores overall, but particularly for smaller units of sound, compared to age-matched controls.
Melby-Lervag et al. (2012) meta-analysis comparing dyslexia vs. reading-level controls
Dyslexic children perform worse on PA tasks even when matched on reading ability. PA deficit in dyslexia not just a byproduct of poor reading experience. Exists independently of reading practice/exposure.
Snowling et al. (1986) repetition of words and non-words dyslexia
Dyslexic children particularly poor at nonword repetition.
Paulesu et al. (1996) dyslexia brain
Weaker and less extensive activation in Broca’s, Wernicke’s, and parietal regions in STM and rhyming tasks.
Snowling et al. (1986) decoding in dyslexia nonword reading
Dyslexics worse at reading nonwords than reading age controls. Nonwords deficits persist into adulthood. (Difficult O->P learning).
Harm and Seidenberg (1999) network model of dyslexia
Degrading phonological representation in the network models dyslexic reading (deficits in nonword reading).
Gallagher et al. (2000)
Recruited 45 month-olds. By age 6, 57% of at-risk group showed delayed literacy development. Unimpaired group equivalent to controls on most measure but potentially mild phonological deficits. Impaired group showed a range of verbal deficits (not limited to phonology).
Phonological deficit pre-dates reading problems. Support for phonological deficit hypothesis but more complicated than that.
Environmental effects on dyslexia
English has deep orthographies (inconsistent letter-sound correspondences). English takes longer to learn and manifestations of dyslexia are more obvious.
Wydell and Butterworth (1999) case AS bilingual Japanese-English and dyslexia
AS was impaired only when reading and spelling English. Skills were normal in Japanese. Poor phonological skills relative to both English and Japanese controls. Dyslexia is not a unitary deficit. also depends on orthographic and phonological structure of the language.
