| In contrast to traditional views of the mental lexicon in which morphological relationships are explicitly represented, I propose an account that suggests instead that 'morphology' reflects degrees of compositionality in complex words and arises predominantly from regularities in the mappings between semantic and phonological codes. Support for this alternative account comes both from results of a computational model and from a series of four cross-modal priming experiments.; The computational results demonstrate that a connectionist model, without an explicit representation of morphological structure, can produce priming results strikingly similar to those from behavioral studies, suggesting that a system which relies on semantics and phonology alone can simulate what appear to be effects of morphological structure. The behavioral results demonstrate that: (1) subjects are sensitive to fine gradations both in the semantic similarities between related lexical items (e.g., teacher-teach; dresser-dress; corner-corn), and in their phonological similarities (e.g., deletion-delete; vanity-vain; introduction-introduce); (2) the degrees of semantic and phonological relatedness of word pairs, when considered in conjunction, predict priming effects, and; (3) the nature of the morphological relationship between primes and targets does not predict priming effects: derived-stem pairs (e.g., teacher-teach), derived-derived pairs (e.g., saintly-sainthood), and pairs with no historical morphological relationship (e.g., trivial-trifle ) all prime, if the words are highly semantically and phonologically related.; The results from the model and the behavioral experiments suggest that morphological structure is an emergent, interlevel representation that mediates computations between semantics and phonology, not an independent component of language. Moreover, I argue that this approach is superior to other approaches, because it accounts for intermediate, graded effects that present a challenge to more traditional, decompositional views of the lexicon. In addition, this account sheds new fight on the longstanding debate within linguistic theory about the appropriate place for morphology, by changing its role to one of convenient description of phenomena that actually lie at the interface of semantics and phonology. Finally, the account provides interesting predictions about acquisition, cross-linguistic studies, and impairment, for which there is currently emerging support. |
