01 NRDC Dyslexia 1-88 update - Texthelp

Developmental dyslexia in adults: a research review 43
‘simple model’ of reading (Gough & Tunmer, 1986) with the observation that the critical
difficulty in dyslexia lies in decoding at the single-word level rather than in comprehending
passages of text (Snowling, 1991). It is worth bearing in mind that word recognition difficulties
are not exclusive to dyslexia; they are also characteristic of poor readers who do not meet the
diagnostic criteria for dyslexia and of good readers who are beginning to read (Seidenberg et
al., 1986).
Nevertheless, while locating the critical difficulty in dyslexia at the level of word recognition,
commentators acknowledge that adult dyslexics also have problems with reading
comprehension and other aspects of literacy (Nicolson et al., 1993). Comprehension is made
more difficult for all people with poor reading skills when they have to allocate attentional
resources to the task of decoding (Sabatini, 2002); it can be difficult enough for ‘good’ readers
when they are faced with unusual texts (like the present one). Listening comprehension,
despite the belief that it is unimpaired in dyslexia, will inevitably become more difficult when
the spoken language uses vocabulary normally acquired through reading or when it employs
the more complex syntax of the written language—two difficulties either created or
exacerbated by low exposure to print—or when utterance length makes greater demands on
verbal memory. There may be a case for locating the core difficulty of dyslexia not in word
recognition without further specification but in rapid and automatic word recognition, where
impairments have serious implications for reading comprehension.
Similarly, this account of reading does not imply that difficulty in decoding is the only problem
for poor readers in general: for these people, especially, comprehension is an important
independent source of difficulty (Cornoldi & Oakhill, 1996). Neither does it imply that, where
comprehension is the critical difficulty in low literacy, any failure of comprehension is
necessarily accompanied by difficulties in decoding regular words, as there is more than one
point at which the acquisition of literacy can founder (Spear-Swerling & Sternberg, 1994).
Although phonological awareness is a good predictor of reading development at the outset
(McBride-Chang & Kail, 2002), it may be a much less efficient predictor of reading ability in
later years (de Jong & van der Leij, 1999), when readers come to rely on it less and less
because of their increasingly automatised (or ‘direct route’) word recognition (Doctor &
Coltheart, 1980). Of special concern is the ‘slump’ observed in children who have succeeded
in learning to decode familiar, regularly-spelled words but who lose momentum when they
encounter less familiar words, particularly when those words are irregularly spelled or have
abstract meanings (Chall et al., 1990). This slump is associated with socio-economic
disadvantage, where the quality of language in the home may be a less than optimal
preparation for schooling (Bernstein, 1971; Feagans & Farran, 1982).
Although the difficulties of dyslexic people do not stop at single-word decoding, the present
review confines its attention to this problem.