Parafoveal processing and transposed-letter effects in dyslexic reading

During parafoveal processing, skilled readers encode letter identity independently of letter position (Johnson et al., 2007). In the current experiment, we examined orthographic parafoveal processing in readers with dyslexia. Specifically, the eye movements of skilled readers and adult readers with dyslexia were recorded during a boundary paradigm experiment (Rayner, 1975). Parafoveal previews were either identical to the target word (e.g., nearly), a transposedletter preview (e.g., enarly), or a substituted-letter preview (e.g., acarly). Dyslexic and non-dyslexic readers demonstrated orthographic parafoveal preview benefits during silent sentence reading and both reading groups encoded letter identity and letter position information parafoveally. However, dyslexic adults showed, that very early in lexical processing, during parafoveal preview, the positional information of a word's initial letters were encoded less flexibly compared to during skilled adult reading. We suggest that dyslexic readers are less able to benefit from correct letter identity information (i.e., in the letter transposition previews) due to the lack of direct mapping of orthography to phonology. The current findings demonstrate that dyslexic readers show consistent and dyslexic-specific reading difficulties in fovea) and parafoveal processing during silent sentence reading.

Automated summary

This study examined orthographic parafoveal processing in readers with dyslexia. The findings showed that both dyslexic and non-dyslexic readers benefited from parafoveal previews during silent sentence reading. However, dyslexic adults encoded the positional information of a word's initial letters less flexibly compared to skilled adult readers, suggesting difficulties in mapping orthography to phonology.