Publications

Displaying 1 - 10 of 10
  • Davidson, D., & Indefrey, P. (2011). Error-related activity and correlates of grammatical plasticity. Frontiers in Psychology, 2: 219. doi:10.3389/fpsyg.2011.00219.

    Abstract

    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.
  • Hanulová, J., Davidson, D. J., & Indefrey, P. (2011). Where does the delay in L2 picture naming come from? Psycholinguistic and neurocognitive evidence on second language word production. Language and Cognitive Processes, 26, 902-934. doi:10.1080/01690965.2010.509946.

    Abstract

    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.
  • Indefrey, P. (2011). Neurobiology of syntax. In P. C. Hogan (Ed.), The Cambridge encyclopedia of the language sciences (pp. 835-838). New York: Cambridge University Press.
  • Indefrey, P. (2011). The spatial and temporal signatures of word production components: a critical update. Frontiers in Psychology, 2(255): 255. doi:10.3389/fpsyg.2011.00255.

    Abstract

    In the first decade of neurocognitive word production research the predominant approach was brain mapping, i.e., investigating the regional cerebral brain activation patterns correlated with word production tasks, such as picture naming and word generation. Indefrey and Levelt (2004) conducted a comprehensive meta-analysis of word production studies that used this approach and combined the resulting spatial information on neural correlates of component processes of word production with information on the time course of word production provided by behavioral and electromagnetic studies. In recent years, neurocognitive word production research has seen a major change toward a hypothesis-testing approach. This approach is characterized by the design of experimental variables modulating single component processes of word production and testing for predicted effects on spatial or temporal neurocognitive signatures of these components. This change was accompanied by the development of a broader spectrum of measurement and analysis techniques. The article reviews the findings of recent studies using the new approach. The time course assumptions of Indefrey and Levelt (2004) have largely been confirmed requiring only minor adaptations. Adaptations of the brain structure/function relationships proposed by Indefrey and Leven (2004) include the precise role of subregions of the left inferior frontal gyrus as well as a probable, yet to date unclear role of the inferior parietal cortex in word production.
  • Van de Meerendonk, N., Indefrey, P., Chwilla, D. J., & Kolk, H. H. (2011). Monitoring in language perception: Electrophysiological and hemodynamic responses to spelling violations. Neuroimage, 54, 2350-2363. doi:10.1016/j.neuroimage.2010.10.022.

    Abstract

    The monitoring theory of language perception proposes that competing representations that are caused by strong expectancy violations can trigger a conflict which elicits reprocessing of the input to check for possible processing errors. This monitoring process is thought to be reflected by the P600 component in the EEG. The present study further investigated this monitoring process by comparing syntactic and spelling violations in an EEG and an fMRI experiment. To assess the effect of conflict strength, misspellings were embedded in sentences that were weakly or strongly predictive of a critical word. In support of the monitoring theory, syntactic and spelling violations elicited similarly distributed P600 effects. Furthermore, the P600 effect was larger to misspellings in the strongly compared to the weakly predictive sentences. The fMRI results showed that both syntactic and spelling violations increased activation in the left inferior frontal gyrus (lIFG), while only the misspellings activated additional areas. Conflict strength did not affect the hemodynamic response to spelling violations. These results extend the idea that the lIFG is involved in implementing cognitive control in the presence of representational conflicts in general to the processing of errors in language perception.
  • Gullberg, M., & Indefrey, P. (Eds.). (2006). The cognitive neuroscience of second language acquisition. Michigan: Blackwell.

    Abstract

    The papers in this volume explore the cognitive neuroscience of second language acquisition from the perspectives of critical/sensitive periods, maturational effects, individual differences, neural regions involved, and processing characteristics. The research methodologies used include functional magnetic resonance imaging (fMRI), positron emission tomography (PET), and event related potentials (ERP). Questions addressed include: Which brain areas are reliably activated in second language processing? Are they the same or different from those activated in first language acquisition and use? What are the behavioral consequences of individual differences among brains? What are the consequences of anatomical and physiological differences, learner proficiency effects, critical/sensitive periods? What role does degeneracy, in which two different neural systems can produce the same behavioral output, play? What does it mean that learners' brains respond to linguistic distinctions that cannot be recognized or produced yet? The studies in this volume provide initial answers to all of these questions.
  • Gullberg, M., & Indefrey, P. (Eds.). (2006). The cognitive neuroscience of second language acquisition [Special Issue]. Language Learning, 56(suppl. 1).
  • Indefrey, P. (2006). A meta-analysis of hemodynamic studies on first and second language processing: Which suggested differences can we trust and what do they mean? Language Learning, 56(suppl. 1), 279-304. doi:10.1111/j.1467-9922.2006.00365.x.

    Abstract

    This article presents the results of a meta-analysis of 30 hemodynamic experiments comparing first language (L1) and second language (L2) processing in a range of tasks. The results suggest that reliably stronger activation during L2 processing is found (a) only for task-specific subgroups of L2 speakers and (b) within some, but not all regions that are also typically activated in native language processing. A tentative interpretation based on the functional roles of frontal and temporal regions is suggested.
  • Indefrey, P., & Gullberg, M. (2006). Introduction. Language Learning, 56(suppl. 1), 1-8. doi:10.1111/j.1467-9922.2006.00352.x.

    Abstract

    This volume is a harvest of articles from the first conference in a series on the cognitive neuroscience of language. The first conference focused on the cognitive neuroscience of second language acquisition (henceforth SLA). It brought together experts from as diverse fields as second language acquisition, bilingualism, cognitive neuroscience, and neuroanatomy. The articles and discussion articles presented here illustrate state-of-the-art findings and represent a wide range of theoretical approaches to classic as well as newer SLA issues. The theoretical themes cover age effects in SLA related to the so-called Critical Period Hypothesis and issues of ultimate attainment and focus both on age effects pertaining to childhood and to aging. Other familiar SLA topics are the effects of proficiency and learning as well as issues concerning the difference between the end product and the process that yields that product, here discussed in terms of convergence and degeneracy. A topic more related to actual usage of a second language once acquired concerns how multilingual speakers control and regulate their two languages.
  • Indefrey, P. (2006). It is time to work toward explicit processing models for native and second language speakers. Journal of Applied Psycholinguistics, 27(1), 66-69. doi:10.1017/S0142716406060103.

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