Publications

Abstract

The current study reports the enhancing effect of a high variability training procedure in the learning of a Japanese geminate-singleton fricative contrast. Dutch natives took part in a five-day training procedure in which they identified geminate and singleton variants of the Japanese fricative /s/. They heard either many repetitions of a limited set of words recorded by a single speaker (simple training) or fewer repetitions of a more variable set of words recorded by multiple speakers (variable training). Pre-post identification evaluations and a transfer test indicated clear benefits of the variable training.

Abstract

The use of word order and intonation to mark focus in child speech has received some attention. However, past work usually examined each device separately or only compared the realizations of focused vs. non-focused constituents. This paper investigates the interaction between word order and intonation in the marking of different focus types in 4- to 5-year old German-speaking children and an adult control group. An answer-reconstruction task was used to elicit syntactic (word order) and intonational focus marking of subject and objects (locus of focus) in three focus types (broad, narrow, and contrastive focus). The results indicate that both children and adults used intonation to distinguish broad from contrastive focus but they differed in the marking of narrow focus. Further, both groups preferred intonation to word order as device for focus marking. But children showed an early sensitivity for the impact of focus type and focus location on word order variation and on phonetic means to mark focus.

Abstract

Previous research on lexically-guided perceptual learning has focussed on contrasts that differ primarily in local cues, such as plosive and fricative contrasts. The present research had two aims: to investigate whether perceptual learning occurs for a contrast with non-local cues, the /l/-/r/ contrast, and to establish whether STRAIGHT can be used to create ambiguous sounds on an /l/-/r/ continuum. Listening experiments showed lexically-guided learning about the /l/-/r/ contrast. Listeners can thus tune in to unusual speech sounds characterised by non-local cues. Moreover, STRAIGHT can be used to create stimuli for perceptual learning experiments, opening up new research possibilities. Index Terms: perceptual learning, morphing, liquids, human word recognition, STRAIGHT.

Abstract

Functional Magnetic Resonance Imaging (fMRI) and Electropencephalography (EEG) are the two techniques that are most often used to study the working brain. With the first technique we use the MRI machine to measure where in the brain the supply of oxygenated blood increases as result of an increased neural activity with a high precision. The temporal resolution of this measure however is limited to a few seconds. With EEG we measure the electrical activity of the brain with millisecond precision by placing electrodes on the skin of the head. We can think of the EEG signal as a signal that consists of multiple superimposed frequencies that vary their strength over time and when performing a cognitive task. Since we measure EEG at the level of the scalp, it is difficult to know where in the brain the signals exactly originate from. For about a decade we are able to measure fMRI and EEG at the same time, which possibly enables us to combine the superior spatial resolution of fMRI with the superior temporal resolution of EEG. To make this possible, we need to understand how the EEG signal is related to the fMRI signal, which is the central theme of this thesis. The main finding in this thesis is that increases in the strength of EEG frequencies below 30 Hz are related to a decrease in the fMRI signal strength, while increases in the strength of frequencies above 40 Hz is related to an increase in the strength of the fMRI signal. Changes in the strength of the low EEG frequencies are however are not coupled to changes in high frequencies. Changes in the strength of low and high EEG frequencies therefore contribute independently to changes in the fMRI signal.

Abstract

We present DiscoGeM, a crowdsourced corpus of 6,505 implicit discourse relations from three genres: political speech,
literature, and encyclopedic texts. Each instance was annotated by 10 crowd workers. Various label aggregation methods
were explored to evaluate how to obtain a label that best captures the meaning inferred by the crowd annotators. The results
show that a significant proportion of discourse relations in DiscoGeM are ambiguous and can express multiple relation senses.
Probability distribution labels better capture these interpretations than single labels. Further, the results emphasize that text
genre crucially affects the distribution of discourse relations, suggesting that genre should be included as a factor in automatic
relation classification. We make available the newly created DiscoGeM corpus, as well as the dataset with all annotator-level
labels. Both the corpus and the dataset can facilitate a multitude of applications and research purposes, for example to
function as training data to improve the performance of automatic discourse relation parsers, as well as facilitate research into
non-connective signals of discourse relations.

Abstract

The present study examined two acoustic cues in the production
of lexical stress in Dutch: spectral tilt and overall intensity.
Sluijter and Van Heuven (1996) reported that spectral tilt is a
more reliable cue to stress than intensity. However, that study
included only a small number of talkers (10) and only syllables
with the vowels /aː/ and /ɔ/.
The present study re-examined this issue in a larger and
more variable dataset. We recorded 38 native speakers of Dutch
(20 females) producing 744 tokens of Dutch segmentally
overlapping words (e.g., VOORnaam vs. voorNAAM, “first
name” vs. “respectable”), targeting 10 different vowels, in
variable sentence contexts. For each syllable, we measured
overall intensity and spectral tilt following Sluijter and Van
Heuven (1996).
Results from Linear Discriminant Analyses showed that,
for the vowel /aː/ alone, spectral tilt showed an advantage over
intensity, as evidenced by higher stressed/unstressed syllable
classification accuracy scores for spectral tilt. However, when
all vowels were included in the analysis, the advantage
disappeared.
These findings confirm that spectral tilt plays a larger role
in signaling stress in Dutch /aː/ but show that, for a larger
sample of Dutch vowels, overall intensity and spectral tilt are
equally important.

Abstract

Op een gemiddelde dag luisteren mensen naar spraak van heel veel verschillende mensen. Die hebben allemaal een ander stemgeluid, waardoor de woorden die zij uitspreken verschillend klinken. Luisteraars hebben daar echter weinig hinder van. Hoe is het mogelijk dat luisteraars zich zo gemakkelijk kunnen aanpassen aan verschillende sprekers? Matthias Sjerps onderzocht in zijn proefschrift een cognitief mechanisme dat luisteraars helpt om zich aan te passen aan de karakteristieken van verschillende sprekers. Hierbij maakt een luisteraar gebruik van informatie in de context. Dit mechanisme blijkt vroeg in de spraakverwerking plaats te vinden. Bovendien beïnvloedt dit mechanisme ook de perceptie van andere geluiden dan spraak. Dit laat zien dat het een zeer breed en algemeen perceptueel mechanisme betreft. Contexteffecten bleken echter sterker voor spraakgeluiden dan voor andere geluiden. Dit suggereert dat het onderzochte mechanisme, ook al is het algemeen en breed toepasbaar, versterkt kan worden door blootstelling aan taal.

Abstract

ELAN is a multimedia annotation tool that has been developed for roughly ten years now and is still being extended and improved in, on average, two or three major updates per year. This paper describes the current state of the application, the main areas of attention of the past few years and the plans for the near future. The emphasis will be on various interoperability issues: interoperability with other tools through file conversions, process based interoperability with other tools by means of commands send to or received from other applications, interoperability on the level of the data model and semantic interoperability.

Abstract

Computational models of reading have differed in terms of whether they propose a single route forming the mapping between orthography and phonology or whether there is a lexical/sublexical route distinction. A critical test of the architecture of the reading system is how it deals with multi-letter graphemes. Rastle and Coltheart (1998) found that the presence of digraphs in nonwords but not in words led to an increase in naming times, suggesting that nonwords were processed via a distinct sequential route to words. In contrast Pagliuca, Monaghan, and McIntosh (2008) implemented a single route model of reading and showed that under conditions of visual noise the presence of digraphs in words did have an effect on naming accuracy. In this study, we investigated whether such digraph effects could be found in both words and nonwords under conditions of visual noise. If so it would suggest that effects on words and nonwords are comparable. A single route connectionist model of reading showed greater accuracy for both words and nonwords containing digraphs. Experimental results showed participants were more accurate in recognising words if they contained digraphs. However contrary to model predictions they were less accurate in recognising nonwords containing digraphs compared to controls. We discuss the challenges faced by both theoretical perspectives in interpreting these findings and in light of a psycholinguistic grain size theory of reading.

Abstract

Mirror mimicry has well-known consequences for the person being mimicked: it increases how positively they feel about the mimicker (the Chameleon Effect). Here we show that anatomical mimicry has the opposite social consequences: a Reverse-Chameleon Effect. To equate mirror and anatomical mimicry, we asked participants to have a face-to-face conversation with a digital human (VIRTUO), in a fully-immersive virtual environment. Participants’ spontaneous head movements were tracked, and VIRTUO mimicked them at a 2-second delay, either mirror-wise, anatomically, or not at all (instead enacting another participant’s movements). Participants who were mimicked mirror-wise rated their social interaction with VIRTUO to be significantly more positive than those who were mimicked anatomically. Participants who were not mimicked gave intermediate ratings. Beyond its practical implications, the Reverse-Chameleon Effect constrains theoretical accounts of how mimicry affects social perception

Abstract

The Language Archive manages one of the largest and most varied sets of natural language data. This data consists of video and audio enriched with annotations. It is available for more than 250 languages, many of which are endangered. Researchers have a need to access this data conveniently and efficiently. We provide several browse and search methods to cover this need, which have been developed and expanded over the years. Metadata and content-oriented search methods can be connected for a more focused search. This article aims to provide a complete overview of the available search mechanisms, with a focus on annotation content search, including a benchmark.

Abstract

Do listeners use lexical stress at an early stage in word learning? Artificial-lexicon studies have shown that listeners can learn new spoken words easily. These studies used non-words differing in consonants and/or vowels, but not differing only in stress. If listeners use stress information in word learning, they should be able to learn new words that differ only in stress (e.g., BInulo-biNUlo). We investigated this issue here. When learning new words, Italian listeners relied on segmental information; they did not take stress information into account. Newly-acquired words differing in stress alone are not automatically represented as different words.

Abstract

This paper presents a method to quantify the spectral characteristics of reduction in speech. Hämäläinen et al. (2009) proposes a measure of spectral reduction which is able to predict a substantial amount of the variation in duration that linguistically motivated variables do not account for. In this paper, we continue studying acoustic reduction in speech by developing a new acoustic measure of reduction, based on local manifold structure in speech. We show that this measure yields significantly improved statistical models for predicting variation in duration.

Abstract

Coordinating with others is hard; and yet we accomplish this every day when we take turns in a conversation. How do we do this? The present study introduces a new method of measuring turn-boundary projection that enables researchers to achieve more valid, flexible, and temporally informative data on online turn projection: tracking an observer’s gaze from the current speaker to the next speaker. In this preliminary investigation, participants consistently looked at the current speaker during their turn. Additionally, they looked to the next speaker before her turn began, and sometimes even before the current speaker finished speaking. This suggests that observer gaze is closely aligned with perceptual processes of turn-boundary projection, and thus may equip the field with the tools to explore how we manage to take turns.

Abstract

Spraakklanken, lettergrepen en woorden worden vaak minder duidelijk uitgesproken in spontane conversaties dan in formelere spreekstijlen. Dit proefschrift presenteert onderzoek naar spraakreductie in spontaan Frans en Spaans. Naar deze talen is tot nu toe weinig spraakreductieonderzoek gedaan. Er worden twee nieuwe grote corpora met spontaan Frans en Spaans beschreven. Op basis van deze corpora heb ik enkele onderzoeken gedaan waarin ik de volgende belangrijke conclusies heb getrokken. Allereerst vond ik dat akoestische data van spontane spraak waardevolle informatie kan geven over de vraag of specifieke reductiefenomenen categoriaal of continu zijn. Verder vond ik, in tegenstelling tot onderzoek naar Germaanse talen, slechts gedeeltelijk bewijs dat spraakreductie in Romaanse talen als het Frans en het Spaans beïnvloed wordt door de eigenschappen en voorspelbaarheid van het woord. Ten derde vond ik door spontaan Frans en Spaans te vergelijken dat spraakreductie tussen talen meer kan verschillen dan je zou verwachten op basis van laboratoriumonderzoek

Abstract

In the AVATecH project the Max-Planck Institute for Psycholinguistics (MPI) and the Fraunhofer institutes HHI and IAIS aim to significantly speed up the process of creating annotations of audio-visual data for humanities research. For this we integrate state-of-theart audio and video pattern recognition algorithms into the widely used ELAN annotation tool. To address the problem of heterogeneous annotation tasks and recordings we provide modular components extended by adaptation and feedback mechanisms to achieve competitive annotation quality within significantly less annotation time. Currently we are designing a large-scale end-user evaluation of the project.

Abstract

Machine learning models of visual action recognition are typically trained and tested on data from specific situations where actions are associated with certain objects. It is an open question how action-object associations in the training set influence a model's ability to generalize beyond trained situations. We set out to identify properties of training data that lead to action recognition models with greater generalization ability. To do this, we take inspiration from a cognitive mechanism called cross-situational learning, which states that human learners extract the meaning of concepts by observing instances of the same concept across different situations. We perform controlled experiments with various types of action-object associations, and identify key properties of action-object co-occurrence in training data that lead to better classifiers. Given that these properties are missing in the datasets that are typically used to train action classifiers in the computer vision literature, our work provides useful insights on how we should best construct datasets for efficiently training for better generalization.

Abstract

Dialects of the same language can differ in the casual speech processes they allow; e.g., British English allows the insertion of [r] at word boundaries in sequences such as saw ice, while American English does not. In two speeded word recognition experiments, American listeners heard such British English sequences; in contrast to non-native listeners, they accurately perceived intended vowel-initial words even with intrusive [r]. Thus despite input mismatches, cross-dialectal word recognition benefits from the full power of native-language processing.

Abstract

prosodic marking of Verum focus (VF) in Italian, which is said to be realized with a pitch accent on the finite verb (e.g. A: Paul has not eaten the banana - B: (No), Paul HAS eaten the banana!). We tried to discover whether and how Italian speakers prosodically mark VF when producing full-fledged sentences using a semi-spontaneous production experiment on 27 speakers. Speech rate and f0 contours were extracted using automatic data processing tools and were subsequently analysed using Functional Data Analysis (FDA), which allowed for automatic visualization of patterns in the contour shapes. Our results show that the postfocal region of VF sentences exhibit faster speech rate and lower f0 compared to non-VF cases. However, an expected consistent difference of f0 effect on the focal region of the VF sentence was not found in this analysis.

Abstract

This research reports the results of eliciting pronouns in two syntactic environments: Object pronouns and quantitative er (Q-er). Thus another type of language is added to the literature on subject and object clitic acquisition in the Romance languages (Jakubowicz et al., 1998; Hamann et al., 1996). Quantitative er is a unique pronoun in the Germanic languages; it has the same distribution as partitive clitics in Romance. Q-er is an N'-anaphor and occurs obligatorily with headless noun phrases with a numeral or weak quantifier. Q-er is licensed only when the context offers an antecedent; it binds an empty position in the NP. Data from typically-developing children aged 5;0-6;0 show that object and Q-er pronouns are not acquired equally; it is proposed that this is due to their different syntax. The use of Q-er involves more sophisticated syntactic knowledge: Q-er occurs at the left edge of the VP and binds an empty position in the NP, whereas object pronouns are simply stand-ins for full NPs and occur in the same position. These Dutch data reveal that pronouns are not used as exclusively as object clitics are in the Romance languages (Varlakosta, in prep.).

Abstract

This paper reports two experiments with vowels and consonants as phoneme detection targets in real words. In the first experiment, two relatively distinct vowels were compared with two confusible stop consonants. Response times to the vowels were longer than to the consonants. Response times correlated negatively with target phoneme length. In the second, two relatively distinct vowels were compared with their corresponding semivowels. This time, the vowels were detected faster than the semivowels. We conclude that response time differences between vowels and stop consonants in this task may reflect differences between phoneme categories in the variability of tokens, both in the acoustic realisation of targets and in the' representation of targets by subjects.

Abstract

People with grapheme-colour synaesthesia experience colour for letters of the alphabet or digits; A can be red and B can be green. How can it be, that people automatically see a colour where only black letters are printed on the paper? With brain scans (fMRI) I showed that (black) letters activate the colour area of the brain (V4) and also a brain area that is important for combining different types of information (SPL). We found that the location where synaesthetes subjectively experience their colours is related to the order in which these brain areas become active. Some synaesthetes see their colour ‘projected onto the letter’, similar to real colour experiences, and in this case colour area V4 becomes active first. If the colours appear like a strong association without a fixed location in space, SPL becomes active first, similar to what happens for normal memories. In a last experiment we showed that in synaesthetes, attention is captured by real colour very strongly, stronger than for control participants. Perhaps this attention effect of colour can explain how letters and colours become coupled in synaesthetes.

Abstract

Marieke van der Linden investigated the neural mechanisms underlying category formation in the human brain. The research in her thesis provides novel insights in how the brain learns, stores, and uses category knowledge, enabling humans to become skilled in categorization. The studies reveal the neural mechanisms through which perceptual as well as conceptual category knowledge is created and shaped by experience. The results clearly show that neuronal sensitivity to object features is affected by categorization training. These findings fill in a missing link between electrophysiological recordings from monkey cortex demonstrating learning-induced sharpening of neuronal selectivity and brain imaging data showing category-specific representations in the human brain. Moreover, she showed that it is specifically the features of an object that are relevant for its categorization that induce selectivity in neuronal populations. Category-learning requires collaboration between many different brain areas. Together these can be seen as the neural correlates of the key points of categorization: discrimination and generalization. The occipitotemporal cortex represents those characteristic features of objects that define its category. The narrowly shape-tuned properties of this area enable fine-grained discrimination of perceptually similar objects. In addition, the superior temporal sulcus forms associations between members or properties (i.e. sound and shape) of a category. This allows the generalization of perceptually different but conceptually similar objects. Last but not least is the prefrontal cortex which is involved in coding behaviourally-relevant category information and thus enables the explicit retrieval of category membership.

Abstract

This thesis investigates the processing of words written in Japanese kanji and Chinese hànzì, i.e. logographic scripts. Special attention is given to the fact that the majority of Japanese kanji have multiple pronunciations (generally depending on the combination a kanji forms with other characters). First, using masked priming, it is established that upon presentation of a Japanese kanji multiple pronunciations are activated. In subsequent experiments using word naming with context pictures it is concluded that both Chinese hànzì and Japanese kanji are read out loud via a direct route from orthography to phonology. However, only Japanese kanji become susceptible to semantic or phonological context effects as a result of a cost due to the processing of multiple pronunciations. Finally, zooming in on the size of the articulatory planning unit in Japanese it is concluded that the mora as a phonological unit best complies with the observed data pattern and not the phoneme or the syllable

Abstract

This paper investigates the effects of novel words on a cognitively plausible computational model of word learning. The model is first familiarized with a set of words, achieving high recognition scores and subsequently offered novel words for training. We show that the model is able to recognize the novel words as different from the previously seen words, based on a measure of novelty that we introduce. We then propose a procedure analogous to novelty preference in infants. Results from simulations of word learning show that adding this procedure to our model speeds up training and helps the model attain higher recognition rates.

Abstract

In this paper an overview of the knowledge components needed for extensive documentation of small languages is given. The Language Archive is striving to offer all these tools to the linguistic community. The major tools in relation to the knowledge components are described. Followed by a discussion on what is currently lacking and possible strategies to move forward.

Abstract

Recent studies using phoneme detection tasks have shown that spoken-language processing is neither facilitated nor interfered with by optional assimilation, but is inhibited by violation of obligatory assimilation. Interpretation of these results depends on an assessment of their generality, specifically, whether they also obtain when listeners are processing nonnative language. Two separate experiments are presented in which native listeners of German and native listeners of Dutch had to detect a target fricative in legal monosyllabic Dutch nonwords. All of the nonwords were correct realisations in standard Dutch. For German listeners, however, half of the nonwords contained phoneme strings which violate the German fricative assimilation rule. Whereas the Dutch listeners showed no significant effects, German listeners detected the target fricative faster when the German fricative assimilation was violated than when no violation occurred. The results might suggest that violation of assimilation rules does not have to make processing more difficult per se.

Abstract

Understanding speech usually seems easy, but it can become noticeably harder when the speaker has a foreign accent. This is because foreign accents add considerable variation to speech. Research on foreign-accented speech shows that participants are able to adapt quickly to this type of variation. Less is known, however, about longer-term maintenance of adaptation. The current study focused on long-term adaptation by exposing native listeners to foreign-accented speech on Day 1, and testing them on comprehension of the accent one day later. Comprehension was thus not tested immediately, but only after a 24 hour period. On Day 1, native Dutch listeners listened to the speech of a Hebrew learner of Dutch while performing a phoneme monitoring task that did not depend on the talker’s accent. In particular, shortening of the long vowel /i/ into /ɪ/ (e.g., lief [li:f], ‘sweet’, pronounced as [lɪf]) was examined. These mispronunciations did not create lexical ambiguities in Dutch. On Day 2, listeners participated in a cross-modal priming task to test their comprehension of the accent. The results will be contrasted with results from an experiment without delayed testing and related to accounts of how listeners maintain adaptation to foreign-accented speech.

Abstract

Foreign-accented speech is often perceived as more difficult to understand than native speech. What causes this potential difficulty, however, remains unknown. In the present study, we compared acoustic similarity and accent ratings of American-accented Dutch with a cross-modal priming task designed to measure online speech processing. We focused on two Dutch diphthongs: ui and ij. Though both diphthongs deviated from standard Dutch to varying degrees and perceptually varied in accent strength, native Dutch listeners recognized words containing the diphthongs easily. Thus, not all foreign-accented speech hinders comprehension, and acoustic similarity and perceived accentedness are not always predictive of processing difficulties.

Abstract

Demonstratives—simple referential devices like this and that—are linguistic universals, but their meaning varies cross-linguistically. In languages like English and Italian, demonstratives are thought to encode the referent’s distance from the producer (e.g., that one means “the one far away from me”),
while in others, like Portuguese and Spanish, they encode relative distance from both producer and receiver (e.g., aquel means “the one far away from both of us”). Here we propose that demonstratives are also sensitive to the receiver’s focus of attention, hence requiring a deeper form of social cognition
than previously thought. We provide initial empirical and computational evidence for this idea, suggesting that producers use
demonstratives to redirect the receiver’s attention towards the intended referent, rather than only to indicate its physical distance.

Abstract

Picture book reading is a common word-learning context from which parents repeatedly name objects to their child and it has been found to facilitate early word learning. To learn the correct word-object mappings in a book-reading context, infants need to be able to link what they see with what they hear. However, given multiple objects on every book page, it is not clear how infants direct their attention to objects named by parents. The aim of the current study is to examine how infants mechanistically discover the correct word-object mappings during book reading in real time. We used head-mounted eye-tracking during parent-infant picture book reading and measured the infant's moment-by-moment visual attention to the named referent. We also examined how gesture cues provided by both the child and the parent may influence infants' attention to the named target. We found that although parents provided many object labels during book reading, infants were not able to attend to the named objects easily. However, their abilities to follow and use gestures to direct the other social partner’s attention increase the chance of looking at the named target during parent naming.