Akira Omaki

FILLER-GAP DEPENDENCIES AND ISLAND CONSTRAINTS IN SECOND-LANGUAGE SENTENCE PROCESSING

Second-language (L2) sentence processing may differ from processing in a native language in a variety of ways, and it has been argued that one major difference is that L2 learners can only construct shallow representations that lack structural details (e.g., Clahsen & Felser, 2006 ). The present study challenges this hypothesis by comparing the extent to which advanced L1 Spanish-L2 English learners and English native speakers make use of the relative clause island constraint in constructing filler-gap dependencies. In offline acceptability judgment and online self-paced reading experiments that used stimuli adapted from Traxler and Pickering ( 1996 ), both the L2 group and the native-speaker control group demonstrated clear evidence for application of the relative clause island constraint. These findings suggest that advanced L2 learners not only build abstract structural representations but also rapidly constrain the active search for a gap location. These results cast doubt on the proposal that L2 learners are unable to build structural representations with grammatical precision.

Linking Parser Development to Acquisition of Syntactic Knowledge.

Traditionally, acquisition of syntactic knowledge and the development of sentence comprehension behaviors have been treated as separate disciplines. This article reviews a growing body of work on the development of incremental sentence comprehension mechanisms and discusses how a better understanding of the developing parser can shed light on two linking problems that plague language acquisition research. The first linking problem is that children’s behavioral data that are observable to researchers do not provide a transparent window into the developing grammar, as children’s immature linguistic behaviors may reflect the immature parser. The second linking problem is that the input data that researchers investigate may not correspond veridically to the intake data that feed the language acquisition mechanisms, as the developing parser may misanalyze and incorrectly represent the input. Based on reviews of child language comprehension studies that shed light on these two linking problems, it is argued that further research is necessary to closely integrate parser development and acquisition of syntactic knowledge.

No Fear of Commitment: Children's Incremental Interpretation in English and Japanese Wh-Questions.

Much work on child sentence processing has demonstrated that children are able to use various linguistic cues to incrementally resolve temporary syntactic ambiguities, but they fail to use syntactic or interpretability cues that arrive later in the sentence. The present study explores whether children incrementally resolve filler-gap dependencies, using Japanese and English ambiguous wh-questions of the form Where did Lizzie tell someone that she was gonna catch butterflies?, in which one could answer either the telling location (main clause interpretation) or the butterfly-catching location (embedded clause interpretation). Three story-based experiments demonstrate two novel findings on children’s incremental interpretation of filler-gap dependencies. First, we observe that English-speaking adults and children generally prefer the main clause interpretation, whereas Japanese adults and children both prefer the embedded clause interpretation. As the linear order of main clause and embedded clause predicates differs between English (main first, embedded second) and Japanese (embedded first, main second), the results indicate that adults and children actively associate the wh-phrase with the first predicate in the sentence. Second, Japanese children were unable to inhibit their embedded clause interpretation bias when the sentence was manipulated to syntactically block such analyses. The failure to inhibit the preferred interpretation suggests that the wh-phrase was incrementally associated with the embedded clause. On the other hand, when the sentence was manipulated to semantically block a plausible interpretation for the embedded clause wh-association, children were able to overcome their strong embedded clause interpretation bias and favored the main clause interpretation. These findings suggest that syntactic and interpretability cues may have distinct impacts on children’s sentence comprehension processes.

Hyper-active gap filling

Much work has demonstrated that speakers of verb-final languages are able to construct rich syntactic representations in advance of verb information. This may reflect general architectural properties of the language processor, or it may only reflect a language-specific adaptation to the demands of verb-finality. The present study addresses this issue by examining whether speakers of a verb-medial language (English) wait to consult verb transitivity information before constructing filler-gap dependencies, where internal arguments are fronted and hence precede the verb. This configuration makes it possible to investigate whether the parser actively makes representational commitments on the gap position before verb transitivity information becomes available. A key prediction of the view that rich pre-verbal structure building is a general architectural property is that speakers of verb-medial languages should predictively construct dependencies in advance of verb transitivity information, and therefore that disruption should be observed when the verb has intransitive subcategorization frames that are incompatible with the predicted structure. In three reading experiments (self-paced and eye-tracking) that manipulated verb transitivity, we found evidence for reading disruption when the verb was intransitive, although no such reading difficulty was observed when the critical verb was embedded inside a syntactic island structure, which blocks filler-gap dependency completion. These results are consistent with the hypothesis that in English, as in verb-final languages, information from preverbal noun phrases is sufficient to trigger active dependency completion without having access to verb transitivity information.

Reduced left lateralization of language in congenitally blind individuals

Language processing depends on a left-lateralized network of frontotemporal cortical regions. This network is remarkably consistent across individuals and cultures. However, there is also evidence that developmental factors, such as delayed exposure to language, can modify this network. Recently, it has been found that, in congenitally blind individuals, the typical frontotemporal language network expands to include parts of “visual” cortices. Here, we report that blindness is also associated with reduced left lateralization in frontotemporal language areas. We analyzed fMRI data from two samples of congenitally blind adults (n = 19 and n = 13) and one sample of congenitally blind children (n = 20). Laterality indices were computed for sentence comprehension relative to three different control conditions: solving math equations (Experiment 1), a memory task with nonwords (Experiment 2), and a “does this come next?” task with music (Experiment 3). Across experiments and participant samples, the frontotemporal language network was less left-lateralized in congenitally blind than in sighted individuals. Reduction in left lateralization was not related to Braille reading ability or amount of occipital plasticity. Notably, we observed a positive correlation between the lateralization of frontotemporal cortex and that of language-responsive occipital areas in blind individuals. Blind individuals with right-lateralized language responses in frontotemporal cortices also had right-lateralized occipital responses to language. Together, these results reveal a modified neurobiology of language in blindness. Our findings suggest that, despite its usual consistency across people, the neurobiology of language can be modified by nonlinguistic experiences.

Similarity of wh-Phrases and Acceptability Variation in wh-Islands

In wh-questions that form a syntactic dependency between the fronted wh-phrase and its thematic position, acceptability is severely degraded when the dependency crosses another wh-phrase. It is well known that the acceptability degradation in wh-island violation ameliorates in certain contexts, but the source of this variation remains poorly understood. In the syntax literature, an influential theory – Featural Relativized Minimality – has argued that the wh-island effect is modulated exclusively by the distinctness of morpho-syntactic features in the two wh-phrases, but psycholinguistic theories of memory encoding and retrieval mechanisms predict that semantic properties of wh-phrases should also contribute to wh-island amelioration. We report four acceptability judgment experiments that systematically investigate the role of morpho-syntactic and semantic features in wh-island violations. The results indicate that the distribution of wh-island amelioration is best explained by an account that incorporates the distinctness of morpho-syntactic features as well as the semantic denotation of the wh-phrases. We argue that an integration of syntactic theories and perspectives from psycholinguistics can enrich our understanding of acceptability variation in wh-dependencies.

Developmental changes in misinterpretation of garden-path wh-questions in French.

This study explores (mis)interpretation of biclausal wh-questions by French-speaking adults and children, aiming to investigate cross-linguistic differences in sentence revision mechanisms. Following previous work in Japanese the ambiguity of wh-questions was manipulated: In ambiguous questions, the fronted wh-phrase could be associated with the first, main-clause verb or the second, embedded-clause verb, while in garden-path questions, an inserted filled-gap prepositional phrase (PP) blocked main-clause attachment. Importantly, French differs from Japanese in that the filled gap arises after the first verb—that is, after the wh-phrase has been interpreted within the main clause. Two story-based comprehension experiments were conducted to probe the effect of word order on revision performance. Adults and children frequently provided main-clause interpretations of ambiguous questions. In filled-gap questions, children displayed relatively acute sensitivity to the filled-gap in wh-argument questions (Experiment 2), but not in wh-adjunct questions (Experiment 1); adults showed surprisingly low sensitivity to it, frequently misinterpreting adjunct and argument questions. Acceptability ratings (Experiment 3) showed that adults systematically prefer in situ questions over wh-fronting questions. We conclude that timing of the error signal influences revision, and that whereas French-speaking children prioritize syntactic cues, adults prioritize distributional information about the optionality of wh-fronting in French.

Developing incrementality in filler-gap dependency processing

Much work has demonstrated that children are able to use bottom-up linguistic cues to incrementally interpret sentences, but there is little understanding of the extent to which childrens comprehension mechanisms are guided by top-down linguistic information that can be learned from distributional regularities in the input. Using a visual world eye tracking experiment and a corpus analysis, the current study investigates whether 5- and 6-year-old children incrementally assign interpretations to temporarily ambiguous wh-questions like What was Emily eating the cake with __? In the visual world eye-tracking experiment, adults demonstrated evidence for active dependency formation at the earliest region (i.e., the verb region), while 6-year-old children demonstrated a spill-over effect of this bias in the subsequent NP region. No evidence for this bias was found in 5-year-olds, although the speed of arrival at the ultimately correct instrument interpretation appears to be modulated by the vocabulary size. These results suggest that adult-like active formation of filler-gap dependencies begins to emerge around age 6. The corpus analysis of filler-gap dependency structures in adult corpora and child corpora demonstrate that the distributional regularities in either corpora are equally in favor of early, incremental completion of filler-gap dependencies, suggesting that the distributional information in the input is either not relevant to this incremental bias, or that 5-year-old children are somehow unable to recruit this information in real-time comprehension. Taken together, these findings shed light on the origin of the incremental processing bias in filler-gap dependency processing, as well as on the role of language experience and cognitive constraints in the development of incremental sentence processing mechanisms.

Linking learning and parsing in bilingual sentence processing

Cunnings (2016) provides a comprehensive review of recent bilingual sentence processing research, and argues that differences in native and non-native sentence processing behaviors are caused by differences in how native speakers and adult second language (L2) learners use memory retrieval mechanisms. The proposed account provides a wider empirical coverage than Shallow Structure Hypothesis (SSH; Clahsen & Felser, 2006), which states that non-native sentence processing mechanisms struggle to represent or use syntactic details in general. While Cunnings’ proposal is undoubtedly a welcome contribution to the field of bilingual sentence processing, it lost some of the empirical strength and theoretical virtues of SSH. For example, unlike Clahsen and Felser (2006) who report a systematic comparison of child sentence processing and adult bilingual processing, Cunnings’ explanation focuses only on adult bilingual sentence processing behaviors, and, as such, provides little discussion of how the proposal relates to broader issues in language acquisition and psycholinguistics. In this commentary, I will discuss perspectives from recent works that aimed to link parser development and first language (L1) acquisition (Fodor, 1998a, 1998b; Omaki & Lidz, 2015; Phillips & Ehrenhofer, 2015), and highlight their relevance to theoretical implications of Cunnings’ proposal (for related discussions in L2 research, see Dekydtspotter & Renaud, 2014).