Syntactic Violations Research Articles

Follow the eyes: gaze and grammaticality

This paper studies the role of eye tracking in detecting grammatical violation in reading tasks. It tests the assumption that encountering syntactic violation has its correspondence in the behavioral patterns associated with gazing. Applying the T-pattern analysis offered by the research environment Theme, it is shown that the observation of grammaticality/agrammaticality in samples of experiments is reflected in the partial correlation of these categories across a number of structural patterns. It is however also shown that their expected difference in the total duration of focusing is not confirmed. It is suggested that associating eye tracking with an additional sound recording or with linguistic ERP studies could widen the categorical spectrum of identifying grammatical violations.

A Functional Magnetic Resonance Imaging Study of Phrase Structure and Subject Island Violations.

In principle, functional neuroimaging provides uniquely informative data in addressing linguistic questions, because it can indicate distinct processes that are not apparent from behavioral data alone. This could involve adjudicating the source of unacceptability via the different patterns of elicited brain responses to different ungrammatical sentence types. However, it is difficult to interpret brain activations to syntactic violations. Such responses could reflect processes that have nothing intrinsically related to linguistic representations, such as domain-general executive function abilities. To facilitate the potential use of functional neuroimaging methods to identify the source of different syntactic violations, we conducted a functional magnetic resonance imaging experiment to identify the brain activation maps associated with two distinct syntactic violation types: phrase structure (created by inverting the order of two adjacent words within a sentence) and subject islands (created by extracting a wh-phrase out of an embedded subject). The comparison of these violations to control sentences surprisingly showed no indication of a generalized violation response, with almost completely divergent activation patterns. Phrase structure violations seemingly activated regions previously implicated in verbal working memory and structural complexity in sentence processing, whereas the subject islands appeared to activate regions previously implicated in conceptual-semantic processing, broadly defined. We review our findings in the context of previous research on syntactic and semantic violations using ERPs. Although our results suggest potentially distinct underlying mechanisms underlying phrase structure and subject island violations, our results are tentative and suggest important methodological considerations for future research in this area.

An fMRI study of phrase structure and subject island violations.

In principle, functional neuroimaging provides uniquely informative data in addressing linguistic questions, because it can indicate distinct processes that are not apparent from behavioral data alone. This could involve adjudicating the source of unacceptability via the different patterns of elicited brain responses to different ungrammatical sentence types. However, it is difficult to interpret brain activations to syntactic violations. Such responses could reflect processes that have nothing intrinsically related to linguistic representations, such as domain-general executive function abilities. In order to facilitate the potential use of functional neuroimaging methods to identify the source of different syntactic violations, we conducted an fMRI experiment to identify the brain activation maps associated with two distinct syntactic violation types: phrase structure (created by inverting the order of two adjacent words within a sentence) and subject islands (created by extracting a wh-phrase out of an embedded subject). The comparison of these violations to control sentences surprisingly showed no indication of a generalized violation response, with almost completely divergent activation patterns. Phrase structure violations seemingly activated regions previously implicated in verbal working memory and structural complexity in sentence processing, whereas the subject islands appeared to activate regions previously implicated in conceptual-semantic processing, broadly defined. We review our findings in the context of previous research on syntactic and semantic violations using event-related potentials. Although our results suggest potentially distinct underlying mechanisms underlying phrase structure and subject island violations, our results are tentative and suggest important methodological considerations for future research in this area.

N400 or P600?—A Systematic Review of ERP Studies on Gender Stereotype Violations

ABSTRACTPsycholinguistic studies using the event‐related brain potential (ERP) technique have found both N400 and P600 effects for gender stereotype violations. The finding of a P600 effect for this type of world knowledge violation is surprizing given that this component is traditionally associated with syntactic violations. In this paper, we set out to systematically analyse design‐ and task patterns of ERP studies investigating gender stereotype violations. Based on our review, we propose a scheme that predicts a P600 effect for gender stereotype violations for stimuli comprising entire sentences, and specifically when the gender stereotype serves to establish coherence in inferences (i.e., expecting a specific referent gender or a stereotype‐appropriate behaviour of the sentence subject based on the gender stereotype information). We predict an N400 effect for gender stereotype information that does not serve to establish coherence in inferences, as well as in priming paradigms. By extension, our predictive scheme suggests that the N400 may reflect a hybrid process of semantic retrieval and integration, while the P600 may reflect a cognitive process of error monitoring, and mental revision. Our study can aid in the interpretation of previous findings and inform future studies investigating gender stereotyping.

Processing of Counterfactual Conditional Sentences with Differential Propositional Truth-Value in Mandarin Chinese: Evidence from ERP

Although many studies document the role of propositional truth-value in human psychological reading behavior, there is a relative paucity of research examining the role of differential propositional truth-value in processing Chinese counterfactual conditionals. This study is to investigate the role of differential propositional value in processing Chinese counterfactual conditionals by means of ERPs (event-related potentials). The study is based on comprehending two types of Chinese counterfactual conditionals, which is propositional truth value introduced by two different markers of conditional conjunctions in the protasis and apodosis, such as true counterfactual conditional markers jiaru (if) & jiu (so) in the sentence wo xiang yu jiaru you tui jiu keyi zai shuixia zhixi (I think if fish had legs so they could stifle under water), and false counterfactual conditional markers ruguo (if) & namo (then) in the sentence wo xiang gou ruguo you lin namo keyi zai shuixia huxi (I think if dogs had scales, then they could breathe under water). Two counterfactual propositional values (i.e. true and false propositional values) are constructed through manipulating sentence counterfactuality between the true and false counterfactual conditional markers in the protasis and the apodosis. Twenty-four full-time Chinese college students participated in the ERP study. The results demonstrated that processing the true counterfactual propositional sentences with conditional markers jiaru (if) & jiu (so) elicited the N400 effect relative to false propositional sentences with conditional markers ruguo (if) & namo (then). Moreover, the counterfactual sentences with true propositional conditions varied from the elicitation of the N400 effect in the protasis and absence of the N400 effect in the apodosis, showing that semantic roles may gradually disappear under the impact of truth value of propositional counterfactual condition, and/or the roles of semantic anomaly was eliminated in the accumulated sentence processing. While for the false counterfactual conditional sentences, elicitations of P300 in the protasis and robust N400 effect in the apodosis were shown, indicating the increasing semantic role in the processing. Interestingly, there was the absence of the P600 effect for processing sentences with syntactic violation, suggesting little extra syntactic cost in processing sentences with false propositional condition.

Syntactic and emotional interplay in second language: emotional resonance but not proficiency modulates affective influences on L2 syntactic processing

ABSTRACT Previous research has demonstrated the influence of emotions during linguistic processing, indicating the interactivity of both processes in the brain. However, little is known regarding such interplay in a second language (L2). This study addressed this question by examining the reading effects of syntactic violations while processing L2 emotional and neutral statements. Forty-six Spanish-English bilinguals with various levels of L2 proficiency and emotional resonance (i.e. capability for emotional experience in L2) were presented with a self-paced sentence reading task. Sentences contained positive (16), neutral (16) and negative (16) verbs, half of them presented in agreement and half in disagreement with the preceding pronoun. Analysis of verb reading times using linear mixed effects modelling revealed a significant interaction between syntactic violation, verb valence and emotional resonance, suggesting that stronger emotional L2 experience results in a higher saliency of negative verbs, reducing the impact of syntactic violations.

Lesion-symptom Mapping of Acceptability Judgments in Chronic Poststroke Aphasia Reveals the Neurobiological Underpinnings of Receptive Syntax.

Disagreements persist regarding the neural basis of syntactic processing, which has been linked both to inferior frontal and posterior temporal regions of the brain. One focal point of the debate concerns the role of inferior frontal areas in receptive syntactic ability, which is mostly assessed using sentence comprehension involving complex syntactic structures, a task that is potentially confounded with working memory. Syntactic acceptability judgments may provide a better measure of receptive syntax by reducing the need to use high working memory load and complex sentences and by enabling assessment of various types of syntactic violations. We therefore tested the perception of grammatical violations by people with poststroke aphasia (n = 25), along with matched controls (n = 16), using English sentences involving errors in word order, agreement, or subcategorization. Lesion data were also collected. Control participants performed near ceiling in accuracy with higher discriminability of agreement and subcategorization violations than word order; aphasia participants were less able to discriminate violations, but, on average, paralleled control participants discriminability of types of violations. Lesion-symptom mapping showed a correlation between discriminability and posterior temporal regions, but not inferior frontal regions. We argue that these results diverge from models holding that frontal areas are amodal core regions in syntactic structure building and favor models that posit a core hierarchical system in posterior temporal regions.

The left posterior sMMN: a marker of syntactic processing compensation in agrammatic aphasia

ABSTRACT Background Agrammatic aphasia poses challenges in assessing grammatical abilities due to language comprehension difficulties. The suitability of sMMN as an indicator of syntactic processing abilities in these individuals remains uncertain. Aims Two ERP experiments were conducted to investigate whether early syntactic mismatch negativity (sMMN) could assess the syntactic processing ability of Chinese-speaking individuals with agrammatic aphasia. Methods & Procedures Prior to the ERP experiments, the Western Aphasia Battery (WAB) and the Northwestern Assessment of Verbs and Sentences-Chinese (NAVS-C) were used to screen people with agrammatism. ERP data were collected for both the agrammatic group (AG) (n = 12) and the control group (CG) (n = 12). The first experiment (Experiment 1) involved a passive tone oddball task to control for the influence of primary sound perception. The second experiment (Experiment 2: experiment 2a and experiment 2b) investigated syntactic processing through a passive speech oddball task. Experiment 2a examined the processing of correct sentences and syntactic violation sentences in context. In contrast, Experiment 2b assessed well-formed sequences and ill-formed sequences out of context. Outcomes & Results The results revealed that frontocentral distributed acoustic MMNs were recorded for the CG between 176 - 196ms in Experiment 1, but not for the AG. In Experiment 2, during the 143 - 173ms window, the left anterior sMMN was exclusively observed for the CG, while the left posterior sMMN was specific to the AG. Furthermore, the amplitudes of the left posterior sMMN (143-173ms) were found to have a negative correlation with scores on sentence comprehension tests: the more negative the sMMN, the lower the scores of people with agrammatic aphasia. Notably, this left posterior MMN was absent in Experiment 1. Conclusions The early posterior sMMN, discovered for the first time in our study, appears to be more sensitive in detecting syntactic processing impairments in agrammatics compared to the early anterior sMMN. This finding has the potential to enhance the precision of aphasia assessment.

Time-travel to “A review and proposal for a model of sensory predictability in auditory language perception”

Since its inception 60 years ago, the mission of Cortex has been to foster a better understanding of cognition and the relationship between the nervous system, behavior in general, and mental processes in particular. Almost 15 years ago, we submitted “a review and proposal” along these lines to the journal, in which we sought to integrate two components that are not often discussed together, namely the basal ganglia and syntactic language functions (Kotz et al., 2009). One of the main motivations was to find potential explanations for two relatively straightforward earlier empirical observations: (i) electroencephalographic event-related potential responses (EEG/ERPs) known to be sensitive markers of syntactic violations in auditory language processing were found to be absent in persons with focal basal ganglia lesions (Friederici et al., 1999; Frisch et al., 2003; Kotz et al., 2003), and (ii) temporally regular rhythmic tone sequences presented before language stimuli were found to compensate for this effect (Kotz et al., 2005; Kotz & Gunter, 2015; Kotz & Schmidt-Kassow, 2015). The critical question was how to reconcile these specific components, the basal ganglia typically associated with motor behavior and language-related syntactic processes, under one hood to foster a better understanding of how the basal ganglia system contributes to auditory language processing. This core question was the starting point for further own research and trying to solve it, unsurprisingly, led to many more questions and rather few answers. It also changed perspectives and established collaborative efforts, sometimes in unsuspected ways and directions. In light of the journal’s anniversary, we therefore want to take this exciting opportunity for some time travel, looking back at our original conception while linking it to more recent considerations, thereby providing some insights that might be useful for future research.

Functional priority of syntax over semantics in Chinese ‘ba’ construction: evidence from eye-tracking during natural reading

AbstractStudies on sentence processing in inflectional languages support that syntactic structure building functionally precedes semantic processing. Conversely, most EEG studies of Chinese sentence processing do not support the priority of syntax. One possible explanation is that the Chinese language lacks morphological inflections. Another explanation may be that the presentation of separate sentence components on individual screens in EEG studies disrupts syntactic framework construction during sentence reading. The present study investigated this explanation using a self-paced reading experiment mimicking rapid serial visual presentation in EEG studies and an eye-tracking experiment reflecting natural reading. In both experiments, Chinese ‘ba’ sentences were presented to Chinese young adults in four conditions that differed across the dimensions of syntactic and semantic congruency. Evidence supporting the functional priority of syntax over semantics was limited to only the natural reading context, in which syntactic violations blocked the processing of semantics. Additionally, we observed a later stage of integrating plausible semantics with a failed syntax. Together, our findings extend the functional priority of syntax to the Chinese language and highlight the importance of adopting more ecologically valid methods when investigating sentence reading.

Attention and schema violations of real world scenes differentially modulate time perception

In the real world, object arrangement follows a number of rules. Some of the rules pertain to the spatial relations between objects and scenes (i.e., syntactic rules) and others about the contextual relations (i.e., semantic rules). Research has shown that violation of semantic rules influences interval timing with the duration of scenes containing such violations to be overestimated as compared to scenes with no violations. However, no study has yet investigated whether both semantic and syntactic violations can affect timing in the same way. Furthermore, it is unclear whether the effect of scene violations on timing is due to attentional or other cognitive accounts. Using an oddball paradigm and real-world scenes with or without semantic and syntactic violations, we conducted two experiments on whether time dilation will be obtained in the presence of any type of scene violation and the role of attention in any such effect. Our results from Experiment 1 showed that time dilation indeed occurred in the presence of syntactic violations, while time compression was observed for semantic violations. In Experiment 2, we further investigated whether these estimations were driven by attentional accounts, by utilizing a contrast manipulation of the target objects. The results showed that an increased contrast led to duration overestimation for both semantic and syntactic oddballs. Together, our results indicate that scene violations differentially affect timing due to violation processing differences and, moreover, their effect on timing seems to be sensitive to attentional manipulations such as target contrast.

ERROR-FREE 2D PICTOGRAMMIC SYNTAX IN A PROGRAMMING LEARNING ENVIRONMENT FOR PRESCHOOL CHILDREN

When mastering the basics of programming by preschoolers, serious difficulties are created by the need to diagnose and correct syntactic errors. With the traditional method of “on-screen” program editing, these difficulties can be avoided by blocking the child’s actions that lead to syntactic violations. Today, the technique of compiling programs from material objects (tangible objects) with command icons printed on them is gaining popularity. When using this technique, no blocking of user actions is possible. In this situation, the authors propose to protect the child from syntactical errors by postulating the two-dimensionality of the program and defining the syntax and semantics of the pictogram programming language for beginners using indentation so that any placement of pictograms in the cells of a two-dimensional table gives a syntactically correct and executable program. This approach has been implemented and tested in the domestic educational environment “PictoMir” of pictogram programming for preschoolers.

An electrophysiological exploration of modifiers embedded in different hierarchies: Insight from short passives in Mandarin

This event-related potentials study explored the processing of Mandarin short passives. We used a syntactic violation paradigm to compare the processing of two auxiliary phrases (i.e., a verb-modifier di-phrase and a noun-modifier de-phrase). In the control condition, the syntactic hierarchy of the di-phrase was lower than that of the de-phrase. In the violation condition, the low-level violation was created by replacing di with de in the auxiliary phrase, while the high-level violation was created by replacing de with di in the auxiliary phrase. The ERP data showed that the noun-modifier elicited the greater left anterior negativity (LAN) and the P600 than the verb-modifier, in both the control condition and the violation condition. We also observed that the LAN induced by the verb-modifier phrase was greater in the control condition than that in the violation condition, while the LAN induced by the noun-modifier was greater in the violation condition than that in the control condition. These results suggested that the greater cortical LAN-P600 might differentiate the high-level hierarchy from the low-level hierarchy. In addition, we tentatively claimed that given the same predicate argument structure, long passives might be the default representational mode of short passives (generally, a constructional alternation might be activated during the processing of the target structure).

Context effects in language comprehension: The role of emotional state and attention on semantic and syntactic processing.

Semantics and syntax are core components of language. The prevailing view was that processing of word meaning and syntactic processing happens in isolation from other systems. In light of proofed interactions between language and other systems, especially with perception, action and emotion, this view became untenable. This article reviews Event-related potential studies conducted at the Donders Centre for Cognition exploring the interplay between language comprehension and a person's emotional state. The research program was aimed at an investigation of the online effects of emotional state on semantic processing and syntactic processing. To this aim we manipulated mood via film fragments (happy vs. sad) before participants read neutral sentences while their EEG was recorded. In Part 1, it is shown that mood impacts online semantic processing (as indicated by N400) and the processing of syntactic violations (as indicated by P600). Part 2 was directed at a further determination of the mechanisms underlying these interactions. The role of heuristics was examined by investigating the effects of mood on the P600 to semantic reversals. The results revealed that mood affects heuristic processing. The next step consisted of an assessment of the role of attention, in the mood-by-semantics and mood-by-syntax interaction. This was accomplished by recording EEG while manipulating attention via task next to emotional state. Participants performed a semantic or syntactic judgment task vs. a letter-size judgment task. The main ERP results were as follows: (i) attention interacts with the mood effect on semantic processing and syntactic processing, respectively, (ii) the effects of mood on semantic processing and syntactic processing are reliable, and (iii) the mood effects on semantic processing are not fixed but context-dependent. In Part 3 the effects of mood on the processing of script knowledge and general world knowledge are presented. Part 4 closes with a discussion of the mechanisms involved in the mood-by-language interactions and recommendations for future research. Regarding the underlying mechanism we propose that heuristics based on semantic expectancies or syntactic expectancies play a key role in the mood-by-language interactions. The results support the view that language takes place in continuous interaction with other (non-language) systems.

Do we parse the background into separate streams in the cocktail party?

In the cocktail party situation, people with normal hearing usually follow a single speaker among multiple concurrent ones. However, there is no agreement in the literature as to whether the background is segregated into multiple streams/speakers. The current study varied the number of concurrent speech streams and investigated target detection and memory for the contents of a target stream as well as the processing of distractors. A male-voiced target stream was either presented alone (single-speech), together with one male-voiced distractor (one-distractor), or a male- and a female-voiced distractor (two-distractor). Behavioral measures of target detection and content tracking performance as well as target- and distractor detection related event-related brain potentials (ERPs) were assessed. We found that the N2 amplitude decreased whereas the P3 amplitude increased from the single-speech to the concurrent speech streams conditions. Importantly, the behavioral effect of distractors differed between the conditions with one vs. two distractor speech streams and the non-zero voltages in the N2 time window for distractor numerals and in the P3 time window for syntactic violations appearing in the non-target speech stream significantly differed between the one- and two-distractor conditions for the same (male) speaker. These results support the notion that the two background speech streams are segregated, as they show that distractors and syntactic violations appearing in the non-target streams are processed even when two speech non-target speech streams are delivered together with the target stream.

Phonotactics and syntax: investigating functional specialisation during structured sequence processing

ABSTRACT Frontal lobe organisation displays a functional gradient, with overarching processing goals located in parts anterior to more subordinate goals, processed more posteriorly. Functional specialisation for syntax and phonology within language relevant areas has been supported by meta-analyses and reviews, but never directly tested experimentally. We tested for organised functional specialisation by manipulating syntactic case and phonotactics, creating violations at the end of otherwise matched and predictable sentences. Both violations led to increased activation in expected language regions. We observe the clearest signs of a functional gradient for language processing in the medial frontal cortex, where syntactic violations activated a more anterior portion compared to the phonotactic violations. A large overlap of syntactic and phonotactic processing in the left inferior frontal gyrus (LIFG) supports the view that general structured sequence processes are located in this area. These findings are relevant for understanding how sentence processing is implemented in hierarchically organised processing steps in the frontal lobe.

Music reading experience modulates eye movement pattern in English reading but not in Chinese reading

Here we tested the hypothesis that in Chinese-English bilinguals, music reading experience may modulate eye movement planning in reading English but not Chinese sentences due to the similarity in perceptual demands on processing sequential symbol strings separated by spaces between music notation and English sentence reading. Chinese–English bilingual musicians and non-musicians read legal, semantically incorrect, and syntactically (and semantically) incorrect sentences in both English and Chinese. In English reading, musicians showed more dispersed eye movement patterns in reading syntactically incorrect sentences than legal sentences, whereas non-musicians did not. This effect was not observed in Chinese reading. Musicians also had shorter saccade lengths when viewing syntactically incorrect than correct musical notations and sentences in an unfamiliar alphabetic language (Tibetan), whereas non-musicians did not. Thus, musicians’ eye movement planning was disturbed by syntactic violations in both music and English reading but not in Chinese reading, and this effect was generalized to an unfamiliar alphabetic language. These results suggested that music reading experience may modulate perceptual processes in reading differentially in bilinguals’ two languages, depending on their processing similarities.

Musical and linguistic syntactic processing in agrammatic aphasia: An ERP study.

Language and music rely on complex sequences organized according to syntactic principles that are implicitly understood by enculturated listeners. Across both domains, syntactic processing involves predicting and integrating incoming elements into higher-order structures. According to the Shared Syntactic Integration Resource Hypothesis (SSIRH; Patel, 2003), musical and linguistic syntactic processing rely on shared resources for integrating incoming elements (e.g., chords, words) into unfolding sequences. One prediction of the SSIRH is that people with agrammatic aphasia (whose deficits are due to syntactic integration problems) should present with deficits in processing musical syntax. We report the first neural study to test this prediction: event-related potentials (ERPs) were measured in response to musical and linguistic syntactic violations in a group of people with agrammatic aphasia (n=7) compared to a group of healthy controls (n=14) using an acceptability judgement task. The groups were matched with respect to age, education, and extent of musical training. Violations were based on morpho-syntactic relations in sentences and harmonic relations in chord sequences. Both groups presented with a significant P600 response to syntactic violations across both domains. The aphasic participants presented with a reduced-amplitude posterior P600 compared to the healthy adults in response to linguistic, but not musical, violations. Participants with aphasia did however present with larger frontal positivities in response to violations in both domains. Intriguingly, extent of musical training was associated with larger posterior P600 responses to syntactic violations of language and music in both groups. Overall, these findings are not consistent with the predictions of the SSIRH, and instead suggest that linguistic, but not musical, syntactic processing may be selectively impaired in stroke-induced agrammatic aphasia. However, the findings also suggest a relationship between musical training and linguistic syntactic processing, which may have clinical implications for people with aphasia, and motivates more research on the relationship between these two domains.

Aesthetic Reactions to Violations in Contemporary Art: The Role of Expertise and Individual Differences

ABSTRACT This study investigated the role of expertise and personality in reactions to challenges in contemporary paintings, here operationalized as violations in syntax and semantics. Thirty-eight expert and 56 naïve art viewers appraised 20 paintings (divided into four groups, i.e. no violation, only syntactic or semantic violation, and both semantic-syntactic violations) on scales of valence, activation, sense-making, understanding and appreciation. Viewing time was also recorded and participants filled in questionnaires measuring the Big Five model of personality and Need for Closure. Separate mixed linear models were fit for each outcome variable (rating scales and viewing time) with the type of violations, expertise and personality measures as predictors. It was found that syntactically violated paintings predicted best viewers’ reaction to art. Such paintings were viewed longer and evoked reactions modulated by individual differences and expertise. Expertise was found to be a positive predictor of understanding and appreciation of paintings with syntactic violations. Conversely, need for closure turned out to be a negative predictor of sense-making, understanding, and liking those types of art. Similarly, people high in neuroticism liked syntactically violated artworks less. Only openness to experience turned out to be a positive predictor of sense-making and activation in all types of stimuli. The results are discussed in terms of elevated challenge, which syntactically violated paintings present, and different strategies of viewers to cope with this.

L2 processing of filled gaps

Abstract This paper investigates how late L2 learners resolve filler-gap dependencies (FGD) in real-time and how proficiency and working memory (WM) modulate their brain responses in an event-related potential (ERP) experiment. A group of intermediate to highly proficient Mandarin Chinese learners of English listened to sentences such as “The zebra that the hippo kissed *the camel on the nose ran far away,” in which the extra noun phrase “the camel” created a ‘filled-gap’ effect. The results show that although L2 behavioral responses are comparable to native speakers and are positively correlated with proficiency and WM span, the brain responses to the filled gap are qualitatively different. Importantly, L2 processing patterns did not become more nativelike with higher proficiency levels or greater WM capacity. Specifically, while the native speakers exhibited a P600 typically observed for syntactic violations and repair, the L2 group produced a prefrontal-central positivity. Similar ERPs have previously been reported to reflect domain-general attentional and non-structural-based processes, suggesting that the L2 group has a reduced sensitivity to structural requirements for gap positing in the online resolution of FGDs. Our findings are discussed in light of various proposals accounting for L1-L2 processing differences, including the Shallow Structure Hypothesis.