Semantic ambiguity in the lexical access of verbs: How data from monolinguals and bilinguals inform a general model of the mental lexicon

This thesis describes an extensive norming study of Spanish verbs and an online language processing study investigating whether bilingual lexical processing is nonselective (both languages are activated) when only one language is required for use. To study bilingual lexical processing, researchers have relied upon words of shared orthography and semantics between languages in order to determine how word form and meaning impact bilingual word recognition. However, because these words have been of exact form overlap through cognates (words sharing form and meaning between languages: banana in Spanish and English) and homographs (words sharing form yet differing in meaning: the English adjective red meaning net in Spanish), it has been difficult to distinguish which language(s) participants engage during processing tasks. The present research addresses this issue by investigating cognate and homographic verbs between languages. Because differences in verb morphology between Spanish and English never result in exact form overlap between languages (e.g., assist and asistir), interlingual cognate and homographic verbs between Spanish and English should ensure that participants operate in one specific language. Hence, utilizing verbs provides an original testing ground to determine if the bilingual language processor is nonselective when operating in one language and to what degree the access depends on form and meaning overlap between languages. An extensive norming study of Spanish verbs produced a reliable list of cognates and homographs with English. The online research indicated that bilingual lexical access is guided not only by form and meaning, but also by how the frequency of a word's meanings from both languages attach to a single form. These results mirror recent discoveries in ambiguity research in monolinguals (e.g., Rodd, Gaskell and Marslen-Wilson, 2002), the implications of which suggest an overriding mechanism of language processing---not just a theory of bilingual lexical processing.