Newborns' Cry Melody Is Shaped by Their Native Language

The central role of the individual in the history of brains

Every species' brain, body and behavior is shaped by the contingencies of their evolutionary history; these exert pressures that change their developmental trajectories. There is, however, another set of contingencies that shape us and other animals: those that occur during a lifetime. In this perspective piece, we show how these two histories are intertwined by focusing on the individual. We suggest that organisms--their brains and behaviors--are not solely the developmental products of genes and neural circuitry but individual centers of action unfolding in time. To unpack this idea, we first emphasize the importance of variation and the central role of the individual in biology. We then go over "errors in time" that we often make when comparing development across species. Next, we reveal how an individual's development is a process rather than a product by presenting a set of case studies. These show developmental trajectories as emerging in the contexts of the "the actual now" and "the presence of the past". Our consideration reveals that individuals are slippery-they are never static; they are a set of on-going, creative activities. In light of this, it seems that taking individual development seriously is essential if we aspire to make meaningful comparisons of neural circuits and behavior within and across species.

Trajectories of brain and behaviour development in the womb, at birth and through infancy

Birth is often seen as the starting point for studying effects of the environment on human development, with much research focused on the capacities of young infants. However, recent imaging advances have revealed that the complex behaviours of the fetus and the uterine environment exert influence. Birth is now viewed as a punctuate event along a developmental pathway of increasing autonomy of the child from their mother. Here we highlight (1) increasing physiological autonomy and perceptual sensitivity in the fetus, (2) physiological and neurochemical processes associated with birth that influence future behaviour, (3) the recalibration of motor and sensory systems in the newborn to adapt to the world outside the womb and (4) the effect of the prenatal environment on later infant behaviours and brain function. Taken together, these lines of evidence move us beyond nature-nurture issues to a developmental human lifespan view beginning within the womb.

The key to understanding core knowledge resides in the fetus

What Babies Know outlines a compelling case for why infancy research is fundamental for conceptualizing what it is to be human. There is another period in human development that is relatively inaccessible, yet is more important. In order to truly understand the nature of core knowledge, perception, and cognition, we must start not with the infant, but with the fetus.

Effect of Age and Unaided Acoustic Hearing on Pediatric Cochlear Implant Users' Ability to Distinguish Yes/No Statements and Questions

PURPOSE

The purpose of this study was to evaluate the ability to discriminate yes/no questions from statements in three groups of children: bilateral cochlear implant (CI) users, nontraditional CI users with aidable hearing preoperatively in the ear to be implanted, and controls with normal hearing. Half of the nontraditional CI users had sufficient postoperative acoustic hearing in the implanted ear to use electric-acoustic stimulation, and half used a CI alone.

METHOD

Participants heard recorded sentences that were produced either as yes/no questions or as statements by three male and three female talkers. Three raters scored each participant response as either a question or a statement. Bilateral CI users (n = 40, 4-12 years old) and normal-hearing controls (n = 10, 4-12 years old) were tested binaurally in the free field. Nontraditional CI recipients (n = 22, 6-17 years old) were tested with direct audio input to the study ear.

RESULTS

For the bilateral CI users, performance was predicted by age but not by 125-Hz acoustic thresholds; just under half (n = 17) of the participants in this group had measurable 125-Hz thresholds in their better ear. For nontraditional CI recipients, better performance was predicted by lower 125-Hz acoustic thresholds in the test ear, and there was no association with participant age. Performance approached that of the normal-hearing controls for some participants in each group.

CONCLUSIONS

Results suggest that a 125-Hz acoustic hearing supports discrimination of yes/no questions and statements in pediatric CI users. Bilateral CI users with little or no acoustic hearing at 125 Hz develop the ability to perform this task, but that ability emerges later than for children with better acoustic hearing. These results underscore the importance of preserving acoustic hearing for pediatric CI users when possible.

Exposure to bilingual or monolingual maternal speech during pregnancy affects the neurophysiological encoding of speech sounds in neonates differently

Introduction

Exposure to maternal speech during the prenatal period shapes speech perception and linguistic preferences, allowing neonates to recognize stories heard frequently in utero and demonstrating an enhanced preference for their mother's voice and native language. Yet, with a high prevalence of bilingualism worldwide, it remains an open question whether monolingual or bilingual maternal speech during pregnancy influence differently the fetus' neural mechanisms underlying speech sound encoding.

Methods

In the present study, the frequency-following response (FFR), an auditory evoked potential that reflects the complex spectrotemporal dynamics of speech sounds, was recorded to a two-vowel /oa/ stimulus in a sample of 129 healthy term neonates within 1 to 3 days after birth. Newborns were divided into two groups according to maternal language usage during the last trimester of gestation (monolingual; bilingual). Spectral amplitudes and spectral signal-to-noise ratios (SNR) at the stimulus fundamental (F0) and first formant (F1) frequencies of each vowel were, respectively, taken as measures of pitch and formant structure neural encoding.

Results

Our results reveal that while spectral amplitudes at F0 did not differ between groups, neonates from bilingual mothers exhibited a lower spectral SNR. Additionally, monolingually exposed neonates exhibited a higher spectral amplitude and SNR at F1 frequencies.

Discussion

We interpret our results under the consideration that bilingual maternal speech, as compared to monolingual, is characterized by a greater complexity in the speech sound signal, rendering newborns from bilingual mothers more sensitive to a wider range of speech frequencies without generating a particularly strong response at any of them. Our results contribute to an expanding body of research indicating the influence of prenatal experiences on language acquisition and underscore the necessity of including prenatal language exposure in developmental studies on language acquisition, a variable often overlooked yet capable of influencing research outcomes.

Lateralization of dorsal fiber tract targeting Broca's area concurs with language skills during development

Language is bounded to the left hemisphere in the adult brain and the functional lateralization can already be observed early during development. Here we investigate whether this is paralleled by a lateralization of the white matter structural language network. We analyze the strength and microstructural properties of language-related fiber tracts connecting temporal and frontal cortices with a separation of two dorsal tracts, one targeting the posterior Broca's area (BA44) and one targeting the precentral gyrus (BA6). In a large sample of young children (3-6 years), we demonstrate that, in contrast to the BA6-targeting tract, the microstructural asymmetry of the BA44-targeting fiber tract significantly correlates locally with different aspects of development. While the asymmetry in its anterior segment reflects age, the asymmetry in its posterior segment is associated with the children's language skills. These findings demonstrate a fine-grained structure-to-function mapping in the lateralized network and go beyond our current view of language-related human brain maturation.

Developmental programming by prenatal sounds: insights into possible mechanisms

In recent years, the impact of prenatal sound on development, notably for programming individual phenotypes for postnatal conditions, has increasingly been revealed. However, the mechanisms through which sound affects physiology and development remain mostly unexplored. Here, I gather evidence from neurobiology, developmental biology, cellular biology and bioacoustics to identify the most plausible modes of action of sound on developing embryos. First, revealing often-unsuspected plasticity, I discuss how prenatal sound may shape auditory system development and determine individuals' later capacity to receive acoustic information. I also consider the impact of hormones, including thyroid hormones, glucocorticoids and androgen, on auditory plasticity. Second, I review what is known about sound transduction to other - non-auditory - brain regions, and its potential to input on classical developmental programming pathways. Namely, the auditory pathway has direct anatomical and functional connectivity to the hippocampus, amygdala and/or hypothalamus, in mammals, birds and anurans. Sound can thus trigger both immediate and delayed responses in these limbic regions, which are specific to the acoustic stimulus and its biological relevance. Third, beyond the brain, I briefly consider the possibility for sound to directly affect cellular functioning, based on evidence in earless organisms (e.g. plants) and cell cultures. Together, the multi-disciplinary evidence gathered here shows that the brain is wired to allow multiple physiological and developmental effects of sound. Overall, there are many unexplored, but possible, pathways for sound to impact even primitive or immature organisms. Throughout, I identify the most promising research avenues for unravelling the processes of acoustic developmental programming.

The Natural Tendency for Wide and Careful Listening: Exploring the Relationship Between Open-Mindedness and Psychological Science

We take open-mindedness to be a component of intellectual humility, as much of the recent empirical literature regarding intellectual humility does but contrary to what some philosophers think. More particularly, we understand intellectual humility as having a self-directed component, which is concerned primarily with the regulation of confidence we have on our own epistemic goods and capacities, and an other-directed component, which is concerned primarily with one's epistemic openness to others so to improve one's epistemic situation. Given that the open-minded person is disposed give new ideas serious consideration, it is crucial that she both listens widely and carefully to other's ideas. In this paper, we examine whether there is evidence to suggest that we have a natural, evolved tendency for this wide and careful listening related to open-mindedness. We conclude that there is indication of a natural tendency for wide listening, especially an in-group tendency. However, careful listening lacks more substantive empirical studies. It seems that human infants are much more inclined to be charitable and attentive to in-group cues or opinions. This is important evidence to deconstruct the idea of a natural tendency of virtuous intellectual humility that opens up the discussion for the role of social learning in cultivating and maintaining a virtuous life.

Contrasting Accounts of Early Speech Perception and Production

Language researchers have historically either dismissed or ignored completely behavioral accounts of language acquisition while at the same time acknowledging the important role of experience in language learning. Many language researchers have also moved away from theories based on an innate generative universal grammar and promoted experience-dependent and usage-based theories of language. These theories suggest that hearing and using language in its context is critical for learning language. However, rather than appealing to empirically derived principles to explain the learning, these theories appeal to inferred cognitive mechanisms. In this article, I describe a usage-based theory of language acquisition as a recent example of a more general cognitive linguistic theory and note both logical and methodological problems. I then present a behavior-analytic theory of speech perception and production and contrast it with cognitive theories. Even though some researchers acknowledge the role of social feedback (they rarely call it reinforcement) in vocal learning, they omit the important role played by automatic reinforcement. I conclude by describing automatic reinforcement as the missing link in a parsimonious account of vocal development in human infants and making comparisons to vocal development in songbirds.

Neural oscillations and speech processing at birth

Are neural oscillations biologically endowed building blocks of the neural architecture for speech processing from birth, or do they require experience to emerge? In adults, delta, theta, and low-gamma oscillations support the simultaneous processing of phrasal, syllabic, and phonemic units in the speech signal, respectively. Using electroencephalography to investigate neural oscillations in the newborn brain we reveal that delta and theta oscillations differ for rhythmically different languages, suggesting that these bands underlie newborns' universal ability to discriminate languages on the basis of rhythm. Additionally, higher theta activity during post-stimulus as compared to pre-stimulus rest suggests that stimulation after-effects are present from birth.

Language Exposure for Preterm Infants is Reduced Relative to Fetuses

OBJECTIVE

To assess changes and deficits in language and auditory exposures consequent to preterm birth and neonatal intensive care unit stay compared with exposures in utero among typically developing fetuses.

STUDY DESIGN

We analyzed over 23 000 hours of auditory exposure data in a cohort study of 27 typically-developing fetuses and 24 preterm infants. Extrauterine exposures for fetuses were captured by having pregnant women wear 24-hour audio recording devices. For preterm infants, recording devices were placed in the infant's crib. Multilevel linear regressions were conducted to test for group differences and effects of infant sex, maternal education, and mother' occupation. A linear mixed-effects model was used to test for an effect of speaker gender.

RESULTS

Fetuses were exposed to an estimated 2.6 ± 1.8 hours/day of nearby, predominantly female language, nearly 5 times greater than 32 ± 12 minutes/day estimated for preterm infants (P < .001). Preterm infants had greater daily exposure to electronic sounds (5.1 ± 2.5 vs 1.3 ± 0.6 hours; P < .001) and noise (4.4 ± 2.1 vs 2.9 ± 2.8 hours; P < .05), with 4.7 ± 3.9 hours/day of silence. Language and extrauterine sound exposure for fetuses showed a marked day/night cyclical pattern, with low exposure during nighttime hours, but preterm infants' exposures showed significantly less change across the 24-hour cycle (P < .001). Maternal occupation requiring frequent communication predicted greater language exposure (P < .05).

CONCLUSIONS

Our findings provide the first comparison of preterm infant auditory exposures to typically-developing fetuses. Some preterm infants may incur deficits of over 150 hours of language exposure over the preterm period. Given known effects of prenatal/preterm language exposure on neurobehavioral outcomes, this magnitude of deficit is alarming.

Reduced Neural Specialization for Word-level Linguistic Prosody in Children with Autism

Children with autism often show atypical brain lateralization for speech and language processing, however, it is unclear what linguistic component contributes to this phenomenon. Here we measured event-related potential (ERP) responses in 21 school-age autistic children and 25 age-matched neurotypical (NT) peers during listening to word-level prosodic stimuli. We found that both groups displayed larger late negative response (LNR) amplitude to native prosody than to nonnative prosody; however, unlike the NT group exhibiting left-lateralized LNR distinction of prosodic phonology, the autism group showed no evidence of LNR lateralization. Moreover, in both groups, the LNR effects were only present for prosodic phonology but not for phoneme-free prosodic acoustics. These results extended the findings of inadequate neural specialization for language in autism to sub-lexical prosodic structures.

Prerequisites of language acquisition in the newborn brain

Learning to decode and produce speech is one of the most demanding tasks faced by infants. Nevertheless, infants typically utter their first words within a year, and phrases soon follow. Here we review cognitive abilities of newborn infants that promote language acquisition, focusing primarily on studies tapping neural activity. The results of these studies indicate that infants possess core adult auditory abilities already at birth, including statistical learning and rule extraction from variable speech input. Thus, the neonatal brain is ready to categorize sounds, detect word boundaries, learn words, and separate speech streams: in short, to acquire language quickly and efficiently from everyday linguistic input.

Melody of Vocants: Fixed Pattern or Shaped by Hearing?

INTRODUCTION

Vocants as infants' first vocalic utterances are produced laryngeally while the vocal tract is maintained in a neutral position. These "primitive" sounds have sometimes been described as largely innate and, therefore, as sounding alike in both healthy and hearing-impaired young infants.

OBJECTIVE

The objective of this study is to compare melody features of vocants, recorded during face-to-face interaction, between infants (N = 8) with profound congenital sensorineural hearing loss (HI group) and age-matched (N = 18) controls (CO) group. The question was as follows: does a lack of auditory feedback have a noticeable effect on melodic features of vocants?

METHODS

The cooing database totalled 6,998 vocalizations (HI: N = 2,847; CO: N = 4,151), all of which had been recorded during the observation period of 60-181 days of age. Identification of the vocants (N = 1,148) was based on broadband spectrograms (KAY-CSL) and auditory impressions. Fundamental frequency (F0) analyses were performed (PRAAT) and the pattern of the F0 contour (melody) analysed using specific in-lab software (CDAP, pw-project). Generalized mixed linear models were used to perform group comparisons.

RESULTS

There was a clear predominance of a simple rising-falling pattern (single melody arcs) in vocants of both groups. Nonetheless, significantly more complex contours, particularly, double-arc structures, were found in vocants of the CO group. Moreover, vocants of the HI group were shorter than those uttered by the CO group, while the mean F0 did not significantly differ.

CONCLUSION

Vocants are characterized by both, innate features, found in HI and CO groups, and features that additionally require a functioning auditory system. Even at an early pre-linguistic stage, somatosensory sensations cannot compensate for a lack of auditory feedback. Vocants might be relevant in the early diagnosis of hearing disorders and assessments of the effectiveness of, or adjustments required to, hearing aids.

Infant Cry Signal Diagnostic System Using Deep Learning and Fused Features

Early diagnosis of medical conditions in infants is crucial for ensuring timely and effective treatment. However, infants are unable to verbalize their symptoms, making it difficult for healthcare professionals to accurately diagnose their conditions. Crying is often the only way for infants to communicate their needs and discomfort. In this paper, we propose a medical diagnostic system for interpreting infants' cry audio signals (CAS) using a combination of different audio domain features and deep learning (DL) algorithms. The proposed system utilizes a dataset of labeled audio signals from infants with specific pathologies. The dataset includes two infant pathologies with high mortality rates, neonatal respiratory distress syndrome (RDS), sepsis, and crying. The system employed the harmonic ratio (HR) as a prosodic feature, the Gammatone frequency cepstral coefficients (GFCCs) as a cepstral feature, and image-based features through the spectrogram which are extracted using a convolution neural network (CNN) pretrained model and fused with the other features to benefit multiple domains in improving the classification rate and the accuracy of the model. The different combination of the fused features is then fed into multiple machine learning algorithms including random forest (RF), support vector machine (SVM), and deep neural network (DNN) models. The evaluation of the system using the accuracy, precision, recall, F1-score, confusion matrix, and receiver operating characteristic (ROC) curve, showed promising results for the early diagnosis of medical conditions in infants based on the crying signals only, where the system achieved the highest accuracy of 97.50% using the combination of the spectrogram, HR, and GFCC through the deep learning process. The finding demonstrated the importance of fusing different audio features, especially the spectrogram, through the learning process rather than a simple concatenation and the use of deep learning algorithms in extracting sparsely represented features that can be used later on in the classification problem, which improves the separation between different infants' pathologies. The results outperformed the published benchmark paper by improving the classification problem to be multiclassification (RDS, sepsis, and healthy), investigating a new type of feature, which is the spectrogram, using a new feature fusion technique, which is fusion, through the learning process using the deep learning model.

Sensorimotor foundations of speech perception in infancy

The perceptual system for speech is highly organized from early infancy. This organization bootstraps young human learners' ability to acquire their native speech and language from speech input. Here, we review behavioral and neuroimaging evidence that perceptual systems beyond the auditory modality are also specialized for speech in infancy, and that motor and sensorimotor systems can influence speech perception even in infants too young to produce speech-like vocalizations. These investigations complement existing literature on infant vocal development and on the interplay between speech perception and production systems in adults. We conclude that a multimodal speech and language network is present before speech-like vocalizations emerge.

Newborns modulate their crawling in response to their native language but not another language

Human newborns can propel themselves to their mother's breast when positioned skin to skin on her abdomen just after birth. For decades, researchers have considered this primitive crawling behavior a spinal reflex, immune to supra spinal control. However, recent research suggests that neonatal crawling is already responsive to visual and olfactory stimuli processed at a supra spinal level. Here we report that a few hours post birth, French newborns can also modulate their crawling in response to their native language - a source of information that is processed supra-spinally. The crawling patterns of 23 French-born newborns were recorded on video and via an infrared motion capture system during two randomly ordered 2-min trials. The newborns were secured on a mini skateboard to facilitate arm and leg movements during their crawling propulsion. They heard a repetitive sequence of the same sentences either in French, their native language, or in English, a rhythmically different and hence discriminable unfamiliar language, on each trial. In French, compared to English, crawling was enhanced, with significantly more arm and leg steps and significantly more and larger trunk rotations in the cephalo-caudal axis. Moreover, newborns rotated their heads and trunk toward the appropriate loud speaker when hearing French but not English. These preliminary findings suggest that newborn crawling is not a simple stereotyped reflex under spinal control, but a complex pattern that can be modulated in response to higher-order, supra-spinally processed stimuli. The findings open fascinating questions about the range of stimuli to which newborn crawling is responsive.

A self-training automatic infant-cry detector

Infant cry is one of the first distinctive and informative life signals observed after birth. Neonatologists and automatic assistive systems can analyse infant cry to early-detect pathologies. These analyses extensively use reference expert-curated databases containing annotated infant-cry audio samples. However, these databases are not publicly accessible because of their sensitive data. Moreover, the recorded data can under-represent specific phenomena or the operational conditions required by other medical teams. Additionally, building these databases requires significant investments that few hospitals can afford. This paper describes an open-source workflow for infant-cry detection, which identifies audio segments containing high-quality infant-cry samples with no other overlapping audio events (e.g. machine noise or adult speech). It requires minimal training because it trains an LSTM-with-self-attention model on infant-cry samples automatically detected from the recorded audio through cluster analysis and HMM classification. The audio signal processing uses energy and intonation acoustic features from 100-ms segments to improve spectral robustness to noise. The workflow annotates the input audio with intervals containing infant-cry samples suited for populating a database for neonatological and early diagnosis studies. On 16 min of hospital phone-audio recordings, it reached sufficient infant-cry detection accuracy in 3 neonatal care environments (nursery—69%, sub-intensive—82%, intensive—77%) involving 20 infants subject to heterogeneous cry stimuli, and had substantial agreement with an expert’s annotation. Our workflow is a cost-effective solution, particularly suited for a sub-intensive care environment, scalable to monitor from one to many infants. It allows a hospital to build and populate an extensive high-quality infant-cry database with a minimal investment.

Back to basics: A re-evaluation of the relevance of imprinting in the genesis of Bowlby's attachment theory

Attachment theory is one of the key theoretical constructs that underpin explorations of human bonding, taking its current form in John Bowlby's amalgamation of ideas from psychoanalysis, developmental psychology and ethology. Such a period of interdisciplinary exchange, and Bowlby's interest in Lorenz' concept of imprinting in particular, have been subject to rather historical and biographical studies, leaving a fine-grained theoretical scrutiny of the exact relationship between imprinting and attachment still pending. This paper attempts to remedy such an omission by exploring the relationships between these two constructs. It critically reviews the theories of imprinting in general, of human imprinting in particular, and of attachment; analysis of the links between these processes bring to the foreground the distinction between supra-individual vs. individual aspects of bonding, the relevance of 'proto-attachment' phases before 'proper' Bowlbyan attachment is attained, and the role of communicative signals during such early phases. The paper outlines potential benefits of considering such elements in the study of early social cognition, particularly in respect of the study of the gaze and the infant-directed communicative register.

Motor constellation theory: A model of infants' phonological development

Every normally developing human infant solves the difficult problem of mapping their native-language phonology, but the neural mechanisms underpinning this behavior remain poorly understood. Here, motor constellation theory, an integrative neurophonological model, is presented, with the goal of explicating this issue. It is assumed that infants' motor-auditory phonological mapping takes place through infants' orosensory "reaching" for phonological elements observed in the language-specific ambient phonology, via reference to kinesthetic feedback from motor systems (e.g., articulators), and auditory feedback from resulting speech and speech-like sounds. Attempts are regulated by basal ganglion-cerebellar speech neural circuitry, and successful attempts at reproduction are enforced through dopaminergic signaling. Early in life, the pace of anatomical development constrains mapping such that complete language-specific phonological mapping is prohibited by infants' undeveloped supralaryngeal vocal tract and undescended larynx; constraints gradually dissolve with age, enabling adult phonology. Where appropriate, reference is made to findings from animal and clinical models. Some implications for future modeling and simulation efforts, as well as clinical settings, are also discussed.

Prenatal development of neonatal vocalizations

Human and non-human primates produce rhythmical sounds as soon as they are born. These early vocalizations are important for soliciting the attention of caregivers. How they develop, remains a mystery. The orofacial movements necessary for producing these vocalizations have distinct spatiotemporal signatures. Therefore, their development could potentially be tracked over the course of prenatal life. We densely and longitudinally sampled fetal head and orofacial movements in marmoset monkeys using ultrasound imaging. We show that orofacial movements necessary for producing rhythmical vocalizations differentiate from a larger movement pattern that includes the entire head. We also show that signature features of marmoset infant contact calls emerge prenatally as a distinct pattern of orofacial movements. Our results establish that aspects of the sensorimotor development necessary for vocalizing occur prenatally, even before the production of sound.

How Tone, Intonation and Emotion Shape the Development of Infants’ Fundamental Frequency Perception

Fundamental frequency (ƒ₀), perceived as pitch, is the first and arguably most salient auditory component humans are exposed to since the beginning of life. It carries multiple linguistic (e.g., word meaning) and paralinguistic (e.g., speakers’ emotion) functions in speech and communication. The mappings between these functions and ƒ₀ features vary within a language and differ cross-linguistically. For instance, a rising pitch can be perceived as a question in English but a lexical tone in Mandarin. Such variations mean that infants must learn the specific mappings based on their respective linguistic and social environments. To date, canonical theoretical frameworks and most empirical studies do not view or consider the multi-functionality of ƒ₀, but typically focus on individual functions. More importantly, despite the eventual mastery of ƒ₀ in communication, it is unclear how infants learn to decompose and recognize these overlapping functions carried by ƒ₀. In this paper, we review the symbioses and synergies of the lexical, intonational, and emotional functions that can be carried by ƒ₀ and are being acquired throughout infancy. On the basis of our review, we put forward the Learnability Hypothesis that infants decompose and acquire multiple ƒ₀ functions through native/environmental experiences. Under this hypothesis, we propose representative cases such as the synergy scenario, where infants use visual cues to disambiguate and decompose the different ƒ₀ functions. Further, viable ways to test the scenarios derived from this hypothesis are suggested across auditory and visual modalities. Discovering how infants learn to master the diverse functions carried by ƒ₀ can increase our understanding of linguistic systems, auditory processing and communication functions.

Rapid learning of a phonemic discrimination in the first hours of life

Human neonates can discriminate phonemes, but the neural mechanism underlying this ability is poorly understood. Here we show that the neonatal brain can learn to discriminate natural vowels from backward vowels, a contrast unlikely to have been learnt in the womb. Using functional near-infrared spectroscopy, we examined the neuroplastic changes caused by 5 h of postnatal exposure to random sequences of natural and reversed (backward) vowels (T1), and again 2 h later (T2). Neonates in the experimental group were trained with the same stimuli as those used at T1 and T2. Compared with controls, infants in the experimental group showed shorter haemodynamic response latencies for forward vs backward vowels at T1, maximally over the inferior frontal region. At T2, neural activity differentially increased, maximally over superior temporal regions and the left inferior parietal region. Neonates thus exhibit ultra-fast tuning to natural phonemes in the first hours after birth.

Voices as Cues to Children's Needs for Caregiving

The aim of this study was to explore the role of voices as cues to adults of children’s needs for potential caregiving during early childhood. To this purpose, 74 college students listened to pairs of 5-year-old versus 10-year-old children verbalizing neutral-content sentences and indicated which voice was better associated with each of 14 traits, potentially meaningful in interactions between young children and adults. Results indicated that children with immature voices were perceived more positively and as being more helpless than children with mature voices. Children’s voices, regardless of the content of speech, seem to be a powerful source of information about children’s need for caregiving for parents and others during the first six years of life.

Phonetic Encoding Contributes to the Processing of Linguistic Prosody at the Word Level: Cross-Linguistic Evidence From Event-Related Potentials

PURPOSE

This study aimed to examine whether abstract knowledge of word-level linguistic prosody is independent of or integrated with phonetic knowledge.

METHOD

Event-related potential (ERP) responses were measured from 18 adult listeners while they listened to native and nonnative word-level prosody in speech and in nonspeech. The prosodic phonology (speech) conditions included disyllabic pseudowords spoken in Chinese and in English matched for syllabic structure, duration, and intensity. The prosodic acoustic (nonspeech) conditions were hummed versions of the speech stimuli, which eliminated the phonetic content while preserving the acoustic prosodic features.

RESULTS

We observed language-specific effects on the ERP that native stimuli elicited larger late negative response (LNR) amplitude than nonnative stimuli in the prosodic phonology conditions. However, no such effect was observed in the phoneme-free prosodic acoustic control conditions.

CONCLUSIONS

The results support the integration view that word-level linguistic prosody likely relies on the phonetic content where the acoustic cues embedded in. It remains to be examined whether the LNR may serve as a neural signature for language-specific processing of prosodic phonology beyond auditory processing of the critical acoustic cues at the suprasyllabic level.

Categorical Perception of Chinese Lexical Tones by Late Second Language Learners With High Proficiency: Behavioral and Electrophysiological Measures

PURPOSE

Although acquisition of Chinese lexical tones by second language (L2) learners has been intensively investigated, very few studies focused on categorical perception (CP) of lexical tones by highly proficient L2 learners. This study was designed to address this issue with behavioral and electrophysiological measures.

METHOD

Behavioral identification and auditory event-related potential (ERP) components for speech discrimination, including mismatch negativity (MMN), N2b, and P3b, were measured in 23 native Korean speakers who were highly proficient late L2 learners of Chinese. For the ERP measures, both passive and active listening tasks were administered to examine the automatic and attention-controlled discriminative responses to within- and across-category differences for carefully chosen stimuli from a lexical tone continuum.

RESULTS

The behavioral task revealed native-like identification function of the tonal continuum. Correspondingly, the active oddball task demonstrated larger P3b amplitudes for the across-category than within-category deviants in the left recording site, indicating clear CP of lexical tones in the attentive condition. By contrast, similar MMN responses in the right recording site were elicited by both the across- and within-category deviants, indicating the absence of CP effect with automatic phonological processing of lexical tones at the pre-attentive stage even in L2 learners with high Chinese proficiency.

CONCLUSION

Although behavioral data showed clear evidence of categorical perception of lexical tones in proficient L2 learners, ERP measures from passive and active listening tasks demonstrated fine-grained sensitivity in terms of response polarity, latency, and laterality in revealing different aspects of auditory versus linguistic processing associated with speech decoding by means of largely implicit native language acquisition versus effortful explicit L2 learning.

Accent discrimination abilities during the first days of life: An fNIRS study

Humans are biologically endowed with the faculty of language. However, the way neonates can crack this complex communicative code is yet not totally understood. While phonetic discrimination has been widely investigated in neonates, less is known about the role of supra-segments patterns in the recognition of native language. Therefore, the aim of this study was to evaluate accent discrimination abilities in newborns in a sentential prosody paradigm. We used near-infared spectroscopy to investigate accent discrimination in 21 full-term born infants within the first days of life. Sentential prosody was used to investigate: (a) native accent, (b) foreign accent, and (c) flattened accent. Neonates revealed a significantly smaller hemodynamic response to native accent compared to flattened accent and foreign accent, respectively. Cluster-based permutation analysis revealed two clusters with a significant difference between the two conditions native accent and foreign accent. The first cluster covered the middle and superior frontal, middle and superior temporal, central, and parietal areas within the left hemisphere. The second cluster, located in the right hemisphere, covered inferior, middle, and superior frontal, central, middle and superior temporal areas. We therefore conclude that neonates can differentiate prosodic features like accents within the same language a few days after birth.

It Is Not Just in the Genes

Asymmetries in the functional and structural organization of the nervous system are widespread in the animal kingdom and especially characterize the human brain. Although there is little doubt that asymmetries arise through genetic and nongenetic factors, an overarching model to explain the development of functional lateralization patterns is still lacking. Current genetic psychology collects data on genes relevant to brain lateralizations, while animal research provides information on the cellular mechanisms mediating the effects of not only genetic but also environmental factors. This review combines data from human and animal research (especially on birds) and outlines a multi-level model for asymmetry formation. The relative impact of genetic and nongenetic factors varies between different developmental phases and neuronal structures. The basic lateralized organization of a brain is already established through genetically controlled embryonic events. During ongoing development, hemispheric specialization increases for specific functions and subsystems interact to shape the final functional organization of a brain. In particular, these developmental steps are influenced by environmental experiences, which regulate the fine-tuning of neural networks via processes that are referred to as ontogenetic plasticity. The plastic potential of the nervous system could be decisive for the evolutionary success of lateralized brains.

Audiometric profiles in children with speech sound disorder: Subclinical hearing loss as a potential factor

In the present study, hearing sensitivity in children with speech sound disorder (SSD) is scrutinized. Middle ear function (wideband tympanometry and acoustic stapedial reflexes, ASR) and inner ear function (audiometric thresholds in the conventional_{1-8 kHz} and extended_{10-16 kHz} high frequency (EHF) range, and distortion product otoacoustic emissions (DPOAEs_{2-10 kHz}) were investigated. Hearing results were analyzed in relation to speech discrimination of phonemic contrasts (quiet and in noise conditions) and reproduction. Thirty-two children with SSD and 41 children with typical development (TD) ages 4-5 years participated. Children with SSD exhibited significantly less sensitive hearing compared to children with TD. This was demonstrated as more absent contralateral ASR (right ear SSD 43.7%; TD 22.0%), a higher prevalence of minimal hearing loss (MHL, > 15 dB HL at one or more frequencies or ears_{1-8 kHz} and PTA ≤ 20 dB HL, SSD 53.1%; TD 24.3%) and EHF hearing impairment (EHF HI, > 20 dB HL at one or more frequencies or ears_{10-16 kHz}, SSD 31.3%; TD 24.3%). At 2 kHz bilaterally, children with SSD showed significantly higher hearing thresholds than children with TD (mean difference, left ear 3.4 dB: right ear 4.3 dB), together with a significantly lower SNR in DPOAEs at 2.2 kHz (left ear 5.1 dB mean difference between groups). In all children, audiometric thresholds at the key-frequencies for speech, 2 and 4 kHz and DPOAEs within similar spectral regions, predicted 7-12% of the variance in phonemic discrimination and reproduction. Overall, these results suggest that hearing should be more fully investigated in children with SSD.

The Soundscape of Neonatal Intensive Care: A Mixed-Methods Study of the Parents' Experience

Parents who have infants hospitalised in neonatal intensive care units (NICUs) experience high levels of stress, including post-traumatic stress disorder (PTSD) symptoms. However, whether sounds contribute to parents’ stress remains largely unknown. Critically, researchers lack a comprehensive instrument to investigate the relationship between sounds in NICUs and parental stress. To address this gap, this report presents the “Soundscape of NICU Questionnaire” (SON-Q), which was developed specifically to capture parents’ perceptions and beliefs about the impact that sound had on them and their infants, from pre-birth throughout the NICU stay and in the first postdischarge period. Parents of children born preterm (n = 386) completed the SON-Q and the Perinatal PTSD Questionnaire (PPQ). Principal Component Analysis identifying underlying dimensions comprising the parental experience of the NICU soundscape was followed by an exploration of the relationships between subscales of the SON-Q and the PPQ. Moderation analysis was carried out to further elucidate relationships between variables. Finally, thematic analysis was employed to analyse one memory of sounds in NICU open question. The results highlight systematic associations between aspects of the NICU soundscape and parental stress/trauma. The findings underscore the importance of developing specific studies in this area and devising interventions to best support parents’ mental health, which could in turn support infants’ developmental outcomes.

Cooperative care and the evolution of the prelinguistic vocal learning

The development of the earliest vocalizations of human infants is influenced by social feedback from caregivers. As these vocalizations change, they increasingly elicit such feedback. This pattern of development is in stark contrast to that of our close phylogenetic relatives, Old World monkeys and apes, who produce mature-sounding vocalizations at birth. We put forth a scenario to account for this difference: Humans have a cooperative breeding strategy, which pressures infants to compete for the attention from caregivers. Humans use this strategy because large brained human infants are energetically costly and born altricial. An altricial brain accommodates vocal learning. To test this hypothetical scenario, we present findings from New World marmoset monkeys indicating that, through convergent evolution, this species adopted a largely identical developmental system-one that includes vocal learning and cooperative breeding.

Acoustic developmental programming: a mechanistic and evolutionary framework

Conditions experienced prenatally, by modulating developmental processes, have lifelong effects on individual phenotypes and fitness, ultimately influencing population dynamics. In addition to maternal biochemical cues, prenatal sound is emerging as a potent alternative source of information to direct embryonic development. Recent evidence suggests that prenatal acoustic signals can program individual phenotypes for predicted postnatal environmental conditions, which improves fitness. Across taxonomic groups, embryos have now been shown to have immediate adaptive responses to external sounds and vibrations, and direct developmental effects of sound and noise are increasingly found. Establishing the full developmental, ecological, and evolutionary impact of early soundscapes will reveal how embryos interact with the external world, and potentially transform our understanding of developmental plasticity and adaptation to changing environments.

Developmental Functional Modules in Infant Vocalizations

Purpose Developmental functional modules (DFMs) are biological modules that are defined by their structural (morphological), functional, or developmental elements, and, in some cases, all three of these. This review article considers the hypothesis that vocal development in the first year of life can be understood in large part with respect to DFMs that characterize the speech production system. Method Literature is reviewed on relevant embryology, orofacial reflexes, craniofacial muscle properties, stages of vocal development, and related topics to identity candidates for DFMs. Results The following DFMs are identified and described: laryngeal, pharyngo-laryngeal, mandibular, velopharyngeal, labial complex, and lingual complex. These DFMs and their submodules, considered along with phenomena such as rhythmic movements, account for several well-documented features of vocal development in the first year of life. The proposed DFMs, rooted in embryologic, histologic, and kinematic properties, serve as low-dimensional control variables for the developing vocal tract. Each DFM is semi-autonomous but interacts with other DFMs to produce patterns of vocal behavior. Discussion Considered in relation to contemporary profiles and models of vocal development in the first year of life, DFMs have interpretive and explanatory value. DFMs complement other approaches in the study of infant vocalizations and are grounded in biology.

Cry features of healthy neonates who passed their newborn hearing screening vs. those who did not

OBJECTIVES

Temporal and fundamental frequency (fo) variations in infant cries provide critical insights into the maturity of vocal control and hearing performances. Earlier research has examined the use of vocalisation properties (in addition to hearing tests) to identify infants at risk of hearing impairment. The aim of this study was to determine whether such an approach could be suitable for neonates.

METHODS

To investigate this, we recruited 74 healthy neonates within their first week of life as our participants, assigning them to either a group that passed the ABR-based NHS (PG, N = 36) or a group that did not, but were diagnosed as normally hearing in follow-up check at 3 months of life, a so-called false-positive group (NPG, N = 36). Spontaneously uttered cries (N = 2330) were recorded and analysed quantitatively. The duration, minimum, maximum and mean fo, as well as two variability measures (fo range, fo sigma), were calculated for each cry utterance, averaged for individual neonates, and compared between the groups.

RESULTS

A multiple analysis of variance (MANOVA) revealed no significant effects. This confirms that cry features reflecting vocal control do not differ between healthy neonates with normal hearing, irrespective of the outcome of their initial NHS.

CONCLUSIONS

Healthy neonates who do not pass the NHS but are normal hearing in the follow-up (false positive cases) have the same cry properties as those with normal hearing who do. This is an essential prerequisite to justify the research strategy of incorporating vocal analysis into NHS to complement ABR measures in identifying hearing-impaired newborns.

The Interaction Between Timescale and Pitch Contour at Pre-attentive Processing of Frequency-Modulated Sweeps

Speech comprehension across languages depends on encoding the pitch variations in frequency-modulated (FM) sweeps at different timescales and frequency ranges. While timescale and spectral contour of FM sweeps play important roles in differentiating acoustic speech units, relatively little work has been done to understand the interaction between the two acoustic dimensions at early cortical processing. An auditory oddball paradigm was employed to examine the interaction of timescale and pitch contour at pre-attentive processing of FM sweeps. Event-related potentials to frequency sweeps that vary in linguistically relevant pitch contour (fundamental frequency F0 vs. first formant frequency F1) and timescale (local vs. global) in Mandarin Chinese were recorded. Mismatch negativities (MMNs) were elicited by all types of sweep deviants. For local timescale, FM sweeps with F0 contours yielded larger MMN amplitudes than F1 contours. A reversed MMN amplitude pattern was obtained with respect to F0/F1 contours for global timescale stimuli. An interhemispheric asymmetry of MMN topography was observed corresponding to local and global-timescale contours. Falling but not rising frequency difference waveforms sweep contours elicited right hemispheric dominance. Results showed that timescale and pitch contour interacts with each other in pre-attentive auditory processing of FM sweeps. Findings suggest that FM sweeps, a type of non-speech signal, is processed at an early stage with reference to its linguistic function. That the dynamic interaction between timescale and spectral pattern is processed during early cortical processing of non-speech frequency sweep signal may be critical to facilitate speech encoding at a later stage.

The duration of intrauterine development influences discrimination of speech prosody in infants

Auditory speech discrimination is essential for normal language development. Children born preterm are at greater risk of language developmental delays. Using functional near-infrared spectroscopy at term-equivalent age, the present study investigated early discrimination of speech prosody in 62 neonates born between week 23 and 41 of gestational age (GA). We found a significant positive correlation between GA at birth and neural discrimination of forward versus backward speech at term-equivalent age. Cluster analysis identified a critical threshold at around week 32 of GA, pointing out the existence of subgroups. Infants born before week 32 of GA exhibited a significantly different pattern of hemodynamic response to speech stimuli compared to infants born at or after week 32 of GA. Thus, children born before the GA of 32 weeks are especially vulnerable to early speech discrimination deficits. To support their early language development, we therefore suggest a close follow-up and additional speech and language therapy especially in the group of children born before week 32 of GA.

Sociodemographic and Pre-Linguistic Factors in Early Vocabulary Acquisition

Here, we studied the beginnings of language development, jointly assessing two groups of precursors, sociodemographic and pre-linguistic, that have previously been studied separately. Thus, the general objective of this study was to explore which factors best explained the acquisition of initial expressive vocabulary. The sample consisted of 504 participants from Catalan-speaking homes with ages ranging between 10 and 18 months. The data were obtained through the MacArthur-Bates Communicative Development Inventories (MCB-CDIs). Vocabulary development shows a lexical spurt at 17 months. Regression analyses show that pre-linguistic factors have more explanatory power of than sociodemographic ones. Within the sociodemographic variables, age, birth order and birth weight explain part of the vocabulary variance. With respect to pre-linguistic variables, imitation, late gestures and phrase comprehension are predictors of the initial vocabulary acquisition. Specifically, imitation and late gestures were the pre-linguistic behaviours that made it possible to distinguish between children with higher and lower levels of vocabulary. We discussed these findings in relation to their relevance for language acquisition and for the early assessment of linguistic competence.

Melody complexity of infants' cry and non-cry vocalisations increases across the first six months

In early infancy, melody provides the most salient prosodic element for language acquisition and there is huge evidence for infants' precocious aptitudes for musical and speech melody perception. Yet, a lack of knowledge remains with respect to melody patterns of infants' vocalisations. In a search for developmental regularities of cry and non-cry vocalisations and for building blocks of prosody (intonation) over the first 6 months of life, more than 67,500 melodies (fundamental frequency contours) of 277 healthy infants from monolingual German families were quantitatively analysed. Based on objective criteria, vocalisations with well-identifiable melodies were grouped into those exhibiting a simple (single-arc) or complex (multiple-arc) melody pattern. Longitudinal analysis using fractional polynomial multi-level mixed effects logistic regression models were applied to these patterns. A significant age (but not sex) dependent developmental pattern towards more complexity was demonstrated in both vocalisation types over the observation period. The theoretical concept of melody development (MD-Model) contends that melody complexification is an important building block on the path towards language. Recognition of this developmental process will considerably improve not only our understanding of early preparatory processes for language acquisition, but most importantly also allow for the creation of clinically robust risk markers for developmental language disorders.

Early peripheral activity alters nascent subplate circuits in the auditory cortex

Cortical function can be shaped by sensory experience during a critical period. The onset of the critical period is thought to coincide with the onset of thalamocortical transmission to the thalamo-recipient layer 4 (L4). In early development, subplate neurons (SPNs), and not L4 neurons, are the first targets of thalamic afferents. SPNs are transiently involved in early development and are largely eliminated during development. Activation of L4 by thalamic afferents coincides with the opening of ear canal (~P11 in mice) and precedes the later critical period. Here, we show in mice that abolishing peripheral function or presenting sound stimuli even before P11 leads to bidirectionally altered functional connectivity of SPNs in auditory cortex. Thus, early sensory experience can sculpt subplate circuits before thalamocortical circuits to L4 are mature. Our results show that peripheral activity shapes cortical circuits in a sequential manner and from earlier ages than has been appreciated.

The origins and development of speech envelope tracking during the first months of life

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The adult brain tracks the modulation of the amplitude of speech, i.e. its envelope.

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We tested if preverbal infants, i.e. newborns & 6-month-olds, track the speech envelope.

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Infants track the envelope phase at both ages in the native language & in unfamiliar languages.

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Infants track the envelope amplitude in the native language at birth but not at 6 months.

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This suggests that phase tracking is unrelated to language experience, whereas amplitude tracking is shaped by experience.

When humans listen to speech, their neural activity tracks the slow amplitude fluctuations of the speech signal over time, known as the speech envelope. Studies suggest that the quality of this tracking is related to the quality of speech comprehension. However, a critical unanswered question is how envelope tracking arises and what role it plays in language development. Relatedly, its causal role in comprehension remains unclear, as some studies have found it to be present even for unintelligible speech. Using electroencephalography, we investigated whether the neural activity of newborns and 6-month-olds is able to track the speech envelope of familiar and unfamiliar languages in order to explore the developmental origins and functional role of envelope tracking. Our results show that amplitude and phase tracking take place at birth for familiar and unfamiliar languages alike, i.e. independently of prenatal experience. However, by 6 months language familiarity modulates the ability to track the amplitude of the speech envelope, while phase tracking continues to be universal. Our findings support the hypothesis that amplitude and phase tracking could represent two different neural mechanisms of oscillatory synchronisation and may thus play different roles in speech perception.

Song Is More Memorable Than Speech Prosody: Discrete Pitches Aid Auditory Working Memory

Vocal music and spoken language both have important roles in human communication, but it is unclear why these two different modes of vocal communication exist. Although similar, speech and song differ in certain design features. One interesting difference is in the pitch intonation contour, which consists of discrete tones in song, vs. gliding intonation contours in speech. Here, we investigated whether vocal phrases consisting of discrete pitches (song-like) or gliding pitches (speech-like) are remembered better, conducting three studies implementing auditory same-different tasks at three levels of difficulty. We tested two hypotheses: that discrete pitch contours aid auditory memory, independent of musical experience ("song memory advantage hypothesis"), or that the higher everyday experience perceiving and producing speech make speech intonation easier to remember ("experience advantage hypothesis"). We used closely matched stimuli, controlling for rhythm and timbre, and we included a stimulus intermediate between song-like and speech-like pitch contours (with partially gliding and partially discrete pitches). We also assessed participants' musicality to evaluate experience-dependent effects. We found that song-like vocal phrases are remembered better than speech-like vocal phrases, and that intermediate vocal phrases evoked a similar advantage to song-like vocal phrases. Participants with more musical experience were better in remembering all three types of vocal phrases. The precise roles of absolute and relative pitch perception and the influence of top-down vs. bottom-up processing should be clarified in future studies. However, our results suggest that one potential reason for the emergence of discrete pitch-a feature that characterises music across cultures-might be that it enhances auditory memory.

Memory Traces Formed in Utero-Newborns' Autonomic and Neuronal Responses to Prenatal Stimuli and the Maternal Voice

In our pilot study, we exposed third-trimester fetuses, from week 34 of gestation onwards, twice daily to a maternal spoken nursery rhyme. Two and five weeks after birth, 34 newborns, who were either familiarized with rhyme stimulation in utero or stimulation naïve, were (re-)exposed to the familiar, as well as to a novel and unfamiliar, rhyme, both spoken with the maternal and an unfamiliar female voice. For the stimulation-naïve group, both rhymes were unfamiliar. During stimulus presentation, heart rate activity and high-density electroencephalography were collected and newborns’ responses during familiar and unfamiliar stimulation were analyzed. All newborns demonstrated stronger speech–brain coupling at 1 Hz during the presentation of the maternal voice vs. the unfamiliar female voice. Rhyme familiarity originating from prenatal exposure had no effect on speech–brain coupling in experimentally stimulated newborns. Furthermore, only stimulation-naïve newborns demonstrated an increase in heart rate during the presentation of the unfamiliar female voice. The results indicate prenatal familiarization to auditory speech and point to the specific significance of the maternal voice already in two- to five-week-old newborns.

Exposure to a second language in infancy alters speech production

We evaluated the impact of exposure to a second language on infants' emerging speech production skills. We compared speech produced by three groups of 12-month-old infants while they interacted with interlocutors who spoke to them in Spanish and English: monolingual English-learning infants who had previously received 5 hours of exposure to a second language (Spanish), English- and Spanish-learning simultaneous bilinguals, and monolingual English-learning infants without any exposure to Spanish. Our results showed that the monolingual English-learning infants with short-term exposure to Spanish and the bilingual infants, but not the monolingual English-learning infants without exposure to Spanish, flexibly matched the prosody of their babbling to that of a Spanish- or English-speaking interlocutor. Our findings demonstrate the nature and extent of benefits for language learning from early exposure to two languages. We discuss the implications of these findings for language organization in infants learning two languages.

Musical Intervals in Infants' Spontaneous Crying over the First 4 Months of Life

INTRODUCTION

Perception and memorizing of melody and rhythm start about the third trimester of gestation. Infants have astonishing musical predispositions, and melody contour is most salient for them.

OBJECTIVE

To longitudinally analyse melody contour of spontaneous crying of healthy infants and to identify melodic intervals. The aim was 3-fold: (1) to answer the question whether spontaneous crying of healthy infants regularly exhibits melodic intervals across the observation period, (2) to investigate whether interval events become more complex with age and (3) to analyse interval size distribution.

METHODS

Weekly cry recordings of 12 healthy infants (6 females) over the first 4 months of life were analysed (6,130 cry utterances) using frequency spectrograms and pitch analyses (PRAAT). A preselection of utterances containing a well-identifiable, noise-free and undisturbed melodic contour was applied to identify and measure melodic intervals in the final subset of 3,114 utterances. Age-dependent frequency of occurrence of melodic intervals was statistically analysed using generalized estimating equations.

RESULTS

85.3% of all preselected melody contours (n = 3,114) either contained single rising or falling melodic intervals or complex events as combinations of both. In total 6,814 melodic intervals were measured. A significant increase in interval occurrence was found characterized by a non-linear age effect (3 developmental phases). Complex events were found to significantly increase linearly with age. In both calculations, no sex effect was found. Interval size distribution showed a maximum of the minor second as the prevailing musical interval in infants' crying over the first 4 months of life.

CONCLUSION

Melodic intervals seem to be a regular phenomenon of spontaneous crying of healthy infants. They are suggested to be a further candidate for developing an early risk marker of vocal control in infants. Subsequent studies are needed to compare healthy infants and infants at risk for respiratory-laryngeal dysfunction to investigate the diagnostic value of the occurrence of melodic intervals and their age-depending complexification.

The vocal repertoire of preterm infants: Characteristics and possible applications

We investigated infants' capacities to express themselves orally at very early developmental stages. Most reports focus on crying when in pain or hungry. We evaluated young preterm infants' spontaneous vocal production in non-painful contexts. We identified a vocal repertoire composed of nine types of vocalisations. High-pitched sounds were associated with relaxed postures, implying a positive valence, whereas long low-pitched vocalisations, associated more with grimaces and muscle tensions, appeared to have a more negative valence. Infants' vocalisations were useful indicators of their internal state in two situations (when exposed to clothing constraints and environmental noises).

Making of the mind

The essence of the mind is consciousness. It emerged early during evolution and ontogeny appears to follow the same process as phylogeny. Consciousness comes from multiple sources, including visual, auditory, sensorimotor and proprioceptive senses. These gradually combine during development to build a unified consciousness, due to the constant interactions between the brain, body, and environment. In the human the emergence of consciousness depends on the activation of the cortex by thalamocortical connections around 24 weeks after conception. Then, the human foetus can be potentially conscious, as it is aware of its body and reacts to touch, smell and sound and shows social expressions in response to external stimuli. However, it is mainly asleep and probably not aware of itself and its environment. In contrast, the newborn infant is awake after its first breaths of air and can be aware of its own self and others, express emotions and share feelings. The development of consciousness is a progressive, stepwise, structural and functional evolution of multiple intricate components. The infant fulfils some of the more basic criteria for consciousness. However, there are some important missing pieces at this stage, as it cannot remember the past and anticipate the future.