Lee Osterhout - US grants

The proposed research will investigate the cognitive and neurological processes underlying language comprehension. Event-related brain potentials (ERPs) will be recorded while subjects read or listen to sentences containing specific deviations from well-formedness. Two approaches are taken in examining ERP effects associated with language comprehension. The first approach focuses on the ERP components themselves, in an attempt to learn more about the cognitive events underlying these effects. Recent work has indicated that syntactic and semantic anomaly elicit distinct ERP effects (the P600 and N400 effects, respectively). The proposed research investigates the hypothesis that these effects are elicited as a function of the linguistic level of the anomaly. The second approach focuses on the process of comprehension. How does the comprehender rapidly derive a single, coherent interpretation of the language input? How quickly are relevant types of information used, and which types of information have precedence over other types of information? The proposed research will use ERP responses to linguistic anomalies to investigate the use of information during language comprehension. Specifically, these experiments will examine the use of information in resolving ambiguity at the syntactic and coreferential levels of analysis. Finally, how similar are the processes that underlie the comprehension of written and spoken language? The proposed research will investigate this question by directly contrasting the ERP response to written and spoken sentences. Although the proposed experiments involve normal adult subjects, one long-term goal is to study language comprehension in children and adults with language disabilities (e.g., the dyslexias and aphasias). The studies proposed here, by furthering our knowledge concerning the cognitive and neural bases of comprehension in normal comprehenders, provide a critical starting point for subsequent ERP investigations of language pathologies.

Many languages of the world show grammatical agreement of some sort, where the grammatical features of a linguistic constituent are visible on another associated constituent. Recent psycholinguistic research has uncovered a number of semantic and syntactic factors that influence how we compute agreement during language production, though much less is known about how these factors interact during language comprehension. Understanding the processing of agreement is also of critical importance in the field of second language acquisition (SLA), as it is frequently observed that second language (L2) learners show considerable trouble with grammatical agreement, often despite many years of formal language instruction and immersion in an L2 environment. Many SLA scholars have proposed that L2 learners' problems with agreement are the result of processing problems, though little research has directly investigated this.

This dissertation research project investigates how subject-verb agreement is computed during real-time sentence comprehension by native speakers of English and by advanced second language learners of English from different linguistic backgrounds, specifically focusing on how a sentence's syntactic complexity influences agreement processing. The experiment uses grammatical agreement phenomena to additionally investigate recent hypotheses that nonnative grammatical contrasts are unacquirable by L2 learners and that L2 learners' language processing systems are radically different from native language systems.

These questions will be addressed by recording event-related brain potentials (ERPs) while participants read sentences in English. ERPs have been shown to be highly sensitive to many facets of native language agreement processing, though no studies have investigated how syntactic complexity affects agreement computation. Additionally, ERPs have only recently been used to study L2 processing. There is thus a paucity of knowledge about the neural substrates underlying L2 agreement processing or how agreement, syntax, and L1 experience interact during L2 processing. The inclusion of modern psycholinguistic and neurophysiological techniques in studying L2 acquisition and processing will therefore complement the existing rich theoretical linguistic literature on L2 grammatical representation. The outcomes of this research will be of interest to cognitive neuroscientists interested in language and to theoretical linguists and psycholinguists studying agreement, its relationship to syntactic structure, and how agreement interacts with syntactic parsing systems. The results will additionally be of interest to theoretical and applied SLA researchers, having potentially significant implications for language acquisition theory and language pedagogy.

Global changes in transportation and communication have placed a premium on the ability to speak two or more languages. However, learning a third language (L3) can interfere with the learner's proficiency in a previously acquired second (L2) language, a phenomenon referred to as language attrition. Fundamental questions about why languages attrite, how they attrite, and what aspects of language are most susceptible to attrition remain unanswered. This proposal seeks to better understand how the learning of a new language (L3) can interfere with the learner's proficiency with a previously acquired non-native language (L2), in the context of real-world language learning among college students. Dr. Lee Osterhout, from the University of Washington, will perform three experiments using a high density EEG-based brain activity measure to longitudinally investigate changes in learners' ability to process sentences in their L3 (Italian) and in their L2 (a similar language, Spanish, or a less similar language, such as Japanese). Because the brain activity measure is differentially sensitive to aspects of linguistic meaning and grammar, the results will provide a specific understanding of what linguistic knowledge (for both the L2 and L3) has been gained or lost, and how the acquisition of one language influences the loss of another.

Given the importance of multi-lingual skills in the modern, inter-connected world, a better understanding of the causes of language attrition will have broad impact. Findings from this project may lead to ways to improve and customize instructional pedagogy with respect to language learning, and to protect previously acquired foreign languages. This project will generate a large data set with broad relevance. Potentially, this data set could be used to study the spatial origins of language-sensitive brain responses, test new mathematical and computational tools for high-density EEG-based brain source imaging, and address the fundamental question of how brain activity, at the temporal scale of milliseconds and from multiple brain regions, changes as a result of learning and "unlearning" outside of the laboratory.