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

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.

ERP Correlates of Altered Orthographic-Phonological Processing in Dyslexia

“…This substitution advantage was found in controls regardless of the lexicality of the letter string and was somewhat larger for pseudowords than word, but the effect was only present for words in children with dyslexia. In sum, it seems that readers with dyslexia have deficits in letter identity and position processing (Reilhac et al, 2012;Ogawa et al, 2016), but to our knowledge, no previous studies examined the electrophysiological correlates of letter identity and letter position encoding in individuals with dyslexia.…”

“…Although a number of studies examined orthographic processing in skilled readers, much less experiments investigated these processes in reading disorders. In their study, Ogawa et al (2016) found impaired orthographic processing in adults with dyslexia. While typically reading Japanese children showed the Stroop effect for real words and their transposed-letter pseudoword pairs, readers with dyslexia showed the Stroop effect for real words only which suggests orthographic processing deficits.…”

“…Though it seems that visual sensitivity for print Kast et al, 2010;Araújo et al, 2012;Mahé et al, 2012) and fundamental orthographic processes like letter identity and letter position encoding (Reilhac et al, 2012;Ogawa et al, 2016) can be affected in dyslexia, phonological deficits are usually more severe (Blomert, 2011;Lété and Fayol, 2013). In addition, even orthographic processes are thought to be tuned by phonology (Maurer and McCandliss, 2007;Meade, 2020); therefore, comparing deficits in orthographic processing and deficits in the integration of orthographic and phonological information is crucial.…”

Stroop interference in children with developmental dyslexia

“…The Stroop effect of DD children is stronger, which is consistent with previous studies. [ 24 , 25 ] For DD children, it takes more time to read the word, resulting in a longer latency for color naming and thus a larger interference effects, [ 26 ] suggesting poor inhibitory abilities of DD children. Our study found differences between DD and non-dyslexic children in early attentional components such as P2, suggesting the prolonged color naming of the incongruent trials by DD children may be due to resource input of early attentional processes.…”

The role of executive function in reading comprehension among beginning readers

“…The reaction time RT (in milliseconds) and accuracy were recorded by the system. The composite score was computed with the formula (Ogawa, Shibasaki, Isomura, & Masataka, 2016), congruent condition RT/ incongruent condition RT x100, in making the accurate response. Thus, higher composite score represents higher inhibition ability.…”