Publications

Abstract

Human communication is inherently multimodal. Auditory speech, but also visual cues can be used to understand another talker. Most studies of audiovisual speech perception have focused on the perception of speech segments (i.e., speech sounds). However, less is known about the influence of visual information on the perception of suprasegmental aspects of speech like lexical stress. In two experiments, we investigated the influence of different visual cues (e.g., facial articulatory cues and beat gestures) on the audiovisual perception of lexical stress. We presented auditory lexical stress continua of disyllabic Dutch stress pairs together with videos of a speaker producing stress on the first or second syllable (e.g., articulating VOORnaam or voorNAAM). Moreover, we combined and fully crossed the face of the speaker producing lexical stress on either syllable with a gesturing body producing a beat gesture on either the first or second syllable. Results showed that people successfully used visual articulatory cues to stress in muted videos. However, in audiovisual conditions, we were not able to find an effect of visual articulatory cues. In contrast, we found that the temporal alignment of beat gestures with speech robustly influenced participants' perception of lexical stress. These results highlight the importance of considering suprasegmental aspects of language in multimodal contexts.

Abstract

Individual differences in using language are prevalent in our daily lives. Language skills are often assessed in vocational (predominantly written language) and diagnostic contexts. Not much is known, however, about individual differences in spoken language skills. The lack of research is in part due to the lack of suitable test instruments. We introduce the Individual Differences in Language Skills (IDLaS-NL) test battery, a set of 31 behavioural tests that can be used to capture variability in language and relevant general cognitive skills in adult speakers of Dutch. The battery was designed to measure word and sentence production and comprehension skills, linguistic knowledge, nonverbal processing speed, working memory, and nonverbal reasoning. The present article outlines the structure of the battery, describes the materials and procedure of each test, and evaluates the battery’s factor structure based on the results of a sample of 748 Dutch adults, aged between 18 and 30 years, most of them students. The analyses demonstrate that the battery has good construct validity and can be reliably administered both in the lab and via the internet. We therefore recommend the battery as a valuable new tool to assess individual differences in language knowledge and skills; this future work may include linking language skills to other aspects of human cognition and life outcomes.

Abstract

Experimental psychologists and psycholinguists increasingly turn to online research for data collection due to the ease of sampling many diverse participants in parallel. Online research has shown promising validity and consistency, but is it suitable for all paradigms? Specifically, is it reliable enough for individual differences research? The current paper reports performance on 15 tasks from a psycholinguistic individual differences battery, including timed and untimed assessments of linguistic abilities, as well as domain-general skills. From a demographically homogenous sample of young Dutch people, 149 participants participated in the lab study, and 515 participated online. Our results indicate that there is no reason to assume that participants tested online will underperform compared to lab-based testing, though they highlight the importance of motivation and the potential for external help (e.g., through looking up answers) online. Overall, we conclude that there is reason for optimism in the future of online research into individual differences.

Abstract

Speakers sometimes produce lexical errors, such as saying “salt” instead of “pepper.” This study aimed to better understand the origin of lexical errors by assessing whether they arise from a hasty selection and premature decision to speak (premature selection hypothesis) or from momentary attentional disengagement from the task (attentional lapse hypothesis). We analyzed data from a speeded picture naming task (Lampe et al., 2023) and investigated whether lexical errors are produced as fast as target (i.e., correct) responses, thus arising from premature selection, or whether they are produced more slowly than target responses, thus arising from lapses of attention. Using ex-Gaussian analyses, we found that lexical errors were slower than targets in the tail, but not in the normal part of the response time distribution, with the tail effect primarily resulting from errors that were not coordinates, that is, members of the target’s semantic category. Moreover, we compared the coordinate errors and target responses in terms of their word-intrinsic properties and found that they were overall more frequent, shorter, and acquired earlier than targets. Given the present findings, we conclude that coordinate errors occur due to a premature selection but in the context of intact attentional control, following the same lexical constraints as targets, while other errors, given the variability in their nature, may vary in their origin, with one potential source being lapses of attention.

Abstract

Many contemporary texts include shortcuts, such as cu or phones4u. The aim of this study was to investigate how the meanings of shortcuts are retrieved. A primed lexical decision paradigm was used with shortcuts and the corresponding words as primes. The target word was associatively related to the meaning of the whole prime (cu/see you – goodbye), to a component of the prime (cu/see you – look), or unrelated to the prime. In Experiment 1, primes were presented for 57 ms. For both word and shortcut primes, responses were faster to targets preceded by whole-related than by unrelated primes. No priming from component-related primes was found. In Experiment 2, the prime duration was 1000 ms. The priming effect seen in Experiment 1 was replicated. Additionally, there was priming from component-related word primes, but not from component-related shortcut primes. These results indicate that the meanings of shortcuts can be retrieved without translating them first into corresponding words.

Abstract

The human cerebellum plays an important role in language, amongst other cognitive and motor functions [1], but a unifying theoretical framework about cerebellar language function is lacking. In an established model of motor control, the cerebellum is seen as a predictive machine, making short-term estimations about the outcome of motor commands. This allows for flexible control, on-line correction, and coordination of movements [2]. The homogeneous cytoarchitecture of the cerebellar cortex suggests that similar computations occur throughout the structure, operating on different input signals and with different output targets [3]. Several authors have therefore argued that this ‘motor’ model may extend to cerebellar nonmotor functions [3], [4] and [5], and that the cerebellum may support prediction in language processing [6]. However, this hypothesis has never been directly tested. Here, we used the ‘Visual World’ paradigm [7], where on-line processing of spoken sentence content can be assessed by recording the latencies of listeners' eye movements towards objects mentioned. Repetitive transcranial magnetic stimulation (rTMS) was used to disrupt function in the right cerebellum, a region implicated in language [8]. After cerebellar rTMS, listeners showed delayed eye fixations to target objects predicted by sentence content, while there was no effect on eye fixations in sentences without predictable content. The prediction deficit was absent in two control groups. Our findings support the hypothesis that computational operations performed by the cerebellum may support prediction during both motor control and language processing.

Abstract

Earlier studies had shown that speakers naming several objects typically look at each object until they have retrieved the phonological form of its name and therefore look longer at objects with long names than at objects with shorter names. We examined whether this tight eye-to-speech coordination was maintained at different speech rates and after increasing amounts of practice. Participants named the same set of objects with monosyllabic or disyllabic names on up to 20 successive trials. In Experiment 1, they spoke as fast as they could, whereas in Experiment 2 they had to maintain a fixed moderate or faster speech rate. In both experiments, the durations of the gazes to the objects decreased with increasing speech rate, indicating that at higher speech rates, the speakers spent less time planning the object names. The eye-speech lag (the time interval between the shift of gaze away from an object and the onset of its name) was independent of the speech rate but became shorter with increasing practice. Consistent word length effects on the durations of the gazes to the objects and the eye speech lags were only found in Experiment 2. The results indicate that shifts of eye gaze are often linked to the completion of phonological encoding, but that speakers can deviate from this default coordination of eye gaze and speech, for instance when the descriptive task is easy and they aim to speak fast.

Abstract

First paragraph: The topic of the workshop from which this volume comes, “Individual Differences in Second Language Learning,” is timely and important for both practical and theoretical reasons. The practical reasons are obvious: While many people have some knowledge of a second or further language, there is enormous variability in how well they know these languages. Much of this variability is, of course, likely to be due to differences in the time spent studying or being immersed in the language, but even in similar learning environments learners differ greatly in how quickly they pick up a language and in their ultimate level of proficiency.

Abstract

We examined the contribution of executive control to individual differences in response time (RT) for naming objects and actions. Following Miyake, Friedman, Emerson, Witzki, Howerter, and Wager (2000), executive control was assumed to include updating, shifting, and inhibiting abilities, which were assessed using operation-span, task switching, and stop-signal tasks, respectively. Study 1 showed that updating ability was significantly correlated with the mean RT of action naming, but not of object naming. This finding was replicated in Study 2 using a larger stimulus set. Inhibiting ability was significantly correlated with the mean RT of both action and object naming, whereas shifting ability was not correlated with the mean naming RTs. Ex-Gaussian analyses of the RT distributions revealed that updating ability was correlated with the distribution tail of both action and object naming, whereas inhibiting ability was correlated with the leading edge of the distribution for action naming and the tail for object naming. Shifting ability provided no independent contribution. These results indicate that the executive control abilities of updating and inhibiting contribute to the speed of naming objects and actions, although there are differences in the way and extent these abilities are involved.

Abstract

In deze bijdrage wordt een modulair model van zinsproductie besproken. De planningsprocessen, die aan de productie van een zin voorafgaan, kunnen in twee hoofdcomponenten onderverdeeld worden: deconceptualisering (het bedenken van de inhoud van de uiting) en de formulering (het vastleggen van de linguïstische vorm). Het formuleringsproces bestaat weer uit twee componenten, te weten de grammatische en fonologische codering. Ook deze componenten bestaan elk weer uit een aantal subcomponenten. Dit artikel beschrijft wat de specifieke taak van iedere component is, hoe deze uitgevoerd wordt en hoe de componenten samenwerken. Tevens worden enkele belangrijke methoden van taalproductie-onderzoek besproken.

Abstract

Four experiments investigated the span of advance planning for phrases and short sentences. Dutch subjects were presented with pairs of objects, which they named using noun-phrase conjunctions (e.g., the translation equivalent of ''the arrow and the bag'') or sentences (''the arrow is next to the bag''). Each display was accompanied by an auditory distracter, which was related in form or meaning to the first or second noun of the utterance or unrelated to both. For sentences and phrases, the mean speech onset time was longer when the distracter was semantically related to the first or second noun and shorter when it was phonologically related to the first noun than when it was unrelated. No phonological facilitation was found for the second noun. This suggests that before utterance onset both target lemmas and the first target form were selected.

Abstract

Investigations of the effects of advance information on movement preparation in Parkinson's disease using reaction time (RT) measures have yielded contradictory results. In order to obtain direct information regarding the time course of movement preparation, we combined RT measurements in a movement precueing task with multi-channel recordings of movement-related potentials in the present study. Movements of the index and middle fingers of the left and right hand were either precued or not by advance information regarding the side (left or right hand) of the required response. Reaction times were slower for patients than for control subjects. Both groups benefited equally from informative precues, indicating that patients utilized the advance information as effectively as control subjects. Lateralization of the movement-preceding cerebral activity [i.e. the lateralized readiness potential (LRP)] confirmed that patients used the available partial information to prepare their responses and started this process no later than controls. In conjunction with EMG onset times, the LRP onset measures allowed for a fractionation of the RTs, which provided clues to the stages where the slowness of Parkinson's disease patients might arise. No definite abnormalities of temporal parameters were found, but differences in the distribution of the lateralized movement-preceding activity between patients and controls suggested differences in the cortical organization of movement preparation. Differences in amplitude of the contingent negative variation (CNV) and differences in the way in which the CNV was modulated by the information given by the precue pointed in the same direction. A difference in amplitude of the P300 between patients and controls suggested that preprogramming a response required more effort from. patients than from control subjects.

Abstract

P. A. Starreveld and W. La Heij (1995) tested the seriality view of lexical access in speech production, according to which lexical selection and the encoding of a word's form proceed in serial order without feedback. In 2 experiments, they looked at the combined effect of semantic and orthographic relatedness of written distracter words in tasks that required conceptually driven naming. They found an interaction between semantic relatedness and orthographic relatedness and argued that the observed interaction refutes the seriality view of lexical access. In this comment, the authors argue that Starreveld and La Heij's rejection of serial access was based on an oversimplified conception of the seriality view and that interaction, rather than additivity, is predicted by existing conceptions of serial access.

Abstract

The CELEX lexical database includes a list of Dutch syllables and their frequencies, based on syllabification of isolated word forms. In connected speech, however, sentence-level phonological rules can modify the syllables and their token frequencies. In order to estimate the changes syllables may undergo in connected speech, an empirical investigation was carried out. A large Dutch text corpus (TROUW) was transcribed, processed by word level rules, and syllabified. The resulting lexeme syllables were evaluated by comparing them to the CELEX lexical database for Dutch. Then additional phonological sentence-level rules were applied to the TROUW corpus, and the frequencies of the resulting connected speech syllables were compared with those of the lexeme syllables from TROUW. The overall correlation between lexeme and speech syllables was very high. However, speech syllables generally had more complex CV structures than lexeme syllables. Implications of the results for research involving syllables are discussed. With respect to the notion of a mental syllabary (a store for precompiled articulatory programs for syllables, see Levelt & Wheeldon, 1994) this study revealed an interesting statistical result. The calculation of the cumulative syllable frequencies showed that 85% of the syllable tokens in Dutch can be covered by the 500 most frequent syllable types, which makes the idea of a syllabary very attractive.