Edith Kaan

The brain circuitry of syntactic comprehension.

Syntactic comprehension is a fundamental aspect of human language, and has distinct properties from other aspects of language (e.g. semantics). In this article, we aim to identify if there is a specific locus of syntax in the brain by reviewing imaging studies on syntactic processing. We conclude that results from neuroimaging support evidence from neuropsychology that syntactic processing does not recruit one specific area. Instead a network of areas including Brocas area and anterior, middle and superior areas of the temporal lobes is involved. However, none of these areas appears to be syntax specific.

Repair, Revision, and Complexity in Syntactic Analysis: An Electrophysiological Differentiation

One of the core aspects of human sentence processing is the ability to detect errors and to recover from erroneous analysis through revision of ambiguous sentences and repair of ungrammatical sentences. In the present study, we used event-related potentials (ERPs) to help identify the nature of these processes by directly comparing ERPs to complex ambiguous sentence structures with and without grammatical violations, and to simpler unambiguous sentence structures with and without grammatical violations. In ambiguous sentences, preference of syntactic analysis was manipulated such that in one condition, the structures agreed with the preferred analysis, and in another condition, a nonpreferred but syntactically correct analysis (garden path) was imposed. Nonpreferred ambiguous structures require revision, whereas ungrammatical structures require repair. We found that distinct ERPs reflected different characteristics of syntactic processing. Specifically, our results are consistent with the idea that a positivity with a posterior distribution across the scalp (posterior P600) is an index of syntactic processing difficulty, including repair and revision, and that a frontally distributed positivity (frontal P600) is related to ambiguity resolution and/ or to an increase in discourse level complexity.

Investigating the effects of distance and number interference in processing subject-verb dependencies: An ERP study

Event-related potentials (ERPs) were used to investigate whether the processing of subject-verb dependencies is influenced by (1) the linear distance between the subject and the verb and (2) the presence of an intervening noun phrase with interfering number features. Linear distance did not affect integration and diagnosis or revision processes at the verb, as indexed by early negative and P600 components. This is in accordance with hierarchy-based models of reanalysis, but is problematic for distance-based integration models. However, tracking of the subject features is affected by linear factors: more judgment errors were made in the long compared to the short condition. Furthermore, the presence of a plural object between the singular subject and the verb led to more judgment errors, and an enhanced positivity around 250 ms for the grammatical verbs. This suggests that linear factors affect feature tracking, but not integration processes following feature retrieval or repair processes following the detection of a mismatch.

Event-Related Potentials and Language Processing: A Brief Overview

Since the publication of the first papers on event-related brain potentials (ERP) and language in the 1980s, the field of electrophysiology of language has evolved a great deal. This article is a brief overview of ERPs and languageprocessing research. It discusses how ERPs are derived, provides the pros and cons of using ERPs for language-processing research, and gives a summary of the major ERP components relevant to research on speech perception (mismatch negativity), word and sentence comprehension (N400, left anterior negativity, P600), and word production (lateralized readiness potential, N200). Additionally, it addresses current controversies concerning the interpretation of these components. Applications of the ERP technique are illustrated with research on first and second language acquisition, bilingualism, and aphasia.

Effects of native language and training on lexical tone perception: An event-related potential study

Tone languages such as Thai use pitch differences to distinguish lexical meaning. Previous behavioral studies have reported that naïve listeners can discriminate among lexical tones, but that native language background affects performance. The present study uses ERPs to determine whether native speakers of a tone language (Mandarin Chinese) and of a non-tone language (English) differ in their pre-attentive discrimination among Thai lexical tones, and whether training has a different effect in these two language groups. EEGs were obtained from 10 native Mandarin Chinese speakers, 10 English and 10 Thai speakers in an oddball paradigm: The Thai syllable [k(h)a:] pronounced with a high rising or low falling tone, was presented as an infrequent deviant amidst a standard mid level tone [k(h)a:] syllable, while participants watched a silent movie. Next, the Chinese and English participants completed a 2-day perceptual identification training on the mid level and low falling tones, and returned for a post training EEG. The low falling tone deviant elicited a Mismatch Negativity (MMN) in all participant groups before and after training; the high rising deviant elicited no, or a smaller, MMN, which became larger after training only in the English group. The high rising deviant also elicited a later negativity (350-650 ms) versus the mid level standard, which decreased after training in the Chinese group. These results suggest that non-Thai speakers can pre-attentively discriminate among Thai tones, but are sensitive to different physical properties of the tones, depending on their native language. English speakers are more sensitive to early pitch differences, whereas native speakers of Mandarin Chinese are more sensitive to the (later) pitch contour.

Thai lexical tone perception in native speakers of Thai, English and Mandarin Chinese: An event-related potentials training study

BackgroundTone languages such as Thai and Mandarin Chinese use differences in fundamental frequency (F0, pitch) to distinguish lexical meaning. Previous behavioral studies have shown that native speakers of a non-tone language have difficulty discriminating among tone contrasts and are sensitive to different F0 dimensions than speakers of a tone language. The aim of the present ERP study was to investigate the effect of language background and training on the non-attentive processing of lexical tones. EEG was recorded from 12 adult native speakers of Mandarin Chinese, 12 native speakers of American English, and 11 Thai speakers while they were watching a movie and were presented with multiple tokens of low-falling, mid-level and high-rising Thai lexical tones. High-rising or low-falling tokens were presented as deviants among mid-level standard tokens, and vice versa. EEG data and data from a behavioral discrimination task were collected before and after a two-day perceptual categorization training task.ResultsBehavioral discrimination improved after training in both the Chinese and the English groups. Low-falling tone deviants versus standards elicited a mismatch negativity (MMN) in all language groups. Before, but not after training, the English speakers showed a larger MMN compared to the Chinese, even though English speakers performed worst in the behavioral tasks. The MMN was followed by a late negativity, which became smaller with improved discrimination. The High-rising deviants versus standards elicited a late negativity, which was left-lateralized only in the English and Chinese groups.ConclusionResults showed that native speakers of English, Chinese and Thai recruited largely similar mechanisms when non-attentively processing Thai lexical tones. However, native Thai speakers differed from the Chinese and English speakers with respect to the processing of late F0 contour differences (high-rising versus mid-level tones). In addition, native speakers of a non-tone language (English) were initially more sensitive to F0 onset differences (low-falling versus mid-level contrast), which was suppressed as a result of training. This result converges with results from previous behavioral studies and supports the view that attentive as well as non-attentive processing of F0 contrasts is affected by language background, but is malleable even in adult learners.

Effects of musical experience and training on pitch contour perception

Abstract This study examined the effects of musical experience and training on pitch contour perception among speakers of a non-tonal language. Fifteen musicians and fifteen non-musicians from various non-tonal language backgrounds were administered pitch contour categorial discrimination baseline task before and after a two-day pitch contour identification training. Although musicians were relatively more accurate than non-musicians in pitch contour identification, their pitch contour abstraction and categorization ability was comparable to that of non-musicians. Pitch contour identification training improved both pitch contour identification and pitch contour abstraction and categorization abilities to the same degree in musicians and non-musicians. In addition, the advantage of the rising pitch contour over the falling pitch contour was observed in both tasks and among both groups of participants. Together, these results suggest that musical experience sharpened the perception of pitch among musicians, but that the auditory systems of both groups are experience-dependent and comparably malleable.

Gapping: Electrophysiological evidence for immediate processing of "missing" verbs in sentence comprehension.

In the present study we use event related potentials (ERPs) to explore the time course of identification and resolution of verb gaps. ERPs were recorded while participants read sentences that contained a verb gap like Ron took/sanded the planks, and Bill Ø the hammer... Plausibility of the critical words (hammer) that followed the verb gap was manipulated. Relative to the plausible control (preceded by took), ERPs to the critical word in the implausible condition (preceded by sanded) showed an N400, followed by a positivity (P600). ERPs to determiners following gapped verbs showed a negativity between 100 and 300 ms, and a positivity between 300 and 500 ms compared to determiners in non-gapping constructions. These results suggest that the sentence processor recognizes a verb gap and reconstructs the verb information at the earliest possible occasion, and that this reconstruction process is different from the reconstruction of antecedents in other filler-gap constructions (e.g., WH gaps).

Effects of NP Type on the Resolution of Word-Order Ambiguities

Locally ambiguous NP1 NP2 V clauses in Dutch are preferably assigned a subject-object rather than an object-subject interpretation, presumably on the basis of structurally based principles such as the Active-Filler Strategy. The present study investigates whether this preference can be affected by a nonconfigurational factor, namely the nature of NP2. The type of an NP (indefinite NPs, full definite NPs, pronouns) conveys information about the discourse status of the NP referent, which, in turn, is associated with a specific syntactic position. More specifically, pronouns are used to refer to given, salient entities in the discourse (topics); and NPs with such referents are generally encoded in subject position. A self-paced reading experiment shows that NP1 NP2 V relative clauses are preferably interpreted as subject-object when NP2 is a full definite NP (e.g., de vrouwen “the women”), but not when NP2 is the second person pronoun jullie (“you”-PL). This suggests that the structural bias for a subject-first order is not as strong as has been previously assumed, but is influenced by discourse information encoded in the NPs. Implications for parsing models are discussed.

Second Language Processing of Filler‐Gap Dependencies by Late Learners

Recent evidence suggests that late learners of second and foreign languages (L2), those who begin learning after puberty, differ as to how they comprehend complex sentences in real time compared to native speakers and early L2 learners. One area in which these differences occur is in the processing of non-local dependencies where constituents are not canonically ordered, such as in sentences containing wh-dependencies: The teacher saw which girl the boy pushed ___ yesterday. This paper presents a brief overview of current research investigating this issue. To this end, differences and similarities between how L1 and L2 speakers use lexical and syntactic information to resolve these types of dependencies are discussed. In addition, a current model of L2 sentence processing is discussed with suggestions for future research.