SPRING Atypical Reading Flashcards
What was dylexia first thought to be
morgan (1896) congenital word blindness
problem of vision and inability to recall how words looked
how does the prevalence of dyslexia change across language
english -4-10%
changes as difficulty in comprehension changes - differences in orthographic consistencies
ie italian prevalence half that of USA
social impact of dyslexia
prevalent in disadvantaged
60% inmates
75% unemployed
85% juiveniles (43% 2 years below reading age and 38% below grade 4 reading age)
what is dyslexia
disorder manifested in difficulty of learning to read despite conventionl instruction, adequate intelligences and socio cultural opportunity
definition primarily focuses on exlusion
what is alexia
inability to read completely
heritability of dyslexia
40% sons with dyslexic fathers
36% daughter with dyslexic mother
50% chance if either parent
at risk 4x more likely to develop dyslexia than norm
gender issues in looking into dyslexia
more boys studied than girls creates bias
olson et al 1989 twin study and heritability of dyslexia
discrimination of words from homophonic nonwords (e.g., rane, rain) compared for pairs of older children with reading disabilities (RD) and younger non-disabled readers matched on word recognition
Phonological coding was substantially lower in RD- unique developmental deficit in phonological coding rather than an equal developmental lag across all component reading skill
RD highly heritable and accounted for most of the heritable variance in their word recognition deficits
describe frith and morton theortical framework
way of assessing influence of biology, cognition and behaviour on dyslexia
biology - brain
cognition - workings of mental components
behaviour - difficulties and observed performance
basic causal model of dyslexia (frith and morton)
biological origin leads to cognitive deficit which is expressed in deficits in behaviour
impacts of remedial teaching on dyslexia (frith and morton)
dyslexia appears to be improved by better teaching but does not make changes to cognition or biology
environmental change
environmental causation of dyslexia (frith and morton)
thought that no cog or bio abnormalities then dyslexia due to environment
ie poor teaching or socioeconomic factors
dyslexia and IQ
not link to IQ but use discrepancy diagnosis so easier to identify in average/above average children as not expected (but poor correlation between the two)
some argue shouldnt base diagnosis on discrepancy BUT may neglect individuals who are good in all other areas and then struggle later on
dysexia and development
developmental disorders change with age
definition of dyslexia is dependent on the underlying problem
diagnoiss also likley to change dependent on language and how to read
main theories of dyslexia
phonological defecit hypothesis (snowling 1995)
double deficit hypothesis (wolf and bowers 1999)
phonological vs surface subtypes (castles and coltheart 1993)
visual theories of dyslexia
magnocellular deficit hyp (stein and walsh 1007) visual attention span (bosse et al 2007) visual stress (wilkins 2002)
miscellaneous theories of dyslexia
cerebellar theory (nicholson and fawcett 1998/habib 2000)
define phonoligical deficit hyp
pa thought tp correlate with reading ability (reciprocal relationship)
wide range of evidence suggests that dyslexics are impaired on variety of PA tasks
ie phoneme deletion (cat without /k/)
phoneme counting and phoneme blending
not a strong case to be made for rhyme
awareness being a significant independent predictor of reading and spelling acquisitio ie not a strong case to be made for rhyme awareness being a significant independent predictor of reading and spelling acquisition.