The Influence of Language Exposure on Lexical and Syntactic Language Processing Tracy Love 1 , Edwin Maas, 1,2 and David Swinney 1 1 University of California, San Diego, La Jolla, CA and 2 San Diego State University, CA Abstract. Previous literature has argued that proficient bilingual speakers often demonstrate monolingual-equivalent struc- tural processing of language (e.g., the processing of structural ambiguities; Frenck-Mestre, 2002). In this paper, we explore this thesis further via on-line examination of the processing of syntactically complex structures with three populations: those who classify as monolingual native English speaker (MNES), those who classify as non-native English speakers (NNES), and those who classify as bilingual native English speakers (BNES). On-line measures of processing of object- relative constructions demonstrated that both NNES and BNES have different patterns of performance as compared to MNES. Further, NINES and BNES speakers perform differently from one another in such processing. The study also examines the activation of lexical information in biasing contexts, and suggests that different processes are at work in the different type of bilinguals examined here. The nature of these differences and the implications for developing sensitive models of on-line language comprehension are developed and discussed. Key words: psycholinguistics, bilingual, on-line, sentence comprehension Introduction There is a wealth of research in the literature explor- ing the moment-by-moment details involved in pro- cessing on-going, fluent speech (across a variety of syntactic constructions) by monolingual listeners. speakers of a language (particularly English). The question of how such evidence may be related to the processing of similar constructions by listeners, speakers of multiple languages is, however, relatively underspecified at this time. In recent years, bilin- gualism has become an increasingly important re- search topic as it provides us with new insights into the potentials for the mental representation and pro- cessing of language in the human mind (e.g., De Groot & Kroll, 1997; Romaine, 1995). Indeed, there seems to be growing consensus that bilinguals are not merely two monolinguals in one person, but rather that the language system of a bilingual may The authors gratefully acknowledge the NIH grant DC 02984, which supported this research. Special thanks to Grace Shaio and Vikki Bouck for their assistance in data collection and analysis. DOI: 10.1027 1618-3169.50.3.204 Experimental Psychology 2003: Vol. 50(3): 204-216 differ in important ways from that of a monolingual both functionally (Dussias, 2001; Grosjean, 1989, 1997) and neurologically (e.g., Kim, Relkin, Lee, & Hirsch, 1997; Perani et al., 1996). Thus, important generalizations may be missed if models of language processing are developed exclusively from research on monolinguals. The level of such generalizations may ultimately hold for processing in general or al- ternatively be stated across all aspects of language as different at each independent level of language analysis. At this point, the evidence for important differences in processing between monolingual and bilingual speakersilisteners is somewhat mixed - with arguments that (at least certain types of) bilin- guals and monolinguals handle language processing in much the same fashion, and of course, with argu- ments holding the opposite position. One issue in this debate centers on the tape of bilingual popula- tion one compares to monolingual population. An- other issue, the one we will begin with here, centers on the level of language processing one is evaluating. Much of the research on bilingualism has focused at the word-processing level of language analysis. This research has used relatively immediate mea- © 2003 Hogrefe & Huber Publishers