<p>Bilingualism and its effect on individuals have been studied within different disciplines. Although the first psychological study of bilingualism was couducted by Cattell as early as 1887, only a few studies have exclusively investigated the effect of bilingualism on memory systems’ functioning. In the field of cognitive psychology of bilingualism, there is some evidence for the positive influence of bilingualism on children’s cognitive ability across various domains but there is little knowledge about the relationship between bilingualism and memory in a lifespan perspective. This thesis’s main aim was to investigate memory systems’ functioning and development in bilingual individuals. To this end, two studies were performed: a cross-sectional study of bilingual children (Study I) and a longitudinal study of young and older adults (Study II). The purpose of Studies I and II was to determine whether there are differences between monolinguals and bilinguals regarding various memory systems’ functioning. Study I compared monolingual and bilingual children’s performance on episodic and semantic memory, and Study II investigated performance on episodic and semantic memory in bilingual younger and older adults. Specifically, these studies aimed to examine a) which memory systems will be affected more as a function of language, and b) to what extent the differences would manifest themselves during a subject’s lifespan. The purpose of Study III was to explain the relation among word representations, lexical access and lexical selection in a bilingual word production paradigm. In this study, a model of bilingual production was developed to explain the results and clarify the role of automatic and controlled processes in using two languages. The results of Studies I and II showed a superiority of bilinguals over monolinguals as well as a variation of association between memory performance and bilingualism across different periods of adulthood. It appears that the lifelong experience of managing two languages enhances control processes, which in turn play an important role in enhancing memory performance. Using a “dual mechanism model”, Study III explains the efficiency of inhibitory processing when having two languages activated.</p>

This report introduces an implemented scheme for generating target- language sentences using a compositional representation of meaning called lexical conceptual structure. Lexical conceptual structure facilitates two crucial operations associated with generation: lexical selection and syntactic realization. The compositional nature of the representation is particularly valuable for these two operations when semantically equivalent source-and-target-language words and phrases are structurally or thematically divergent. To determine the correct lexical items and syntactic realization associated with the surface form in such cases, the underlying lexical-semantic forms are systematically mapped to the target-language syntactic structures. The model described constitutes a lexical-semantic extension to UNITRAN.

Bilingualism and its effect on individuals have been studied within different disciplines. Although the first psychological study of bilingualism was couducted by Cattell as early as 1887, only a few studies have exclusively investigated the effect of bilingualism on memory systems’ functioning. In the field of cognitive psychology of bilingualism, there is some evidence for the positive influence of bilingualism on children’s cognitive ability across various domains but there is little knowledge about the relationship between bilingualism and memory in a lifespan perspective. This thesis’s main aim was to investigate memory systems’ functioning and development in bilingual individuals. To this end, two studies were performed: a cross-sectional study of bilingual children (Study I) and a longitudinal study of young and older adults (Study II). The purpose of Studies I and II was to determine whether there are differences between monolinguals and bilinguals regarding various memory systems’ functioning. Study I compared monolingual and bilingual children’s performance on episodic and semantic memory, and Study II investigated performance on episodic and semantic memory in bilingual younger and older adults. Specifically, these studies aimed to examine a) which memory systems will be affected more as a function of language, and b) to what extent the differences would manifest themselves during a subject’s lifespan. The purpose of Study III was to explain the relation among word representations, lexical access and lexical selection in a bilingual word production paradigm. In this study, a model of bilingual production was developed to explain the results and clarify the role of automatic and controlled processes in using two languages. The results of Studies I and II showed a superiority of bilinguals over monolinguals as well as a variation of association between memory performance and bilingualism across different periods of adulthood. It appears that the lifelong experience of managing two languages enhances control processes, which in turn play an important role in enhancing memory performance. Using a “dual mechanism model”, Study III explains the efficiency of inhibitory processing when having two languages activated.

No description available.

This report describes the organization and content of lexical information required for the task of machine translation. In particular, the lexical-conceptual basis for UNITRAN, an implemented machine translation system, will be described. UNITRAN uses an underlying form called lexical conceptual structure to perform lexical selection and syntactic realization. Lexical word entries have two levels of description: the first is an underlying lexical-semantic representation that is derived from hierarchically organized primitives, and the second is a mapping from this representation to a corresponding syntactic structure. The interaction of these two levels will be discussed and the lexical selection and syntactic realization processes will be described.

Current research in Natural Language Processing (NLP) tends to exploit corpus resources as a way of overcoming the problem of knowledge acquisition. Statistical analysis of corpora can reveal trends and probabilities of occurrence, which have proved to be helpful in various ways. Machine Translation (MT) is no exception to this trend. Many MT researchers have attempted to extract knowledge from parallel bilingual corpora. The MT problem is generally decomposed into two sub-problems: lexical selection and reordering of the selected words. This research addresses the problem of lexical selection of open-class lexical items in the framework of MT. The work reported in this thesis investigates different methodologies to handle this problem, using a corpus-based approach. The current framework can be applied to any language pair, but we focus on Arabic and English. This is because Arabic words are hugely ambiguous and thus pose a challenge for the current task of lexical selection. We use a challenging Arabic-English parallel corpus, containing many long passages with no punctuation marks to denote sentence boundaries. This points to the robustness of the adopted approach. In our attempt to extract lexical equivalents from the parallel corpus we focus on the co-occurrence relations between words. The current framework adopts a lexicon-free approach towards the selection of lexical equivalents. This has the double advantage of investigating the effectiveness of different techniques without being distracted by the properties of the lexicon and at the same time saving much time and effort, since constructing a lexicon is time-consuming and labour-intensive. Thus, we use as little, if any, hand-coded information as possible. The accuracy score could be improved by adding hand-coded information. The point of the work reported here is to see how well one can do without any such manual intervention. With this goal in mind, we carry out a number of preprocessing steps in our framework. First, we build a lexicon-free Part-of-Speech (POS) tagger for Arabic. This POS tagger uses a combination of rule-based, transformation-based learning (TBL) and probabilistic techniques. Similarly, we use a lexicon-free POS tagger for English. We use the two POS taggers to tag the bi-texts. Second, we develop lexicon-free shallow parsers for Arabic and English. The two parsers are then used to label the parallel corpus with dependency relations (DRs) for some critical constructions. Third, we develop stemmers for Arabic and English, adopting the same knowledge -free approach. These preprocessing steps pave the way for the main system (or proposer) whose task is to extract translational equivalents from the parallel corpus. The framework starts with automatically extracting a bilingual lexicon using unsupervised statistical techniques which exploit the notion of co-occurrence patterns in the parallel corpus. We then choose the target word that has the highest frequency of occurrence from among a number of translational candidates in the extracted lexicon in order to aid the selection of the contextually correct translational equivalent. These experiments are carried out on either raw or POS-tagged texts. Having labelled the bi-texts with DRs, we use them to extract a number of translation seeds to start a number of bootstrapping techniques to improve the proposer. These seeds are used as anchor points to resegment the parallel corpus and start the selection process once again. The final F-score for the selection process is 0.701. We have also written an algorithm for detecting ambiguous words in a translation lexicon and obtained a precision score of 0.89.

La production du langage est une activité cognitive longtemps restée étudiée de manière isolée des processus cognitifs plus généraux pouvant sous-tendre sa réalisation. Notre approche a été de contribuer à la dynamique naissante d’une ouverture de la psycholinguistique aux autres domaines de la psychologie cognitive, en spécifiant les interactions qu’entretiennent les mécanismes langagiers avec les mécanismes attentionnels. Pour ce faire, nous avons notamment étudié dans quelle mesure la production d’une information linguistique isolée repose sur des mécanismes de sélection. Conjointement, nous avons tenté de mettre en évidence les mécanismes attentionnels sous-tendant ces mécanismes de sélection lexicale. Les sélections de deux types de mots grammaticaux ont été comparées : les mots de la classe ouverte et les mots de la classe fermée. Les résultats ont révélé que la sélection des deux types de mots, les mots de la classe fermée qui structurent la phrase et les mots de la classe ouverte qui lui donnent un sens, recrutent des ressources attentionnelles. Aussi, nous avons montré que l’effet d’interférence sémantique –supposé affecter un mécanisme de compétition à l’étape de sélection lexicale- peut être résolu avant l’engagement de ressources attentionnelles. Ce résultat suggère que l’effet d’interférence sémantique reflète un mécanisme situé avant la sélection lexicale. Une dernière étude s’est proposé d’explorer la dynamique temporelle de notre système de production à sélectionner plusieurs mots dans un contexte de production de séquences de mots, tel que celui de syntagmes nominaux. Les résultats chronométriques ont révélé que les mots sont sélectionnés de manière strictement séquentielle, une dynamique suggérant que le recrutement de ressources attentionnelles pour la sélection d’une information linguistique isolée peut contraindre leur agencement dans un contexte de production plus naturel. / Language production is a cognitive activity long studied in isolation from more general cognitive processes that could underlie its achievement. Our approach aimed to contribute to the emerging dynamics of the opening of psycholinguistics to other domains of cognitive psychology by specifying how linguistic mechanisms interact with attentional mechanisms. To do so, we first investigated to which extent producing a single linguistic unit relies on selection mechanisms. Also, we highlighted the attentional mechanisms underlying these lexical selection mechanisms: The selections of two types of grammatical words were compared: open- and closed- class words. Results revealed that the selections of both, closed-class words structuring the phrase, and open-class words conveying meaning, require attentional resources. In a third study, we showed that the semantic interference effect - affecting a competition mechanism supposedly taking place at the level of lexical selection- can in fact be resolved before the involvement of central attentional resources. This suggests that this semantic interference effect possibly reflects a mechanism taking place prior to lexical selection. In a last study, we explored the temporal dynamics of our production system when engaged in the selection of several words within a sequence, using noun phrases. Chronometric results revealed that words are selected strictly sequentially. This dynamics suggests that the way attentional resources are recruited for the selection of an isolated linguistic unit can constrain the way several words are produced in a more natural speaking context.

Der Sprechakt teilt sich in zwei Vorgänge: Zunächst muss das richtige Wort aus dem mentalen Lexikon abgerufen werden und anschließend wird es in der Kommunikation verwendet. Zur Erforschung des ersteren Vorgangs werden oft Ein-Personen-Studien verwendet, in denen durch Beobachten der Reaktion auf Stimuli (z. B. Bilder) die Mikrostruktur des lexikalisch- semantischen Systems beleuchtet wird. Für die Anwendung von Sprache in der Kommunikation hingegen nutzt man Partnerexperimente, um die Koordination zwischen den Gesprächspartnern zu beobachten und zu ergründen, wie sich gegenseitiges Verstehen und biografisches Wissen darauf auswirken. Wenig erforscht ist aber, wie ein von einem Gesprächspartner eingebrachter Bedeutungskontext die traditionell in Ein-Personen-Studien untersuchten lexikalisch-semantischen Effekte beeinflusst. Im Rahmen meiner Dissertation möchte ich die Lücke zwischen den beiden Forschungsansätzen schließen, indem ich einen kommunikativen Kontext in etablierte Paradigmen der Bildbenennung integriere. Hierzu betrachte ich zunächst klassische semantische Kontexteffekte, die durch nähere oder entferntere kategorische Relationen zwischen Begriffen hervorgerufen werden (Studie 1), um anschließend lose thematische Beziehungen zu untersuchen, die mit alltäglichen Ereignissen verbunden sind (Studie 2 & Studie 3). Um die hochgradig verflochtenen Ebenen der lexikalischen und semantischen Verarbeitung voneinander zu trennen, habe ich ereigniskorrelierte Hirnpotentiale (ERPs) eingesetzt, um die elektrophysiologischen Signaturen des konzeptuellen Primings und der lexikalischen Auswahl zu verfolgen. Die vorliegende Arbeit liefert sowohl theoretische als auch praktische Beiträge. Erstens stützen unsere Ergebnisse die theoretischen Annahmen, dass sich semantisches Priming und lexikalische Interferenz vorübergehend überschneiden und gemeinsam das Benennungsverhalten in einem Trade-off beeinflussen. Auch die Gegenwart eines Kommunikationspartners kann Auswirkungen auf dieses Zusammenspiel haben. Zweitens ergänzen diese Ergebnisse die aktuelle Literatur zu verschiedenen Arten von semantischen Beziehungen, wie z. B. Nulleffekte für entfernte Beziehungen und Kontexteffekte, die systematisch mit der Stärke der Verwandtschaft zunehmen. Und schließlich bietet unser neuartiges Design eines kommunikativen Kontextes ein praktisches Instrument, um die Lücke zwischen Ein-Personen-Studien und Kommunikationsstudien zu schließen. Alles in allem tragen diese Ergebnisse zu einem besseren Verständnis der neuronalen Mechanismen unseres Sprachproduktionssystems bei, das in der Lage ist, sich flexibel sowohl an sprachliche als auch an soziale Kontexte anzupassen. / Speaking could be divided into two processes: first, the correct word must be retrieved from the mental lexicon, and then it is used in communication. To study the former process, single-person studies are often used, in which the microstructure of the lexical-semantic system is illuminated by observing reaction times to name stimuli (e.g., pictures). For the language use in communication, on the other hand, partner experiments are used to observe coordination between interlocutors and to explore how mutual understanding and biographical knowledge affect it. However, how a meaningful context brought by an interlocutor influences the established lexical-semantic effects from single-person studies remains underexplored. Within the scope of my dissertation, I aim to bridge the gap between these two research approaches by integrating a communicative context into well-established picture naming paradigms. To this end, I first investigate classic semantic context effects induced by close or distant categorical relations (Study 1), and then examine loose thematic relations associated with everyday events (Study 2 & Study 3). To separate the highly intertwined strata of lexical and semantic processing, I used event-related brain potentials (ERPs) to track the electrophysiological signatures of conceptual priming and lexical selection. The present work makes both theoretical and practical contributions. First, our results support the theoretical assumptions that semantic priming and lexical interference temporarily overlap, and jointly modulate naming behavior in a trade-off. Such interplay may be greatly influenced by the presence of a communicating partner. Second, these findings add to the current literature on different types of semantic relations, such as null effects for distant relations and context effects that systematically increase with the strength of relatedness. Finally, our novel design of a communicative context provides a practical tool to bridge the gap between single-person studies and communication studies. All in all, these findings advance our understanding of the neural mechanisms of our speech production system, which is capable of flexibly adapting to both linguistic and social contexts.

Der Prozess der lexikalischen Selektion, d.h. die Auswahl der richtigen Wörter zur Übermittlung einer intendierten Botschaft, ist noch nicht hinreichend verstanden. Insbesondere wurde kaum erforscht, inwiefern Bedeutungsaspekte, welche in sensomotorischen Erfahrungen gründen, diesen Prozess der Sprachproduktion beeinflussen. Die Rolle dieser Bedeutungsaspekte wurde mit zwei Studien untersucht, in denen Probanden Sätze vervollständigten. In Studie 1 wurde der visuelle Eindruck der Satzfragmente manipuliert, so dass die Sätze auf- oder absteigend am Bildschirm erschienen. In Studie 2 mussten die Probanden Kopfbewegungen nach oben oder unten ausführen, während sie die Satzfragmente hörten. Wir untersuchten, ob räumliche Aspekte der produzierten Wörter durch die räumlichen Manipulationen sowie die räumlichen Eigenschaften der präsentierten Satzfragmente beeinflusst werden. Die vertikale visuelle Manipulation in Studie 1 wirkte sich nicht auf die räumlichen Attribute der produzierten Wörter aus. Die Kopfbewegungen in Studie 2 führten zu einem solchen Effekt – bei Kopfbewegungen nach oben waren die Referenten der produzierten Wörter weiter oben im Raum angesiedelt als nach Bewegungen nach unten (und anders herum). Darüber hinaus war dieser Effekt stärker, je ausgeprägter die interozeptive Sensibilität der Probanden war. Zudem beeinflussten die räumlichen Aspekte der Satzfragmente die räumlichen Eigenschaften der produzierten Wörter in beiden Studien. Somit zeigt diese Arbeit, dass in der Erfahrung basierende Bedeutungsanteile, welche entweder in Sprache eingebettet sind oder durch körperliche Aktivität reaktiviert werden, die Auswahl der Wörter beim Sprechen beeinflussen und dass interindividuelle Unterschiede diesen Effekt modulieren. Die Befunde werden in Bezug zu Theorien der Semantik gesetzt. Darüber hinaus wird das Methodenrepertoire erweitert, indem mit Studie 3 ein Ansatz für die Durchführung von Online-Sprachproduktionsexperimenten mit Bildbenennung vorgestellt wird. / The process of lexical selection, i.e. producing the right words to get an intended message across, is not well understood. Specifically, meaning aspects grounded in sensorimotor experiences and their role during lexical selection have not been investigated widely. Here, we investigated the role of experientially grounded meaning aspects with two studies in which participants had to produce a noun to complete sentences which described sceneries. In Study 1, the visual appearance of sentence fragments was manipulated and they seemed to move upwards or downwards on screen. In Study 2, participants moved their head up- or downwards while listening to sentence fragments. We investigated whether the spatial properties of the freely chosen nouns are influenced by the spatial manipulations as well as by the spatial properties of the sentences. The vertical visual manipulation used in Study 1 did not influence the spatial properties of the produced words. However, the body movements in Study 2 influenced participants’ lexical choices, i.e. after up-movements the referents of the produced words were higher up compared to after downward movements (and vice verse). Furthermore, there was an increased effect of movement on the spatial properties of the produced nouns with higher levels of participants’ interoceptive sensibility. Additionally, the spatial properties of the stimulus sentences influenced the spatial properties of the produced words in both studies. Thus, experientially grounded meaning aspects which are either embedded in text or reactivated via bodily manipulations may influence which words we chose when speaking, and interindividual differences may moderate these effects. The findings are related to current theories of semantics. Furthermore, this dissertation enhances the methodological repertoire of language production researchers by showing how language production studies with overt articulation in picture naming tasks can be run online (Study 3).