Pseudo-Family Size Influences theProcessing of French Inflections: Evidence in Favor of a Supra-LexicalAccount

Since Rumelhart & McClelland (1986) first presented their connectionist model of the English past tense system, the nature of morphological representation has divided psycholinguists. This question is central in debates about the nature of cognition, since it concerns the understanding of how the lexicon is organized in terms of structural units, and how these units interact with each other during lexical access. One of this domain’s important controversies concerns the description of the core units of the lexicon, namely the morpheme versus lexeme problem. The former posits that a unit smaller than the word, preserving basic semantic and orthographic/phonological characteristics and commonly called morpheme is the structural unit of the lexicon, whereas the later argues that morphology is primarily a set of systematic correspondences between the forms and meanings of the words, and that the source of morphology is the network of paradigmatic relations between the existing words of a language. This position implies that it is the word that forms the basis of morphological operations, and that morphology cannot be simply defined as the concatenation of morphemes into words. As pointed out by Aronoff (1994), it is better to speak of lexeme-based morphology, because the term 'word-based' has led to the misunderstanding that it is the concrete form of a word that is the basis for morphological operations. However, it is often an abstract stem form of a lexeme, which never surfaces as a concrete word form, that constitutes the basis for morphological operations, and hence, the term ‘lexeme-based’ is more appropriate. This lexeme-based view of morphology is shared by many morphologists (Bybee 1988; 2001, Booij 2002): morphology is not the “syntax of morphemes”, but the extension of patterns of existing systematic form-meaning correspondences between words. The Dutch tradition of morphological studies provided some pieces of convincing evidence for this view, see the work by Harald Baayen and his colleagues on family size effects (e.g. de Jong et al. 2000). The morpheme based approach has lead to models claiming a general and mandatory decomposition of the surface form (Taft 1981; Taft & Forster 1975), and more recently to theorizations in which decomposition occurs for some words, but not for others (e.g. Caramazza et al. 1988; Marslen-Wilson et al. 1994; Schreuder & Baayen 1995; Pinker 1991). Complex words are recognized either by applying a general computational rule that parses the word into its morphemes or by retrieving directly from memory the whole word form. This ‘dual-route’ approach, which includes a variety of theoretical frames, has to be reconciled with findings that suggest that morphological processing is not an ‘all or none’ phenomenon and that different levels of semantic, orthographic or phonological similarity induce graded effects of morphological facilitation, at least as far as the priming technique is concerned (Frost et al. 2000; Plaut & Gonnerman 2000, Rueckl et al. 1997; Seidenberg & Gonnerman 2000; Velan et al. 2005). One of the difficulties of the study of morphology for alphabetic languages – in which the vast majority of research is conducted – is not only that morphology is correlated with semantic, orthographic and phonological factors, but also that stems and inflected or derived words exist as free word-forms, entertaining with each other different relations. These relations have been shown to be relevant to morphological processing: with the masked priming technique, Grainger et al. (1991) have