Publications

Abstract

During listening to spoken language, the perceptual system needs to adapt frequently to changes in talkers, and thus to considerable interindividual variability in the articulation of a given speech sound. This thesis investigated a learning process which allows listeners to use stored lexical representations to modify the interpretation of a speech sound when a talker's articulation of that sound is consistently unclear or ambiguous. The questions that were addressed in this research concerned the robustness of such perceptual learning, a potential role for sleep, and whether learning is specific to the speech of one talker or, alternatively, generalises to other talkers. A further study aimed to identify the underlying functional neuroanatomy by using magnetic resonance imaging methods. The picture that emerged for lexically-guided perceptual learning is that learning occurs very rapidly, is highly specific, and remains remarkably robust both over time and under exposure to speech from other talkers.

Abstract

The present doctoral thesis investigates the temporal characteristics of the retrieval of semantic and syntactic word properties in language comprehension. In particular, an attempt is made to assess the retrieval order of semantic category and grammatical gender information, using the lateralized readiness potential and the inhibition-related N2 effect. Chapter 1 contains a general introduction. Chapter 2 reports an experiment that employs the two-choice go/nogo task in combination with EEG recordings to establish the retrieval order of semantic category and grammatical gender for written words presented in isolation. The results point to a time course where semantic information becomes available before syntactic information. Chapter 3 focuses on the retrieval of grammatical gender. In order to examine whether gender retrieval can be speeded up by context, nouns are presented in gender congruent and gender incongruent prime-target pairs and reaction times for gender decisions are measured. For stimulus onset asynchronies of 100 ms and 0 ms, gender congruent pairs show faster responses than incongruent ones, whereas there is no effect of gender congruity for a stimulus onset asynchrony of 300 ms. A simulation with a localist computational model that implements competition between gender representations (WEAVER; Roelofs, 1992) is able to capture these findings. In chapter 4, the gender congruency manipulation is transferred to another ERP experiment with the two-choice go/nogo task. As the time course of gender retrieval is altered through primes, the order relative to semantic category retrieval is assessed again. The results indicate that with gender congruent primes, grammatical gender becomes available before semantic category. Such a reversal of retrieval order, as compared to chapter 2, implies a parallel rather than a serial discrete arrangement of the retrieval processes, since the latter variant precludes changes in retrieval order. Finally, chapter 5 offers a summary and general discussion of the main findings.

Abstract

Sarah Schimke onderzocht hoe mensen die op volwassen leeftijd naar een ander land verhuizen de taal van dit land leren, ook zonder veel taalinstructie te krijgen. Twee groepen werden onderzocht: Turkse immigranten in Frankrijk en Turkse immigranten in Duitsland. De resultaten laten zien dat volwassen leerlingen in het begin van het verwervingsproces een gemakkelijkere variatie van de doeltaal creëren. Er worden wel woorden van de doeltaal verworven en gebruikt, maar er wordt een gesimplificeerde grammatica toegepast. In het bijzonder gebruiken leerlingen in deze fase geen finietheid, dus geen morfologische variaties van werkwoorden. Schimke toont aan dat als finietheid wordt verworven, dit de grammatica van de leerlingen sterk verandert en dat deze veel sterker op de doeltaalgrammatica begint te lijken. Ook toont ze aan dat dit proces door karakteristieken van de doeltaal, zoals de woordvolgorde en de complexiteit van de morfologie, wordt beïnvloed