Publications

Abstract

Models of cognitive processes often include simplifications, idealisations, and fictionalisations, so how should we learn about cognitive processes from such models? Particularly in cognitive science, when many features of the target system are unknown, it is not always clear which simplifications, idealisations, and so on, are appropriate for a research question, and which are highly misleading. Here we use a case-study from studies of language evolution, and ideas from philosophy of science, to illustrate a robustness approach to learning from models. Robust properties are those that arise across a range of models, simulations and experiments, and can be used to identify key causal structures in the models, and the phenomenon, under investigation. For example, in studies of language evolution, the emergence of compositional structure is a robust property across models, simulations and experiments of cultural transmission, but only under pressures for learnability and expressivity. This arguably illustrates the principles underlying real cases of language evolution. We provide an outline of the robustness approach, including its limitations, and suggest that this methodology can be productively used throughout cognitive science. Perhaps of most importance, it suggests that different modelling frameworks should be used as tools to identify the abstract properties of a system, rather than being definitive expressions of theories.

Abstract

n this study we investigated the durational correlates of lexical stress and pitch accent at normal and fast speech rate in Dutch. Previous literature on English shows that durations of lexically unstressed vowels are reduced more than stressed vowels when speakers increase their speech rate. We found that the same holds for Dutch, irrespective of whether the unstressed vowel is schwa or a "full" vowel. In the same line, we expected that vowels in words without a pitch accent would be shortened relatively more than vowels in words with a pitch accent. This was not the case: if anything, the accented vowels were shortened relatively more than the unaccented vowels. We conclude that duration is an important cue for lexical stress, but not for pitch accent.

Abstract

Listeners find it relatively difficult to recognize words that are similar-sounding to other known words. In contrast, when asked to identify spoken nonwords, listeners perform better when the nonwords are similar to many words in their language. These effects of sound similarity have been assessed in multiple ways, and both sublexical (phonotactic probability) and lexical (neighborhood) effects have been reported, leading to models that incorporate multiple stages of processing. One prediction that can be derived from these models is that there may be differences among individuals in the size of these similarity effects as a function of working memory abilities. This study investigates how item-individual characteristics of nonwords (both phonotactic probability and neighborhood density) interact with listener-individual characteristics (such as cognitive abilities and hearing sensitivity) in the perceptual identification of nonwords. A set of nonwords was used in which neighborhood density and phonotactic probability were not correlated. In our data, neighborhood density affected identification more reliably than did phonotactic probability. The first study, with young adults, showed that higher neighborhood density particularly benefits nonword identification for those with poorer attention-switching control. This suggests that it may be easier to focus attention on a novel item if it activates and receives support from more similar-sounding neighbors. A similar study on nonword identification with older adults showed increased neighborhood density effects for those with poorer hearing, suggesting that activation of long-term linguistic knowledge is particularly important to back up auditory representations that are degraded as a result of hearing loss.

Abstract

Studies on fast speech have shown that word-level timing of fast speech differs from that of normal rate speech in that unstressed syllables are shortened more than stressed syllables as speech rate increases. An earlier experiment showed that the intelligibility of time-compressed speech could not be improved by making its temporal organisation closer to natural fast speech. To test the hypothesis that segmental intelligibility is more important than prosodic timing in listening to timecompressed speech, the intelligibility of bisyllabic words was tested in three time-compression conditions: either stressed and unstressed syllable were compressed to the same degree, or the stressed syllable was compressed more than the unstressed syllable, or the reverse. As was found before, imitating wordlevel timing of fast speech did not improve intelligibility over linear compression. However, the results did not confirm the hypothesis either: there was no difference in intelligibility between the three compression conditions. We conclude that segmental intelligibility plays an important role, but further research is necessary to decide between the contributions of prosody and segmental intelligibility to the word-level intelligibility of time-compressed speech.

Abstract

The configuration of a spatial layout has a substantial effect on the acquisition and the representation of the environment. In four experiments, we investigated navigation difficulties arising at oblique angled intersections. In the first three studies we investigated specific arrow-fork configurations. In dependence on the branch subjects use to enter the intersection different decision latencies and numbers of errors arise. If subjects see the intersection as a fork, it is more difficult to find the correct way as if it is seen as an arrow. In a fourth study we investigated different heuristics people use while making a detour around a barrier. Detour behaviour varies with the perspective. If subjects learn and navigate through the maze in a field perspective they use a heuristic of preferring right angled paths. If they have a view from above and acquire their knowledge in an observer perspective they use oblique angled paths more often.

Abstract

In 7 experiments the authors investigated the locus of word frequency effects in speech production. Experiment 1 demonstrated a frequency effect in picture naming that was robust over repetitions. Experiments 2, 3, and 7 excluded contributions from object identification and initiation of articulation. Experiments 4 and 5 investigated whether the effect arises in accessing the syntactic word (lemma) by using a grammatical gender decision task. Although a frequency effect was found, it dissipated under repeated access to word's gender. Experiment 6 tested whether the robust frequency effect arises in accessing the phonological form (lexeme) by having Ss translate words that produced homophones. Low-frequent homophones behaved like high-frequent controls, inheriting the accessing speed of their high-frequent homophone twins. Because homophones share the lexeme, not the lemma, this suggests a lexeme-level origin of the robust effect.

Abstract

Language processing is influenced by multiple sources of information. We examined whether the performance in simultaneous interpreting would be improved when providing two sources of information, the auditory speech as well as corresponding lip-movements, in comparison to presenting the auditory speech alone. Although there was an improvement in sentence recognition when presented with visible speech, there was no difference in performance between these two presentation conditions when bilinguals simultaneously interpreted from English to German or from English to Spanish. The reason why visual speech did not contribute to performance could be the presentation of the auditory signal without noise (Massaro, 1998). This hypothesis should be tested in the future. Furthermore, it should be investigated if an effect of visible speech can be found for other contexts, when visual information could provide cues for emotions, prosody, or syntax.

Abstract

An audio and video corpus of speech addressed to 28 11-month-olds is described. The corpus allows comparisons between adult speech directed towards infants, familiar adults and unfamiliar adult addressees, as well as of caregivers’ word teaching strategies across word classes. Summary data show that infant-directed speech differed more from speech to unfamiliar than familiar adults; that word teaching strategies for nominals versus verbs and adjectives differed; that mothers mostly addressed infants with multi-word utterances; and that infants’ vocabulary size was unrelated to speech rate, but correlated positively with predominance of continuous caregiver speech (not of isolated words) in the input.

Abstract

Second language (L2) research often involves analyses of acoustic measures of fluency. The studies investigating fluency, however, have been difficult to compare because the measures of fluency that were used differed widely. One of the differences between studies concerns the lower cut-off point for silent pauses, which has been set anywhere between 100 ms and 1000 ms. The goal of this paper is to find an optimal cut-off point. We calculate acoustic measures of fluency using different pause thresholds and then relate these measures to a measure of L2 proficiency and to ratings on fluency.

Abstract

Anthropology began by comparing aspects of kinship across cultures, while linguists interested in semantic domains such as kinship necessarily compare across languages. In this chapter I show how phylogenetic comparative methods from evolutionary biology can be used to study evolutionary processes relating to kinship and kinship terminologies across language and culture.

Abstract

This special issue “Evolutionary Approaches to Cross-Cultural Anthropology” brings together scholars from the fields of behavioral ecology, evolutionary psychology, and cultural evolution whose cross-cultural work draws on evolutionary theory and methods. The papers here are a subset of those presented at a symposium we organized for the 2011 meeting of the Society for Cross-Cultural Research held in Charleston, South Carolina. Collectively, our authors show how an engagement with cultural variation has enriched evolutionary anthropology, and these papers showcase how cross-cultural research can benefit from the theoretical and methodological contributions of an evolutionary approach.

Abstract

BACKGROUND: Cognitive consequences at school age associated with prenatal methylmercury (MeHg) exposure may need to take into account nutritional and sociodemographic cofactors as well as relevant genetic polymorphisms. METHODS: A subsample (n = 1,311) of the Avon Longitudinal Study of Parents and Children (Bristol, UK) was selected, and mercury (Hg) concentrations were measured in freeze-dried umbilical cord tissue as a measure of MeHg exposure. A total of 1135 children had available data on 247 single-nucleotide polymorphisms (SNPs) within relevant genes, as well as the Wechsler Intelligence Scale for Children Intelligence Quotient (IQ) scores at age 8 years. Multivariate regression models were used to assess the associations between MeHg exposure and IQ and to determine possible gene-environment interactions. RESULTS: Hg concentrations indicated low background exposures (mean = 26 ng/g, standard deviation = 13). Log10-transformed Hg was positively associated with IQ, which attenuated after adjustment for nutritional and sociodemographic cofactors. In stratified analyses, a reverse association was found in higher social class families (for performance IQ, P value for interaction = 0.0013) among whom there was a wider range of MeHg exposure. Among 40 SNPs showing nominally significant main effects, MeHg interactions were detected for rs662 (paraoxonase 1) and rs1042838 (progesterone receptor) (P <} 0.05) and for rs3811647 (transferrin) and rs2049046 (brain-derived neurotrophic factor) (P {< 0.10). CONCLUSIONS: In this population with a low level of MeHg exposure, there were only equivocal associations between MeHg exposure and adverse neuropsychological outcomes. Heterogeneities in several relevant genes suggest possible genetic predisposition to MeHg neurotoxicity in a substantial proportion of the population. Future studies need to address this possibility.

Abstract

The current study investigates auditory-motor coupling in musically trained participants using a Stroop-type task that required the execution of simple finger sequences according to aurally presented number sequences (e.g., "2," " 4," "5," "3," "1"). Digital remastering was used to manipulate the pitch contour of the number sequences such that they were either congruent or incongruent with respect to the resulting action sequence. Conservatoire-level violinists showed a strong effect of congruency manipulation (increased response time for incongruent vs. congruent trials), in comparison to a control group of non-musicians. In Experiment 2, this paradigm was used to determine whether pedagogical background would influence this effect in a group of young violinists. Suzuki-trained violinists differed significantly from those with no musical background, while traditionally-trained violinists did not. The findings extend previous research in this area by demonstrating that obligatory audio-motor coupling is directly related to a musicians' expertise on their instrument of study and is influenced by pedagogy.

Abstract

Both emotion and reward are primary modulators of cognition: Emotional word content enhances word processing, and reward expectancy similarly amplifies cognitive processing from the perceptual up to the executive control level. Here, we investigate how these primary regulators of cognition interact. We studied how the anticipation of gain or loss modulates the neural time course (event-related potentials, ERPs) related to processing of emotional words. Participants performed a semantic categorization task on emotional and neutral words, which were preceded by a cue indicating that performance could lead to monetary gain or loss. Emotion-related and reward-related effects occurred in different time windows, did not interact statistically, and showed different topographies. This speaks for an independence of reward expectancy and the processing of emotional word content. Therefore, privileged processing given to emotionally valenced words seems immune to short-term modulation of reward. Models of language comprehension should be able to incorporate effects of reward and emotion on language processing, and the current study argues for an architecture in which reward and emotion do not share a common neurobiological mechanism

Abstract

When you compare the behavior of two different age groups which are trying to master the same sensori-motor or cognitive skill, you are likely to discover varying learning routes: different stages, different intervals between stages, or even different orderings of stages. Such heterogeneous learning trajectories may be caused by at least six different types of factors: (1) Initial state: the kinds and levels of skills the learners have available at the onset of the learning episode. (2) Learning mechanisms: rule-based, inductive, connectionist, parameter setting, and so on. (3) Input and feedback characteristics: learning stimuli, information about success and failure. (4) Information processing mechanisms: capacity limitations, attentional biases, response preferences. (5) Energetic variables: motivation, emotional reactions. (6) Final state: the fine-structure of kinds and levels of subskills at the end of the learning episode. This applies to language acquisition as well. First and second language learners probably differ on all six factors. Nevertheless, the debate between advocates and opponents of the Fundamental Difference Hypothesis concerning L1 and L2 acquisition have looked almost exclusively at the first two factors. Those who believe that L1 learners have access to Universal Grammar whereas L2 learners rely on language processing strategies, postulate different learning mechanisms (UG parameter setting in L1, more general inductive strategies in L2 learning). Pienemann opposes this view and, based on his Processability Theory, argues that L1 and L2 learners start out from different initial states: they come to the grammar learning task with different structural hypotheses (SOV versus SVO as basic word order of German).

Abstract

This paper presents a theory of the syntactic aspects of human sentence production. An important characteristic of unprepared speech is that overt pronunciation of a sentence can be initiated before the speaker has completely worked out the meaning content he or she is going to express in that sentence. Apparently, the speaker is able to build up a syntactically coherent utterance out of a series of syntactic fragments each rendering a new part of the meaning content. This incremental, left-to-right mode of sentence production is the central capability of the proposed Incremental Procedural Grammar (IPG). Certain other properties of spontaneous speech, as derivable from speech errors, hesitations, self-repairs, and language pathology, are accounted for as well. The psychological plausibility thus gained by the grammar appears compatible with a satisfactory level of linguistic plausibility in that sentences receive structural descriptions which are in line with current theories of grammar. More importantly, an explanation for the existence of configurational conditions on transformations and other linguistics rules is proposed. The basic design feature of IPG which gives rise to these psychologically and linguistically desirable properties, is the “Procedures + Stack” concept. Sentences are built not by a central constructing agency which overlooks the whole process but by a team of syntactic procedures (modules) which work-in parallel-on small parts of the sentence, have only a limited overview, and whose sole communication channel is a stock. IPG covers object complement constructions, interrogatives, and word order in main and subordinate clauses. It handles unbounded dependencies, cross-serial dependencies and coordination phenomena such as gapping and conjunction reduction. It is also capable of generating self-repairs and elliptical answers to questions. IPG has been implemented as an incremental Dutch sentence generator written in LISP.

Abstract

Human speakers often produce sentences incrementally. They can start speaking having in mind only a fragmentary idea of what they want to say, and while saying this they refine the contents underlying subsequent parts of the utterance. This capability imposes a number of constraints on the design of a syntactic processor. This paper explores these constraints and evaluates some recent computational sentence generators from the perspective of incremental production.

Abstract

A new cognitive architecture is proposed for the syntactic aspects of human sentence processing. The architecture, called Unification Space, is biologically inspired but not based on neural nets. Instead it relies on biosynthesis as a basic metaphor. We use simulated annealing as an optimization technique which searches for the best configuration of isolated syntactic segments or subtrees in the final parse tree. The gradually decaying activation of individual syntactic nodes determines the ‘global excitation level’ of the system. This parameter serves the function of ‘computational temperature’ in simulated annealing. We have built a computer implementation of the architecture which simulates well-known sentence understanding phenomena. We report successful simulations of the psycholinguistic effects of clause embedding, minimal attachment, right association and lexical ambiguity. In addition, we simulated impaired sentence understanding as observable in agrammatic patients. Since the Unification Space allows for contextual (semantic and pragmatic) influences on the syntactic tree formation process, it belongs to the class of interactive sentence processing models.

Abstract

Science is currently under-utilized as a tool for effective policy and program design. A key part of this research-to-practice gap lies in the ineffectiveness of current models of science translation. Drawing on theory and methods from anthropology and cognitive linguistics, this study explores the role of cultural models and metaphor in the practice of science communication and translation. Qualitative interviews and group sessions, along with quantitative framing experiments, were used to design and test the effectiveness of a set of explanatory metaphors in translating the science of executive function. Developmental and cognitive scientists typically define executive function as a multi-dimensional set of related abilities that include working memory, inhibitory control, and cognitive flexibility. The study finds one metaphor in particular—the brain's air traffic control system—to be effective in bridging gaps between expert and public understandings on this issue and in so doing improving the accessibility of scientific information to members of the public as they reason about public policy issues. Findings suggest both a specific tool that can be used in efforts to translate the science of executive function and a theory and methodology that can be employed to design and test metaphors as communication devices on other science and social issues.

Abstract

Why do languages have the categories they do? It has been argued that spatial terms in the world’s languages reflect categories that support highly informative communication, and that this accounts for the spatial categories found across languages. However, this proposal has been tested against only nine languages, and in a limited fashion. Here, we consider two new languages: Maijɨki, an under-documented language of Peruvian Amazonia, and English. We analyze spatial data from these two new languages and the original nine, using thorough and theoretically targeted computational tests. The results support the hypothesis that spatial terms across dissimilar languages enable near-optimally informative communication, over an influential competing hypothesis

Abstract

This article reviews research that has investigated the role of verbal working memory (VWM) in sentence comprehension in both typical and atypical developmental populations. Two theoretical approaches that specify different roles for VWM in sentence comprehension are considered: (i) capacity-limit approaches, which treat VWM as a theoretical primitive that causally constrains language processing and acquisition, and (ii) the experience-based approach, which argues that VWM is an emergent property of long-term linguistic knowledge. The empirical literature relevant to these different approaches is then reviewed. Although there has been considerable recent research on the topic, it is concluded that the current role of working memory in sentence comprehension in development is unclear, calling for a greater number of controlled systematic developmental studies on the topic.

Abstract

This research investigated the developing inter-relationships between language, graphic symbolism and symbolic play both concurrently and longitudinally from the fourth to the fifth year of childhood. Sixty children (n = 60) aged between 3 and 4 years completed multiple assessments of language and assessments of graphic symbolism, symbolic play and non-verbal intelligence. A year later, 31 children (n = 31) were re-tested using the same assessments. The findings revealed that skills within each symbolic domain were inter-related during the fourth year, appearing to develop in a domain-general type fashion based upon a common underlying symbolic mechanism. However, between the fourth and the fifth years, only language had predictive validity, suggesting a shift towards the verbal mediation of symbolic play and graphic symbolism as language becomes progressively internalized (Vygotsky, 1962, 1978).

Abstract

The previous literature has suggested that the hand movement in co-speech gestures and signs consists of a series of phases with qualitatively different dynamic characteristics. In this paper, we propose a syntagmatic rule system for movement phases that applies to both co-speech gestures and signs. Descriptive criteria for the rule system were developed for the analysis video-recorded continuous production of signs and gesture. It involves segmenting a stream of body movement into phases and identifying different phase types. Two human coders used the criteria to analyze signs and cospeech gestures that are produced in natural discourse. It was found that the criteria yielded good inter-coder reliability. These criteria can be used for the technology of automatic recognition of signs and co-speech gestures in order to segment continuous production and identify the potentially meaningbearing phase.

Abstract

In the first, critical part of this study, a small sample of simple German sentences with their empirically determined pitch contours is used to demonstrate the incorrectness of numerous currently hold views of German sentence intonation. In the second, more constructive part, several interrogative sentence types are analysed and an attempt is made to show that intonation, besides other functions, indicates the permantently changing 'thematic score' in on-going discourse as well as certain validity claims.

Abstract

The German Perfekt has two quite different temporal readings, as illustrated by the two possible continuations of the sentence Peter hat gearbeitet in i, ii, respectively: (i) Peter hat gearbeitet und ist müde. Peter has worked and is tired. (ii) Peter hat gearbeitet und wollte nicht gestört werden. Peter has worked and wanted not to be disturbed. The first reading essentially corresponds to the English present perfect; the second can take a temporal adverbial with past time reference ('yesterday at five', 'when the phone rang', and so on), and an English translation would require a past tense ('Peter worked/was working'). This article shows that the Perfekt has a uniform temporal meaning that results systematically from the interaction of its three components-finiteness marking, auxiliary and past participle-and that the two readings are the consequence of a structural ambiguity. This analysis also predicts the properties of other participle constructions, in particular the passive in German.

Abstract

Chinese has a number of particles such as le, guo, zai and zhe that add a particular aspectual value to the verb to which they are attached. There have been many characterisations of this value in the literature. In this paper, we review several existing influential accounts of these particles, including those in Li and Thompson (1981), Smith (1991), and Mangione and Li (1993). We argue that all these characterisations are intuitively plausible, but none of them is precise.We propose that these particles serve to mark which part of the sentence''s descriptive content is asserted, and that their aspectual value is a consequence of this function. We provide a simple and precise definition of the meanings of le, guo, zai and zhe in terms of the relationship between topic time and time of situation, and show the consequences of their interaction with different verb expressions within thisnew framework of interpretation.

Abstract

During the last 25 years, second language acquisition (SLA) research hasmade considerable progress, but is still far from proving a solid basis for foreign language teaching, or from a general theory of SLA. In addition, its status within the linguistic disciplines is still very low. I argue this has not much to do with low empirical or theoretical standards in the field—in this regard, SLA research is fully competitive—but with a particular perspective on the acquisition process: SLA researches learners' utterances as deviations from a certain target, instead of genuine manifestations of underlying language capacity; it analyses them in terms of what they are not rather than what they are. For some purposes such a "target deviation perspective" makes sense, but it will not help SLA researchers to substantially and independently contribute to a deeper understanding of the structure and function of the human language faculty. Therefore, these findings will remain of limited interest to other scientists until SLA researchers consider learner varieties a normal, in fact typical, manifestation of this unique human capacity.

Abstract

Starting with Ross (1970), various proposals have been made to classify elliptical coordinations and to characterize different languages according to the types of ellipses which they admit. Sanders (1977) discusses four of these proposals, shows that they are inadequate on various grounds and proposes a fifth typology whose central claim is 'evidently correct', as he states (p. 258). In the following, I shall briefly outline this typology and then show that it is inadequate, too. Since there is only one language 1 know — German — I will take all my examples from this language. Moreover, all examples will be straightforward and easy to be judged.