Infants relax in response to unfamiliar foreign lullabies

What rhythm production can tell us about culture

Jacoby and colleagues used an iterative rhythm reproduction paradigm with listeners from around the world to provide evidence for both rhythm universals (simple-integer ratios 1:1 and 2:1) and cross-cultural variation for specific rhythmic categories that can be linked to local music traditions in different regions of the world.

The difference of affect improvement effect of music intervention in aerobic exercise at different time periods

Objectives: A randomized controlled experimental design that combines exercise and music intervention was adopted in this study to verify whether this approach could help improve human affect. The differences in the effect of music listening on affective improvement were compared in four different periods: before, during, and after aerobic power cycling exercise and the whole exercise course. Method: A total of 140 subjects aged 19-30 years (average age: 23.6 years) were recruited and randomly divided into four music intervention groups, namely, the pre-exercise, during-exercise, post-exercise, and the whole-course groups. The subjects' demographic and sociological variables and daily physical activities were collected using questionnaires. Individual factors, such as the subjects' noise sensitivity, personality traits, and degree of learning burnout, were collected via scale scoring. A laboratory in Zhejiang Normal University was selected as the experimental site. The testing procedure can be summarized as follows. In a quiet environment, the subjects were asked to sit quietly for 5 min after completing a preparation work, and then they were informed to take a pre-test. The four subject groups wore headphones and completed 20 min of aerobic cycling (i.e., 7 min of moderate-intensity cycling [50%*HRR + RHR] + 6 min of low-intensity interval cycling [30%*HRR + RHR] + 7 min of moderate-intensity cycling [50%*HRR + RHR] after returning to a calm state (no less than 20 min) for post-testing. The affect improvement indicators (dependent variables) collected in the field included blood pressure (BP), positive/negative affect, and heart rate variability indicators (RMSSD, SDNN, and LF/HF). Results: 1) Significant differences were found in the participants' systolic BP (SBP) indices and the effect of improvement of the positive affect during the exercise-music intervention among the four groups at different durations for the same exercise intensity (F = 2.379, p = 0.030, ɳp 2 = 0.058; F = 2.451, p = 0.043, ɳp 2 = 0.091). 2) Music intervention for individuals during exercise contribute more to the reduction of SBP than the other three time periods (F = 3.170, p = 0.047, ɳp 2 = 0.068). Improvement in the participants' negativity affective score was also better during exercise, and it was significantly different than the other three time periods (F = 5.516, p = 0.006, ɳp 2 = 0.113). No significant differences were found in the improvement effects of the other effective indicators for the four periods. Conclusion: Exercise combined with music intervention has a facilitative effect on human affect improvement, and listening to music during exercise has a better impact on affective improvement than music interventions at the other periods. When people perform physical activities, listening to music during exercise positively affects the progress effect among them.

Toddlers' affective responses to sociomoral scenes: Insights from physiological measures

A growing literature suggests that preverbal infants are sensitive to sociomoral scenes and prefer prosocial agents over antisocial agents. It remains unclear, however, whether and how emotional processes are implicated in infants' responses to prosocial/antisocial actions. Although a recent study found that infants and toddlers showed more positive facial expressions after viewing helping (vs. hindering) events, these findings were based on naïve coder ratings of facial activity; furthermore, effect sizes were small. The current studies examined 18- and 24-month-old toddlers' real-time reactivity to helping and hindering interactions using three physiological measures of emotion-related processes. At 18 months, activity in facial musculature involved in smiling/frowning was explored via facial electromyography (EMG). At 24 months, stress (sweat) was explored via electrodermal activity (EDA). At both ages, arousal was explored via pupillometry. Behaviorally, infants showed no preferences for the helper over the hinderer across age groups. EMG analyses revealed that 18-month-olds showed higher corrugator activity (more frowning) during hindering (vs. helping) actions, followed by lower corrugator activity (less frowning) after hindering (vs. helping) actions finished. These findings suggest that antisocial actions elicited negativity, perhaps followed by brief disengagement. EDA analyses revealed no significant event-related differences. Pupillometry analyses revealed that both 18- and 24-month-olds' pupils were smaller after viewing hindering (vs. helping), replicating recent evidence with 5-month-olds and suggesting that toddlers also show less arousal following hindering than following helping. Together, these results provide new evidence with respect to whether and how arousal/affective processes are involved when infants process sociomoral scenarios.

Early social communication through music: State of the art and future perspectives

A growing body of research shows that the universal capacity for music perception and production emerges early in development. Possibly building on this predisposition, caregivers around the world often communicate with infants using songs or speech entailing song-like characteristics. This suggests that music might be one of the earliest developing and most accessible forms of interpersonal communication, providing a platform for studying early communicative behavior. However, little research has examined music in truly communicative contexts. The current work aims to facilitate the development of experimental approaches that rely on dynamic and naturalistic social interactions. We first review two longstanding lines of research that examine musical interactions by focusing either on the caregiver or the infant. These include defining the acoustic and non-acoustic features that characterize infant-directed (ID) music, as well as behavioral and neurophysiological research examining infants' processing of musical timing and pitch. Next, we review recent studies looking at early musical interactions holistically. This research focuses on how caregivers and infants interact using music to achieve co-regulation, mutual engagement, and increase affiliation and prosocial behavior. We conclude by discussing methodological, technological, and analytical advances that might empower a comprehensive study of musical communication in early childhood.

Universal interpretations of vocal music

Despite the variability of music across cultures, some types of human songs share acoustic characteristics. For example, dance songs tend to be loud and rhythmic, and lullabies tend to be quiet and melodious. Human perceptual sensitivity to the behavioral contexts of songs, based on these musical features, suggests that basic properties of music are mutually intelligible, independent of linguistic or cultural content. Whether these effects reflect universal interpretations of vocal music, however, is unclear because prior studies focus almost exclusively on English-speaking participants, a group that is not representative of humans. Here, we report shared intuitions concerning the behavioral contexts of unfamiliar songs produced in unfamiliar languages, in participants living in Internet-connected industrialized societies (n = 5,516 native speakers of 28 languages) or smaller-scale societies with limited access to global media (n = 116 native speakers of three non-English languages). Participants listened to songs randomly selected from a representative sample of human vocal music, originally used in four behavioral contexts, and rated the degree to which they believed the song was used for each context. Listeners in both industrialized and smaller-scale societies inferred the contexts of dance songs, lullabies, and healing songs, but not love songs. Within and across cohorts, inferences were mutually consistent. Further, increased linguistic or geographical proximity between listeners and singers only minimally increased the accuracy of the inferences. These results demonstrate that the behavioral contexts of three common forms of music are mutually intelligible cross-culturally and imply that musical diversity, shaped by cultural evolution, is nonetheless grounded in some universal perceptual phenomena.

Learning to pause: Fidelity of and biases in the developmental acquisition of gaps in the communicative signals of a songbird

The temporal organization of sounds used in social contexts can provide information about signal function and evoke varying responses in listeners (receivers). For example, music is a universal and learned human behavior that is characterized by different rhythms and tempos that can evoke disparate responses in listeners. Similarly, birdsong is a social behavior in songbirds that is learned during critical periods in development and used to evoke physiological and behavioral responses in receivers. Recent investigations have begun to reveal the breadth of universal patterns in birdsong and their similarities to common patterns in speech and music, but relatively little is known about the degree to which biological predispositions and developmental experiences interact to shape the temporal patterning of birdsong. Here, we investigated how biological predispositions modulate the acquisition and production of an important temporal feature of birdsong, namely the duration of silent pauses ("gaps") between vocal elements ("syllables"). Through analyses of semi-naturally raised and experimentally tutored zebra finches, we observed that juvenile zebra finches imitate the durations of the silent gaps in their tutor's song. Further, when juveniles were experimentally tutored with stimuli containing a wide range of gap durations, we observed biases in the prevalence and stereotypy of gap durations. Together, these studies demonstrate how biological predispositions and developmental experiences differently affect distinct temporal features of birdsong and highlight similarities in developmental plasticity across birdsong, speech, and music. RESEARCH HIGHLIGHTS: The temporal organization of learned acoustic patterns can be similar across human cultures and across species, suggesting biological predispositions in acquisition. We studied how biological predispositions and developmental experiences affect an important temporal feature of birdsong, namely the duration of silent intervals between vocal elements ("gaps"). Semi-naturally and experimentally tutored zebra finches imitated the durations of gaps in their tutor's song and displayed some biases in the learning and production of gap durations and in gap variability. These findings in the zebra finch provide parallels with the acquisition of temporal features of speech and music in humans.

Music in the Middle: A Culture-Cognition-Mediator Model of Musical Functionality

Music is both universal, appearing in every known human culture, and culture-specific, often defying intelligibility across cultural boundaries. This duality has been the source of debate within the broad community of music researchers, and there have been significant disagreements both on the ontology of music as an object of study and the appropriate epistemology for that study. To help resolve this tension, I present a culture-cognition-mediator model that situates music as a mediator in the mutually constitutive cycle of cultures and selves representing the ways individuals both shape and are shaped by their cultural environments. This model draws on concepts of musical grammars and schema, contemporary theories in developmental and cultural psychology that blur the distinction between nature and nurture, and recent advances in cognitive neuroscience. Existing evidence of both directions of causality is presented, providing empirical support for the conceptual model. The epistemological consequences of this model are discussed, specifically with respect to transdisciplinarity, hybrid research methods, and several potential empirical applications and testable predictions as well as its import for broader ontological conversations around the evolutionary origins of music itself.

The (Co)Evolution of Language and Music Under Human Self-Domestication

Together with language, music is perhaps the most distinctive behavioral trait of the human species. Different hypotheses have been proposed to explain why only humans perform music and how this ability might have evolved in our species. In this paper, we advance a new model of music evolution that builds on the self-domestication view of human evolution, according to which the human phenotype is, at least in part, the outcome of a process similar to domestication in other mammals, triggered by the reduction in reactive aggression responses to environmental changes. We specifically argue that self-domestication can account for some of the cognitive changes, and particularly for the behaviors conducive to the complexification of music through a cultural mechanism. We hypothesize four stages in the evolution of music under self-domestication forces: (1) collective protomusic; (2) private, timbre-oriented music; (3) small-group, pitch-oriented music; and (4) collective, tonally organized music. This line of development encompasses the worldwide diversity of music types and genres and parallels what has been hypothesized for languages. Overall, music diversity might have emerged in a gradual fashion under the effects of the enhanced cultural niche construction as shaped by the progressive decrease in reactive (i.e., impulsive, triggered by fear or anger) aggression and the increase in proactive (i.e., premeditated, goal-directed) aggression.

Universality, domain-specificity, and development of psychological responses to music

Humans can find music happy, sad, fearful, or spiritual. They can be soothed by it or urged to dance. Whether these psychological responses reflect cognitive adaptations that evolved expressly for responding to music is an ongoing topic of study. In this Review, we examine three features of music-related psychological responses that help to elucidate whether the underlying cognitive systems are specialized adaptations: universality, domain-specificity, and early expression. Focusing on emotional and behavioural responses, we find evidence that the relevant psychological mechanisms are universal and arise early in development. However, the existing evidence cannot establish that these mechanisms are domain-specific. To the contrary, many findings suggest that universal psychological responses to music reflect more general properties of emotion, auditory perception, and other human cognitive capacities that evolved for non-musical purposes. Cultural evolution, driven by the tinkering of musical performers, evidently crafts music to compellingly appeal to shared psychological mechanisms, resulting in both universal patterns (such as form-function associations) and culturally idiosyncratic styles.

The Effect of Contingent Singing on Infants with Bronchopulmonary Dysplasia in the Neonatal Intensive Care Unit

A significant component of care for infants with bronchopulmonary dysplasia (BPD) is providing an optimal environment for supporting neurodevelopment and growth. Interventions that support the behavioral and physiologic stability of this population may play an important role in improving overall outcomes. Contingent singing is a music intervention that allows the caregiver to tailor certain musical elements, such as rhythm and tempo, to match behavioral and physiologic cues and support the infant in achieving optimal stabilization. A randomized crossover design was used to study the effect of contingent singing on the behavioral state and physiologic measures compared to standard care practices in the neonatal intensive care unit (NICU). Data were collected on a sample of 37 infants diagnosed with BPD. There were no significant differences in the physiologic measures or behavioral states of infants in the contingent singing sessions compared to control sessions. Parents and staff reported favorable views of music therapy in the NICU, and there were no adverse responses from infants during contingent singing. Further research is needed to determine the effectiveness of this intervention on the physiologic stability of infants with BPD.

A systematic review and Bayesian meta-analysis of the acoustic features of infant-directed speech

When speaking to infants, adults often produce speech that differs systematically from that directed to other adults. To quantify the acoustic properties of this speech style across a wide variety of languages and cultures, we extracted results from empirical studies on the acoustic features of infant-directed speech. We analysed data from 88 unique studies (734 effect sizes) on the following five acoustic parameters that have been systematically examined in the literature: fundamental frequency (f₀), f₀ variability, vowel space area, articulation rate and vowel duration. Moderator analyses were conducted in hierarchical Bayesian robust regression models to examine how these features change with infant age and differ across languages, experimental tasks and recording environments. The moderator analyses indicated that f₀, articulation rate and vowel duration became more similar to adult-directed speech over time, whereas f₀ variability and vowel space area exhibited stability throughout development. These results point the way for future research to disentangle different accounts of the functions and learnability of infant-directed speech by conducting theory-driven comparisons among different languages and using computational models to formulate testable predictions.

Investigating the effect of synchronized movement on toddlers' word learning

The effect of interpersonal behavioral synchrony on children's behavior is an emerging field rich with research potential. While studies demonstrate its effect on affiliative and prosocial outcomes, the role of synchronized movement on children's specific learning outcomes has not yet been investigated experimentally. One possibility is that synchrony, as a coordinated social activity, encourages perceived social bonds, leading to heightened attention, and better information retention. Equally likely is that physiological, rather than social learning, mechanisms mediate the effect, given the previously demonstrated role of autonomic arousal in attentional fluctuations, cognitive engagement, problem solving, exploration, and curiosity. The present study investigated the behavioral and physiological effects of synchrony conceptualized as induced, interpersonal, behavioral, movement-based interaction, on word learning in 2.5-year-old children. In a laboratory experiment, toddlers engaged in either a synchronous or an asynchronous movement-based interaction with an adult experimenter while listening to an upbeat children's song. After the (a)synchronous movement episode, the same experimenter engaged children in a word learning task. During the (a)synchrony and learning phases, children's physiological arousal was continuously recorded, resulting in heart rate and skin conductance response measures. Following a caregiver-child free play break, children were tested on their novel word retention. The results indicated that children learned novel labels at equal rates during the learning phase in both conditions, and their retention at test did not differ between conditions: although above chance retention of novel labels was found only following the synchronous, but not the asynchronous episode, the cross-episode comparisons did not reach statistical significance. Physiological arousal indices following the (a)synchrony episode did not differ between conditions and did not predict better word learning, although skin conductance response was higher during the learning than the movement episode. This study contributes to our understanding of the underlying cognitive and physiological mechanisms of interpersonal behavioral synchrony in the knowledge acquisition domain and paves the way to future investigations.

Acoustic regularities in infant-directed speech and song across cultures

When interacting with infants, humans often alter their speech and song in ways thought to support communication. Theories of human child-rearing, informed by data on vocal signalling across species, predict that such alterations should appear globally. Here, we show acoustic differences between infant-directed and adult-directed vocalizations across cultures. We collected 1,615 recordings of infant- and adult-directed speech and song produced by 410 people in 21 urban, rural and small-scale societies. Infant-directedness was reliably classified from acoustic features only, with acoustic profiles of infant-directedness differing across language and music but in consistent fashions. We then studied listener sensitivity to these acoustic features. We played the recordings to 51,065 people from 187 countries, recruited via an English-language website, who guessed whether each vocalization was infant-directed. Their intuitions were more accurate than chance, predictable in part by common sets of acoustic features and robust to the effects of linguistic relatedness between vocalizer and listener. These findings inform hypotheses of the psychological functions and evolution of human communication.

The Effect of Music Intervention on Fetal Education via Doppler Fetal Monitor

This study focused on the effects of music intervention on fetal education in pregnant women. The fetal heart rate of the fetus at 30–38 weeks of gestational age was monitored by an ultrasound Doppler fetal monitor, and differences in the frequency of fetal movement responses to familiar and unfamiliar music courses were recorded and analyzed. The analysis results showed that the fetuses had less fetal movement to fixed singing activities, with a mean of 0.7 and a standard deviation of 0.79. On the contrary, the fetuses had significant fetal movement responses to irregular singing, with a mean of 1.73 and a standard deviation of 1.37. The results showed that the fetus receives external sounds through hearing, and a pregnant woman singing fixed music to her fetus can stabilize the frequency of fetal movement, promote the health of herself and the fetus, and establish maternal-fetal bonding.

Anticipatory regulation of cardiovascular system on the emergence of auditory-motor interaction in young infants

Humans develop auditory-motor interaction to produce a variety of rhythmic sounds using body movements, which are often produced and amplified with tools, such as drumming. The extended production of sounds allows us to express a wide range of emotions, accompanied by physiological changes. According to previous studies, even young infants enhance movements in response to auditory feedback. However, their exhibition of physiological adaptation on the emergence of auditory-motor interaction is unclear. We investigated the movement and cardiac changes associated with auditory feedback to spontaneous limb movements in 3-month-old infants. The results showed that infants increased the frequency of limb movements inducing auditory feedback, while they exhibited a more regular rhythm of the limb movements. Furthermore, heart rate increase associated with the limb movement was first inhibited immediately after the timing of the auditory feedback, which may reflect sustained attention to the auditory stimuli. Then, through auditory-motor experience, the heart rate increase was inhibited even prior to the auditory feedback, leading to suppression of the peak intensity of the heart rate increase. These findings suggest that young infants regulate the cardiovascular system as well as limb movements in anticipation of the auditory feedback. The anticipatory regulation associated with movement and attentional changes may contribute to reduced cardiovascular stress in auditory-motor interaction, and provide a developmental basis for more sophisticated goal-directed behavior of producing rhythmic sounds.

Singing to infants matters: Early singing interactions affect musical preferences and facilitate vocabulary building

This research revealed that the frequency of reported parent-infant singing interactions predicted 6-month-old infants' performance in laboratory music experiments and mediated their language development in the second year. At 6 months, infants (n = 36) were tested using a preferential listening procedure assessing their sustained attention to instrumental and sung versions of the same novel tunes whilst the parents completed an ad-hoc questionnaire assessing home musical interactions with their infants. Language development was assessed with a follow-up when the infants were 14-month-old (n = 26). The main results showed that 6-month-olds preferred listening to sung rather than instrumental melodies, and that self-reported high levels of parental singing with their infants [i] were associated with less pronounced preference for the sung over the instrumental version of the tunes at 6 months, and [ii] predicted significant advantages on the language outcomes in the second year. The results are interpreted in relation to conceptions of developmental plasticity.

A neural population selective for song in human auditory cortex

How is music represented in the brain? While neuroimaging has revealed some spatial segregation between responses to music versus other sounds, little is known about the neural code for music itself. To address this question, we developed a method to infer canonical response components of human auditory cortex using intracranial responses to natural sounds, and further used the superior coverage of fMRI to map their spatial distribution. The inferred components replicated many prior findings, including distinct neural selectivity for speech and music, but also revealed a novel component that responded nearly exclusively to music with singing. Song selectivity was not explainable by standard acoustic features, was located near speech- and music-selective responses, and was also evident in individual electrodes. These results suggest that representations of music are fractionated into subpopulations selective for different types of music, one of which is specialized for the analysis of song.

Online testing in developmental science: A guide to design and implementation

At present, most developmental psychology experiments use participants from a mere subsection of the world's population. Moreover, like other fields of psychology, many studies in developmental psychology suffer from low statistical power due to small samples and limited observations. Online testing holds promise as a way to achieve more representative and robust, better powered experiments. As participants do not have to visit in person, it is easier to access populations living further away from a developmental lab, enabling testing of more diverse populations (e.g., urban vs rural areas, various different nationalities or geographies), both within and beyond the researcher's home country. Furthermore, due to the codified nature of browser-based online testing, it is possible for multiple labs to carry out the exact same study, allowing for better replications. Because of these advantages, developmental researchers have started to move experiments online so that caregivers and their children can participate from their home environments. However, the transition from traditional lab testing to remote online testing brings many challenges. Laboratory studies of infant and child development are typically conducted under highly standardized conditions to control factors, such as distractors, distance to the screen, movement, and lighting, and often rely on specialized equipment for measuring behavior. In this chapter, we provide a guide for researchers considering online testing of a developmental population. The different sections comprise an overview of the decision-making processes and the state-of-the-art advances associated with, as well as tangible recommendations for, online data collection.

Musicality in human vocal communication: an evolutionary perspective

Studies show that specific vocal modulations, akin to those of infant-directed speech (IDS) and perhaps music, play a role in communicating intentions and mental states during human social interaction. Based on this, we propose a model for the evolution of musicality-the capacity to process musical information-in relation to human vocal communication. We suggest that a complex social environment, with strong social bonds, promoted the appearance of musicality-related abilities. These social bonds were not limited to those between offspring and mothers or other carers, although these may have been especially influential in view of altriciality of human infants. The model can be further tested in other species by comparing levels of sociality and complexity of vocal communication. By integrating several theories, our model presents a radically different view of musicality, not limited to specifically musical scenarios, but one in which this capacity originally evolved to aid parent-infant communication and bonding, and even today plays a role not only in music but also in IDS, as well as in some adult-directed speech contexts. This article is part of the theme issue 'Voice modulation: from origin and mechanism to social impact (Part II)'.

Vocal communication across cultures: theoretical and methodological issues

The study of human vocal communication has been conducted primarily in Western, educated, industrialized, rich, democratic (WEIRD) societies. Recently, cross-cultural investigations in several domains of voice research have been expanding into more diverse populations. Theoretically, it is important to understand how universals and cultural variations interact in vocal production and perception, but cross-cultural voice research presents many methodological challenges. Experimental methods typically used in WEIRD societies are often not possible to implement in many populations such as rural, small-scale societies. Moreover, theoretical and methodological issues are often unnecessarily intertwined. Here, I focus on three areas of cross-cultural voice modulation research: (i) vocal signalling of formidability and dominance, (ii) vocal emotions, and (iii) production and perception of infant-directed speech. Research in these specific areas illustrates challenges that apply more generally across the human behavioural sciences but also reveals promise as we develop our understanding of the evolution of human communication. This article is part of the theme issue 'Voice modulation: from origin and mechanism to social impact (Part II)'.

Across demographics and recent history, most parents sing to their infants and toddlers daily

Music is universally prevalent in human society and is a salient component of the lives of young families. Here, we studied the frequency of singing and playing recorded music in the home using surveys of parents with infants (N = 945). We found that most parents sing to their infant on a daily basis and the frequency of infant-directed singing is unrelated to parents' income or ethnicity. Two reliable individual differences emerged, however: (i) fathers sing less than mothers and (ii) as infants grow older, parents sing less. Moreover, the latter effect of child age was specific to singing and was not reflected in reports of the frequency of playing recorded music. Last, we meta-analysed reports of the frequency of infant-directed singing and found little change in its frequency over the past 30 years, despite substantial changes in the technological environment in the home. These findings, consistent with theories of the psychological functions of music, in general, and infant-directed singing, in particular, demonstrate the everyday nature of music in infancy. This article is part of the theme issue 'Voice modulation: from origin and mechanism to social impact (Part I)'.

Diurnal fluctuations in musical preference

The rhythm of human life is governed by diurnal cycles, as a result of endogenous circadian processes evolved to maximize biological fitness. Even complex aspects of daily life, such as affective states, exhibit systematic diurnal patterns which in turn influence behaviour. As a result, previous research has identified population-level diurnal patterns in affective preference for music. By analysing audio features from over two billion music streaming events on Spotify, we find that the music people listen to divides into five distinct time blocks corresponding to morning, afternoon, evening, night and late night/early morning. By integrating an artificial neural network with Spotify's API, we show a general awareness of diurnal preference in playlists, which is not present to the same extent for individual tracks. Our results demonstrate how music intertwines with our daily lives and highlight how even something as individual as musical preference is influenced by underlying diurnal patterns.

Sound sleep: Lullabies as a test case for the neurobiological effects of music

Music is part of the cultural practice and, at the same time, is interwoven with biology through its effects on the brain and its likely evolutionary origin. Studies on music, however, are traditionally based on the humanities and often carried out in a purely historical context, without much input from neuroscience and biology. Here, we argue that lullabies are a particularly suited test case to study the biological versus cultural aspects of music.

Toward a productive evolutionary understanding of music

We discuss approaches to the study of the evolution of music (sect. R1); challenges to each of the two theories of the origins of music presented in the companion target articles (sect. R2); future directions for testing them (sect. R3); and priorities for better understanding the nature of music (sect. R4).

The influence of maternal singing on well-being, postpartum depression and bonding - a randomised, controlled trial

BACKGROUND

Postpartum depression is fairly common in new mothers and moreover associated with impaired bonding and poor maternal well-being. The aim of the present study was to investigate the impact of a mother-infant singing intervention within the first three months after birth on maternal well-being, depressive symptoms and bonding.

METHODS

120 women who were recruited at the maternity ward at the University Clinic in Düsseldorf took part in this prospective, randomised-controlled study. Beside the baseline measurement 1-3 days after childbirth, depressive symptoms, maternal well-being and mother-infant bonding were evaluated with questionnaires before (two weeks after birth) and after (twelve weeks after birth) the intervention took place. The experimental group (n = 59) participated in several singing intervention sessions while the control group (n = 61) did not. In the intervention group, salivary cortisol as well as attachment and mood were assessed immediately before and after the singing sessions.

RESULTS

The participants of the intervention group showed a significant reduction of cortisol (p = .023) and an improvement of attachment and mood from start to end of the intervention session (all p ≤ .008). However, no prolonged effects were revealed beyond the intervention sessions as the two groups did not differ regarding the alterations of the primary outcomes postpartum depression (interaction effect p = .187) and postpartum bonding (interaction effect p = .188) in the 10-week period from two up to twelve weeks after childbirth (all p > .05). Additional analyses of singing habits at home in both groups, revealed that only in the singing group more frequent singing was associated with less anxiety and more well-being of the mother.

CONCLUSION

Singing towards the infant seems to have positive immediate effects on the well-being of new mothers (on subjective variables as well as physiological measurements). However, the intervention did not lead to more long lasting positive effects although several limitations should be considered.

TRIAL REGISTRATION

DRKS00015178 (registered at the German Clinical Trial Registry), date of registration: 09.11.2018.

The song, not the singer: Infants prefer to listen to familiar songs, regardless of singer identity

Parent's infant-directed vocalizations are highly dynamic and emotive compared to their adult-directed counterparts, and correspondingly, more effectively capture infants' attention. Infant-directed singing is a specific type of vocalization that is common throughout the world. Parents tend to sing a small handful of songs in a stereotyped way, and a number of recent studies have highlighted the significance of familiar songs in young children's social behaviors and evaluations. To date, no studies have examined whether infants' responses to familiar versus unfamiliar songs are modulated by singer identity (i.e., whether the singer is their own parent). In the present study, we investigated 9- to 12-month-old infants' (N = 29) behavioral and electrodermal responses to relatively familiar and unfamiliar songs sung by either their own mother or another infant's mother. Familiar songs recruited more attention and rhythmic movement, and lower electrodermal levels relative to unfamiliar songs. Moreover, these responses were robust regardless of whether the singer was their mother or a stranger, even when the stranger's rendition differed greatly from their mothers' in mean fundamental frequency and tempo. Results indicate that infants' interest in familiar songs is not limited to idiosyncratic characteristics of their parents' song renditions, and points to the potential for song as an effective early signifier of group membership.

Music therapy for stress reduction: a systematic review and meta-analysis

Music therapy is increasingly being used as an intervention for stress reduction in both medical and mental healthcare settings. Music therapy is characterized by personally tailored music interventions initiated by a trained and qualified music therapist, which distinguishes music therapy from other music interventions, such as 'music medicine', which concerns mainly music listening interventions offered by healthcare professionals. To summarize the growing body of empirical research on music therapy, a multilevel meta-analysis, containing 47 studies, 76 effect sizes and 2.747 participants, was performed to assess the strength of the effects of music therapy on both physiological and psychological stress-related outcomes, and to test potential moderators of the intervention effects. Results showed that music therapy showed an overall medium-to-large effect on stress-related outcomes (d = .723, [.51-.94]). Larger effects were found for clinical controlled trials (CCT) compared to randomized controlled trials (RCT), waiting list controls instead of care as usual (CAU) or other stress-reducing interventions, and for studies conducted in Non-Western countries compared to Western countries. Implications for both music therapy and future research are discussed.

Origins of music in credible signaling

Music comprises a diverse category of cognitive phenomena that likely represent both the effects of psychological adaptations that are specific to music (e.g., rhythmic entrainment) and the effects of adaptations for non-musical functions (e.g., auditory scene analysis). How did music evolve? Here, we show that prevailing views on the evolution of music - that music is a byproduct of other evolved faculties, evolved for social bonding, or evolved to signal mate quality - are incomplete or wrong. We argue instead that music evolved as a credible signal in at least two contexts: coalitional interactions and infant care. Specifically, we propose that (1) the production and reception of coordinated, entrained rhythmic displays is a co-evolved system for credibly signaling coalition strength, size, and coordination ability; and (2) the production and reception of infant-directed song is a co-evolved system for credibly signaling parental attention to secondarily altricial infants. These proposals, supported by interdisciplinary evidence, suggest that basic features of music, such as melody and rhythm, result from adaptations in the proper domain of human music. The adaptations provide a foundation for the cultural evolution of music in its actual domain, yielding the diversity of musical forms and musical behaviors found worldwide.