Regularity and Irregularity in an Inflectionally Complex Language: Evidence form Polish

Regularity and Irregularity in an Inflectionally Complex Language: Evidence from Polish Agnieszka Reid (agnieszka.reid@mrc-cbu.cam.ac.uk) William Marslen-Wilson (william.marslen-wilson@mrc-cbu.cam.ac.uk) MRC Cognition and Brain Sciences Unit, 15 Chaucer Road, Cambridge CB2 2EF, UK. Abstract We report two experiments which address the question of whether there is support for single or dual mechanisms in the processing of Polish regular and irregular nouns and verbs. The data from an immediate cross-modal priming experiment (verbs and nouns) revealed that there was significant priming, irrespective of regularity, for both verbs and nouns. The re- sults for verbs were replicated in a second experiment using delayed repetition auditory-auditory priming. The outcome from both experiments is in line with the results reported from research on Italian and French but not with English and German, and suggest that Polish regulars and irregulars are processed by a single underlying cognitive system. Introduction There has been a long lasting debate as to the implications of English regular and irregular verbs for the universal properties of human cognitive mechanisms (Marslen-Wilson & Tyler, 1998; Pinker, 1999). The protagonists of a dual mechanism approach (Pinker & Prince, 1991) have claimed that English regular past tense forms are processed by a symbolic rule, which concatenates allomorphic suffixes (-ed or -d or -t) to the verb stem, while the irregular past tense forms are processed as whole forms in an associative mem- ory. In contrast, the proponents of the single mechanism (Plunkett & Marchman, 1993; Rumelhart & McClelland, 1986) claim that regular and irregular English verbs are processed and represented in the same way, by a distributed connectionist system, operating without symbols and syn- tax. We focus here on the experimental work probing the on- line processing and representation of regular and irregular forms in the adult mental lexicon. Much of this work has of course focused on English, chiefly using a variety of prim- ing paradigms. In early work, for example, Stanners, Neiser, Hernon and Hallet (1979) tested the representation of regu- lar and irregular verbs using visual priming with a delay. The authors found that regular inflected verbs primed their bases as effectively as identity primes. In contrast the ir- regular past tenses primed their bases significantly less than identity primes. Marslen-Wilson, Hare and Older (1995) investigated the representation of English regular and ir- regular verbs using a cross-modal lexical decision paradigm. The authors contrasted regular verbs (jumped/jump), with irregular verbs which fell into two classes: semi-weak verbs (burnt/burn) with irregular alveolar inflection, and vowel change verbs (gave/give). The results showed that there was significant priming for the regulars, but no priming for ei- ther sub-class of irregular verbs. Evidence for behavioural differences of this type, sug- gesting asymmetries in the underlying systems supporting the processing of regular and irregular forms, can be inter- preted as support for a dual mechanism approach. It is im- portant, however, to apply these techniques cross- linguistically, to develop a broader perspective on the proc- essing consequences of regularity and irregularity, and to evaluate the universality of the claims being made. Cross-linguistic behavioural studies Although cross-linguistic research is in its early stages it has already suggested interesting contrasts between English and German as opposed to Italian and French. Sonnenstuhl, Eisenbeiss and Clahsen (1999) probed the representation of regular and irregular German verbs as well as regular and irregular noun plurals, using the cross-modal paradigm. Significant priming for both regulars and irregu- lars was obtained. The regulars were as effective as identity primes, whereas the irregulars were significantly less effec- tive than identity primes. The authors argued that these data, consistent with English, provide support for the dual mechanism where the regulars are processed as a stem and an affix, generated by a rule, whereas irregulars are proc- essed as full lexical items. Both English and German belong to the same West Ger- manic language family and share many similarities. In addi- tional research we have begun to look at languages from different sub-families which show different distributions of regulars and irregulars as well as of inflectional suffixation. Significant cross-modal priming has been found for Italian regular and irregular verbs (Orsolini & Marslen-Wilson 1997). For regular verb pairs, the prime was typically a first or third conjugation past definite form, paired with either an infintive target (as in gioc-a-rono/gioc-are ‘they played/to play’) or with a past participle target (as in am-a-rono/am- a-to ‘they loved/loved’). These conditions were contrasted with irregular verb pairs, such as sce-s-ero/scend-ere ‘they got down, past definite’/to get down, infinitive’, with idio- syncratic alternations, comparable to English irregular alter- nations, but occurring in a much more constrained and pre- dictable morphological environment. Significant priming