This article presents MANULEX, 1 the f irst French linguistic tool that provides grade-based frequency lists of the 1.9 million words found in first-grade, secondgrade, and third-to fifth-grade French elementary school readers. The database contains 48,886 nonlemmatized entries and 23,812 lemmatized entries. It was compiled to supply the French counterpart to such works on the English language as Carroll, Davis, and Richman's (1971) American Heritage Word Frequency Book andZeno, Ivenz, Millard, andDuvvuri's (1995) Corpus-based word frequency counts are established as robust predictors of word recognition performance. Consequently, they are widely used in psycholinguistic research. Burgess and Livesay (1998) found them in almost 20% of the papers published in the main experimental psychology reviews. The word frequency effect, first noted by Cattell (1886), is one of the earliest empirical observations in cognitive psychology. Cattell demonstrated that the frequency of occurrence of a word in a language affects even the most basic processing of that word (its speed of recognition). Since this pioneering work, word frequency has been a persisting subject of study for investigators concerned with word recognition: High-frequency words are recognized more quickly and with greater accuracy than are low-frequency words, whatever the measure and task considered (for a review on word frequency effects, see Monsell, 1991). In fact, all current models of word recognition must incorporate word frequency in their activation mechanisms (for a review, see Jacobs & Grainger, 1994). Since the 1980s, for example, word frequency counts have been used mostly in connectionist modeling to simulate language development (Plaut, McClelland, Seidenberg, & Patterson, 1996;Seidenberg & McClelland, 1989). As has been described by Zevin and Seidenberg (2002), in these models, knowledge is encoded as weights on connections between units, which reflect the cumulative effects of exposure to all the words. Learning the meaning of a word is thought to be dependent on exposure to that word in its linguistic contexts, and corpus-based word frequency counts are interpreted as a reflection of such individual experiences with a word.Thus, a crucial variable for understanding language development and, particularly, the reading process is the Support for this research was provided by two national grants, Cognitive Sciences and Schools and Cognitive Sciences (2001, AL16b), and by subsidies from the National Institute of Pedagogical Research (INRP, 1997(INRP, , 1998(INRP, , 1999 This article presents MANULEX, a Web-accessible database that provides grade-level word frequency lists of nonlemmatized and lemmatized words (48,886 and 23,812 entries, respectively) computed from the 1.9 million words taken from 54 French elementary school readers. Word frequencies are provided for four levels: first grade (G1), second grade (G2), third to fifth grades (G3-5), and all grades (G1-5). The frequencies were computed following the methods described by Carroll,...

Perceptual discrimination between speech sounds belonging to different phoneme categories is better than that between sounds falling within the same category. This property, known as "categorical perception," is weaker in children affected by dyslexia. Categorical perception develops from the predispositions of newborns for discriminating all potential phoneme categories in the world's languages. Predispositions that are not relevant for phoneme perception in the ambient language are usually deactivated during early childhood. However, the current study shows that dyslexic children maintain a higher sensitivity to phonemic distinctions irrelevant in their linguistic environment. This suggests that dyslexic children use an allophonic mode of speech perception that, although without straightforward consequences for oral communication, has obvious implications for the acquisition of alphabetic writing. Allophonic perception specifically affects the mapping between graphemes and phonemes, contrary to other manifestations of dyslexia, and may be a core deficit.