Publications

Abstract

Computational models can reflect the complexity of human behaviour by implementing multiple constraints within their architecture, and/or by taking into account the variety and richness of the environment to which the human is responding. We explore the second alternative in a model of word recognition that learns to map spoken words to visual and semantic representations of the words’ concepts. Critically, we employ a phonological representation utilising coarse-coding of the auditory stream, to mimic early stages of language development that are not dependent on individual phonemes to be isolated in the input, which may be a consequence of literacy development. The model was tested at different stages during training, and was able to simulate key behavioural features of word recognition in children: a developing effect of semantic information as a consequence of language learning, and a small but earlier effect of phonological information on word processing. We additionally tested the role of visual information in word processing, generating predictions for behavioural studies, showing that visual information could have a larger effect than semantics on children’s performance, but that again this affects recognition later in word processing than phonological information. The model also provides further predictions for performance of a mature word recognition system in the absence of fine-coding of phonology, such as in adults who have low literacy skills. The model demonstrated that such phonological effects may be reduced but are still evident even when multiple distractors from various modalities are present in the listener’s environment. The model demonstrates that complexity in word recognition can emerge from a simple associative system responding to the interactions between multiple sources of information in the language learner’s environment.

Abstract

Multimodal integration is a central characteristic of human cognition. However our understanding of the interaction between modalities and its influence on behaviour is still in its infancy. This paper examines the value of the Hub & Spoke framework (Plaut, 2002; Rogers et al., 2004; Dilkina et al., 2008; 2010) as a tool for exploring multimodal interaction in cognition. We present a Hub and Spoke model of language–vision information interaction and report the model’s ability to replicate a range of phonological, visual and semantic similarity word-level effects reported in the Visual World Paradigm (Cooper, 1974; Tanenhaus et al, 1995). The model provides an explicit connection between the percepts of language and the distribution of eye gaze and demonstrates the scope of the Hub-and-Spoke architectural framework by modelling new aspects of multimodal cognition.

Abstract

Previous studies show that children do not become adult-like in learning to set the scene and introduce referents in their narrations until 9 years of age and even beyond. However, they investigated spoken languages, thus we do not know much about how these skills are acquired in sign languages, where events are expressed in visually similar ways to the real world events, unlike in spoken languages. The results of the current study demonstrate that deaf children (3;5–9;10 years) acquiring Turkish Sign Language, and hearing children (3;8–9;11 years) acquiring spoken Turkish both acquire scene-setting and referent introduction skills at similar ages. Thus the modality of the language being acquired does not have facilitating or hindering effects in the development of these skills.

Abstract

We investigate how the lexical nature of weak definites influences the phenomenon of direct object scrambling in Dutch. Earlier experiments have indicated that weak definites are more resistant to scrambling than strong definites. We examine how the notion of weak definiteness used in this experimental work can be reduced to lexical connectedness. We explore four different ways of quantifying the relation between a direct object and the verb. Our results show that predictability of a verb given the object (verb cloze probability) provides the best fit to the weak/strong distinction used in the earlier experiments

Abstract

Left dislocation is characterized by a sentence-initial element which is crossreferenced in the remainder of the sentence, and often set off by an intonation break. Because of these properties, left dislocation has been analyzed as an extraclausal phenomenon. Whether or not left dislocation can occur within subordinate clauses has been a matter of debate in the literature, but has never been checked against corpus data. This paper presents data from Avatime, a Kwa (Niger-Congo) language spoken in Ghana, showing that left dislocation occurs within subordinate clauses in spontaneous discourse. This poses a problem for the extraclausal analysis of left dislocation. I show that this problem can best be solved by assuming that Avatime allows the embedding of units larger than a clause

Abstract

The aim of this paper is to discuss the repercussions of a conceptual orientation on two crucial parts of the Role and Reference Grammar (RRG) linking algorithm, that is, semantic representation and constructional schemas. Firstly, it is argued that adopting FunGramKB’s notion of conceptual logical structure (CLS) over standard RRG logical structures (LSs) has numerous advantages since meaning has now access to conceptual knowledge and therefore a CLS provides a format that goes beyond those aspects that are syntactically visible. The second part introduces the notion of the grammaticon, the component where constructional schemas actually reside. RRG constructional schemas are analyzed within a conceptual framework like that provided in FunGramKB. In essence, it is shown that a conceptual orientation to the RRG linking system by the addition of CLSs enriches the semantic representations in it substantially

Abstract

Within the first few years of life, children acquire many of the building blocks of their native language. This not only involves knowledge about the linguistic structure of spoken language, but also knowledge about the way in which this linguistic structure surfaces in their speech input. In this chapter, we review how infants and toddlers cope with differences between speakers and accents. Within the context of milestones in early speech perception, we examine how voice and accent characteristics are integrated during language processing, looking closely at the advantages and disadvantages of speaker and accent familiarity, surface-level deviation between two utterances, variability in the input, and prior speaker exposure. We conclude that although deviation from the child’s standard can complicate speech perception early in life, young listeners can overcome these additional challenges. This suggests that early spoken language processing is flexible and adaptive to the listening situation at hand.

Abstract

The term “event” is a controversial concept, and the “same” activity or situation can be linguistically encoded in many different ways. The aim of this task is to explore features of event representation in the language of study, in particular, multi-verb constructions, event typicality, and event complexity. The task consists of a description and recollection task using film stimuli, and a subsequent re-enactment of certain scenes by other participants on the basis of these descriptions. The first part of the task collects elaborate and concise descriptions of complex events in order to examine how these are segmented into macro-events, what kind of information is expressed, and how the information is ordered. The re-enactment task is designed to examine what features of the scenes are stereotypically implied.

Abstract

This dissertation focuses on syntactic comprehension problems in patients with Broca's aphasia from an electrophysiological perspective. The central objective of this dissertation was to further explore what syntax-related event-related brain potential (ERP) effects can reveal about the nature of the deficit that underlies syntactic comprehension problems in patients with Broca's aphasia. Chapter two to four describe experiments in which event-related brain potentials were recorded while subjects (Broca patients, non-aphasic patients with a right-hemisphere lesion, and healthy elderly controls) were presented with sentences that contained either violations of syntactic constraints or were syntactically correct. Chapter two investigates ERP effects of subject-verb agreement violations in the different subject groups, and seeks to answer the following questions: Do agrammatic comprehenders show sensitivity to subject-verb agreement violations as indicated by a syntax-related ERP effect? In addition, does the severity of the syntactic comprehension impairment in the Broca patients affect the ERP responses? Chapter three describes an investigation of whether Broca patients show sensitivity to violations of word order as indicated by a syntax-related ERP effect, and whether the ERP responses in the Broca patients are affected by the severity of their syntactic comprehension impairment. Chapter four reports on ERP effects of violations of word-category. In addition, also a semantic violation condition was added to track possible dissociations in the sensitivity to semantic and syntactic information in the Broca patients. Chapter five describes the development of a paradigm in which the electrophysiological approach and the classical sentence-picture matching approach are combined. In this chapter, the ERP method is applied to study on-line thematic role assignment in Broca patients during sentence-picture matching. Also the relation between ERP effects and behavioral responses is pursued. Finally, Chapter 6 provides a summary of the main findings of the experiments and a general discussion.

Abstract

When we want to describe a path through space, but do not share a common perceptual field with a conversation partner, language has to work doubly hard. This task investigates how people communicate the navigation of space in the absence of shared visual cues, as well as collecting data on motion verbs and the roles of symmetry and landmarks in route description. Two speakers (separated by a curtain or other barrier) are each given a model of a landscape, and one participant describes standard routes through this landscape for the other to match.

Abstract

The encoding of apparently ‘simple’ movement concepts such as ‘COME’ and ‘GO’ can differ widely across languages (e.g., in regard to specifying direction of motion relative to the speaker). This questionnaire is used to identify the range of use of basic motion verbs in a language, and investigate semantic parameters that are involved in high frequency ‘COME’ and ‘GO’-like terms.