Publications

Abstract

This chapter describes the challenges that modern digital language archives are faced with. One essential aspect of such an archive is to have a rich metadata catalog such that the archived resources can be easily discovered. The challenge of the archive is to obtain these rich metadata descriptions from the depositors without creating too much overhead for them. The rapid changes in storage technology, file formats and encoding standards make it difficult to build a long-lasting repository, therefore archives need to be set up in such a way that a straightforward and automated migration process to newer technology is possible whenever certain technology becomes obsolete. Other problems arise from the fact that there are many different groups of users of the archive, each of them with their own specific expectations and demands. Often conflicts exist between the requirements for different purposes of the archive, e.g. between long-term preservation of the data versus direct access to the resources via the web. The task of the archive is to come up with a technical solution that works well for most usage scenarios.

Abstract

Natural human interaction involves the fast-paced exchange of speaker turns. Crucially, if a next speaker waited with planning their turn until the current speaker was finished, language production models would predict much longer turn transition times than what we observe. Next speakers must therefore prepare their turn in parallel to listening. Visual signals likely play a role in this process, for example by helping the next speaker to process the ongoing utterance and thus prepare an appropriately-timed response.

To understand how visual signals contribute to the timing of turn-taking, and to move beyond the mostly qualitative studies of gesture in conversation, we examined unconstrained, computer-mediated conversations between 20 pairs of participants while systematically manipulating speaker visibility. Using motion tracking and manual gesture annotation, we assessed 1) how visibility affected the timing of turn transitions, and 2) whether use of co-speech gestures and 3) the communicative kinematic features of these gestures were associated with changes in turn transition timing.

We found that 1) decreased visibility was associated with less tightly timed turn transitions, and 2) the presence of gestures was associated with more tightly timed turn transitions across visibility conditions. Finally, 3) structural and salient kinematics contributed to gesture’s facilitatory effect on turn transition times.

Our findings suggest that speaker visibility--and especially the presence and kinematic form of gestures--during conversation contributes to the temporal coordination of conversational turns in computer-mediated settings. Furthermore, our study demonstrates that it is possible to use naturalistic conversation and still obtain controlled results.

Abstract

Prevoicing is the presence of vocal fold vibration during the closure of initial voiced plosives (negative VOT). The presence or absence of prevoicing is generally used to describe the voicing distinction in Dutch initial plosives. However, a phonetic study showed that prevoicing is frequently absent in Dutch. This article discusses the role of prevoicing in the production and perception of Dutch plosives. Furthermore, two cross-modal priming experiments are presented that examined the effect of prevoicing variation on word recognition. Both experiments showed no difference between primes with 12, 6 or 0 periods of prevoicing, even though a third experiment indicated that listeners could discriminate these words. These results are discussed in light of another priming experiment that did show an effect of the absence of prevoicing, but only when primes had a voiceless word competitor. Phonetic detail appears to influence lexical access only when it helps to distinguish between lexical candidates.

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

Pointing gestures are recognised to be a primary manifestation of human social cognition and communicative capacity. The goal of this task is to collect empirical descriptions of pointing practices in different cultural settings.