Publications

Abstract

In this paper we investigate acoustic differences between vowels in syllables that do or do not carry lexical stress. In doing so, we concentrated on segmental acoustic phonetic features that are conventionally assumed to differ between stressed and unstressed syllables, viz. Duration, Energy and Spectral Tilt. The speech material in this study differs from the type of material used in previous research: instead of specially constructed sentences we used phonetically rich sentences from the Dutch POLYPHONE corpus. Most of the Duration, Energy and Spectral Tilt features that we used in the investigation show statistically significant differences for the population means of stressed and unstressed vowels. However, it also appears that the distributions overlap to such an extent that automatic detection of stressed and unstressed syllables yields correct classifications of 72.6% at best. It is argued that this result is due to the large variety in the ways in which the abstract linguistic feature `lexical stress' is realized in the acoustic speech signal. Our findings suggest that a lexical stress detector has little use for a single pass decoder in an automatic speech recognition (ASR) system, but could still play a useful role as an additional knowledge source in a multi-pass decoder.

Abstract

An essential phenomenon in the development towards syntactic maturity after early childhood is the increasing use of so-called sentence-combining transformations. Especially by using subordination, complex sentences are produced. The research reported here is an attempt to arrive at a more adequate characterization and explanation. Our starting point was an analysis of 280 texts written by Dutch-speaking pupils of the two highest grades of the primary school and the four lowest grades of three different types of secondary education. It was examined whether systematic shifts in the use of certain groups of so-called function words could be traced. We concluded that the development of the syntactic formulating ability can be characterized as an increase in connectivity: the use of all kinds of function words which explicitly mark logico-semantic relations between propositions. This development starts by inserting special adverbs and coordinating conjunctions resulting in various types of coordination. In a later stage, the syntactic patterning of the sentence is affected as well (various types of subordination). The increase in sentence complexity is only one aspect of the entire development. An explanation for the increase in connectivity is offered based upon a distinction between narrative and expository language use. The latter, but not the former, is characterized by frequent occurrence of connectives. The development in syntactic formulating ability includes a high level of skill in expository language use. Speed of development is determined by intensity of training, e.g. in scholastic and occupational settings.

Abstract

An event-related brain potentials experiment was carried out to examine the interplay of referential and structural factors during sentence processing in discourse. Subjects read (Dutch) sentences beginning like “David told the girl that … ” in short story contexts that had introduced either one or two referents for a critical singular noun phrase (“the girl”). The waveforms showed that within 280 ms after onset of the critical noun the reader had already determined whether the noun phrase had a unique referent in earlier discourse. Furthermore, this referential information was immediately used in parsing the rest of the sentence, which was briefly ambiguous between a complement clause (“ … that there would be some visitors”) and a relative clause (“ … that had been on the phone to hang up”). A consistent pattern of P600/SPS effects elicited by various subsequent disambiguations revealed that a two-referent discourse context had led the parser to initially pursue the relative-clause alternative to a larger extent than a one-referent context. Together, the results suggest that during the processing of sentences in discourse, structural and referential sources of information interact on a word-by-word basis.

Abstract

The temporal properties of semantic and phonological processes in speech production were investigated in a new experimental paradigm using movement-related brain potentials. The main experimental task was picture naming. In addition, a 2-choice reaction go/no-go procedure was included, involving a semantic and a phonological categorization of the picture name. Lateralized readiness potentials (LRPs) were derived to test whether semantic and phonological information activated motor processes at separate moments in time. An LRP was only observed on no-go trials when the semantic (not the phonological) decision determined the response hand. Varying the position of the critical phoneme in the picture name did not affect the onset of the LRP but rather influenced when the LRP began to differ on go and no-go trials and allowed the duration of phonological encoding of a word to be estimated. These results provide electrophysiological evidence for early semantic activation and later phonological encoding.

Abstract

An introductory study of the perception of stochastically specified events is reported. The initial problem was to determine whether the perceiver can split visual input data of this kind into random and determined components. The inability of subjects to do so with the stimulus material used (a filmlike sequence of dot patterns), led to the more general question of how subjects code this kind of visual material. To meet the difficulty of defining the subjects' responses, two experiments were designed. In both, patterns were presented as a rapid sequence of dots on a screen. The patterns were more or less disturbed by “noise,” i.e. the dots did not appear exactly at their proper places. In the first experiment the response was a rating on a semantic scale, in the second an identification from among a set of alternative patterns. The results of these experiments give some insight in the coding systems adopted by the subjects. First, noise appears to be detrimental to pattern recognition, especially to patterns with little spread. Second, this shows connections with the factors obtained from analysis of the semantic ratings, e.g. easily disturbed patterns show a large drop in the semantic regularity factor, when only a little noise is added.

Abstract

We report a series of experiments examining the effects on word processing of insertion of an optional epenthetic vowel in word-final consonant clusters in Dutch. Such epenthesis turns film, for instance, into film. In a word-reversal task listeners treated words with and without epenthesis alike, as monosyllables, suggesting that the variant forms both activate the same canonical representation, that of a monosyllabic word without epenthesis. In both lexical decision and word spotting, response times to recognize words were significantly faster when epenthesis was present than when the word was presented in its canonical form without epenthesis. It is argued that addition of the epenthetic vowel makes the liquid consonants constituting the first member of a cluster more perceptible; a final phoneme-detection experiment confirmed that this was the case. These findings show that a transformed variant of a word, although it contacts the lexicon via the representation of the canonical form, can be more easily perceptible than that canonical form.

Abstract

Pitch, intonation, and speech rate were analyzed in a collection of everyday speech heard by one Dutch infant between the ages of six and nine months. Components of each of these variables were measured in the speech of three adult speakers (mother, father, baby-sitter) when they addressed the infant, and when they addressed another adult. The results are in line with previously reported findings which are usually based on laboratory or prearranged settings: infant-directed speech in a natural setting exhibits more pitch variation, a larger number of simple intonation contours, and slower speech rate than does adult-directed speech.

Abstract

Dutch distinguishes at least four sentence types: statements and questions, the latter type being subdivided into wh-questions (beginning with a question word), yes/no-questions (with inversion of subject and finite), and declarative questions (lexico-syntactically identical to statement). Acoustically, each of these (sub)types was found to have clearly distinct global F0-patterns, as well as a characteristic distribution of final rises [1,2]. The present paper explores the separate contribution of parameters of global downtrend and size of accent-lending pitch movements versus aspects of the terminal rise to the human identification of the four sentence (sub)types, at various positions in the time-course of the utterance. The results show that interrogativity in Dutch can be identified at an early point in the utterance. However, wh-questions are not distinct from statements.

Abstract

As a preliminary to further research on musical consonance an explanatory investigation was made on the different modes of judgment of musical intervals. This was done by way of a semantic differential. Subjects rated 23 intervals against 10 scales. In a factor analysis three factors appeared: pitch, evaluation and fusion. The relation between these factors and some physical characteristics has been investigated. The scale consonant-dissonant showed to be purely evaluative (in opposition to Stumpf's theory). This evaluative connotation is not in accordance with the musicological meaning of consonance. Suggestions to account for this difference have been given.

Abstract

Jescheniak and Levelt (Jescheniak, J.-D., Levelt, W.J.M. 1994. Journal of Experimental Psychology: Learning, Memory and Cognition 20 (4), 824–843) have suggested that the speed with which native speakers of a gender-marking language retrieve the grammatical gender of a noun from their mental lexicon may depend on the recency of earlier access to that same noun's gender, as the result of a mechanism that is dedicated to facilitate gender-marked anaphoric reference to recently introduced discourse entities. This hypothesis was tested in two picture naming experiments. Recent gender access did not facilitate the production of gender-marked adjective noun phrases (Experiment 1), nor that of gender-marked definite article noun phrases (Experiment 2), even though naming times for the latter utterances were sensitive to the gender of a written distractor word superimposed on the picture to be named. This last result replicates and extends earlier gender-specific picture-word interference results (Schriefers, H. 1993. Journal of Experimental Psychology: Learning, Memory, and Cognition 19 (4), 841–850), showing that one can selectively tap into the production of grammatical gender agreement during speaking. The findings are relevant to theories of speech production and the representation of grammatical gender for that process.

Abstract

Meermalen is getracht om syntactische formuleenuuirdigheid direct en objectief te meten aan de hand van gesproken of geschreven teksten. Uitgangspunt hierbij vormde in de regel de syntactische complexiteit van de geproduceerde taaluitingen. Dit heeft echter niet geleid tot een plausibele, duidelijk omschreven en praktisch bruikbare index. N.a.v. een kritische bespreking van de notie complexiteit wordt in dit artikel als nieuw criterium voorgesteld de connectiviteit van de taaluitingen; de expliciete aanduiding van logiscli-scmantische relaties tussen proposities. Connectiviteit is gemakkelijk scoorbaar aan de hand van functiewoorden die verschillende vormen van nevenschikkend en onderschikkend zinsverband markeren. Deze nieuwe index ondetrangt de kritiek die op complexiteit gegeven kon worden, blijkt duidelijk te discrimineren tussen groepen leerlingen die van elkaar verschillen naar leeftijd en opleidingsniveau, en sluit aan bij recente taalpsychologische en sociolinguïstische theorie. Tot besluit worden enige onderwijskundige implicaties aangegeven.

Abstract

In two ERP experiments we investigated how and when the language comprehension system relates an incoming word to semantic representations of an unfolding local sentence and a wider discourse. In experiment 1, subjects were presented with short stories. The last sentence of these stories occasionally contained a critical word that, although acceptable in the local sentence context, was semantically anomalous with respect to the wider discourse (e.g., "Jane told the brother that he was exceptionally slow" in a discourse context where he had in fact been very quick). Relative to coherent control words (e.g., "quick"), these discourse-dependent semantic anomalies elicited a large N400 effect that began at about 200-250 ms after word onset. In experiment 2, the same sentences were presented without their original story context. Although the words that had previously been anomalous in discourse still elicited a slightly larger average N400 than the coherent words, the resulting N400 effect was much reduced, showing that the large effect observed in stories was related to the wider discourse. In the same experiment, single sentences that contained a clear local semantic anomaly elicited a standard sentence-dependent N400 effect (e.g., Kutas & Hillyard, 1980). The N400 effects elicited in discourse and in single sentences had the same time course, overall morphology, and scalp distribution. We argue that these findings are most compatible with models of language processing in which there is no fundamental distinction between the integration of a word in its local (sentence-level) and its global (discourse-level) semantic context.

Abstract

We review the implications of recent ERP evidence for when and how grammatical gender agreement constrains sentence parsing. In some theories of parsing, gender is assumed to immediately and categorically block gender-incongruent phrase structure alternatives from being pursued. In other theories, the parser initially ignores gender altogether. The ERP evidence we discuss suggests an intermediate position, in which grammatical gender does not immediately block gender-incongruent phrase structures from being considered, but is used to dispose of them shortly thereafter.

Abstract

Motor-related brain potentials were used to examine the time course of grammatical and phonological processes during noun phrase production in Dutch. In the experiments, participants named colored pictures using a no-determiner noun phrase. On half of the trials a syntactic-phonological classification task had to be performed before naming. Depending on the outcome of the classifications, a left or a right push-button response was given (go trials), or no push-button response was given (no-go trials). Lateralized readiness potentials (LRPs) were derived to test whether syntactic and phonological information affected the motor system at separate moments in time. The results showed that when syntactic information determined the response-hand decision, an LRP developed on no-go trials. However, no such effect was observed when phonological information determined response hand. On the basis of the data, it can be estimated that an additional period of at least 40 ms is needed to retrieve a word's initial phoneme once its lemma has been retrieved. These results provide evidence for the view that during speaking, grammatical processing precedes phonological processing in time.

Abstract

Tzeltal, a Mayan language spoken in southern Mexico, exhibits allo-morphy of an unusual type. The vowel quality of the perfective suffix is determined by the number of syllables in the stem to which it is attaching. This paper presents previously unpublished data of this allomorphy and demonstrates that a syllable-count analysis of the phenomenon is the proper one. This finding is put in a more general context of segment-prosody interaction in allomorphy.

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

Three experiments examined the time course of phonological encoding in speech production. A new methodology is introduced in which subjects are required to monitor their internal speech production for prespecified target segments and syllables. Experiment 1 demonstrated that word initial target segments are monitored significantly faster than second syllable initial target segments. The addition of a concurrent articulation task (Experiment 1b) had a limited effect on performance, excluding the possibility that subjects are monitoring a subvocal articulation of the carrier word. Moreover, no relationship was observed between the pattern of monitoring latencies and the timing of the targets in subjects′ overt speech. Subjects are not, therefore, monitoring an internal phonetic representation of the carrier word. Experiment 2 used the production monitoring task to replicate the syllable monitoring effect observed in speech perception experiments: responses to targets were faster when they corresponded to the initial syllable of the carrier word than when they did not. We conclude that subjects are monitoring their internal generation of a syllabified phonological representation. Experiment 3 provides more detailed evidence concerning the time course of the generation of this representation by comparing monitoring latencies to targets within, as well as between, syllables. Some amendments to current models of phonological encoding are suggested in light of these results.

Abstract

The purpose of this paper is to question some of the basic assumpiions concerning motion verbs. In particular, it examines the assumption that "come" and "go" are lexical universals which manifest a universal deictic Opposition. Against the background offive working hypotheses about the nature of'come" and ''go", this study presents a comparative investigation of t wo unrelated languages—Mparntwe Arrernte (Pama-Nyungan, Australian) and Longgu (Oceanic, Austronesian). Although the pragmatic and deictic "suppositional" complexity of"come" and "go" expressions has long been recognized, we argue that in any given language the analysis of these expressions is much more semantically and systemically complex than has been assumed in the literature. Languages vary at the lexical semantic level äs t o what is entailed by these expressions, äs well äs differing äs t o what constitutes the prototype and categorial structure for such expressions. The data also strongly suggest that, ifthere is a lexical universal "go", then this cannof be an inherently deictic expression. However, due to systemic Opposition with "come", non-deictic "go" expressions often take on a deictic Interpretation through pragmatic attribution. Thus, this crosslinguistic investigation of "come" and "go" highlights the need to consider semantics and pragmatics äs modularly separate.

Abstract

L'A. étudie les corrélations entre structure syntaxique et fonction pragmatique dans les alternances de voix en akatek, une langue maya appartenant au sous-groupe Q'anjob'ala. Les alternances pragmatiques de voix sont les mécanismes par lesquels les langues encodent les différents degrés de topicalité des deux principaux participants d'un événement sémantiquement transitif, l'agent et le patient. A l'aide d'une analyse quantitative, l'A. évalue la topicalité de ces participants et identifie les structures syntaxiques permettant d'exprimer les quatre principales fonctions de voix en akatek : active-directe, inverse, passive et antipassive