Semantic, Phonological, and Lexical Influences on Regular and Irregular Inflection

Regular and irregular inflections have become an important tool for understanding mechanisms underlying human language and cognition. Regular-irregular homophones such as rang the bell/ringed the city challenge connectionist models in which phonological information is the only input to the inflection process. Models of language that differentiate between lexicon and grammar attribute these inflectional differences to distinct lexical or morphological representations while connectionist models distinguish them by semantic features. Ramscar (2002) argued for the semantic account by showing that people extend irregular inflection to novel words similar in sound and meaning to existing irregulars, however generalizations may have been based on analogy to those exact words rather than overlap of semantic features. We presented people with novel words that independently varied in phonological and semantic similarity to existing irregulars and found that semantics only had an effect when the level of similarity was high and when it was accompanied by high phonological similarity—the combination that evokes a particular existing verb. Results are problematic for a model that appeals both to semantic and phonological similarity and supports theories that posit distinct lexical representations.