Grapheme-phoneme processing of single words

Often used in cognitive studies measuring reaction times and in functional imaging studies, the subtraction paradigm is based on the comparison of performance on tasks presupposed to refer to different cognitive levels of processing. Within the framework of the study of phonological processing of words, manipulating the grapheme-phoneme transparency of stimuli can represent a means of counteracting the methodological drawbacks inherent to the subtraction paradigm. Thus, the purpose of this study was to determine the effect of the level of difficulty of grapheme-phoneme matching on the processing of transparent and nontransparent words. Grapheme-phoneme matching was carried out both on the final syllable of words and on sublexical segments within the word. The results indicate that processing is faster for the transparent than for the nontransparent stimuli. This task will now have to be reintroduced in brain imaging studies aiming to look at different levels of difficulty for grapheme-phoneme matching.