Natasha Tokowicz

IMPLICIT AND EXPLICIT MEASURES OF SENSITIVITY TO VIOLATIONS IN SECOND LANGUAGE GRAMMAR: An Event-Related Potential Investigation

We used event-related brain potentials (ERPs) to investigate the contributions of explicit and implicit processes during second language (L2) sentence comprehension. We used a L2 grammaticality judgment task (GJT) to test 20 native English speakers enrolled in the first four semesters of Spanish while recording both accuracy and ERP data. Because end-of-sentence grammaticality judgments are open to conscious inspection, we reasoned that they can be influenced by strategic processes that reflect on formal rules and therefore reflect primarily offline explicit processing. On the other hand, because ERPs are a direct reflection of online processing, they reflect automatic, nonreflective, implicit responses to stimuli ( Osterhout, Bersick, & McLaughlin, 1997 ; Rugg et al., 1998 ; Tachibana et al., 1999 ). We used a version of the GJT adapted for the ERP environment. The experimental sentences varied the form of three different syntactic constructions: (a) tense-marking, which is formed similarly in the first language (L1) and the L2; (b) determiner number agreement, which is formed differently in the L1 and the L2; and (c) determiner gender agreement, which is unique to the L2. We examined ERP responses during a time period between 500 and 900 ms following the onset of the critical (violation or matched control) word in the sentence because extensive past research has shown that grammatical violations elicit a positive-going deflection in the ERP waveform during this period (e.g., the “P600”; Osterhout & Holcomb, 1992 ). We found that learners were sensitive (i.e., showed different brain responses to grammatical and ungrammatical sentences) to violations in L2 for constructions that are formed similarly in the L1 and the L2, but were not sensitive to violations for constructions that differ in the L1 and the L2. Critically, a robust grammaticality effect was found in the ERP data for the construction that was unique to the L2, suggesting that the learners were implicitly sensitive to these violations. Judgment accuracy was near chance for all constructions. These findings suggest that learners are able to implicitly process some aspects of L2 syntax even in early stages of learning but that this knowledge depends on the similarity between the L1 and the L2. Furthermore, there is a divergence between explicit and implicit measures of L2 learning, which might be due to the behavioral task demands (e.g., McLaughlin, Osterhout, & Kim, 2004 ). We conclude that comparing ERP and behavioral data could provide a sensitive method for measuring implicit processing. This research was supported by a National Institutes of Health Individual National Research Service Award (NIH HD42948-01) awarded to Natasha Tokowicz and a National Institutes of Health Institutional National Research Service Award (T32 MH19102) awarded to Brian MacWhinney. We thank Beatrice DeAngelis, Dayne Grove, Kwan Hansongkitpong, Katie Keil, Lee Osterhout, Chuck Perfetti, Kelley Sacco, Alex Waid, and Eddie Wlotko for their assistance with this project. We gratefully acknowledge the comments of Rod Ellis, Jan Hulstijn, Albert Valdman, and the two anonymous SSLA reviewers on earlier versions of this manuscript. A portion of these results was presented at the 43rd Annual Meeting of the Psychonomic Society (2002, November).

The development of lexical fluency in a second language

A goal of second language (L2) learning is to enable learners to understand and speak L2 words without mediation through the first language (L1). However, psycholinguistic research suggests that lexical candidates are routinely activated in L1 when words in L2 are processed. In this article we describe two experiments that examined the acquisition of L2 lexical fluency. In Experiment 1, two groups of native English speakers, one more and one less fluent in French as their L2, performed word naming and translation tasks. Learners were slower and more error prone to name and to translate words into L2 than more fluent bilinguals. However, there was also an asymmetry in translation performance such that forward translation was slower than backward translation. Learners were also slower than fluent bilinguals to name words in English, the L1 of both groups. In Experiment 2, we compared the performance of native English speakers at early stages of learning French or Spanish to the performance of fluent bilinguals on the same tasks. The goal was to determine whether the apparent cost to L1 reading was a consequence of L2 learning or a reflection of differences in cognitive abilities between learners and bilinguals. Experiment 2 replicated the main features of Experiment 1 and showed that bilinguals scored higher than learners on a measure of L1 reading span, but that this difference did not account for the apparent cost to L1 naming.We consider the implications of these results for models of the developing lexicon.

The Revised Hierarchical Model: A critical review and assessment.

Brysbaert and Duyck (2009) suggest that it is time to abandon the Revised Hierarchical Model (Kroll and Stewart, 1994) in favor of connectionist models such as BIA+ (Dijkstra and Van Heuven, 2002) that more accurately account for the recent evidence on nonselective access in bilingual word recognition. In this brief response, we first review the history of the Revised Hierarchical Model (RHM), consider the set of issues that it was proposed to address, and then evaluate the evidence that supports and fails to support the initial claims of the model. Although 15 years of new research findings require a number of revisions to the RHM, we argue that the central issues to which the model was addressed, the way in which new lexical forms are mapped to meaning and the consequence of language learning history for lexical processing, cannot be accounted for solely within models of word recognition.

The roles of study-abroad experience and working-memory capacity in the types of errors made during translation

We examined the effects of study-abroad experience (SAE) and working-memory capacity (WMC) on the types of errors made during single-word translation from the first language to the second language, contrasting non-response with meaning errors (i.e. when individuals translate semantically-related words instead of the target word). SAE and WMC interacted; individuals with more SAE and higher WMC made as many meaning as non-response errors, whereas individuals in the other groups made more non-response than meaning errors. We conclude that SAE encourages the use of approximate translations to communicate, but only higher WMC learners can do so because this strategy requires multiple items to be maintained in memory simultaneously. A speech-production model is adapted to capture our results and demonstrate the effects of differential working memory demands on producing correct translations, meaning errors, and non-response errors.

Number of meanings and concreteness: Consequences of ambiguity within and across languages

We examined the effects of concreteness and ambiguity on language processing. In Experiment 1, English–Spanish bilinguals translated words with a single translation. Contrary to past findings, we observed no concrete-word advantage in translation latency. In Experiment 2, English–Spanish bilinguals translated words with one and more than one translation. Words with multiple translations were translated more slowly and showed the typical concrete-word advantage. Words with one translation showed a reversal of the typical concrete-word advantage in latency. Further, concrete words were uninfluenced by ambiguity. In Experiment 3, we explored whether the interaction between concreteness and ambiguity was a general property of the language processing system. Supporting this idea, in a monolingual lexical decision task, we found an interaction between concreteness and number of meanings analogous to the interaction in translation. We discuss the common mechanism that may lead to this interaction in both within and cross-language processing.

Event-related brain potentials and second language learning: syntactic processing in late L2 learners at different L2 proficiency levels

There are several major questions in the literature on late second language (L2) learning and processing. Some of these questions include: Can late L2 learners process an L2 in a native-like way? What is the nature of the differences in L2 processing among L2 learners at different levels of L2 proficiency? In this article, we review studies that addressed these questions using event-related brain potentials (ERPs) in late learners and that focused on syntactic processing. ERPs provide an on-line, millisecond-by-millisecond record of the brain’s electrical activity during cognitive processing. ERP measures can thus provide valuable information on the timing and degree of neural activation as language processing (here: syntactic processing in L2) unfolds over time. After discussing the use of ERPs for the study of L2 learning and processing, we review electrophysiological studies on syntactic and morphosyntactic processing in late L2 learners with different levels of L2 proficiency. The currently available evidence indicates that patterns of neural activity in the brain during syntactic and morphosyntactic processing can be modulated by various, possibly interrelated, factors including the similarity or dissimilarity of syntactic structures in L2 and L1, the exact nature of the syntactic structure L2 learners seek to comprehend and the concomitant expectancies they can generate with regard to violations in this structure, and the L2 learners’ level of L2 proficiency. Together these studies show that ERPs can successfully elucidate subtle differences in syntactic processing between L2 learners and native speakers, and among L2 learners at different levels of L2 proficiency, which are difficult to detect or that might have remained undetected with behavioural measures.

Semantic ambiguity within and across languages: An integrative review

Semantic ambiguity often occurs within a language (e.g., the word “organ” in English means both a body part and a musical instrument), but it can also cross a language boundary, such that a given word form is shared in two languages, but its meanings are different (e.g., the word “angel” means “sting” in Dutch). Bilingual individuals are therefore faced not only with ambiguity in each of their languages, but also with ambiguity across languages. The current review focuses on studies that explored such cross-language ambiguity and examines how the results from these studies can be integrated with what we have learned about within-language ambiguity resolution. In particular, this review examines how interactions of frequency and context manifest themselves in ambiguity that crosses a language boundary and call for the inclusion of language context as a contributing factor. An extension of the monolingual reordered access model (Duffy, Morris, & Rayner, 1988) is outlined to discuss the interactions between these factors. Furthermore, the effects of the similarity between the two meanings, task differences, and individual differences are explored. This review highlights the need for studies that test within- and cross-language ambiguity in the same individuals before strong conclusions can be made about the nature of interactions between frequency, semantic context, and language context.

Bidirectional transfer: The effect of sharing a translation

This study investigated reciprocal influences between the first and second languages of bilingual speakers. Participants were monolingual English speakers and bilingual speakers of English and Hebrew who learned Hebrew either as a first language or as a second language. Participants rated the semantic similarity of English word pairs that either shared a Hebrew translation or did not, and that varied in their baseline relatedness in English. Shared-translation pairs (e.g., tool and dish are both translated as “kli” in Hebrew) were rated as more similar in meaning than different-translation pairs by both bilingual groups, but not by the monolinguals. Knowledge of Hebrew influenced the way bilinguals processed words in English not only when Hebrew was the native language but also when it was learned as a second language later in life. These findings provide evidence for bidirectional transfer, and emphasise the dynamic nature of the bilingual lexicon.

Ambiguous words are harder to learn

Relatively little is known about the role of ambiguity in adult second-language learning. In this study, native English speakers learned Dutch–English translation pairs that either mapped in a one-to-one fashion (unambiguous items) in that a Dutch word uniquely corresponded to one English word, or mapped in a one-to-many fashion (ambiguous items), with two Dutch translations corresponding to a single English word. These two Dutch translations could function as exact synonyms, corresponding to a single meaning, or could correspond to different meanings of an ambiguous English word (e.g., wisselgeld denotes the monetary meaning of the word change, and verandering denotes alteration). Several immediate and delayed tests revealed that such translation ambiguity creates a challenge for learners. Furthermore, words with multiple translations corresponding to the same meaning are more difficult to learn than words with multiple translations corresponding to multiple meanings, suggesting that a one-to-many mapping underlies this ambiguity disadvantage.

Are Pumpkins Better than Heaven? An ERP Investigation of Order Effects in the Concrete-Word Advantage.

The present study investigated the cognitive and neural mechanisms underlying the processing of concrete and abstract words by recording event-related potentials (ERPs) while participants performed an English lexical decision task. Concrete and abstract words were presented in three stimulus-order conditions: abstract before concrete, concrete before abstract, and mixed. Beginning between 125 and 175 ms, nonwords elicited significantly more negative responses than real words. Between 300 and 500 ms, concrete words elicited significantly more negative responses than abstract words in the abstract-first and mixed conditions, but not in the concrete-first condition. We discuss our findings in relation to a feature activation framework and conclude that order of presentation provides a context for words that dynamically interacts with activation of a words meaning features, thus allowing word order to modulate the concreteness effect.