Mother-infant Vocal Interactions Research Articles

Synchrony in mother-infant vocal interactions revealed through timed event sequences

This report extends a previous cross-cultural study of synchrony in mother-infant vocal interactions (Bornstein et al., 2015) to immigrant samples. Immigrant dyads from three cultures of origin (Japan, South Korea, South America) living in the same culture of destination (the United States) were compared to nonmigrant dyads in those same cultures of origin and to nonmigrant European American dyads living in the same culture of destination (the United States). This article highlights an underutilized analysis to assess synchrony in mother-infant interaction and extends cross-cultural research on mother-infant vocal interaction. Timing of onsets and offsets of maternal speech to infants and infant nondistress vocalizations were coded separately from 50-min recorded naturalistic observations of mothers and infants. Odds ratios were computed to analyze synchrony in mother-infant vocal interactions. Synchrony was analyzed in three ways -- contingency of timed event sequences, mean differences in contingency by acculturation level and within dyads, and coordination of responsiveness within dyads. Immigrant mothers were contingently responsive to their infants’ vocalizations, but only Korean immigrant infants were contingently responsive to their mothers’ vocalizations. For the Japanese and South American comparisons, immigrant mothers were more contingently responsive than their infants (but not robustly so for South American immigrants). For the Korean comparison, mean differences in contingent responsiveness were found among acculturation groups (culture of origin, immigrant, culture of destination), but not between mothers and infants. Immigrant dyads’ mean levels of responsiveness did not differ. Immigrant mothers’ and infants’ levels of responsiveness were coordinated. Strengths and flexibility of the timed event sequential analytic approach to assessing synchrony in mother-infant interactions are discussed, particularly for culturally diverse samples.

Temporal Coordination in Mother-Infant Vocal Interaction: A Cross-Cultural Comparison.

Temporal coordination of vocal exchanges between mothers and their infants emerges from a developmental process that relies on the ability of communication partners to co-coordinate and predict each other’s turns. Consequently, the partners engage in communicative niche construction that forms a foundation for language in human infancy. While robust universals in vocal turn-taking have been found, differences in the timing of maternal and infant vocalizations have also been reported across cultures. In this study, we examine the temporal structure of vocal interactions in 38 mother–infant dyads in the first two years across two cultures—American and Lebanese—by studying observed and randomized distributions of vocalizations, focusing on both gaps and overlaps in naturalistic 10-min vocal interactions. We conducted a series of simulations using Kolmogorov–Smirnov (K–S) tests to examine whether the observed responsivity patterns differed from randomly generated simulations of responsivity patterns in both Arabic and English for mothers responding to infants and for infants responding to mothers. Results revealed that both mothers and infants engaged in conversational alternation, with mothers acting similarly across cultures. By contrast, significant differences were observed in the timing of infant responses to maternal utterances, with the Lebanese infants’ tendency to cluster their responses in the first half-second after the offset of the Lebanese mothers’ utterances to a greater extent than their American counterparts. We speculate that the results may be due to potential phonotactic differences between Arabic and English and/or to differing child-rearing practices across Lebanese and American cultures. The findings may have implications for early identification of developmental disorders such as autism spectrum disorders within and across cultures.

Mother-Infant Contingent Vocalizations in 11 Countries

Mother-infant vocal interactions serve multiple functions in child development, but it remains unclear whether key features of these interactions are community-common or community-specific. We examined rates, interrelations, and contingencies of vocal interactions in 684 mothers and their 5½-month-old infants in diverse communities in 11 countries (Argentina, Belgium, Brazil, Cameroon, France, Israel, Italy, Japan, Kenya, South Korea, and the United States). Rates of mothers’ and infants’ vocalizations varied widely across communities and were uncorrelated. However, collapsing the data across communities, we found that mothers’ vocalizations to infants were contingent on the offset of the infants’ nondistress vocalizing, infants’ vocalizations were contingent on the offset of their mothers’ vocalizing, and maternal and infant contingencies were significantly correlated. These findings point to the beginnings of dyadic conversational turn taking. Despite broad differences in the overall talkativeness of mothers and infants, maternal and infant contingent vocal responsiveness is found across communities, supporting essential functions of turn taking in early-childhood socialization.

A longitudinal study of coordination in mother-infant vocal interaction from age 4 to 10 months.

This is a longitudinal study of development in coordinated mother-infant vocal interaction from 4 to 10 months (N = 41) focusing on the development of turn-taking patterns and time spent in coordinated vocal interaction. Data analyses were carried out using multistate analysis. Both mothers and infants were found to coordinate their own vocalizations with their partners' vocalizations. The infants had a predominant pattern of covocalizing, whereas the mothers had a predominant turn-taking pattern at all ages (4, 7, and 10 months). However, a significant reduction in the duration of covocalization was found between 4 and 7 months, due to less covocalizing compared to turn-taking from the infants. In addition, time spent in coordinated vocal interaction increased significantly between 4 and 7 months and a development for the infants was found from repeated vocalizations toward single vocalizations between maternal turns. Taken together, these findings indicate a developmental process of fine-tuning and increasing the turn-taking format for vocal communication, characterizing adult communication, before the development of speech. In addition, our results indicate that this development starts earlier and is more prolonged than has been hypothesized from previous research. (PsycINFO Database Record

Do you hear the same? Cardiorespiratory responses between mothers and infants during tonal and atonal music.

This study examined the effects of tonal and atonal music on respiratory sinus arrhythmia (RSA) in 40 mothers and their 3-month-old infants. The tonal music fragment was composed using the structure of a harmonic series that corresponds with the pitch ratio characteristics of mother–infant vocal dialogues. The atonal fragment did not correspond with a tonal structure. Mother–infant ECG and respiration were registered along with simultaneous video recordings. RR-interval, respiration rate, and RSA were calculated. RSA was corrected for any confounding respiratory and motor activities. The results showed that the infants’ and the mothers’ RSA-responses to the tonal and atonal music differed. The infants showed significantly higher RSA-levels during the tonal fragment than during the atonal fragment and baseline, suggesting increased vagal activity during tonal music. The mothers showed RSA-responses that were equal to their infants only when the infants were lying close to their bodies and when they heard the difference between the two fragments, preferring the tonal above the atonal fragment. The results are discussed with regard to music-related topics, psychophysiological integration and mother-infant vocal interaction processes.

Possible role of mother-daughter vocal interactions on the development of species-specific song in gibbons.

Mother-infant vocal interactions play a crucial role in the development of human language. However, comparatively little is known about the maternal role during vocal development in nonhuman primates. Here, we report the first evidence of mother-daughter vocal interactions contributing to vocal development in gibbons, a singing and monogamous ape species. Gibbons are well known for their species-specific duets sung between mates, yet little is known about the role of intergenerational duets in gibbon song development. We observed singing interactions between free-ranging mothers and their sub-adult daughters prior to emigration. Daughters sang simultaneously with their mothers at different rates. First, we observed significant acoustic variation between daughters. Co-singing rates between mother and daughter were negatively correlated with the temporal precision of the song’s synchronization. In addition, songs of daughters who co-sang less with their mothers were acoustically more similar to the maternal song than any other adult female’s song. All variables have been reported to be influenced by social relationships of pairs. Therefore those correlations would be mediated by mother-daughter social relationship, which would be modifiable in daughter’s development. Here we hypothesized that daughters who co-sing less often, well-synchronize, and converge acoustically with the maternal acoustic pattern would be at a more advanced stage of social independence in sub-adult females prior to emigration. Second, we observed acoustic matching between mothers and daughters when co-singing, suggesting short-term vocal flexibility. Third, we found that mothers adjusted songs to a more stereotyped pattern when co-singing than when singing alone. This vocal adjustment was stronger for mothers with daughters who co-sang less. These results indicate the presence of socially mediated vocal flexibility in gibbon sub-adults and adults, and that mother-daughter co-singing interactions may enhance vocal development. More comparative work, notably longitudinal and experimental, is now needed to clarify maternal roles during song development.

Phrasing and fragmented time in “pathological” mother-infant vocal interaction

This paper presents the results of an ecological perturbation study of mother-infant vocal interaction. We compared the temporal organisation of spontaneous interactions between 3–month-old infants and mothers who suffered from “borderline personality disorder” and control mothers and infants. Previous studies of vocal interaction have shown that they present a hierarchical temporal organisation. This study focused specifically on “phrasal” units in the flow of expressive sounds produced by mothers and infants that can be segmented according to rules similar to those used by music performers, composers and listeners. Phrases in interaction are perceived and shaped by features such as final lengthening, pausing or lowered pitch and intensity. Acoustic analyses of audio recordings of 34 mother-infant dyads were performed. Results showed that the interactions of mothers with “borderline personality disorder” contained fewer “phrases” with longer phrase final pauses than those of control dyads. These findings suggest that the temporal organisation and quality of vocalisation, rather than the degree of maternal involvement, has a fundamental effect on the infant's motivation to partake in lively interaction.

Chimpanzees are not proto-hominins and early human mothers may not have foraged alone

Modeling the evolution of human behavior, including language, is a complex but important undertaking. The over-reliance on chimpanzees as models to assess basal hominin patterns and the implicit assumption that hominin mothers did not have significant assistance in caring for young weaken this model for the emergence of language from mother-infant vocal interactions.

Expressions of belonging: the effect of acculturation on the rhythm and harmony of mother-infant vocal interaction

The rhythmic structure of naturally occurring mother-infant vocal interaction was analysed within three different cultural contexts. Previous research suggests that rhythm is used universally to facilitate the sharing of affect and meaning. Well-timed mother-infant communication is thought to permit a particular form of direct mind-to-mind communication. The purpose of the study was to ascertain whether one of the functions of this “intersubjective” communication is to allow culturally significant experiences to be shared at a non-verbal and affect-bound level. The main hypothesis was that changes in the cultural identity of the mother, and her sense of emotional security, would significantly affect the rhythmic organisation of non-verbal vocal interaction. Out of thirty-six mother-infant dyads studied, twelve were from India and lived in India, twelve were from India and lived in France, and twelve were from France and lived in France. The results suggest that immigrant dyads have significantly less well-timed vocal interactions than non-immigrant dyads and that this is due to an identity confusion on the part of the immigrant mother. Other factors that may influence the rhythmicity of the vocal interactions of immigrant dyads were examined. Results also highlighted cultural differences in the nature and form of the mothers’ vocalisations.

Acoustic properties that determine adults' preferences for 3-month-old infant vocalizations

When videotapes of 3-month-old infants who engaged in social vocalization are presented, the quality of their vocalizations affects the viewing adult's perceived favorableness of infants. In general, adults prefer infants who produce so-called “syllabic” as compared with “vocalic” sounds. In this study, we attempted to quantitatively determine the acoustic properties that distinguished these two types of vocalizations. Results of our acoustical analysis of Canadian infants reveal that syllabic and vocalic sounds differ from one another in two parameters, duration and degree of nasality of vocalizations. Naturalistic observations of Japanese mother-infant vocal interactions suggest that those acoustical properties indeed differentially affect responses of the mother to infant vocalizations. When listening to those vocalizations that vary in degree of nasality but do not differ in duration, Japanese adults perceive less nasal sounds as more favorable. Adults' preference for 3-month-old infants' vocalizations appear to be determined largely by differences in nasality, and the phenomenon could be cross-linguistically universal.

Conversational and anticonversational turntaking in mother-infant vocal interactions: J. Jaffe, B. Beebe, S. W. Anderson, S. Feldstein, C. Crown, and M. Jasnow, Psychiatry, Columbia University, New York, New York

Conversational and anticonversational turntaking in mother-infant vocal interactions: J. Jaffe, B. Beebe, S. W. Anderson, S. Feldstein, C. Crown, and M. Jasnow, Psychiatry, Columbia University, New York, New York

Adult-Like Temporal Characteristics of Mother-Infant Vocal Interactions

29 mothers and their 9-month-old-infants participated in a semistructured play episode. The temporal patterning of their vocal behavior was analyzed by means of a computerized analogue-to-digital conversion system (AVTA). Time-series regression analysis was employed to determine interpersonal influence over the course of the exchange for a variety of temporal parameters. The analysis revealed that the dyads engaged in alternating vocalization to a greater degree than simultaneous vocalization, and that there is a pattern of mutual influence (interpersonal accommodation) for switching pauses. The results suggest that some of the formal attributes observed in conversational exchanges between adult speakers are observable prior to the emergence of linguistic competence.

Adult-like Temporal Characteristics of Mother-Infant Vocal Interactions

Adult-like Temporal Characteristics of Mother-Infant Vocal Interactions