Orthographic Reading Deficits in Dyslexic Japanese Children: Examining the Transposed-Letter Effect in the Color-Word Stroop Paradigm.

Shino Ogawa,Tomoko Isomura,Masahiro Shibasaki,Nobuo Masataka

doi:10.3389/fpsyg.2016.00767

Shino Ogawa, Tomoko Isomura + Show 2 more

Open Access

https://doi.org/10.3389/fpsyg.2016.00767

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Abstract

In orthographic reading, the transposed-letter effect (TLE) is the perception of a transposed-letter position word such as “cholocate” as the correct word “chocolate.” Although previous studies on dyslexic children using alphabetic languages have reported such orthographic reading deficits, the extent of orthographic reading impairment in dyslexic Japanese children has remained unknown. This study examined the TLE in dyslexic Japanese children using the color-word Stroop paradigm comprising congruent and incongruent Japanese hiragana words with correct and transposed-letter positions. We found that typically developed children exhibited Stroop effects in Japanese hiragana words with both correct and transposed-letter positions, thus indicating the presence of TLE. In contrast, dyslexic children indicated Stroop effects in correct letter positions in Japanese words but not in transposed, which indicated an absence of the TLE. These results suggest that dyslexic Japanese children, similar to dyslexic children using alphabetic languages, may also have a problem with orthographic reading.

Highlights

Dyslexia is a developmental disorder characterized by reading difficulty in children and adults of normal intelligence who have the motivation to read accurately and fluently (Shaywitz and Shaywitz, 2005)
Stroop effects were observed for both correct words and transposed-letter nonwords, and neither error rate nor gender confounded the Stroop effects in adults. These results suggested that normal Japanese adults utilize orthographic reading when recognizing transposed-letter nonwords in the color-word Stroop paradigm
Because of many individual differences in dyslexic children, larger sample sizes will be required in future studies. We found that both normal adults and typically developing (TD) children exhibited Stroop effects in Japanese hiragana words with transposed-letter positions, indicating the presence of transposed-letter effect (TLE) in orthographic reading

Summary

Introduction

Dyslexia is a developmental disorder characterized by reading difficulty in children and adults of normal intelligence who have the motivation to read accurately and fluently (Shaywitz and Shaywitz, 2005). Dyslexia is estimated in ∼5–12% of participants who used English as a primary language (Katusic et al, 2001). Dyslexia has been found in participants with non-alphabetic languages, such as Japanese, but at much lower percentages (Uno et al, 2009). This suggests that differences in the architecture of English and Japanese may be associated with a propensity to dyslexia at least partly; research that compares dyslexia in different language systems may provide important insights into its mechanism. The underlying mechanisms of dyslexia have far remained largely unclear (Gabrieli, 2009; Dehaene et al, 2010). For dyslexic users of alphabetic languages, both these routes are believed to be impaired

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