TY - JOUR
T1 - Does pronounceability modulate the letter string deficit of children with dyslexia? A study with the rate and amount model
AU - Marinelli, Chiara V.
AU - Traficante, Daniela
AU - Zoccolotti, Pierluigi
PY - 2014
Y1 - 2014
N2 - The locus of the deficit of children with dyslexia in dealing with strings of letters may be a deficit at a pre-lexical graphemic level or an inability to bind orthographic and phonological information. We evaluate these alternative hypotheses in two experiments by examining the role of stimulus pronounceability in a lexical decision task and in at forced- choice letter discrimination task (Reicher-Wheeler paradigm). Seventeen 4th grade children with dyslexia and 24 peer control readers participated to two experiments. In the lexical decision task children were presented with high-, low-frequency words, pronounceable pseudowords (such as DASU) and unpronounceable non-words (such as RNGM) of 4-, 5- or 6- letters. No sign of group by pronounceability interaction was found when overadditivity was taken into account. Children with dyslexia were impaired when they had to process strings, not only of pronounceable stimuli but also of unpronounceable stimuli, a deficit well accounted for by a single global factor. Complementary results were obtained with the Reicher-Wheeler paradigm: both groups of children gained in accuracy in letter discrimination in the context of pronounceable primes (words and pseudowords) compared to unpronounceable primes (non-words). No global factor was detected in this task which requires the discrimination between a target letter and a competitor but does not involve simultaneous letter- string processing. Overall, children with dyslexia show a selective difficulty in simultaneously processing a letter string as a whole, independent of its pronounceability; however, when the task involves isolated letter processing, also these children can make use of the ortho-phono-tactic information derived from a previously seen letter string. This pattern of findings is in keeping with the idea that an impairment in pre-lexical graphemic analysis may be a core deficit in developmental dyslexia.
AB - The locus of the deficit of children with dyslexia in dealing with strings of letters may be a deficit at a pre-lexical graphemic level or an inability to bind orthographic and phonological information. We evaluate these alternative hypotheses in two experiments by examining the role of stimulus pronounceability in a lexical decision task and in at forced- choice letter discrimination task (Reicher-Wheeler paradigm). Seventeen 4th grade children with dyslexia and 24 peer control readers participated to two experiments. In the lexical decision task children were presented with high-, low-frequency words, pronounceable pseudowords (such as DASU) and unpronounceable non-words (such as RNGM) of 4-, 5- or 6- letters. No sign of group by pronounceability interaction was found when overadditivity was taken into account. Children with dyslexia were impaired when they had to process strings, not only of pronounceable stimuli but also of unpronounceable stimuli, a deficit well accounted for by a single global factor. Complementary results were obtained with the Reicher-Wheeler paradigm: both groups of children gained in accuracy in letter discrimination in the context of pronounceable primes (words and pseudowords) compared to unpronounceable primes (non-words). No global factor was detected in this task which requires the discrimination between a target letter and a competitor but does not involve simultaneous letter- string processing. Overall, children with dyslexia show a selective difficulty in simultaneously processing a letter string as a whole, independent of its pronounceability; however, when the task involves isolated letter processing, also these children can make use of the ortho-phono-tactic information derived from a previously seen letter string. This pattern of findings is in keeping with the idea that an impairment in pre-lexical graphemic analysis may be a core deficit in developmental dyslexia.
KW - dyslexia
KW - lexical decision
KW - dyslexia
KW - lexical decision
UR - http://hdl.handle.net/10807/63522
U2 - 10.3389/fpsyg.2014.01353
DO - 10.3389/fpsyg.2014.01353
M3 - Article
SN - 1664-1078
SP - 1
EP - 16
JO - Frontiers in Psychology
JF - Frontiers in Psychology
ER -