Douglas J. Davidson

An inverse relation between event-related and time-frequency violation responses in sentence processing.

The relationship between semantic and grammatical processing in sentence comprehension was investigated by examining event-related potential (ERP) and event-related power changes in response to semantic and grammatical violations. Sentences with semantic, phrase structure, or number violations and matched controls were presented serially (1.25 words/s) to 20 participants while EEG was recorded. Semantic violations were associated with an N400 effect and a theta band increase in power, while grammatical violations were associated with a P600 effect and an alpha/beta band decrease in power. A quartile analysis showed that for both types of violations, larger average violation effects were associated with lower relative amplitudes of oscillatory activity, implying an inverse relation between ERP amplitude and event-related power magnitude change in sentence processing.

Where does the delay in L2 picture naming come from? Psycholinguistic and neurocognitive evidence on second language word production

Bilinguals are slower when naming a picture in their second language than when naming it in their first language. Although the phenomenon has been frequently replicated, it is not known what causes the delay in the second language. In this article we discuss at what processing stages a delay might arise according to current models of bilingual processing and how the available behavioural and neurocognitive evidence relates to these proposals. Suggested plausible mechanisms, such as frequency or interference effects, are compatible with a naming delay arising at different processing stages. Haemodynamic and electrophysiological data seem to point to a postlexical stage but are still too scarce to support a definite conclusion.

Functional Mixed-Effect Models for Electrophysiological Responses

In electro/psychophysiological experiments, linear mixed-effect modeling is an effective statistical technique for data repeatedly observed from the same experimental participants or stimulus items. This review describes the application of mixed-effect modeling to functional responses, in particular those observed in event-related EEG or MEG experiments, using a discrete wavelet transform. The technique is illustrated with a design with several covariates, and procedures for generating posterior samples and computing a Bayesian false discovery rate are described.

Error-related activity and correlates of grammatical plasticity.

Cognitive control involves not only the ability to manage competing task demands, but also the ability to adapt task performance during learning. This study investigated how violation-, response-, and feedback-related electrophysiological (EEG) activity changes over time during language learning. Twenty-two Dutch learners of German classified short prepositional phrases presented serially as text. The phrases were initially presented without feedback during a pre-test phase, and then with feedback in a training phase on two separate days spaced 1 week apart. The stimuli included grammatically correct phrases, as well as grammatical violations of gender and declension. Without feedback, participants’ classification was near chance and did not improve over trials. During training with feedback, behavioral classification improved and violation responses appeared to both types of violation in the form of a P600. Feedback-related negative and positive components were also present from the first day of training. The results show changes in the electrophysiological responses in concert with improving behavioral discrimination, suggesting that the activity is related to grammar learning.

Plasticity of grammatical recursion in German learners of Dutch

Previous studies have examined cross-serial and embedded complement clauses in West Germanic in order to distinguish between different types of working memory models of human sentence processing, as well as different formal language models. Here, adult plasticity in the use of these constructions is investigated by examining the response of German-speaking learners of Dutch using magnetoencephalography (MEG). In three experimental sessions spanning their initial acquisition of Dutch, participants performed a sentence-scene matching task with Dutch sentences including two different verb constituent orders (Dutch verb order, German verb order), and in addition rated similar constructions in a separate rating task. The average planar gradient of the evoked field to the initial verb within the cluster revealed a larger evoked response for the German order relative to the Dutch order between 0.2 to 0.4 s over frontal sensors after 2 weeks, but not initially. The rating data showed that constructions consistent with Dutch grammar, but inconsistent with the German grammar were initially rated as unacceptable, but this preference reversed after 3 months. The behavioural and electrophysiological results suggest that cortical responses to verb order preferences in complement clauses can change within 3 months after the onset of adult language learning, implying that this aspect of grammatical processing remains plastic into adulthood.

Words that second language learners are likely to hear, read, and use

In the present study, we explore whether multiple data sources may be more effective than single sources at predicting the words that language learners are likely to know. Second language researchers have hypothesized that there is a relationship between word frequency and the likelihood that words will be encountered or used by second language learners, but it is not yet clear how this relationship should be effectively measured. An analysis of word frequency measures showed that spoken language frequency alone may predict the occurrence of words in learner textbooks, but that multiple corpora as well as textbook status can improve predictions of learner usage.

Electrophysiological correlates of morphosyntactic integration in German phrasal context

The morphosyntactic paradigm of an inflected word can influence isolated word recognition, but its role in multiple-word phrasal integration is less clear. We examined the electrophysiological response to adjectives in short German prepositional phrases to evaluate whether strong and weak forms of the adjective show a differential response, and whether paradigm variables are related to this response. Twenty native German speakers classified serially presented phrases as grammatically correct or not while the electroencephalogram (EEG) was recorded. A functional mixed effects model of the response to grammatically correct trials revealed a differential response to strong and weak forms of the adjectives. This response difference depended on whether the preceding preposition imposed accusative or dative case. The lexically conditioned information content of the adjectives modulated a later interval of the response. The results indicate that grammatical context modulates the response to morphosyntactic information content, and lends support to the role of paradigm structure in integrative phrasal processing.

Second language acquisition

This article reviews neurocognitive evidence on second language (L2) processing at speech sound, word, and sentence levels. Hemodynamic (functional magnetic resonance imaging and positron emission tomography) data suggest that L2s are implemented in the same brain structures as the native language but with quantitative differences in the strength of activation that are modulated by age of L2 acquisition and L2 proficiency. Electrophysiological data show a more complex pattern of first and L2 similarities and differences, providing some, although not conclusive, evidence for qualitative differences between L1 and L2 syntactic processing.