Proceedings of the Annual Meeting of the Cognitive Science Society

We used a cross-modal repetition priming task to investigate the mental representation of regular and irregular past tense forms in English. Subjects heard a spoken prime (such as walked) immediately followed by lexical decision to a visual probe (such as walk). W e contrasted three types of English verbs, varying in the phonological and morphological regularity of their past tense inflection. These were (i) Regular verbs {jump/jumped), with the regular 1-61 inflection and no stem change, (ii) Semi-Weak verbs {burn/burnt, feel/felt), with irregular alveolar inflection and some phonologically regular stem vowel change, and (iii) Vowel Change verbs {sing/sang, give/gave), which mark past tense through phonologically irregular changes in the stem vowel. T h e stem forms of these verbs were presented in three prime conditions ~ preceded either by the Identity Prime, a Past Tense Prime, or a Control Prime. T h e Identity Prime significantly facilitated lexical decision responses for all three verb classes, but the Past Tense Prime, while significantly facilitating responses in the Regular verb class, produced no overall effect for the Semi-Weak verbs, and significant interference for the Vowel Change verbs. W e conclude that phonological irregularity in the relation between a stem and an inflected form can lead to very different lexical structures than w e find for more regular phonological relationships.