Boudelaa, S. 1 & Marslen-Wilson, W. 2, 3
1 United Arab Emirates University, Linguistics Department. Al Ain, UAE
2 MRC Cognition and Brain Sciences Unit, Cambridge, UK
3 University of Cambridge, Department of Experimental Psychology, Cambridge, UK
In studies of English regular and irregular inflectional morphology, there is substantial evidence that regular inflection engages decompositional processes where suffixes are stripped off and stems are used to access the lexicon, while irregular inflection relies instead on whole-form access processes. The interpretation of these results as evidence for the critical role of regularity is undermined, however, by the several confounds intrinsic to the English contrast. Here we re-examine the role of regularity per se in the context of Arabic inflectional morphology, where the plural system allows novel and unconfounded contrasts between regular („sound‟) plurals), irregular („broken‟) plurals and regular „dual‟ plurals‟ applying to both sound plural and broken plural stems. In three priming experiments, using masked, cross-modal and intra-modal auditory-auditory tasks, regular stems (e.g., “fal~AH” farmer) were paired with (a) a plural prime “fal~AHuwn” farmers, formed using the regular plural suffix “uwn”, (b) a dual prime “fal~AHAn” two farmers with the regular dual suffix “An” , (c) a semantically related prime “ArD” land, and (d) a phonologically related prime “fulAn” individual. Similarly, a set of irregular stems (e.g. “Haris” guard) were paired with irregular “broken plural” primes (e.g., “Hur~As” guards); dual primes (e.g., “HArisAn” two guards), semantically related primes (e.g., “baw~Ab” door keeper) and phonologically related primes (e.g., “HAsuwb” computer). Mixed linear effects models show equally strong priming by dual primes, and plural primes regardless of regularity after partialling out semantic and phonological effects. This pattern of results was consistent across the three experiments suggesting that the regularity contrast per se does not invoke differential processing mechanisms. Instead both regularly inflected and irregularly inflected Arabic nouns undergo the same obligatory decomposition process into roots and word patterns to access the lexicon. This underlines the necessity for cross-linguistic investigations in determining the organising principles of lexical systems.