Publications

Abstract

We have recently developed a new model of human speech recognition, based on automatic speech recognition techniques [1]. The present paper has two goals. First, we show that the new model performs well in the recognition of lexically ambiguous input. These demonstrations suggest that the model is able to operate in the same optimal way as human listeners. Second, we discuss how to relate the behaviour of a recogniser, designed to discover the optimum path through a word lattice, to data from human listening experiments. We argue that this requires a metric that combines both path-based and word-based measures of recognition performance. The combined metric varies continuously as the input speech signal unfolds over time.

Abstract

In this paper, we present a novel computational model of human speech recognition – called SpeM – based on the theory underlying Shortlist. We will show that SpeM, in combination with an automatic phone recogniser (APR), is able to simulate the human speech recognition process from the acoustic signal to the ultimate recognition of words. This joint model takes an acoustic speech file as input and calculates the activation flows of candidate words on the basis of the degree of fit of the candidate words with the input. Experiments showed that SpeM outperforms Shortlist on the recognition of ‘real-life’ input. Furthermore, SpeM performs only slightly worse than an off-the-shelf full-blown automatic speech recogniser in which all words are equally probable, while it provides a transparent computationally elegant paradigm for modelling word activations in human word recognition.

Abstract

This study investigated the encoding of metrical information during speech production in Dutch. In Experiment 1, participants were asked to judge whether bisyllabic picture names had initial or final stress. Results showed significantly faster decision times for initially stressed targets (e.g., LEpel 'spoon') than for targets with final stress (e.g., liBEL 'dragon fly'; capital letters indicate stressed syllables) and revealed that the monitoring latencies are not a function of the picture naming or object recognition latencies to the same pictures. Experiments 2 and 3 replicated the outcome of the first experiment with bi- and trisyllabic picture names. These results demonstrate that metrical information of words is encoded rightward incrementally during phonological encoding in speech production. The results of these experiments are in line with Levelt's model of phonological encoding.

Abstract

This study investigates whether age and/or hearing loss influence the perception of the emotion dimensions arousal (calm vs. aroused) and valence (positive vs. negative attitude) in conversational speech fragments. Specifically, this study focuses on the relationship between participants' ratings of affective speech and acoustic parameters known to be associated with arousal and valence (mean F0, intensity, and articulation rate). Ten normal-hearing younger and ten older adults with varying hearing loss were tested on two rating tasks. Stimuli consisted of short sentences taken from a corpus of conversational affective speech. In both rating tasks, participants estimated the value of the emotion dimension at hand using a 5-point scale. For arousal, higher intensity was generally associated with higher arousal in both age groups. Compared to younger participants, older participants rated the utterances as less aroused, and showed a smaller effect of intensity on their arousal ratings. For valence, higher mean F0 was associated with more negative ratings in both age groups. Generally, age group differences in rating affective utterances may not relate to age group differences in hearing loss, but rather to other differences between the age groups, as older participants' rating patterns were not associated with their individual hearing loss.

Abstract

The basic idea behind this task is to find out how languages encode basic shape distinctions such as dimensionality, axial geometry, relative size, etc. More specifically, we want to find out (i) which formal means are used cross linguistically to encode basic shape distinctions, and (ii) which are the semantic distinctions that are made in this domain. In languages with many shape-classifiers, these distinctions are encoded (at least partially) in classifiers. In other languages, positional verbs, descriptive modifiers, such as “flat”, “round”, or nouns such as “cube”, “ball”, etc. might be the preferred means. In this context, we also want to investigate what other “grammatical work” shapeencoding expressions possibly do in a given language, e.g. unitization of mass nouns, or anaphoric uses of shape-encoding classifiers, etc. This task further seeks to determine the role of shape-related parameters which underlie the design of objects in the semantics of the system under investigation.

Abstract

This project aims to investigate how speakers of various languages in indigenous cultures verbally reason about moral issues. The ways in which a solution for a moral problem is found, phrased and justified will be taken as the basis for researching reasoning processes that manifest themselves verbally in the speakers’ arguments put forward to solve a number of moral problems which will be presented to them in the form of unfinished story plots or scenarios that ask for a solution. The plots chosen attempt to present common problems in human society and human behaviour. They should function to elicit moral discussion and/or moral arguments in groups of consultants of at least three persons.

Abstract

In this study it is argued that scope, as a property of scope‐creating operators, is a real and important element in the semantico‐grammatical description of languages. The notion of scope is illustrated and, as far as possible, defined. A first idea is given of the ‘grammar of scope’, which defines the relation between scope in the logically structured semantic analysis (SA) of sentences on the one hand and surface structure on the other. Evidence is adduced showing that peripheral preposition phrases (PPPs) in the surface structure of sentences represent scope‐creating operators in SA, and that external datives fall into this category: they are scope‐creating PPPs. It follows that, in English and Dutch, the internal dative (I gave John a book) and the external dative (I gave a book to John) are not simple syntactic variants expressing the same meaning. Instead, internal datives are an integral part of the argument structure of the matrix predicate, whereas external datives represent scope‐creating operators in SA. In the Romance languages, the (non‐pronominal) external dative has been re‐analysed as an argument type dative, but this has not happened in English and Dutch, which have many verbs that only allow for an external dative (e.g. donate, reveal). When both datives are allowed, there are systematic semantic differences, including scope differences.

Abstract

Three experiments examined whether infants recognise functors in phrases, and whether their representations of functors are phonetically well specified. Eight- and 13- month-old English infants heard monosyllabic lexical words preceded by real functors (e.g., the, his) versus nonsense functors (e.g., kuh); the latter were minimally modified segmentally (but not prosodically) from real functors. Lexical words were constant across conditions; thus recognition of functors would appear as longer listening time to sequences with real functors. Eightmonth- olds' listening times to sequences with real versus nonsense functors did not significantly differ, suggesting that they did not recognise real functors, or functor representations lacked phonetic specification. However, 13-month-olds listened significantly longer to sequences with real functors. Thus, somewhere between 8 and 13 months of age infants learn familiar functors and represent them with segmental detail. We propose that accumulated frequency of functors in input in general passes a critical threshold during this time.

Abstract

Size analysis can be an important part of heap consumption analysis. This paper is a part of ongoing work about typing support for checking output-on-input size dependencies for function definitions in a strict functional language. A significant restriction for our earlier results is that inner data structures (e.g. in a list of lists) all must have the same size. Here, we make a big step forwards by overcoming this limitation via the introduction of higher-order size annotations such that variate sizes of inner data structures can be expressed. In this way the analysis becomes applicable for general, polymorphic nested lists.

Abstract

The effect of literacy on phonological processing has been described in terms of a virus that “infects all speech processing” (Frith, 1998). Empirical data has established that literacy leads to changes to the way in which phonological information is processed. Harm & Seidenberg (1999) demonstrated that a connectionist network trained to map between English orthographic and phonological representations display’s more componential phonological processing than a network trained only to stably represent the phonological forms of words. Within this study we use a similar model yet manipulate the transparency of orthographic-to-phonological mappings. We observe that networks trained on a transparent orthography are better at restoring phonetic features and phonemes. However, networks trained on non-transparent orthographies are more likely to restore corrupted phonological segments with legal, coarser linguistic units (e.g. onset, coda). Our study therefore provides an explicit description of how differences in orthographic transparency can lead to varying strains and symptoms of the ‘literacy virus’.

Abstract

When processing language, the cognitive system has access to information from a range of modalities (e.g. auditory, visual) to support language processing. Language mediated visual attention studies have shown sensitivity of the listener to phonological, visual, and semantic similarity when processing a word. In a computational model of language mediated visual attention, that models spoken word processing as the parallel integration of information from phonological, semantic and visual processing streams, we simulate such effects of competition within modalities. Our simulations raised untested predictions about stronger and earlier effects of visual and semantic similarity compared to phonological similarity around the rhyme of the word. Two visual world studies confirmed these predictions. The model and behavioral studies suggest that, during spoken word comprehension, multimodal information can be recruited rapidly to constrain lexical selection to the extent that phonological rhyme information may exert little influence on this process.

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

Developmental studies show that it takes longer for
children learning spoken languages to acquire viewpointdependent
spatial relations (e.g., left-right, front-behind),
compared to ones that are not viewpoint-dependent (e.g.,
in, on, under). The current study investigates how
children learn to express viewpoint-dependent relations
in a sign language where depicted spatial relations can be
communicated in an analogue manner in the space in
front of the body or by using body-anchored signs (e.g.,
tapping the right and left hand/arm to mean left and
right). Our results indicate that the visual-spatial
modality might have a facilitating effect on learning to
express these spatial relations (especially in encoding of
left-right) in a sign language (i.e., Turkish Sign
Language) compared to a spoken language (i.e.,
Turkish).

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

This paper addresses the question how to compare reaction times computed by a computational model of speech comprehension with observed reaction times by participants. The question is based on the observation that reaction time sequences substantially differ per participant, which raises the issue of how exactly the model is to be assessed. Part of the variation in reaction time sequences is caused by the so-called local speed: the current reaction time correlates to some extent with a number of previous reaction times, due to slowly varying variations in attention, fatigue etc. This paper proposes a method, based on time series analysis, to filter the observed reaction times in order to separate the local speed effects. Results show that after such filtering the between-participant correlations increase as well as the average correlation between participant and model increases. The presented technique provides insights into relevant aspects that are to be taken into account when comparing reaction time sequences

Abstract

Tone languages are often reported to make use of utterancelevel intonation as well as of lexical tone. We test the alternative hypotheses that a) the coexistence of lexical tone and utterance-level intonation in tone languages results in a diminished functional load for intonation, and b) that lexical tone and intonation can coexist in tone languages without undermining each other’s functional load in a substantial way. In order to do this, we collected data from two large typological databases, and performed mixed-effects and phylogenetic regression analyses controlling for genealogical and areal factors to estimate the probability of a language exhibiting grammatical devices for encoding polar questions given its status as a tonal or an intonation-only language. Our analyses indicate that, while both tone and intonational languages tend to develop grammatical devices for marking polar questions above chance level, tone languages do this at a significantly higher frequency, with estimated probabilities ranging between 0.88 and .98. This statistical bias provides cross-linguistic empirical support to the view that the use of tonal features to mark lexical contrasts leads to a diminished functional load for utterance-level intonation.

Abstract

We investigate the realization and discrimination of lexical stress contrasts in pitch-unaccented words in phrase-medial position in Spanish, a context in which intonational pitch accents are frequently absent. Results from production and perception experiments show that in this context durational and intensity cues to stress are produced by speakers and used by listeners above chance level. However, due to substantial amounts of phonetic overlap between stress categories in production, and of numerous errors in the identification of stress categories in perception, we suggest that, in the absence of intonational cues, Spanish speakers engaged in online language use must rely on contextual information in order to distinguish stress contrasts.

Abstract

Measuring the quality of metadata is only possible by assessing the quality of the underlying schema and the metadata instance. We propose some factors that are measurable automatically for metadata according to the CMD framework, taking into account the variability of schemas that can be defined in this framework. The factors include among others the number of elements, the (re-)use of reusable components, the number of filled in elements. The resulting score can serve as an indicator of the overall quality of the CMD instance, used for feedback to metadata providers or to provide an overview of the overall quality of metadata within a reposi-tory. The score is independent of specific schemas and generalizable. An overall assessment of harvested metadata is provided in form of statistical summaries and the distribution, based on a corpus of harvested metadata. The score is implemented in XQuery and can be used in tools, editors and repositories

Abstract

This study investigates whether a clear distinction can be made between the prosody of continuation statements and polar questions in conversational French, which are both typically produced with final rising intonation. We show that the two utterance types can be distinguished over chance level by several pitch, duration, and intensity cues. However, given the substantial amount of phonetic overlap and the nature of the observed differences between the two utterance types (i.e. overall F0 scaling, final intensity drop and degree of final lengthening), we propose that variability in the phonetic detail of intonation rises in French is due to the effects of interactional factors (e.g. turn-taking context, type of speech act) rather than to the existence of two distinct rising intonation contour types in this language.

Abstract

This Field Manual entry has been superceded by the published version: Van Staden, M., & Majid, A. (2006). Body colouring task. Language Sciences, 28(2-3), 158-161. doi:10.1016/j.langsci.2005.11.004.

Abstract

We report four experiments in which English and Italian monolinguals detected clicks in continous speech in their native language. Two of the experiments used an off-line location task, and two used an on-line reaction time task. Despite there being large differences between English and Italian with respect to rhythmic characteristics, very similar response patterns were found for the two language groups. It is concluded that the process of click detection operates independently from language-specific differences in perceptual processing at the sublexical level.

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