Graphemes are perceptual reading units

Graphemes are commonly defined as the written representation of phonemes. F or example, the word 'BREAD' is composed of the four phonemes /b/, /r/, /e/ and /d/, and consequently, of the four graphemes 'B', 'R','EA', and 'D'. G raphemes can thus be considered the minimal 'functional bridges' in the map ping between orthography and phonology. In the present study we investigate d the hypothesis that graphemes are processed as perceptual units by the re ading system. If the reading system processes graphemes as units, then dete cting a letter in a word should be harder when this letter is embedded in a multi-letter grapheme than when it corresponds to a single-letter grapheme . In Experiment 1A. done in English, participants were slower to detect a t arget letter in a word when the target letter was embedded in multi-letter grapheme (i.e,'A' in 'BEACH') than when it corresponded to a single-letter grapheme (i.e. 'A' in 'PLACE'). In Experiment 1B, this effect was replicate d in French. In Experiment 2, done in English, this grapheme effect remaine d when phonemic similarity between the target letter alone and the target l etter inside the word was controlled. Together, the results are consistent with the assumption that graphemes are processed as perceptual reading unit s in alphabetic writing systems such as English or French. (C) 2000 Publish ed by Elsevier Science B.V, All rights reserved.