ASPM-lexical tone association in speakers of a tone language: Direct evidence for the genetic-biasing hypothesis of language evolution

Age-related changes in lexical tones and intonation in Cantonese infant-directed speech: A longitudinal study

This longitudinal study investigated modifications in lexical tones and intonation in Cantonese infant-directed speech (IDS) to children aged 15 and 23 months. The results showed that to children at both ages, mothers increased intonational pitch height and pitch variability across utterances, and produced lexical tones with generally larger tonal space and greater intra-talker tone variation within categories in IDS compared to adult-directed speech. No significant changes were found in either lexical tones or intonation in IDS between the two ages. In addition, positive correlations were found between the degree of age-related changes in tonal space and intonational exaggerations in IDS as children grow older. The findings were discussed with a focus on the co-occurrence of an increase in tone variation along with tonal space expansion, the age-related changes in lexical tones and intonation, and the associations between the lexical and prosodic pitch modifications.

Language follows a distinct mode of extra-genomic evolution

As one of the most specific, yet most diverse of human behaviors, language is shaped by both genomic and extra-genomic evolution. Sharing methods and models between these modes of evolution has significantly advanced our understanding of language and inspired generalized theories of its evolution. Progress is hampered, however, by the fact that the extra-genomic evolution of languages, i.e. linguistic evolution, maps only partially to other forms of evolution. Contrasting it with the biological evolution of eukaryotes and the cultural evolution of technology as the best understood models, we show that linguistic evolution is special by yielding a stationary dynamic rather than stable solutions, and that this dynamic allows the use of language change for social differentiation while maintaining its global adaptiveness. Linguistic evolution furthermore differs from technological evolution by requiring vertical transmission, allowing the reconstruction of phylogenies; and it differs from eukaryotic biological evolution by foregoing a genotype vs phenotype distinction, allowing deliberate and biased change. Recognising these differences will improve our empirical tools and open new avenues for analyzing how linguistic, cultural, and biological evolution interacted with each other when language emerged in the hominin lineage. Importantly, our framework will help to cope with unprecedented scientific and ethical challenges that presently arise from how rapid cultural evolution impacts language, most urgently from interventional clinical tools for language disorders, potential epigenetic effects of technology on language, artificial intelligence and linguistic communicators, and global losses of linguistic diversity and identity. Beyond language, the distinctions made here allow identifying variation in other forms of biological and cultural evolution, developing new perspectives for empirical research.

Infant-directed speech facilitates word learning through attentional mechanisms: An fNIRS study of toddlers

The speech register that adults especially caregivers use when interacting with infants and toddlers, that is, infant-directed speech (IDS) or baby talk, has been reported to facilitate language development throughout the early years. However, the neural mechanisms as well as why IDS results in such a developmental faciliatory effect remain to be investigated. The current study uses functional near-infrared spectroscopy (fNIRS) to evaluate two alternative hypotheses of such a facilitative effect, that IDS serves to enhance linguistic contrastiveness or to attract the child's attention. Behavioral and fNIRS data were acquired from twenty-seven Cantonese-learning toddlers 15-20 months of age when their parents spoke to them in either an IDS or adult-directed speech (ADS) register in a naturalistic task in which the child learned four disyllabic pseudowords. fNIRS results showed significantly greater neural responses to IDS than ADS register in the left dorsolateral prefrontal cortex (L-dlPFC), but opposite response patterns in the bilateral inferior frontal gyrus (IFG). The differences in fNIRS responses to IDS and to ADS in the L-dlPFC and the left parietal cortex (L-PC) showed significantly positive correlations with the differences in the behavioral word-learning performance of toddlers. The same fNIRS measures in the L-dlPFC and right PC (R-PC) of toddlers were significantly correlated with pitch range differences of parents between the two speech conditions. Together, our results suggest that the dynamic prosody in IDS increased toddlers' attention through greater involvement of the left frontoparietal network that facilitated word learning, compared to ADS. RESEARCH HIGHLIGHTS: This study for the first time examined the neural mechanisms of how infant-directed speech (IDS) facilitates word learning in toddlers. Using fNIRS, we identified the cortical regions that were directly involved in IDS processing. Our results suggest that IDS facilitates word learning by engaging a right-lateralized prosody processing and top-down attentional mechanisms in the left frontoparietal networks. The language network including the inferior frontal gyrus and temporal cortex was not directly involved in IDS processing to support word learning.

Cross-cultural adaptation and psychometric properties of the Mainland Chinese version of the manchester orofacial pain disability scale (MOPDS) among college students

BACKGROUND

Orofacial pain (OFP) is a highly prevalent disorder in mainland China that predisposes to an associated physical and psychological disability. There is lack of a good properties mainland Chinese version of instrument to examine OFP. This study aims to cross-cultural adaptation and evaluate psychometrics properties of the Manchester Orofacial Pain Disability Scale (MOPDS) in mainland Chinese Mandarin context.

METHODS

Translation and cross-cultural adaption of the mainland Chinese version MOPDS were conducted following accepted guidelines of self-report measures. Chinese college students (N = 1039) completed the mainland Chinese version of the MOPDS for item analysis, reliability and validity tests, and measurement invariance analysis, and after a one-month interval, around 10% of the sample (n = 110) were invited to retest. To conduct the CFA and measurement invariance analysis, Mplus 8.4 was used. IBM SPSS Statistics 26 software were used for all additional studies.

RESULTS

We found that the mainland Chinese version of MOPDS contains 25 items, divided into two categories: physical disability and psychological disability. The scale demonstrated excellent internal reliability, test-retest reliability, and validity. The measurement invariance results proved that the scale could be applied to people of different gender, age, and health consultation status.

CONCLUSIONS

The results demonstrated the mainland Chinese version of MOPDS has good psychometric properties and can be used to measure the level of physical and psychological disability of Chinese OFP peoples.

Language experience predicts music processing in a half-million speakers of fifty-four languages

Tonal languages differ from other languages in their use of pitch (tones) to distinguish words. Lifelong experience speaking and hearing tonal languages has been argued to shape auditory processing in ways that generalize beyond the perception of linguistic pitch to the perception of pitch in other domains like music. We conducted a meta-analysis of prior studies testing this idea, finding moderate evidence supporting it. But prior studies were limited by mostly small sample sizes representing a small number of languages and countries, making it challenging to disentangle the effects of linguistic experience from variability in music training, cultural differences, and other potential confounds. To address these issues, we used web-based citizen science to assess music perception skill on a global scale in 34,034 native speakers of 19 tonal languages (e.g., Mandarin, Yoruba). We compared their performance to 459,066 native speakers of other languages, including 6 pitch-accented (e.g., Japanese) and 29 non-tonal languages (e.g., Hungarian). Whether or not participants had taken music lessons, native speakers of all 19 tonal languages had an improved ability to discriminate musical melodies on average, relative to speakers of non-tonal languages. But this improvement came with a trade-off: tonal language speakers were also worse at processing the musical beat. The results, which held across native speakers of many diverse languages and were robust to geographic and demographic variation, demonstrate that linguistic experience shapes music perception, with implications for relations between music, language, and culture in the human mind.

A large-scale repository of spoken narratives in French, German and Spanish from Cantonese-speaking learners

Interdisciplinary research on foreign language learning has important implications for learning and education. In this paper, we present the Repository of Third Language (L3) Spoken Narratives from Modern Language Learners in Hong Kong (L3HK Repository). This database contains 906 audio recordings and annotated transcripts of spoken narratives in French, German, and Spanish that were elicited from Cantonese-speaking (L1) young adults using a wordless picture book, "Frog, Where Are You?". All participants spoke English as the second language (L2) and learned the target language as a third language (L3). We collected their demographic information, answers to a motivation questionnaire, parental socioeconomic status, and music background. Furthermore, for a subset of participants, we collected their L1 and L2 proficiency scores and additional experimental data on working memory and music perception. This database is valuable for examining cross-sectional changes in foreign language learning. The extensive data on phenotypes provide opportunities to explore learner-internal and learner-external factors in foreign language learning outcomes. These data may also be helpful for those who work on speech recognition.

Biolinguistics: A Scientometric Analysis of Research on (Children's) Molecular Genetics of Speech and Language (Disorders)

There are numerous children and adolescents throughout the world who are either diagnosed with speech and language disorders or manifest any of them as a result of another disorder. Meanwhile, since the emergence of language as an innate capability, the question of whether it constitutes a behaviour or an innate ability has been debated for decades. There have been several theories developed that support and demonstrate the biological foundations of human language. Molecular evidence of the biological basis of language came from the FOXP2 gene, also known as the language gene. Taking a closer look at both human language and biology, biolinguistics is at the core of these inquiries-attempting to understand the aetiologies of the genetics of speech and language disorders in children and adolescents. This paper presents empirical evidence based on both scientometrics and bibliometrics. We collected data between 1935 and 2022 from Scopus, WOS, and Lens. A total of 1570 documents were analysed from Scopus, 1440 from the WOS, and 5275 from Lens. Bibliometric analysis was performed using Excel based on generated reports from these three databases. CiteSpace 5.8.R3 and VOSviewer 1.6.18 were used to conduct the scientometric analysis. Eight bibliometric and eight scientometric indicators were used to measure the development of the field of biolinguistics, including but not limited to the production size of knowledge, the most examined topics, and the most frequent concepts and variables. A major finding of our study is identifying the most examined topics in the genetics of speech and language disorders. These included: gestural communication, structural design, cultural evolution, neural network, language tools, human language faculty, evolutionary biology, molecular biology, and theoretical perspective on language evolution.

Cross-linguistic patterns of speech prosodic differences in autism: A machine learning study

Differences in speech prosody are a widely observed feature of Autism Spectrum Disorder (ASD). However, it is unclear how prosodic differences in ASD manifest across different languages that demonstrate cross-linguistic variability in prosody. Using a supervised machine-learning analytic approach, we examined acoustic features relevant to rhythmic and intonational aspects of prosody derived from narrative samples elicited in English and Cantonese, two typologically and prosodically distinct languages. Our models revealed successful classification of ASD diagnosis using rhythm-relative features within and across both languages. Classification with intonation-relevant features was significant for English but not Cantonese. Results highlight differences in rhythm as a key prosodic feature impacted in ASD, and also demonstrate important variability in other prosodic properties that appear to be modulated by language-specific differences, such as intonation.

Contributions of common genetic variants to specific languages and to when a language is learned

Research over the past two decades has identified a group of common genetic variants explaining a portion of variance in native language ability. The present study investigates whether the same group of genetic variants are associated with different languages and languages learned at different times in life. We recruited 940 young adults who spoke from childhood Chinese and English as their first (native) (L1) and second (L2) language, respectively, who were learners of a new, third (L3) language. For the variants examined, we found a general decrease of contribution of genes to language functions from native to foreign (L2 and L3) languages, with variance in foreign languages explained largely by non-genetic factors such as musical training and motivation. Furthermore, genetic variants that were found to contribute to traits specific to Chinese and English respectively exerted the strongest effects on L1 and L2. These results seem to speak against the hypothesis of a language- and time-universal genetic core of linguistic functions. Instead, they provide preliminary evidence that genetic contribution to language may depend at least partly on the intricate language-specific features. Future research including a larger sample size, more languages and more genetic variants is required to further explore these hypotheses.

Language and nonlanguage factors in foreign language learning: evidence for the learning condition hypothesis

The question of why native and foreign languages are learned with a large performance gap has prompted language researchers to hypothesize that they are subserved by fundamentally different mechanisms. However, this hypothesis may not have taken into account that these languages can be learned under different conditions (e.g., naturalistic vs. classroom settings). With a large sample of 636 third language (L3) learners who learned Chinese and English as their first (L1) and second (L2) languages, the present study examined the association of learning success across L1-L3. We argue that learning conditions may reveal how these languages are associated in terms of learning success. Because these languages were learned under a continuum of naturalistic to classroom conditions from L1 to L3, this sample afforded us a unique opportunity to evaluate the hypothesis that similar learning conditions between languages could be an important driving force determining language learning success. After controlling for nonlanguage factors such as musical background and motivational factors and using a convergence of analytics including the general linear models, the structural equation models, and machine learning, we found that the closer two languages were on the continuum of learning conditions, the stronger their association of learning success. Specifically, we found a significant association between L1 and L2 and between L2 and L3, but not between L1 and L3. Our results suggest that learning conditions may have important implications for the learning success of L1-L3.

Tone and genes: New cross-linguistic data and methods support the weak negative effect of the "derived" allele of ASPM on tone, but not of Microcephalin

While it is generally accepted that language and speech have genetic foundations, and that the widespread inter-individual variation observed in many of their aspects is partly driven by variation in genes, it is much less clear if differences between languages may also be partly rooted in our genes. One such proposal is that the population frequencies of the so-called "derived" alleles of two genes involved in brain growth and development, ASPM and Microcephalin, are related to the probability of speaking a tone language or not. The original study introducing this proposal used a cross-linguistic statistical approach, showing that these associations are "special" when compared with many other possible relationships between genetic variants and linguistic features. Recent experimental evidence supports strongly a negative effect of the "derived" allele of ASPM on tone perception and/or processing within individuals, but failed to find any effect for Microcephalin. Motivated by these experimental findings, I conduct here a cross-linguistic statistical test, using a larger and updated dataset of 175 samples from 129 unique (meta)populations, and a battery of methods including mixed-effects regression (Bayesian and maximum-likelihood), mediation and path analysis, decision trees and random forests, using permutations and restricted sampling to control for the confounding effects of genealogy (language families) and contact (macroareas). Overall, the results support a negative weak effect of ASPM-D against the presence of tone above and beyond the strong confounding influences of genealogy and contact, but they suggest that the original association between tone and MCPH1 might have been a false positive, explained by differences between populations and languages within and outside Africa. Thus, these cross-linguistic population-scale statistical results are fully consonant with the inter-individual-level experimental results, and suggest that the observed linguistic diversity may be, at least in some cases, partly driven by genetic diversity.

Interindividual Variation Refuses to Go Away: A Bayesian Computer Model of Language Change in Communicative Networks

Treating the speech communities as homogeneous entities is not an accurate representation of reality, as it misses some of the complexities of linguistic interactions. Inter-individual variation and multiple types of biases are ubiquitous in speech communities, regardless of their size. This variation is often neglected due to the assumption that “majority rules,” and that the emerging language of the community will override any such biases by forcing the individuals to overcome their own biases, or risk having their use of language being treated as “idiosyncratic” or outright “pathological.” In this paper, we use computer simulations of Bayesian linguistic agents embedded in communicative networks to investigate how biased individuals, representing a minority of the population, interact with the unbiased majority, how a shared language emerges, and the dynamics of these biases across time. We tested different network sizes (from very small to very large) and types (random, scale-free, and small-world), along with different strengths and types of bias (modeled through the Bayesian prior distribution of the agents and the mechanism used for generating utterances: either sampling from the posterior distribution [“sampler”] or picking the value with the maximum probability [“MAP”]). The results show that, while the biased agents, even when being in the minority, do adapt their language by going against their a priori preferences, they are far from being swamped by the majority, and instead the emergent shared language of the whole community is influenced by their bias.

Cultural Evolution of Genetic Heritability

Behavioral genetics and cultural evolution have both revolutionized our understanding of human behavior-largely independent of each other. Here we reconcile these two fields under a dual inheritance framework, offering a more nuanced understanding of the interaction between genes and culture. Going beyond typical analyses of gene-environment interactions, we describe the cultural dynamics that shape these interactions by shaping the environment and population structure. A cultural evolutionary approach can explain, for example, how factors such as rates of innovation and diffusion, density of cultural sub-groups, and tolerance for behavioral diversity impact heritability estimates, thus yielding predictions for different social contexts. Moreover, when cumulative culture functionally overlaps with genes, genetic effects become masked, unmasked, or even reversed, and the causal effects of an identified gene become confounded with features of the cultural environment. The manner of confounding is specific to a particular society at a particular time, but a WEIRD (Western, educated, industrialized, rich, democratic) sampling problem obscures this boundedness. Cultural evolutionary dynamics are typically missing from models of gene-to-phenotype causality, hindering generalizability of genetic effects across societies and across time. We lay out a reconciled framework and use it to predict the ways in which heritability should differ between societies, between socioeconomic levels and other groupings within some societies but not others, and over the life course. An integrated cultural evolutionary behavioral genetic approach cuts through the nature-nurture debate and helps resolve controversies in topics such as IQ.

The sounds of prehistoric speech

Evidence is reviewed for widespread phonological and phonetic tendencies in contemporary languages. The evidence is based largely on the frequency of sound types in word lists and in phoneme inventories across the world's languages. The data reviewed point to likely tendencies in the languages of the Upper Palaeolithic. These tendencies include the reliance on specific nasal and voiceless stop consonants, the relative dispreference for posterior voiced consonants and the use of peripheral vowels. More tenuous hypotheses related to prehistoric languages are also reviewed. These include the propositions that such languages lacked labiodental consonants and relied more heavily on vowels, when contrasted to many contemporary languages. Such hypotheses suggest speech has adapted to subtle pressures that may in some cases vary across populations. This article is part of the theme issue 'Reconstructing prehistoric languages'.

Musicians show enhanced perception, but not production, of native lexical tones

Many studies have reported a musical advantage in perceiving lexical tones among non-native listeners, but it is unclear whether this advantage also applies to native listeners, who are likely to show ceiling-like performance and thus mask any potential musical advantage. The ongoing tone merging phenomenon in Hong Kong Cantonese provides a unique opportunity to investigate this as merging tone pairs are reported to be difficult to differentiate even among native listeners. In the present study, native Cantonese musicians and non-musicians were compared based on discrimination and identification of merging Cantonese tone pairs to determine whether a musical advantage in perception will be observed, and if so, whether this is seen on the phonetic and/or phonological level. The tonal space of the subjects' lexical tone production was also compared. Results indicated that the musicians outperformed the non-musicians on the two perceptual tasks, as indexed by a higher accuracy and faster reaction time, particularly on the most difficult tone pair. In the production task, however, there was no group difference in various indices of tonal space. Taken together, musical experience appears to facilitate native listeners' perception, but not production, of lexical tones, which partially supports a music-to-language transfer effect.

Lifelong Tone Language Experience does not Eliminate Deficits in Neural Encoding of Pitch in Autism Spectrum Disorder

Atypical pitch processing is a feature of Autism Spectrum Disorder (ASD), which affects non-tone language speakers' communication. Lifelong auditory experience has been demonstrated to modify genetically-predisposed risks for pitch processing. We examined individuals with ASD to test the hypothesis that lifelong auditory experience in tone language may eliminate impaired pitch processing in ASD. We examined children's and adults' Frequency-following Response (FFR), a neurophysiological component indexing early neural sensory encoding of pitch. Univariate and machine-learning-based analytics suggest less robust pitch encoding and diminished pitch distinctions in the FFR from individuals with ASD. Contrary to our hypothesis, results point to a linguistic pitch encoding impairment associated with ASD that may not be eliminated even by lifelong sensory experience.

Sinking In: The Peripheral Baldwinisation of Human Cognition

The Baldwin effect is a hypothetical process in which a learned response to environmental change evolves a genetic basis. Modelling has shown that the Baldwin effect offers a plausible and elegant explanation for the emergence of complex behavioural traits, but there is little direct empirical evidence for its occurrence. We highlight experimental evidence of the Baldwin effect and argue that it acts preferentially on peripheral rather than on central cognitive processes. Careful scrutiny of research on taste-aversion and fear learning, language, and imitation indicates that their efficiency depends on adaptively specialised input and output processes: analogues of scanner and printer interfaces that feed information to core inference processes and structure their behavioural expression.