Bonding and Attachment with Baby in the Womb or in the Neonatal Intensive Care Unit: The Critical Role of Early Emotional Connections

Bonding and attachment are known to be critically important for the well-being of infants and children. Both bonding and attachment can begin before birth, which impacts fetal and infant brain development and may improve birth outcomes. Babies in the womb and preterm babies in the neonatal intensive care unit (NICU) can hear and respond to maternal voices with positive effects on physiologic stability, brain development, and language development. Supporting emotional connections before and after birth is the responsibility and the privilege of health-care providers who care for pregnant mothers and babies in the NICU.

Effects of parents' voice on reducing heel puncture pain in high-risk newborns: A randomized controlled trial

BACKGROUND

High-risk newborns, such as premature or severely ill infants, often experience painful treatments and separation from their parents. While previous studies have focused on the positive impacts of a mother's voice on newborns' physiology and pain response, research on the father's voice and vocal acoustics in high-risk newborns is limited.

AIM

To examine whether parents' voices reduce heel puncture pain in high-risk newborns and the relationship between parents' vocal acoustics, physiological parameters and pain response.

STUDY DESIGN

A randomized controlled clinical trial was conducted with 105 high-risk newborn-parent dyads. Participants were randomly assigned to three groups: recorded mother's voice, recorded father's voice or control group without any recorded voice. Outcome measures included heart rate, respiratory rate, oxygen saturation and pain response assessed using the Neonatal Infant Pain Scale. Data analysis utilized generalized estimation equations, and parents' vocal acoustics were analysed using Praat voice credit software.

RESULTS

The mother's voice group exhibited significantly lower heart rates at 1, 5 and 10 min after the procedure, along with lower respiratory rates and pain levels at 5 and 10 min after the procedure compared with the control group. Similarly, the father's voice group demonstrated significantly lower heart rates at 1 and 5 min after the procedure, decreased respiratory rates at 5 and 10 min after the procedure and reduced pain levels at 1 and 5 to 10 min after the procedure compared with the control group. Higher minimum and mean pitches in parents' voices correlated with slower heart rates, while slower parental speech was associated with reduced newborn pain.

CONCLUSION

Both maternal and paternal vocal interventions alleviated pain during heel puncture procedures among high-risk newborns.

RELEVANCE TO CLINICAL PRACTICE

The noninvasive intervention serves as a reference for parental participation in care. Nurses can help parents to intervene with the acoustic characteristics that alleviate pain among high-risk newborns.

Unveiling the development of human voice perception: Neurobiological mechanisms and pathophysiology

The human voice is a critical stimulus for the auditory system that promotes social connection, informs the listener about identity and emotion, and acts as the carrier for spoken language. Research on voice processing in adults has informed our understanding of the unique status of the human voice in the mature auditory cortex and provided potential explanations for mechanisms that underly voice selectivity and identity processing. There is evidence that voice perception undergoes developmental change starting in infancy and extending through early adolescence. While even young infants recognize the voice of their mother, there is an apparent protracted course of development to reach adult-like selectivity for human voice over other sound categories and recognition of other talkers by voice. Gaps in the literature do not allow for an exact mapping of this trajectory or an adequate description of how voice processing and its neural underpinnings abilities evolve. This review provides a comprehensive account of developmental voice processing research published to date and discusses how this evidence fits with and contributes to current theoretical models proposed in the adult literature. We discuss how factors such as cognitive development, neural plasticity, perceptual narrowing, and language acquisition may contribute to the development of voice processing and its investigation in children. We also review evidence of voice processing abilities in premature birth, autism spectrum disorder, and phonagnosia to examine where and how deviations from the typical trajectory of development may manifest.

Voice categorization in the four-month-old human brain

Voices are the most relevant social sounds for humans and therefore have crucial adaptive value in development. Neuroimaging studies in adults have demonstrated the existence of regions in the superior temporal sulcus that respond preferentially to voices. Yet, whether voices represent a functionally specific category in the young infant's mind is largely unknown. We developed a highly sensitive paradigm relying on fast periodic auditory stimulation (FPAS) combined with scalp electroencephalography (EEG) to demonstrate that the infant brain implements a reliable preferential response to voices early in life. Twenty-three 4-month-old infants listened to sequences containing non-vocal sounds from different categories presented at 3.33 Hz, with highly heterogeneous vocal sounds appearing every third stimulus (1.11 Hz). We were able to isolate a voice-selective response over temporal regions, and individual voice-selective responses were found in most infants within only a few minutes of stimulation. This selective response was significantly reduced for the same frequency-scrambled sounds, indicating that voice selectivity is not simply driven by the envelope and the spectral content of the sounds. Such a robust selective response to voices as early as 4 months of age suggests that the infant brain is endowed with the ability to rapidly develop a functional selectivity to this socially relevant category of sounds.

Contingent Mother's Voice Intervention Targeting Feeding in Hospitalized Infants with Critical Congenital Heart Defects

Infants with critical congenital heart defects (CCHD) are at high risk for feeding challenges and neurodevelopmental delays; however, few interventions promoting the neurodevelopmental progression of feeding have been studied with this population. Contingent mother's voice has been successfully used as positive reinforcement for non-nutritive suck (NNS) in studies with preterm infants, leading to improved weight gain and more rapid cessation of tube feedings; however, this type of intervention has not been studied in infants with CCHD. This study aimed to determine whether an NNS-training protocol using the mother's voice as positive reinforcement and validated in preterm infants could improve oral feeding outcomes in hospitalized infants with CCHD undergoing cardiac surgical procedures. Infants were randomized to receive the contingent mother's voice intervention before or after cardiac surgery, with a control comparison group receiving passive exposure to the mother's voice after surgery. There were no significant differences in discharge weight, PO intake, length of stay, time to full feeds, or feeding status at 1-month post-discharge between infants who received contingent mother's voice compared to those who did not. There were significant differences in PO intake and time to full feeds following surgery based on infants' pre-enrollment PO status and severity of illness. At 1-month post-discharge, parents of infants in the intervention group expressed a higher rate of positive feelings and fewer concerns regarding their infant's feeding compared to parents of infants in the control group. While the current protocol of 5 sessions was not associated with improved feeding outcomes in infants with CCHD, it empowered parents to contribute to their infant's care and demonstrated the feasibility of using the mother's voice as positive reinforcement for infants with CCHD. Further study of timing, intensity, and duration of interventions leveraging the mother's voice in this population is needed. ClinicalTrials.gov Identifier: NCT03035552.

The Response of the Infant to the Father's Voice: An Evidence-Based Review

BACKGROUND

Premature infants are at increased risk for language delays. The auditory system hears sounds at 25 weeks' gestation; therefore, infants in the neonatal intensive care unit (NICU) may miss crucial language exposure during the period when neural pathways for language processing are developing. Supporting the synergistic relationship between fathers and newborns promotes connections through early language to strengthen engagement and promote infant neurodevelopment.

PURPOSE

To determine what is known about preterm infants' response to the male voice.

DATA SOURCES

Three databases and forward searching of reference lists were used to locate articles addressing the clinical question: "What strategies can be used in the NICU to support purposeful language development?"

STUDY SELECTION

Empiric, primary research studies were included if they were published in English without date restriction.

DATA EXTRACTION

The authors evaluated each study's quality using a validated 16-item assessment tool (QATSDD) developed for studies with diverse designs; data were extracted and organized following Garrard's Matrix Method.

RESULTS

The aim of this evidence-based review is to report the way an infant responds to the paternal voice. Findings promote a better understanding of individual infant response to paternal voice, including conversational turns and engagement behaviors. Although informative, this review highlights a clear gap in the evidence, supporting standardized methodology.

IMPLICATIONS FOR PRACTICE AND RESEARCH

Fathers should be encouraged to communicate vocally early and often to facilitate bonding in the NICU. Encouraged future study of father-infant communication to support bonding, relationship building, and neurodevelopmental outcomes is paramount.

Concept and considerations of a medical device: the active noise cancelling incubator

Background

An increasingly 24/7 connected and urbanised world has created a silent pandemic of noise-induced hearing loss. Ensuring survival to children born (extremely) preterm is crucial. The incubator is a closed medical device, modifying the internal climate, and thus providing an environment for the child, as safe, warm, and comfortable as possible. While sound outside the incubator is managed and has decreased over the years, managing the noise inside the incubator is still a challenge.

Method

Using active noise cancelling in an incubator will eliminate unwanted sounds (i.e., from the respirator and heating) inside the incubator, and by adding sophisticated algorithms, normal human speech, neonatal intensive care unit music-based therapeutic interventions, and natural sounds will be sustained for the child in the pod. Applying different methods such as active noise cancelling, motion capture, sonological engineering. and sophisticated machine learning algorithms will be implemented in the development of the incubator.

Projected Results

A controlled and active sound environment in and around the incubator can in turn promote the wellbeing, neural development, and speech development of the child and minimise distress caused by unwanted noises. While developing the hardware and software pose individual challenges, it is about the system design and aspects contributing to it. On the one hand, it is crucial to measure the auditory range and frequencies in the incubator, as well as the predictable sounds that will have to be played back into the environment. On the other, there are many technical issues that have to be addressed when it comes to algorithms, datasets, delay, microphone technology, transducers, convergence, tracking, impulse control and noise rejection, noise mitigation stability, detection, polarity, and performance.

Conclusion

Solving a complex problem like this, however, requires a de-disciplinary approach, where each discipline will realise its own shortcomings and boundaries, and in turn will allow for innovations and new avenues. Technical developments used for building the active noise cancellation-incubator have the potential to contribute to improved care solutions for patients, both infants and adults.Code available at: 10.3389/fped.2023.1187815.

Association of infants' feeding pattern up to 2 years postpartum with mothers' mental and physical health: the Japan Environment and Children's Study

BACKGROUND

Exclusive breastfeeding, a longer breastfeeding duration, and interaction with the baby during lactation improve mothers' mental health. However, few studies have targeted women around 2.5 years after childbirth, when women are still considered to have been in a period of mental and physical health vulnerability. This study examined this aspect in a large cohort of mother-child pairs.

METHODS

Data were obtained from 85,735 mothers in an ongoing nationwide birth cohort study in Japan. Exposures were exclusive breastfeeding (yes/no), continued breastfeeding up to 2 years (yes/no), and interaction with the baby during feeding (yes/no). Outcomes were mothers' mental and physical health 2.5 years after childbirth measured using Mental and Physical Component Summary scores (MCS and PCS scores, respectively) from the 8-item Short-Form Health Survey. Generalized additive mixed model analysis was used to derive each estimate for the three exposures and their interactions, with each "no" answer as reference.

RESULTS

Exclusive breastfeeding and interaction with the baby during feeding were associated with MCS score increases of 0.28 (95%CI: 0.10-0.47) and 0.41 (95%CI: 0.29-0.54), respectively. However, no associations were found for continued breastfeeding up to 2 years and no interactions were identified. No significant differences were observed for PCS scores.

LIMITATIONS

All variables were measured using a self-administered questionnaire.

CONCLUSIONS

Continued exclusive breastfeeding until 6 months and interaction with the baby during feeding may help to promote mother's mental health 2.5 years after childbirth. These findings further strengthen the rationale for the World Health Organization's recommended lactation practices.

Newborns discriminate utterance-level prosodic contours

Prosody is the fundamental organizing principle of spoken language, carrying lexical, morphosyntactic, and pragmatic information. It, therefore, provides highly relevant input for language development. Are infants sensitive to this important aspect of spoken language early on? In this study, we asked whether infants are able to discriminate well-formed utterance-level prosodic contours from ill-formed, backward prosodic contours at birth. This deviant prosodic contour was obtained by time-reversing the original one, and super-imposing it on the otherwise intact segmental information. The resulting backward prosodic contour was thus unfamiliar to the infants and ill-formed in French. We used near-infrared spectroscopy (NIRS) in 1-3-day-old French newborns (n = 25) to measure their brain responses to well-formed contours as standards and their backward prosody counterparts as deviants in the frontal, temporal, and parietal areas bilaterally. A cluster-based permutation test revealed greater responses to the Deviant than to the Standard condition in right temporal areas. These results suggest that newborns are already capable of detecting utterance-level prosodic violations at birth, a key ability for breaking into the native language, and that this ability is supported by brain areas similar to those in adults. RESEARCH HIGHLIGHTS: At birth, infants have sophisticated speech perception abilities. Prosody may be particularly important for early language development. We show that newborns are already capable of discriminating utterance-level prosodic contours. This discrimination can be localized to the right hemisphere of the neonate brain.

Developmental Changes in the Perception of Vocal Loudness and Voice Quality in 3- to 6-Year-Old Children

PURPOSE

The study's primary aim was to investigate developmental changes in the perception of vocal loudness and voice quality in children 3-6 years of age. A second aim was to evaluate a testing procedure-the intermodal preferential looking paradigm (IPLP)-for the study of voice perception in young children.

METHOD

Participants were categorized in two age groups: 3- to 4-year-olds and 5- to 6-year-olds. Children were tested remotely via a Zoom appointment and completed two perceptual tasks: (a) voice discrimination and (b) voice identification. Each task consisted of two tests: a vocal loudness test and a voice quality test.

RESULTS

Children in the 5- to 6-year-old group were significantly more accurate than children in the 3- to 4-year-old group in discriminating and identifying differences between voices for both loudness and voice quality. The IPLP, used in the identification task, was found to successfully detect differences between the age groups for overall accuracy and for most of the sublevels of vocal loudness and voice quality.

CONCLUSIONS

Results suggest that children's ability to discriminate and identify differences in vocal loudness and voice quality improves with age. Findings also support the use of the IPLP as a useful tool to study voice perception in young children.

The prenatal video-feedback intervention to promote positive parenting for expectant fathers (VIPP-PRE): Two case studies

Although parenting interventions including expectant fathers are scarce, they yield promising results. The Prenatal Video‐feedback Intervention to promote Positive Parenting (VIPP‐PRE) is a recently developed intervention, that is both manualized and personalized, aiming to enhance paternal sensitivity and involvement before the birth of the baby. Illustrating the intervention process, the current study presents two case studies of expectant fathers receiving VIPP‐PRE (clinical trial registration NL62696.058.17). The VIPP‐PRE program is described along with the individual dyads’ prenatal video fragments and feedback specific for each father‐fetus dyad. In addition, changes in paternal sensitivity and involvement levels are presented, as well as fathers’ and intervener's evaluation of the intervention. VIPP‐PRE promises to be a feasible short‐term and potentially effective parenting intervention for expectant fathers. Currently, a randomized controlled trial (RCT) is under review that systematically investigates the efficacy of the VIPP‐PRE. Here we aim to provide further information on the intervention process, as well as fathers’ and intervener's evaluations of this process, and the benefits of using ultrasound imaging in a parenting intervention.

Assessment and Management of Pain in Preterm Infants: A Practice Update

Infants born preterm are at a high risk for repeated pain exposure in early life. Despite valid tools to assess pain in non-verbal infants and effective interventions to reduce pain associated with medical procedures required as part of their care, many infants receive little to no pain-relieving interventions. Moreover, parents remain significantly underutilized in provision of pain-relieving interventions, despite the known benefit of their involvement. This narrative review provides an overview of the consequences of early exposure to untreated pain in preterm infants, recommendations for a standardized approach to pain assessment in preterm infants, effectiveness of non-pharmacologic and pharmacologic pain-relieving interventions, and suggestions for greater active engagement of parents in the pain care for their preterm infant.

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.

Development and feasibility of the prenatal video-feedback intervention to promote positive parenting for expectant fathers

Objective: the transition period in which men become fathers might provide an important window of opportunity for parenting interventions that may produce long-term positive effects on paternal care and, consequently, child development. Existing prenatal programs traditionally focus on maternal and infant health and seldom involve the father.Study design: This paper describes an interaction-based prenatal parenting intervention program for first-time fathers using ultrasound images, the Prenatal video Feedback Intervention to promote Positive Parenting (VIPP-PRE). We randomised a group of expectant fathers (N = 73) to either the VIPP-PRE or a control condition.Results: Expectant fathers thought the VIPP-PRE was more helpful and influenced their insights into their babies to a greater extent than the control condition. Expectant fathers receiving the VIPP-PRE reported that they particularly liked seeing and interacting with their unborn children as well as receiving feedback on these interactions. The intervention was well received and was considered feasible by both expectant fathers and sonographers and midwives.Discussion: We discuss the VIPP-PRE based on the experiences and perspectives of fathers, interveners, and sonographers and midwives.

Beyond the Words: Comparing Interpersonal Engagement Between Maternal and Paternal Infant-Directed Speech Acts

The present study investigates the way infants express their emotions in relation to parental feelings between maternal and paternal questions and direct requests. We therefore compared interpersonal engagement accompanying parental questions and direct requests between infant–mother and infant–father interactions. We video-recorded spontaneous communication between 11 infant–mother and 11 infant–father dyads—from the 2nd to the 6th month—in their home. The main results of this study are summarized as follows: (a) there are similarities in the way preverbal infants use their affections in spontaneous interactions with their mothers and fathers to express signs of sensitivity in sharing knowledge through questions and direct requests; and (b) the developmental trajectories of face-to-face emotional coordination in the course of parental questions descend in a similar way for both parents across the age range of this study. Regarding the developmental trajectories of emotional non-coordination, there is evidence of a linear trend in terms of age difference between the parents’ gender with fathers showing the steeper slope. The results are discussed in relation to the theory of intersubjectivity.

Herausforderungen und Bedürfnisse von Familien mit Neugeborenen mit Zwerchfellhernie - Musiktherapie als unterstützende Maßnahme?

Challenges and needs of families of newborns with congenital diaphragmatic hernia - Music therapy as a supportive intervention? Abstract. Background: Newborns with diaphragmatic hernia (CDH) spend the first weeks of their lives in intensive care, which is extremely stressful for them and their families. Music therapy is already used in neonatology for premature infants to stabilize the child, to support the parents and to strengthen attachment and bonding. However, the benefits for term infants receiving intensive care and their families has not yet been comprehensively investigated. Aim: The aim of this paper was to investigate the specific needs, challenges and experiences of children with CDH and their parents and to derive appropriate music therapy interventions. Methods: Using the CAQDAS software f4analyse 15 parents' reports were examined with a qualitative content structuring analysis. Music therapy aspects were illustrated using a hypothetical case example. Results: Parents suffer above all from organisational and emotional challenges. They want to take care of their child and seek to be close despite limited influence on health and treatment. They are supported by their social environment and the medical staff. Protective factors include successful self-care, detachment and trust in a positive outcome. Conclusion: Additional to medical aspects like the withdrawal, bonding and attachment and parental well-being are of great importance. Music therapy literature offers the description of interventions, which address these aspects.

I know that voice! Mothers' voices influence children's perceptions of emotional intensity

The ability to interpret others' emotions is a critical skill for children's socioemotional functioning. Although research has emphasized facial emotion expressions, children are also constantly required to interpret vocal emotion expressed at or around them by individuals who are both familiar and unfamiliar to them. The current study examined how speaker familiarity, specific emotions, and the acoustic properties that comprise affective prosody influenced children's interpretations of emotional intensity. Participants were 51 7- and 8-year-olds presented with speech stimuli spoken in happy, angry, sad, and nonemotional prosodies by both each child's mother and another child's mother unfamiliar to the target child. Analyses indicated that children rated their own mothers as more intensely emotional compared with the unfamiliar mothers and that this effect was specific to angry and happy prosodies. Furthermore, the acoustic properties predicted children's emotional intensity ratings in different patterns for each emotion. The results are discussed in terms of the significance of the mother's voice in children's development of emotional understanding.

The Overlooked Tradition of "Personal Music" and Its Place in the Evolution of Music

This is an attempt to describe and explain so-called timbre-based music as a special system of musicking, communication, and psychological and social usage, which along with its corresponding beliefs constitutes a viable alternative to “frequency-based” music. Unfortunately, the current scientific research into music has been skewed almost entirely in favor of the frequency-based music prevalent in the West. Subsequently, whenever samples of timbre-based music attract the attention of Western researchers, these are usually interpreted as “defective” implementations of frequency-based music. The presence of discrete pitch is often regarded as the structural criterion that distinguishes music from non-music. We would like to present evidence to the contrary—in support of the existence of indigenous music systems based on the discretization and patterning of aspects of timbre, rather than pitch. This evidence comes mainly from extensive ethnographic research systematically conducted in eastern European and Asian parts of Russia from the 1890s. It involved the efforts of thousands of specialists and was coordinated by dozens of research institutions, and it has included not just ethnomusicology but linguistics, philology, organology, archaeology, anthropology, geography, and religious, and social studies. Much of the data has not been translated into Western languages. Although some Soviet-era publications were tainted by Marxist ideology, many researchers strove to provide accurate information (despite at times having been prosecuted for their work), and post-1990 research undertook a substantial revision of ideologically compromised concepts. Timbre-based tonal organization (TO) differs from that based on frequency in its personal orientation: musicking here occurs primarily for oneself and/or for close relatives/friends. Collective music-making is rare and exceptional. The foundation of timbre-based music seems to have vocal roots and rests on “personal song”—a system of personal identification through individualized patterns of rhythm, timbre, and pitch contour, utilized like a “human voice”—whose sound enables the recognition of a particular individual. The instrumental counterpart of the personalized singing tradition is the jaw harp tradition. The jaw harp is the principal musical instrument for at least 21 ethnicities in Russia, who occupy over half the territory of the country. The evolution of its TO forms the backbone for the development of timbre-based music art. Here, we provide the acoustic, socio-cultural, geographic, and chronological overview of timbre-based music.

Mechanisms of Timing, Timbre, Repertoire, and Entrainment in Neuroplasticity: Mutual Interplay in Neonatal Development

Neonatal brain development relies on a combination of critical factors inclusive of genetic predisposition, attachment, and the conditions of the pre and postneonatal environment. The status of the infant’s developing brain in its most vulnerable state and the impact that physiological elements of music, silences and sounds may make in the earliest stages of brain development can enhance vitality. However, little attention has been focused on the integral aspects of the music itself. This article will support research that has hypothesized conditions of music therapeutic applications in an effort to further validate models of neurobehavioral care that have optimized conditions for growth, inclusive of recommendations leading toward the enhancement of self-regulatory behaviors.

Preparing for Life After Birth: Introducing the Concepts of Intrauterine and Extrauterine Sensory Entrainment in Mammalian Young

Presented is an updated understanding of the development of sensory systems in the offspring of a wide range of terrestrial mammals, the prenatal exposure of those systems to salient stimuli, and the mechanisms by which that exposure can embed particular sensory capabilities that prepare newborns to respond appropriately to similar stimuli they may encounter after birth. Taken together, these are the constituents of the phenomenon of "trans-natal sensory continuity" where the embedded sensory capabilities are considered to have been "learnt" and, when accessed subsequently, they are said to have been "remembered". An alternative explanation of trans-natal sensory continuity is provided here in order to focus on the mechanisms of "embedding" and "accessing" instead of the potentially more subjectively conceived outcomes of "learning" and "memory". Thus, the mechanistic concept of "intrauterine sensory entrainment" has been introduced, its foundation being the well-established neuroplastic capability of nervous systems to respond to sensory inputs by reorganising their neural structures, functions, and connections. Five conditions need to be met before "trans-natal sensory continuity" can occur. They are (1) sufficient neurological maturity to support minimal functional activity in specific sensory receptor systems in utero; (2) the presence of sensory stimuli that activate their aligned receptors before birth; (3) the neurological capability for entrained functions within specific sensory modalities to be retained beyond birth; (4) specific sensory stimuli that are effective both before and after birth; and (5) a capability to detect those stimuli when or if they are presented after birth in ways that differ (e.g., in air) from their presentation via fluid media before birth. Numerous beneficial outcomes of this process have been reported for mammalian newborns, but the range of benefits depends on how many of the full set of sensory modalities are functional at the time of birth. Thus, the breadth of sensory capabilities may be extensive, somewhat restricted, or minimal in offspring that are, respectively, neurologically mature, moderately immature, or exceptionally immature at birth. It is noted that birth marks a transition from intrauterine sensory entrainment to extrauterine sensory entrainment in all mammalian young. Depending on their neurological maturity, extrauterine entrainment contributes to the continuing maturation of the different sensory systems that are operational at birth, the later development and maturation of the systems that are absent at birth, and the combined impact of those factors on the behaviour of newborn and young mammals. Intrauterine sensory entrainment helps to prepare mammalian young for life immediately after birth, and extrauterine sensory entrainment continues this process until all sensory modalities develop full functionality. It is apparent that, overall, extrauterine sensory entrainment and its aligned neuroplastic responses underlie numerous postnatal learning and memory events which contribute to the maturation of all sensory capabilities that eventually enable mammalian young to live autonomously.

Towards the Womb of Neonatal Intensive Care

Within the mother's womb, life finds its first stirrings. The womb shelters the fetus, the growing child within. We recognize the existential traces of a wombed existence when a newborn calms in response to being held; when a newborn stills in response to his or her mother's heartbeat; and, when a newborn startles in the presence of bright light. Yet, how does experiential human life begin within another human being? What are the conditions and paths of becoming for the fetus within the womb? And for the child born early, what "womb" welcomes the premature child in neonatal intensive care?

Neurodevelopmental Follow-up of Preterm Infants: What Is New?

There is increasing evidence of ongoing changes occurring in short-term and long-term motor and language outcomes in former premature infants. As rates of moderate to severe cerebral palsy (CP) have decreased, there has been increased awareness of the impact of mild CP and of developmental coordination disorder on the preterm population. Language delays and disorders continue to be among the most common outcomes. In conjunction with medical morbidities, there is increased awareness of the negative impact of family psycho-socioeconomic adversities on preterm outcomes and of the importance of intervention for these adversities beginning in the neonatal ICU.

Dissociating Long and Short-term Memory in Three-Month-Old Infants Using the Mismatch Response to Voice Stimuli

Auditory event-related potentials (ERPs) have been successfully used in adults as well as in newborns to discriminate recall of longer-term and shorter-term memories. Specifically the Mismatch Response (MMR) to deviant stimuli of an oddball paradigm is larger if the deviant stimuli are highly familiar (i.e., retrieved from long-term memory) than if they are unfamiliar, representing an immediate change to the standard stimuli kept in short-term memory. Here, we aimed to extend previous findings indicating a differential MMR to familiar and unfamiliar deviants in newborns (Beauchemin et al., 2011), to 3-month-old infants who are starting to interact more with their social surroundings supposedly based on forming more (social) long-term representations. Using a voice discrimination paradigm, each infant was repeatedly presented with the word “baby” (400 ms, interstimulus interval: 600 ms, 10 min overall duration) pronounced by three different female speakers. One voice that was unfamiliar to the infants served as the frequently presented “standard” stimulus, whereas another unfamiliar voice served as the “unfamiliar deviant” stimulus, and the voice of the infant’s mother served as the “familiar deviant.” Data collection was successful for 31 infants (mean age = 100 days). The MMR was determined by the difference between the ERP to standard stimuli and the ERP to the unfamiliar and familiar deviant, respectively. The MMR to the familiar deviant (mother’s voice) was larger, i.e., more positive, than that to the unfamiliar deviant between 100 and 400 ms post-stimulus over the frontal and central cortex. However, a genuine MMR differentiating, as a positive deflection, between ERPs to familiar deviants and standard stimuli was only found in the 300–400 ms interval. On the other hand, a genuine MMR differentiating, as a negative deflection, between ERPs to unfamiliar deviants from ERPs to standard stimuli was revealed for the 200–300 ms post-stimulus interval. Overall results confirm a differential MMR response to unfamiliar and familiar deviants in 3-month-olds, with the earlier negative MMR to unfamiliar deviants likely reflecting change detection based on comparison processes in short-term memory, and the later positive MMR to familiar deviants reflecting subsequent long-term memory-based processing of stimulus relevance.

Revisiting vocal perception in non-human animals: a review of vowel discrimination, speaker voice recognition, and speaker normalization

The extent to which human speech perception evolved by taking advantage of predispositions and pre-existing features of vertebrate auditory and cognitive systems remains a central question in the evolution of speech. This paper reviews asymmetries in vowel perception, speaker voice recognition, and speaker normalization in non-human animals - topics that have not been thoroughly discussed in relation to the abilities of non-human animals, but are nonetheless important aspects of vocal perception. Throughout this paper we demonstrate that addressing these issues in non-human animals is relevant and worthwhile because many non-human animals must deal with similar issues in their natural environment. That is, they must also discriminate between similar-sounding vocalizations, determine signaler identity from vocalizations, and resolve signaler-dependent variation in vocalizations from conspecifics. Overall, we find that, although plausible, the current evidence is insufficiently strong to conclude that directional asymmetries in vowel perception are specific to humans, or that non-human animals can use voice characteristics to recognize human individuals. However, we do find some indication that non-human animals can normalize speaker differences. Accordingly, we identify avenues for future research that would greatly improve and advance our understanding of these topics.

An acoustic gap between the NICU and womb: a potential risk for compromised neuroplasticity of the auditory system in preterm infants

The intrauterine environment allows the fetus to begin hearing low-frequency sounds in a protected fashion, ensuring initial optimal development of the peripheral and central auditory system. However, the auditory nursery provided by the womb vanishes once the preterm newborn enters the high-frequency (HF) noisy environment of the neonatal intensive care unit (NICU). The present article draws a concerning line between auditory system development and HF noise in the NICU, which we argue is not necessarily conducive to fostering this development. Overexposure to HF noise during critical periods disrupts the functional organization of auditory cortical circuits. As a result, we theorize that the ability to tune out noise and extract acoustic information in a noisy environment may be impaired, leading to increased risks for a variety of auditory, language, and attention disorders. Additionally, HF noise in the NICU often masks human speech sounds, further limiting quality exposure to linguistic stimuli. Understanding the impact of the sound environment on the developing auditory system is an important first step in meeting the developmental demands of preterm newborns undergoing intensive care.