Publications

Abstract

Models of speech production assume that syllables play a functional role in the process of word-form encoding in speech production. In this study, we investigate this claim and specifically provide evidence about the level at which syllables come into play. We report two studies using an odd-man-out variant of the implicit priming paradigm to examine the role of the syllable during the process of word formation. Our results show that this modified version of the implicit priming paradigm can trace the emergence of syllabic structure during spoken word generation. Comparing these results to prior syllable priming studies, we conclude that syllables emerge at the interface between phonological and phonetic encoding. The results are discussed in terms of the WEAVER++ model of lexical access.

Abstract

Speakers use external auditory feedback to monitor their own speech. Feedback distortion has been found to increase activity in the superior temporal areas. Using fMRI, the present study investigates the neural correlates of processing verbal feedback without distortion. In a blocked design, the following conditions were presented: (1) overt picture-naming, (2) overt picture-naming while pink noise was presented to mask external feedback, (3) covert picture-naming, (4) listening to the picture names (previously recorded from participants' own voices), and (5) listening to pink noise. The results show that auditory feedback processing involves a network of different areas related to general performance monitoring and speech-motor control. These include the cingulate cortex and the bilateral insula, supplementary motor area, bilateral motor areas, cerebellum, thalamus and basal ganglia. Our findings suggest that the anterior cingulate cortex, which is often implicated in error-processing and conflict-monitoring, is also engaged in ongoing speech monitoring. Furthermore, in the superior temporal gyrus, we found a reduced response to speaking under normal feedback conditions. This finding is interpreted in the framework of a forward model according to which, during speech production, the sensory consequence of the speech-motor act is predicted to attenuate the sensitivity of the auditory cortex. Hum Brain Mapp 2007. © 2007 Wiley-Liss, Inc.

Abstract

This study addressed how bilingual speakers switch between their first and second language when speaking. Event-related brain potentials (ERPs) and naming latencies were measured while unbalanced German (L1)-Dutch (L2) speakers performed a picture-naming task. Participants named pictures either in their L1 or in their L2 (blocked language conditions), or participants switched between their first and second language unpredictably (mixed language condition). Furthermore, form similarity between translation equivalents (cognate status) was manipulated. A cognate facilitation effect was found for L1 and L2 indicating phonological activation of the non-response language in blocked and mixed language conditions. The ERP data also revealed small but reliable effects of cognate status. Language switching resulted in equal switching costs for both languages and was associated with a modulation in the ERP waveforms (time windows 275-375 ms and 375-475 ms). Mixed language context affected especially the L1, both in ERPs and in latencies, which became slower in L1 than L2. It is suggested that sustained and transient components of language control should be distinguished. Results are discussed in relation to current theories of bilingual language processing.

Abstract

The present study concerns individual differences in gesture production. We used correlational and multiple regression analyses to examine the relationship between individuals’ cognitive abilities and empathy levels and their gesture frequency and saliency. We chose predictor variables according to experimental evidence of the functions of gesture in speech production and communication. We examined 3 types of gestures: representational gestures, conduit gestures, and palm-revealing gestures. Higher frequency of representational gestures was related to poorer visual and spatial working memory, spatial transformation ability, and conceptualization ability; higher frequency of conduit gestures was related to poorer visual working memory, conceptualization ability, and higher levels of empathy; and higher frequency of palm-revealing gestures was related to higher levels of empathy. The saliency of all gestures was positively related to level of empathy. These results demonstrate that cognitive abilities and empathy levels are related to individual differences in gesture frequency and saliency

Abstract

Language and action systems are highly interlinked. A critical piece of evidence is that speech and its accompanying gestures are tightly synchronized. Five experiments were conducted to test 2 hypotheses about the synchronization of speech and gesture. According to the interactive view, there is continuous information exchange between the gesture and speech systems, during both their planning and execution phases. According to the ballistic view, information exchange occurs only during the planning phases of gesture and speech, but the 2 systems become independent once their execution has been initiated. In all experiments, participants were required to point to and/or name a light that had just lit up. Virtual reality and motion tracking technologies were used to disrupt their gesture or speech execution. Participants delayed their speech onset when their gesture was disrupted. They did so even when their gesture was disrupted at its late phase and even when they received only the kinesthetic feedback of their gesture. Also, participants prolonged their gestures when their speech was disrupted. These findings support the interactive view and add new constraints on models of speech and gesture production

Abstract

Koriat (1981) demonstrated that an association from the target to a preceding prime, in the absence of an association from the prime to the target, facilitates lexical decision and referred to this effect as "backward priming". Backward priming is of relevance, because it can provide information about the mechanism underlying semantic priming effects. Following Neely (1991), we distinguish three mechanisms of priming: spreading activation, expectancy, and semantic matching/integration. The goal was to determine which of these mechanisms causes backward priming, by assessing effects of backward priming on a language-relevant ERP component, the N400, and reaction time (RT). Based on previous work, we propose that the N400 priming effect reflects expectancy and semantic matching/integration, but in contrast with RT does not reflect spreading activation. Experiment 1 shows a backward priming effect that is qualitatively similar for the N400 and RT in a lexical decision task. This effect was not modulated by an ISI manipulation. Experiment 2 clarifies that the N400 backward priming effect reflects genuine changes in N400 amplitude and cannot be ascribed to other factors. We will argue that these backward priming effects cannot be due to expectancy but are best accounted for in terms of semantic matching/integration.

Abstract

“Gesture-first” theories dismiss ancestral great apes’ vocalization as a substrate for language evolution based on the claim that extant apes exhibit minimal learning and volitional control of vocalization. Contrary to this claim, we present data of novel learned and voluntarily controlled vocal behaviors produced by a human-fostered gorilla (G. gorilla gorilla). These behaviors demonstrate varying degrees of flexibility in the vocal apparatus (including diaphragm, lungs, larynx, and supralaryngeal articulators), and are predominantly performed in coordination with manual behaviors and gestures. Instead of a gesture-first theory, we suggest that these findings support multimodal theories of language evolution in which vocal and gestural forms are coordinated and supplement one another

Abstract

When we talk, we often make hand movements called gestures at the same time. Although just about everyone gestures when they talk, we usually do not even notice the gestures. Our hand gestures play an important role in helping us learn and remember! When we see other people gesturing when they talk—or when we gesture when we talk ourselves—we are more likely to remember the information being talked about than if gestures were not involved. Our hand gestures can even indicate when we are ready to learn new things! In this article, we explain how gestures can help learning. To investigate this, we studied children learning a new mathematical concept called equivalence. We hope that this article will help you notice when you, your friends and family, and your teachers are gesturing, and that it will help you understand how those gestures can help people learn.

Abstract

Previous research has shown significant effects of race and accent on children’s developing social preferences. Accounts of the primacy of accent biases in the evolution and ontogeny of discriminant cooperation have been proposed, but lack systematic cross-cultural investigation. We report three controlled studies conducted with 5−10 year old children across four towns in the Brazilian Amazon, selected for their variation in racial and accent homogeneity/heterogeneity. Study 1 investigated participants’ (N = 289) decisions about friendship and sharing across color-contrasted pairs of target individuals: Black-White, Black-Pardo (Brown), Pardo-White. Study 2 (N = 283) investigated effects of both color and accent (Local vs Non-Local) on friendship and sharing decisions. Overall, there was a significant bias toward the lighter colored individual. A significant preference for local accent mitigates but does not override the color bias, except in the site characterized by both racial and accent heterogeneity. Results also vary by participant age and color. Study 3 (N = 235) reports results of an accent discrimination task that shows an overall increase in accuracy with age. The research suggests that cooperative preferences based on accent and race develop differently in response to locally relevant parameters of racial and linguistic variation.

Abstract

Interactive effects between allelic variants of the serotonin transporter (5-HTT) promoter-linked polymorphic region (5-HTTLPR) and stressors on depression symptoms have been documented, as well as questioned, by meta-analyses. Translational models of constitutive 5-htt reduction and experimentally controlled stressors often led to inconsistent behavioral and molecular findings and often did not include females. The present study sought to investigate the effect of 5-htt genotype, maternal separation, and sex on the expression of stress-related candidate genes in the rat hippocampus and frontal cortex. The mRNA expression levels of Avp, Pomc, Crh, Crhbp, Crhr1, Bdnf, Ntrk2, Maoa, Maob, and Comt were assessed in the hippocampus and frontal cortex of 5-htt ± and 5-htt +/+ male and female adult rats exposed, or not, to daily maternal separation for 180 min during the first 2 postnatal weeks. Gene- and brain region-dependent, but sex-independent, interactions between 5-htt genotype and maternal separation were found. Gene expression levels were higher in 5-htt +/+ rats not exposed to maternal separation compared with the other experimental groups. Maternal separation and 5-htt +/− genotype did not yield additive effects on gene expression. Correlative relationships, mainly positive, were observed within, but not across, brain regions in all groups except in non-maternally separated 5-htt +/+ rats. Gene expression patterns in the hippocampus and frontal cortex of rats exposed to maternal separation resembled the ones observed in rats with reduced 5-htt expression regardless of sex. These results suggest that floor effects of 5-htt reduction and maternal separation might explain inconsistent findings in humans and rodents

Abstract

We report an investigation of the perception of American English phonemes by Dutch listeners proficient in English. Listeners identified either the consonant or the vowel in most possible English CV and VC syllables. The syllables were embedded in multispeaker babble at three signal-to-noise ratios (16 dB, 8 dB, and 0 dB). Effects of signal-to-noise ratio on vowel and consonant identification are discussed as a function of syllable position and of relationship to the native phoneme inventory. Comparison of the results with previously reported data from native listeners reveals that noise affected the responding of native and non-native listeners similarly.

Abstract

Contemporary methods of computational cognitive modeling have recently been criticized by Addyman and French (2012) on the grounds that they have not kept up with developments in computer technology and human–computer interaction. They present a manifesto for change according to which, it is argued, modelers should devote more effort to making their models accessible, both to non-modelers (with an appropriate easy-to-use user interface) and modelers alike. We agree that models, like data, should be freely available according to the normal standards of science, but caution against confusing implementations with specifications. Models may embody theories, but they generally also include implementation assumptions. Cognitive modeling methodology needs to be sensitive to this. We argue that specification, replication and experimentation are methodological approaches that can address this issue.

Abstract

In this study, we compared the performance of a long short-term memory (LSTM) neural network to the behavior of human participants on a language task that requires hierarchically structured knowledge. We show that humans interpret ambiguous noun phrases, such as second blue ball, in line with their hierarchical constituent structure. LSTMs, instead, only do
so after unambiguous training, and they do not systematically generalize to novel items. Overall, the results of our simulations indicate that a model can behave hierarchically without relying on hierarchical constituent structure.

Abstract

Individual alpha frequency (IAF) is a promising electrophysiological marker of interindividual differences in cognitive function. IAF has been linked with trait-like differences in information processing and general intelligence, and provides an empirical basis for the definition of individualized frequency bands. Despite its widespread application, however, there is little consensus on the optimal method for estimating IAF, and many common approaches are prone to bias and inconsistency. Here, we describe an automated strategy for deriving two of the most prevalent IAF estimators in the literature: peak alpha frequency (PAF) and center of gravity (CoG). These indices are calculated from resting-state power spectra that have been smoothed using a Savitzky-Golay filter (SGF). We evaluate the performance characteristics of this analysis procedure in both empirical and simulated EEG data sets. Applying the SGF technique to resting-state data from n = 63 healthy adults furnished 61 PAF and 62 CoG estimates. The statistical properties of these estimates were consistent with previous reports. Simulation analyses revealed that the SGF routine was able to reliably extract target alpha components, even under relatively noisy spectral conditions. The routine consistently outperformed a simpler method of automated peak detection that did not involve spectral smoothing. The SGF technique is fast, open source, and available in two popular programming languages (MATLAB, Python), and thus can easily be integrated within the most popular M/EEG toolsets (EEGLAB, FieldTrip, MNE-Python). As such, it affords a convenient tool for improving the reliability and replicability of future IAF-related research.

Abstract

During conversation, interlocutors rapidly switch between speaker and listener
roles and take turns at talk. How do they achieve such fine coordination?
Most research has concentrated on the role of prediction, but listeners
must also prepare a response in advance (assuming they wish to respond)
and articulate this response at the appropriate moment. Such mechanisms
may overlap with the processes of comprehending the speaker’s incoming
turn and predicting its end. However, little is known about the stages of
response preparation and production. We discuss three questions pertaining
to such stages: (1) Do listeners prepare their own response in advance?,
(2) Can listeners buffer their prepared response?, and (3) Does buffering
lead to interference with concurrent comprehension? We argue that fine
coordination requires more than just an accurate prediction of the interlocutor’s
incoming turn: Listeners must also simultaneously prepare their own
response.

Abstract

During conversation, there is often little gap between interlocutors’ utterances. In two pairs of experiments, we manipulated the content predictability of yes/no questions to investigate whether listeners achieve such coordination by (i) preparing a response as early as possible or (ii) predicting the end of the speaker’s turn. To assess these two mechanisms, we varied the participants’ task: They either pressed a button when they thought the question was about to end (Experiments 1a and 2a), or verbally answered the questions with either yes or no (Experiments 1b and 2b). Predictability effects were present when participants had to prepare a verbal response, but not when they had to predict the turn-end. These findings suggest content prediction facilitates turn-taking because it allows listeners to prepare their own response early, rather than because it helps them predict when the speaker will reach the end of their turn.

Abstract

Research suggests that during conversation, interlocutors coordinate their utterances by predicting the speaker’s forthcoming utterance and its end. In two experiments, we used a button-pressing task, in which participants pressed a button when they thought a speaker reached the end of their utterance, to investigate what role the wider discourse plays in turn-end prediction. Participants heard two-utterance sequences, in which the content of the second utterance was or was not constrained by the content of the first. In both experiments, participants responded earlier, but not more precisely, when the first utterance was constraining rather than unconstraining. Response times and precision were unaffected by whether they listened to dialogues or monologues (Experiment 1) and by whether they read the first utterance out loud or silently (Experiment 2), providing no indication that activation of production mechanisms facilitates prediction. We suggest that content predictions aid comprehension but not turn-end prediction.

Abstract

In three experiments, listeners detected vowel or consonant targets in lists of CV syllables constructed from five vowels and five consonants. Responses were faster in a predictable context (e.g., listening for a vowel target in a list of syllables all beginning with the same consonant) than in an unpredictable context (e.g., listening for a vowel target in a list of syllables beginning with different consonants). In Experiment 1, the listeners’ native language was Dutch, in which vowel and consonant repertoires are similar in size. The difference between predictable and unpredictable contexts was comparable for vowel and consonant targets. In Experiments 2 and 3, the listeners’ native language was Spanish, which has four times as many consonants as vowels; here effects of an unpredictable consonant context on vowel detection were significantly greater than effects of an unpredictable vowel context on consonant detection. This finding suggests that listeners’ processing of phonemes takes into account the constitution of their language’s phonemic repertoire and the implications that this has for contextual variability.

Abstract

Single nucleotide polymorphisms (SNPs) within the MIR137, TCF4, and ZNF804A genes show genome-wide association to schizophrenia. However, the biological basis for the associations is unknown. Here, we tested the effects of these genes on brain structure in 1300 healthy adults. Using volumetry and voxel-based morphometry, neither gene-wide effects—including the combined effect of the genes—nor single SNP effects—including specific psychosis risk SNPs—were found on total brain volume, grey matter, white matter, or hippocampal volume. These results suggest that the associations between these risk genes and schizophrenia are unlikely to be mediated via effects on macroscopic brain structure.

Abstract

This paper discusses some improvements in recent and planned versions of the multimodal annotation tool ELAN, which are targeted at improving the usability of annotated files. Increased support for multilingual documents is provided, by allowing for multilingual vocabularies and by specifying a language per document, annotation layer (tier) or annotation. In addition, improvements in the search possibilities and the display of the results have been implemented, which are especially relevant in the interpretation of the results of complex multi-tier searches.

Abstract

Collocations generated by concordancers are a standard instrument in the exploitation of text corpora for the analysis of language use. Multimodal corpora show similar types of patterns, activities that frequently occur together, but there is no tool that offers facilities for visualising such patterns. Examples include timing of eye contact with respect to speech, and the alignment of activities of the two hands in signed languages. This paper describes recent enhancements to the standard CLARIN tools ELAN and TROVA for multimodal annotation to address these needs: first of all the query and concordancing functions were improved, and secondly the tools now generate visualisations of multilayer collocations that allow for intuitive explorations and analyses of multimodal data. This will provide a boost to the linguistic fields of gesture and sign language studies, as it will improve the exploitation of multimodal corpora.

Abstract

In this study we test the hypothesis that symbolic play represents a fertile context for language acquisition because its inherent ambiguity elicits communicative behaviours that positively influence development. Infant-caregiver dyads (N = 54) participated in two 20-minute play sessions six months apart (Time 1 = 18 months, Time 2 = 24 months). During each session the dyads played with two sets of toys that elicited either symbolic or functional play. The sessions were transcribed and coded for several features of dyadic interaction and speech; infants’ linguistic proficiency was measured via parental report. The two play contexts resulted in different communicative and linguistic behaviour. Notably, the symbolic play condition resulted in significantly greater conversational turn-taking than functional play, and also resulted in the greater use of questions and mimetics in infant-directed speech (IDS). In contrast, caregivers used more imperative clauses in functional play. Regression analyses showed that unique properties of symbolic play (i.e., turn-taking, yes-no questions, mimetics) positively predicted children’s language proficiency, whereas unique features of functional play (i.e., imperatives in IDS) negatively predicted proficiency. The results provide evidence in support of the hypothesis that symbolic play is a fertile context for language development, driven by the need to negotiate meaning.

Abstract

Recent constituent priming experiments show that Dutch and German prefixed verbs prime their stem, regardless of semantic transparency (e.g. Smolka et al. [(2014). ‘Verstehen’ (‘understand’) primes ‘stehen’ (‘stand’): Morphological structure overrides semantic compositionality in the lexical representation of German complex verbs. Journal of Memory and Language, 72, 16–36. https://doi.org/10.1016/j.jml.2013.12.002]). We examine whether the processing of opaque verbs (e.g. herhalen “repeat”) involves the retrieval of only the whole-word meaning, or whether the lexical-semantic meaning of the stem (halen as “take/get”) is retrieved as well. We report the results of an auditory semantic priming experiment with Dutch prefixed verbs, testing whether the recognition of a semantic associate to the stem (BRENGEN “bring”) is facilitated by the presentation of an opaque prefixed verb. In contrast to prior visual studies, significant facilitation after semantically opaque primes is found, which suggests that the lexical-semantic meaning of stems in opaque words is retrieved. We examine the implications that these findings have for auditory word recognition, and for the way in which different types of meanings are represented and processed.

Abstract

A recent debate in the morphological literature concerns the status of derivational affixes. While some linguists (Marantz 1997, 2001; Marvin 2003) consider derivational affixes a type of functional morpheme that realizes a categorial head, others (Lowenstamm 2015; De Belder 2011) argue that derivational affixes are roots. Our proposal, which finds its empirical basis in a study of Dutch derivational affixes, takes a middle position. We argue that there are two types of derivational affixes: some that are roots (i.e. lexical morphemes) and others that are categorial heads (i.e. functional morphemes). Affixes that are roots show ‘flexible’ categorial behavior, are subject to ‘lexical’ phonological rules, and may trigger idiosyncratic meanings. Affixes that realize categorial heads, on the other hand, are categorially rigid, do not trigger ‘lexical’ phonological rules nor allow for idiosyncrasies in their interpretation.

Abstract

In the previous decade, dozens of studies involving thousands of children across several research disciplines have made use of a combined daylong audio-recorder and automated algorithmic analysis called the LENAⓇ system, which aims to assess children’s language environment. While the system’s prevalence in the language acquisition domain is steadily growing, there are only scattered validation efforts on only some of its key characteristics. Here, we assess the LENAⓇ system’s accuracy across all of its key measures: speaker classification, Child Vocalization Counts (CVC), Conversational Turn Counts (CTC), and Adult Word Counts (AWC). Our assessment is based on manual annotation of clips that have been randomly or periodically sampled out of daylong recordings, collected from (a) populations similar to the system’s original training data (North American English-learning children aged 3-36 months), (b) children learning another dialect of English (UK), and (c) slightly older children growing up in a different linguistic and socio-cultural setting (Tsimane’ learners in rural Bolivia). We find reasonably high accuracy in some measures (AWC, CVC), with more problematic levels of performance in others (CTC, precision of male adults and other children). Statistical analyses do not support the view that performance is worse for children who are dissimilar from the LENAⓇ original training set. Whether LENAⓇ results are accurate enough for a given research, educational, or clinical application depends largely on the specifics at hand. We therefore conclude with a set of recommendations to help researchers make this determination for their goals.

Abstract

The present study investigated the neural correlates of infant discrimination of very similar linguistic varieties (Quebecois and Parisian French) using functional Near InfraRed Spectroscopy. In line with previous behavioral and electrophysiological data, there was no evidence that 3-month-olds discriminated the two regional accents, whereas 5-month-olds did, with the locus of discrimination in left anterior perisylvian regions. These neuroimaging results suggest that a developing language network relying crucially on left perisylvian cortices sustains infants' discrimination of similar linguistic varieties within this early period of infancy.

Abstract

Speaker diarization (answering 'who spoke when') is a widely researched subject within speech technology. Numerous experiments have been run on datasets built from broadcast news, meeting data, and call centers—the task sometimes appears close to being solved. Much less work has begun to tackle the hardest diarization task of all: spontaneous conversations in real-world settings. Such diarization would be particularly useful for studies of language acquisition, where researchers investigate the speech children produce and hear in their daily lives. In this paper, we study audio gathered with a recorder worn by small children as they went about their normal days. As a result, each child was exposed to different acoustic environments with a multitude of background noises and a varying number of adults and peers. The inconsistency of speech and noise within and across samples poses a challenging task for speaker diarization systems, which we tackled via retraining and data augmentation techniques. We further studied sources of structured variation across raw audio files, including the impact of speaker type distribution, proportion of speech from children, and child age on diarization performance. We discuss the extent to which these findings might generalize to other samples of speech in the wild.

Abstract

There are increasing reports that individual variation in behavioral and neurophysiological measures of infant speech processing predicts later language outcomes, and specifically concurrent or subsequent vocabulary size. If such findings are held up under scrutiny, they could both illuminate theoretical models of language development and contribute to the prediction of communicative disorders. A qualitative, systematic review of this emergent literature illustrated the variety of approaches that have been used and highlighted some conceptual problems regarding the measurements. A quantitative analysis of the same data established that the bivariate relation was significant, with correlations of similar strength to those found for well-established nonlinguistic predictors of language. Further exploration of infant speech perception predictors, particularly from a methodological perspective, is recommended.

Abstract

Typically, the point vowels [i,ɑ,u] are acoustically more peripheral in infant-directed speech (IDS) compared to adult-directed speech (ADS). If caregivers seek to highlight lexically relevant contrasts in IDS, then two sounds that are contrastive should become more distinct, whereas two sounds that are surface realizations of the same underlying sound category should not. To test this prediction, vowels that are phonemically contrastive ([i-ɪ] and [eɪ-ε]), vowels that map onto the same underlying category ([æ- ] and [ε- ]), and the point vowels [i,ɑ,u] were elicited in IDS and ADS by American English mothers of two age groups of infants (four- and eleven-month-olds). As in other work, point vowels were produced in more peripheral positions in IDS compared to ADS. However, there was little evidence of hyperarticulation per se (e.g. [i-ɪ] was hypoarticulated). We suggest that across-the-board lexically based hyperarticulation is not a necessary feature of IDS.

Abstract

When we imagine objects or events, we often engage in multisensory mental imagery. Yet, investigations of mental imagery have typically focused on only one sensory modality — vision. One reason for this is that the most common tool for the measurement of imagery, the questionnaire, has been restricted to unimodal ratings of the object. We present a new mental imagery questionnaire that measures multisensory imagery. Specifically, the newly developed Vividness of Wine Imagery Questionnaire (VWIQ) measures mental imagery of wine in the visual, olfactory, and gustatory modalities. Wine is an ideal domain to explore multisensory imagery because wine drinking is a multisensory experience, it involves the neglected chemical senses (smell and taste), and provides the opportunity to explore the effect of experience and expertise on imagery (from wine novices to experts). The VWIQ questionnaire showed high internal consistency and reliability, and correlated with other validated measures of imagery. Overall, the VWIQ may serve as a useful tool to explore mental imagery for researchers, as well as individuals in the wine industry during sommelier training and evaluation of wine professionals.

Abstract

In the wild, chimpanzees (Pan troglodytes) are often faced with clumped food resources that they may know how to access but abstain from doing so due to social pressures. To better understand how social settings influence resource acquisition, we tested fifteen semi-wild chimpanzees from two social groups alone and in the presence of others. We investigated how resource acquisition was affected by relative social dominance, whether collaborative problem solving or (active or passive) sharing occurred amongst any of the dyads, and whether these outcomes were related to relationship quality as determined from six months of observational data. Results indicated that chimpanzees, regardless of rank, obtained fewer rewards when tested in the presence of others compared to when they were tested alone. Chimpanzees demonstrated behavioral inhibition; chimpanzees who showed proficient skill when alone often abstained from solving the task when in the presence of others. Finally, individuals with close social relationships spent more time together in the problem solving space, but collaboration and sharing were infrequent and sessions in which collaboration or sharing did occur contained more instances of aggression. Group living provides benefits and imposes costs, and these findings highlight that one cost of group living may be diminishing productive individual behaviors.

Abstract

Recent debates have questioned the extent to which culturally-transmitted norms drive behavioral variation in resource sharing across human populations. We shed new light on this discussion by examining the group-level variation in the social dynamics and resource sharing of chimpanzees, a species that is highly social and forms long-term community associations but differs from humans in the extent to which cultural norms are adopted and enforced. We rely on theory developed in primate socioecology to guide our investigation in four neighboring chimpanzee groups at a sanctuary in Zambia. We used a combination of experimental and observational approaches to assess the distribution of resource holding potential in each group. In the first assessment, we measured the proportion of the population that gathered in a resource-rich zone, in the second we assessed naturally occurring social spacing via social network analysis, and in the third we assessed the degree to which benefits were equally distributed within the group. We report significant, stable group-level variation across these multiple measures, indicating that group-level variation in resource sharing and social tolerance is not necessarily reliant upon human-like cultural norms.

Abstract

A large amount of variability exists across human brains; revealed initially on a small scale by postmortem studies and,
more recently, on a larger scale with the advent of neuroimaging. Here we compared structural variability between human
and macaque monkey brains using grey and white matter magnetic resonance imaging measures. The monkey brain was
overall structurally as variable as the human brain, but variability had a distinct distribution pattern, with some key areas
showing high variability. We also report the first evidence of a relationship between anatomical variability and evolutionary
expansion in the primate brain. This suggests a relationship between variability and stability, where areas of low variability
may have evolved less recently and have more stability, while areas of high variability may have evolved more recently and
be less similar across individuals. We showed specific differences between the species in key areas, including the amount of
hemispheric asymmetry in variability, which was left-lateralized in the human brain across several phylogenetically recent
regions. This suggests that cerebral variability may be another useful measure for comparison between species and may add
another dimension to our understanding of evolutionary mechanisms.

Abstract

Handedness has been extensively studied because of its relationship with language and the over-representation of left-handers in some neurodevelopmental disorders. Using data from the UK Biobank, 23andMe and the International Handedness Consortium, we conducted a genome-wide association meta-analysis of handedness (N = 1,766,671). We found 41 loci associated (P < 5 × 10−8) with left-handedness and 7 associated with ambidexterity. Tissue-enrichment analysis implicated the CNS in the aetiology of handedness. Pathways including regulation of microtubules and brain morphology were also highlighted. We found suggestive positive genetic correlations between left-handedness and neuropsychiatric traits, including schizophrenia and bipolar disorder. Furthermore, the genetic correlation between left-handedness and ambidexterity is low (rG = 0.26), which implies that these traits are largely influenced by different genetic mechanisms. Our findings suggest that handedness is highly polygenic and that the genetic variants that predispose to left-handedness may underlie part of the association with some psychiatric disorders.

Abstract

We report associations between vowel sounds, graphemes, and colours collected online from over 1000 Dutch speakers. We provide open materials including a Python implementation of the structure measure, and code for a single page web application to run simple cross-modal tasks. We also provide a full dataset of colour-vowel associations from 1164 participants, including over 200 synaesthetes identified using consistency measures. Our analysis reveals salient patterns in cross-modal associations, and introduces a novel measure of isomorphism in cross-modal mappings. We find that while acoustic features of vowels significantly predict certain mappings (replicating prior work), both vowel phoneme category and grapheme category are even better predictors of colour choice. Phoneme category is the best predictor of colour choice overall, pointing to the importance of phonological representations in addition to acoustic cues. Generally, high/front vowels are lighter, more green, and more yellow than low/back vowels. Synaesthetes respond more strongly on some dimensions, choosing lighter and more yellow colours for high and mid front vowels than non-synaesthetes. We also present a novel measure of cross-modal mappings adapted from ecology, which uses a simulated distribution of mappings to measure the extent to which participants' actual mappings are structured isomorphically across modalities. Synaesthetes have mappings that tend to be more structured than non-synaesthetes, and more consistent colour choices across trials correlate with higher structure scores. Nevertheless, the large majority (~70%) of participants produce structured mappings, indicating that the capacity to make isomorphically structured mappings across distinct modalities is shared to a large extent, even if the exact nature of mappings varies across individuals. Overall, this novel structure measure suggests a distribution of structured cross-modal association in the population, with synaesthetes on one extreme and participants with unstructured associations on the other.

Abstract

Language-specific differences in the size and distribution of the phonemic repertoire can have implications for the task facing listeners in recognising spoken words. A language with more phonemes will allow shorter words and reduced embedding of short words within longer ones, decreasing the potential for spurious lexical competitors to be activated by speech signals. We demonstrate that this is the case via comparative analyses of the vocabularies of English and Spanish. A language which uses suprasegmental as well as segmental contrasts, however, can substantially reduce the extent of spurious embedding.

Abstract

Listeners rely on native-language rhythm in segmenting speech; in different languages, stress-, syllable- or mora-based rhythm is exploited. This language-specificity affects listening to non- native speech, if native procedures are applied even though inefficient for the non-native language. However, speakers of two languages with similar rhythmic interpretation should segment their own and the other language similarly. This was observed to date only for related languages (English-Dutch; French-Spanish). We now report experiments in which Japanese listeners heard Telugu, a Dravidian language unrelated to Japanese, and Telugu listeners heard Japanese. In both cases detection of target sequences in speech was harder when target boundaries mismatched mora boundaries, exactly the pattern that Japanese listeners earlier exhibited with Japanese and other languages. These results suggest that Telugu and Japanese listeners use similar procedures in segmenting speech, and support the idea that languages fall into rhythmic classes, with aspects of phonological structure affecting listeners' speech segmentation.

Abstract

Native American English and non-native(Dutch)listeners identified either the consonant or the vowel in all possible American English CV and VC syllables. The syllables were embedded in multispeaker babble at three signal-to-noise ratios(0, 8, and 16 dB). The phoneme identification
performance of the non-native listeners was less accurate than that of the native listeners. All listeners were adversely affected by noise. With these isolated syllables, initial segments were harder to identify than final segments. Crucially, the effects of language background and noise did not interact; the performance asymmetry between the native and non-native groups was not significantly different across signal-to-noise ratios. It is concluded that the frequently reported disproportionate difficulty of non-native listening under disadvantageous conditions is not due to a disproportionate increase in phoneme misidentifications.

Abstract

The retiring academic may look back upon, inter alia, years of conference attendance. Speech error researchers are uniquely fortunate because they can collect data in any situation involving communication; accordingly, the retiring speech error researcher will have collected data at those conferences. We here address the issue of whether error data collected in situations involving conviviality (such as at conferences) is representative of error data in general. Our approach involved a comparison, across three levels of linguistic processing, between a specially constructed Conviviality Sample and the largest existing source of speech error data, the newly available Fromkin Speech Error Database. The results indicate that there are grounds for regarding the data in the Conviviality Sample as a better than average reflection of the true population of all errors committed. These findings encourage us to recommend further data collection in collaboration with like-minded colleagues.

Abstract

Part of the remarkable efficiency of listening is
accommodation to unfamiliar talkers’ specific
pronunciations by retuning of phonemic intercategory
boundaries. Such retuning occurs in second
(L2) as well as first language (L1); however, recent
research with emigrés revealed successful adaptation
in the environmental L2 but, unprecedentedly, not in
L1 despite continuing L1 use. A possible explanation
involving relative exposure to novel talkers is here
tested in heritage language users with Mandarin as
family L1 and English as environmental language. In
English, exposure to an ambiguous sound in
disambiguating word contexts prompted the expected
adjustment of phonemic boundaries in subsequent
categorisation. However, no adjustment occurred in
Mandarin, again despite regular use. Participants
reported highly asymmetric interlocutor counts in the
two languages. We conclude that successful retuning
ability requires regular exposure to novel talkers in
the language in question, a criterion not met for the
emigrés’ or for these heritage users’ L1.

Abstract

Assimilation of place of articulation across a nasal and a following stop consonant is obligatory in Japanese, but not in Dutch. In four experiments the processing of assimilated forms by speakers of Japanese and Dutch was compared, using a task in which listeners blended pseudo-word pairs such as ranga-serupa. An assimilated blend of this pair would be rampa, an unassimilated blend rangpa. Japanese listeners produced significantly more assimilated than unassimilated forms, both with pseudo-Japanese and pseudo-Dutch materials, while Dutch listeners produced significantly more unassimilated than assimilated forms in each materials set. This suggests that Japanese listeners, whose native-language phonology involves obligatory assimilation constraints, represent the assimilated nasals in nasal-stop sequences as unmarked for place of articulation, while Dutch listeners, who are accustomed to hearing unassimilated forms, represent the same nasal segments as marked for place of articulation.

Abstract

In two experiments, Mandarin listeners resolved potential syntactic ambiguities in spoken utterances in (a) their native language (L1) and (b) English which they had learned as a second language (L2). A new disambiguation task was used, requiring speeded responses to select the correct meaning for structurally ambiguous sentences. Importantly, the ambiguities used in the study are identical in Mandarin and in English, and production data show that prosodic disambiguation of this type of ambiguity is also realised very similarly in the two languages. The perceptual results here showed however that listeners’ response patterns differed for L1 and L2, although there was a significant increase in similarity between the two response patterns with increasing exposure to the L2. Thus identical ambiguity and comparable disambiguation patterns in L1 and L2 do not lead to immediate application of the appropriate L1 listening strategy to L2; instead, it appears that such a strategy may have to be learned anew for the L2.

Abstract

A distinction between strong and weak vowels can be drawn on the basis of vowel quality, of stress, or of both factors. An experiment was conducted in which sets of contextually matched word-intial vowels ranging from clearly strong to clearly weak were cross-spliced, and the naturalness of the resulting words was rated by listeners. The ratings showed that in general cross-spliced words were only significantly less acceptable than unspliced words when schwa was not involved; this supports a categorical distinction based on vowel quality.

Abstract

Using a phoneme detection task, the present series of
experiments examines whether listeners can entrain to
different combinations of prosodic cues to predict where focus
will fall in an utterance. The stimuli were recorded by four
female native speakers of Australian English who happened to
have used different prosodic cues to produce sentences with
prosodic focus: a combination of duration cues, mean and
maximum F0, F0 range, and longer pre-target interval before
the focused word onset, only mean F0 cues, only pre-target
interval, and only duration cues. Results revealed that listeners
can entrain in almost every condition except for where
duration was the only reliable cue. Our findings suggest that
listeners are flexible in the cues they use for focus processing.

Abstract

Dutch listeners outperform native listeners in identifying syllable stress in English. This is because lexical stress is more useful in recognition of spoken words of Dutch than of English, so that Dutch listeners pay greater attention to stress in general. We examined Dutch listeners’ use of the acoustic correlates of English stress. Primary- and secondary-stressed syllables differ significantly on acoustic measures, and some differences, in F0 especially, correlate with data of earlier listening experiments. The correlations found in the Dutch responses were not paralleled in data from native listeners. Thus the acoustic cues which distinguish English primary versus secondary stress are better exploited by Dutch than by native listeners.

Abstract

In contrast to initial L1 vocabularies, which of necessity depend largely on heard exemplars, L2 vocabulary construction can draw on a variety of knowledge sources. This can lead to richer stored knowledge about the phonology of the L2 than the listener's prelexical phonetic processing capacity can support, and thus to mismatch between the level of detail required for accurate lexical mapping and the level of detail delivered by the prelexical processor. Experiments on spoken word recognition in L2 have shown that phonetic contrasts which are not reliably perceived are represented in the lexicon nonetheless. This lexical representation of contrast must be based on abstract knowledge, not on veridical representation of heard exemplars. New experiments confirm that provision of abstract knowledge (in the form of spelling) can induce lexical representation of a contrast which is not reliably perceived; but also that experience (in the form of frequency of occurrence) modulates the mismatch of phonetic and lexical processing. We conclude that a correct account of word recognition in L2 (as indeed in L1) requires consideration of both abstract and episodic information.

Abstract

The difficulty of listening to speech in noise is exacerbated when the speech is in the listener’s L2 rather than L1. In this study, Spanish and Dutch users of English as an L2 identified American English consonants in a constant intervocalic context. Their performance was compared with that of L1 (British English) listeners, under quiet conditions and when the speech was masked by speech from another talker or by noise. Masking affected performance more for the Spanish listeners than for the L1 listeners, but not for the Dutch listeners, whose performance was worse than the L1 case to about the same degree in all conditions. There were, however,large differences in the pattern of results across individual consonants, which were consistent with differences in how consonants are identified in the respective L1s.

Abstract

Listeners adapt rapidly to previously unheard talkers by
adjusting phoneme categories using lexical knowledge, in a
process termed lexically-guided perceptual learning. Although
this is firmly established for listening in the native language
(L1), perceptual flexibility in second languages (L2) is as yet
less well understood. We report two experiments examining L1
and L2 perceptual learning, the first in Mandarin-English late
bilinguals, the second in Australian learners of Mandarin. Both
studies showed stronger learning in L1; in L2, however,
learning appeared for the English-L1 group but not for the
Mandarin-L1 group. Phonological mapping differences from
the L1 to the L2 are suggested as the reason for this result.

Abstract

Languages contain tens of thousands of words, but these are constructed from a tiny handful of phonetic elements. Consequently, words resemble one another, or can be embedded within one another, a coup stick snot with standing. me process of spoken-word recognition by human listeners involves activation of multiple word candidates consistent with the input, and direct competition between activated candidate words. Further, human listeners are sensitive, at an early, prelexical, stage of speeeh processing, to constraints on what could potentially be a word of the language.

Abstract

Speech signals originate as a sequence of linguistic units selected by speakers, but these units are necessarily realised in the suprasegmental dimensions of time, frequency and amplitude. For this reason prosodic structure has been viewed as a mandatory target of language processing by both speakers and listeners. In apparent contradiction, however, prosody has also been argued to be ancillary rather than core linguistic structure, making processing of prosodic structure essentially optional. In the present tribute to one of the luminaries of prosodic research for the past quarter century, we review evidence from studies of the processing of lexical stress and focal accent which reconciles these views and shows that both claims are, each in their own way, fully true.

Abstract

Vocabularies contain hundreds of thousands of words built from only a handful of phonemes; longer words inevitably tend to contain shorter ones. Recognising speech thus requires distinguishing intended words from accidentally present ones. Acoustic information in speech is used wherever it contributes significantly to this process; but as this review shows, its contribution differs across languages, with the consequences of this including: identical and equivalently present information distinguishing the same phonemes being used in Polish but not in German, or in English but not in Italian; identical stress cues being used in Dutch but not in English; expectations about likely embedding patterns differing across English, French, Japanese.

Abstract

Listeners' recognition of spoken language involves complex decoding processes: The continuous speech stream must be segmented into its component words, and words must be recognized despite great variability in their pronunciation (due to talker differences, or to influence of phonetic context, or to speech register) and despite competition from many spuriously present forms supported by the speech signal. L1 listeners deal more readily with all levels of this complexity than L2 listeners. Fortunately, the decoding processes necessary for competent L2 listening can be taught in the classroom. Evidence-based methodologies targeted at the development of efficient speech decoding include teaching of minimal pairs, of phonotactic constraints, and of reduction processes, as well as the use of dictation and L2 video captions.

Abstract

The phoneme detection task is widely used in spoken word recognition research. Alphabetically literate participants, however, are more used to explicit representations of letters than of phonemes. The present study explored whether phoneme detection is sensitive to how target phonemes are, or may be, orthographically realised. Listeners detected the target sounds [b,m,t,f,s,k] in word-initial position in sequences of isolated English words. Response times were faster to the targets [b,m,t], which have consistent word-initial spelling, than to the targets [f,s,k], which are inconsistently spelled, but only when listeners’ attention was drawn to spelling by the presence in the experiment of many irregularly spelled fillers. Within the inconsistent targets [f,s,k], there was no significant difference between responses to targets in words with majority and minority spellings. We conclude that performance in the phoneme detection task is not necessarily sensitive to orthographic effects, but that salient orthographic manipulation can induce such sensitivity.

Abstract

Speakers and listeners have a shared goal: to communicate. The processes of speech perception and of speech production interact in many ways under the constraints of this communicative goal; such interaction is as characteristic of prosodic processing as of the processing of other aspects of linguistic structure. Two of the major uses of prosodic information in situations of communication are to encode salience and segmentation, and these themes unite the contributions to the symposium introduced by the present review.

Abstract

One of a listener's major tasks in understanding continuous speech is segmenting the speech signal into separate words. When listening conditions are difficult, speakers can help listeners by deliberately speaking more clearly. In four experiments, we examined how word boundaries are produced in deliberately clear speech. In an earlier report we showed that speakers do indeed mark word boundaries in clear speech, by pausing at the boundary and lengthening pre-boundary syllables; moreover, these effects are applied particularly to boundaries preceding weak syllables. In English, listeners use segmentation procedures which make word boundaries before strong syllables easier to perceive; thus marking word boundaries before weak syllables in clear speech will make clear precisely those boundaries which are otherwise hard to perceive. The present report presents supplementary data, namely prosodic analyses of the syllable following a critical word boundary. More lengthening and greater increases in intensity were applied in clear speech to weak syllables than to strong. Mean F0 was also increased to a greater extent on weak syllables than on strong. Pitch movement, however, increased to a greater extent on strong syllables than on weak. The effects were, however, very small in comparison to the durational effects we observed earlier for syllables preceding the boundary and for pauses at the boundary.

Abstract

This study evaluates whether early vocalizations develop in similar ways in children across diverse cultural contexts. We analyze data from daylong audio recordings of 49 children (1–36 months) from five different language/cultural backgrounds. Citizen scientists annotated these recordings to determine if child vocalizations contained canonical transitions or not (e.g., “ba” vs. “ee”). Results revealed that the proportion of clips reported to contain canonical transitions increased with age. Furthermore, this proportion exceeded 0.15 by around 7 months, replicating and extending previous findings on canonical vocalization development but using data from the natural environments of a culturally and linguistically diverse sample. This work explores how crowdsourcing can be used to annotate corpora, helping establish developmental milestones relevant to multiple languages and cultures. Lower inter‐annotator reliability on the crowdsourcing platform, relative to more traditional in‐lab expert annotators, means that a larger number of unique annotators and/or annotations are required, and that crowdsourcing may not be a suitable method for more fine‐grained annotation decisions. Audio clips used for this project are compiled into a large‐scale infant vocalization corpus that is available for other researchers to use in future work.

Abstract

Two experiments examined the dynamics of lexical activation in spoken-word recognition. In both, the key materials were pairs of onset-matched picturable nouns varying in frequency. Pictures associated with these words, plus two distractor pictures were displayed. A gating task, in which participants identified the picture associated with gradually lengthening fragments of spoken words, examined the availability of discriminating cues in the speech waveforms for these pairs. There was a clear frequency bias in participants’ responses to short, ambiguous fragments, followed by a temporal window in which discriminating information gradually became available. A visual-world experiment examined speech contingent eye movements. Fixation analyses suggested that frequency influences lexical competition well beyond the point in the speech signal at which the spoken word has been fully discriminated from its competitor (as identified using gating). Taken together, these data support models in which the processing dynamics of lexical activation are a limiting factor on recognition speed, over and above the temporal unfolding of the speech signal.

Abstract

The authors used 2 “visual-world” eye-tracking experiments to examine lexical access using Dutch constructions in which the verb did or did not place semantic constraints on its subsequent subject noun phrase. In Experiment 1, fixations to the picture of a cohort competitor (overlapping with the onset of the referent’s name, the subject) did not differ from fixations to a distractor in the constraining-verb condition. In Experiment 2, cross-splicing introduced phonetic information that temporarily biased the input toward the cohort competitor. Fixations to the cohort competitor temporarily increased in both the neutral and constraining conditions. These results favor models in which mapping from the input onto meaning is continuous over models in which contextual effects follow access of an initial form-based competitor set.

Abstract

The neural mechanism for selectively tuning in to a target speaker while tuning out the others in a multi-speaker situation (i.e., the cocktail-party effect) remains elusive. Here we addressed this issue by measuring brain activity simultaneously from a listener and from multiple speakers while they were involved in naturalistic conversations. Results consistently show selectively enhanced interpersonal neural synchronization (INS) between the listener and the attended speaker at left temporal–parietal junction, compared with that between the listener and the unattended speaker across different multi-speaker situations. Moreover, INS increases significantly prior to the occurrence of verbal responses, and even when the listener’s brain activity precedes that of the speaker. The INS increase is independent of brain-to-speech synchronization in both the anatomical location and frequency range. These findings suggest that INS underlies the selective process in a multi-speaker situation through neural predictions at the content level but not the sensory level of speech.

Abstract

Researchers interested in face processing have recently debated whether access to the name of a known person occurs in parallel with retrieval of semantic-biographical codes, rather than in a sequential fashion. Recently, Schweinberger, Burton, and Kelly (2001) took a failure to obtain a semantic context effect in a manual syllable judgment task on names of famous faces as support for this position. In two experiments, we compared the effects of visually presented categorically related prime words with either objects (e.g. prime: animal; target: dog) or faces of celebrities (e.g. prime: actor; target: Bruce Willis) as targets. Targets were either manually categorized with regard to the number of syllables (as in Schweinberger et al.), or they were overtly named. For neither objects nor faces was semantic priming obtained in syllable decisions; crucially, however, priming was obtained when objects and faces were overtly named. These results suggest that both face and object naming are susceptible to semantic context effects

Abstract

This work was supported by grants from the French Agence Nationale de la Recherche (ANR-2010-BLAN-1901) and from French Fondation de France to Anne Christophe, from the National Institute of Child Health and Human Development (HD054448) to Cynthia Fisher, Fondation Fyssen and Ecole de Neurosciences de Paris to Alex Cristia, and a PhD fellowship from the Direction Générale de l'Armement (DGA, France) supported by the PhD program FdV (Frontières du Vivant) to Isabelle Dautriche. We thank Isabelle Brunet for the recruitment, Michel Dutat for the technical support, and Hernan Anllo for his puppet mastery skill. We are grateful to the families that participated in this study. We also thank two anonymous reviewers for their comments on an earlier draft of this manuscript.

Abstract

The relationship between semantic and grammatical processing in sentence comprehension was investigated by examining event-related potential (ERP) and event-related power changes in response to semantic and grammatical violations. Sentences with semantic, phrase structure, or number violations and matched controls were presented serially (1.25 words/s) to 20 participants while EEG was recorded. Semantic violations were associated with an N400 effect and a theta band increase in power, while grammatical violations were associated with a P600 effect and an alpha/beta band decrease in power. A quartile analysis showed that for both types of violations, larger average violation effects were associated with lower relative amplitudes of oscillatory activity, implying an inverse relation between ERP amplitude and event-related power magnitude change in sentence processing.

Abstract

We present written naming norms from 153 young adult Dutch speakers for 1397 photographs (the BOSS set; see Brodeur, Dionne-Dostie, Montreuil, & Lepage, 2010; Brodeur, Guérard, & Bouras, 2014). From the norming study, we report the preferred (modal) name, alternative names, name agreement, and average object agreement. In addition, the data base includes Zipf frequency, word prevalence and Age of Acquisition for the modal picture names collected. Furthermore, we describe a subset of 359 photographs with very good name agreement and a subset of 35 photos with two common names. These sets may be particularly valuable for designing experiments. Though the participants typed the object names, comparisons with other datasets indicate that the collected norms are valuable for spoken naming studies as well.

Abstract

This article surveys what is currently known about the complex interplay between genetics and the language sciences. It focuses not only on the genetic architecture of language and speech, but also on their interactions on the cultural and evolutionary timescales. Given the complexity of these issues and their current state of flux and high dynamism, this article surveys the main findings and topics of interest while also briefly introducing the main relevant methods, thus allowing the interested reader to fully appreciate and understand them in their proper context. Of course, not all the relevant publications and resources are mentioned, but this article aims to select the most relevant, promising, or accessible for nonspecialists.

Abstract

One of the best-known types of non-independence between languages is caused by genealogical relationships due to descent from a common ancestor. These can be represented by (more or less resolved and controversial) language family trees. In theory, one can argue that language families should be built through the strict application of the comparative method of historical linguistics, but in practice this is not always the case, and there are several proposed classifications of languages into language families, each with its own advantages and disadvantages. A major stumbling block shared by most of them is that they are relatively difficult to use with computational methods, and in particular with phylogenetics. This is due to their lack of standardization, coupled with the general non-availability of branch length information, which encapsulates the amount of evolution taking place on the family tree. In this paper I introduce a method (and its implementation in R) that converts the language classifications provided by four widely-used databases (Ethnologue, WALS, AUTOTYP and Glottolog) intothe de facto Newick standard generally used in phylogenetics, aligns the four most used conventions for unique identifiers of linguistic entities (ISO 639-3, WALS, AUTOTYP and Glottocode), and adds branch length information from a variety of sources (the tree's own topology, an externally given numeric constant, or a distance matrix). The R scripts, input data and resulting Newick trees are available under liberal open-source licenses in a GitHub repository (https://github.com/ddediu/lgfam-newick), to encourage and promote the use of phylogenetic methods to investigate linguistic diversity and its temporal dynamics.

Abstract

The correlations between interpopulation genetic and linguistic diversities are mostly noncausal (spurious), being due to historical processes and geographical factors that shape them in similar ways. Studies of such correlations usually consider allele frequencies and linguistic groupings (dialects, languages, linguistic families or phyla), sometimes controlling for geographic, topographic, or ecological factors. Here, we consider the relation between allele frequencies and linguistic typological features. Specifically, we focus on the derived haplogroups of the brain growth and development-related genes ASPM and Microcephalin, which show signs of natural selection and a marked geographic structure, and on linguistic tone, the use of voice pitch to convey lexical or grammatical distinctions. We hypothesize that there is a relationship between the population frequency of these two alleles and the presence of linguistic tone and test this hypothesis relative to a large database (983 alleles and 26 linguistic features in 49 populations), showing that it is not due to the usual explanatory factors represented by geography and history. The relationship between genetic and linguistic diversity in this case may be causal: certain alleles can bias language acquisition or processing and thereby influence the trajectory of language change through iterated cultural transmission.

Abstract

Here we re-evaluate our 2013 paper on the antiquity of language (Dediu and Levinson, 2013) in the light of a surge of new information on human evolution in the last half million years. Although new genetic data suggest the existence of some cognitive differences between Neanderthals and modern humans — fully expected after hundreds of thousands of years of partially separate evolution, overall our claims that Neanderthals were fully articulate beings and that language evolution was gradual are further substantiated by the wealth of new genetic, paleontological and archeological evidence briefly reviewed here.

Abstract

This paper argues that inter-individual and inter-group variation in language acquisition, perception, processing and production, rooted in our biology, may play a largely neglected role in sound change. We begin by discussing the patterning of these differences, highlighting those related to vocal tract anatomy with a foundation in genetics and development. We use our ArtiVarK database, a large multi-ethnic sample comprising 3D intraoral optical scans, as well as structural, static and real-time MRI scans of vocal tract anatomy and speech articulation, to quantify the articulatory strategies used to produce the North American English /r/ and to statistically show that anatomical factors seem to influence these articulatory strategies. Building on work showing that these alternative articulatory strategies may have indirect coarticulatory effects, we propose two models for how biases due to variation in vocal tract anatomy may affect sound change. The first involves direct overt acoustic effects of such biases that are then reinterpreted by the hearers, while the second is based on indirect coarticulatory phenomena generated by acoustically covert biases that produce overt “at-a-distance” acoustic effects. This view implies that speaker communities might be “poised” for change because they always contain pools of “standing variation” of such biased speakers, and when factors such as the frequency of the biased speakers in the community, their positions in the communicative network or the topology of the network itself change, sound change may rapidly follow as a self-reinforcing network-level phenomenon, akin to a phase transition. Thus, inter-speaker variation in structured and dynamic communicative networks may couple the initiation and actuation of sound change.

Abstract

Linguistic diversity is affected by multiple factors, but it is usually assumed that variation in the anatomy of our speech organs
plays no explanatory role. Here we use realistic computer models of the human speech organs to test whether inter-individual
and inter-group variation in the shape of the hard palate (the bony roof of the mouth) affects acoustics of speech sounds. Based
on 107 midsagittal MRI scans of the hard palate of human participants, we modelled with high accuracy the articulation of a set
of five cross-linguistically representative vowels by agents learning to produce speech sounds. We found that different hard
palate shapes result in subtle differences in the acoustics and articulatory strategies of the produced vowels, and that these
individual-level speech idiosyncrasies are amplified by the repeated transmission of language across generations. Therefore,
we suggest that, besides culture and environment, quantitative biological variation can be amplified, also influencing language.