skip to main content


Title: The social functions of babbling: acoustic and contextual characteristics that facilitate maternal responsiveness
Abstract

What is the social function of babbling? An important function of prelinguistic vocalizing may be to elicit parental behavior in ways that facilitate the infant's own learning about speech and language. Infants use parental feedback to their babbling to learn new vocal forms, but the microstructure of parental responses to babbling has not been studied. To enable precise manipulation of the proximal infant cues that may influence maternal behavior, we used a playback paradigm to assess mothers’ responsiveness to prerecorded audiovisual clips of unfamiliar infants’ noncry prelinguistic vocalizations and actions. Acoustic characteristics and directedness of vocalizations were manipulated to test their efficacy in structuring social interactions. We also compared maternal responsiveness in the playback paradigm and in free play with their own infants. Maternal patterns of reactions to babbling were stable across both tasks. In the playback task, we found specific vocal cues, such as the degree of resonance and the transition timing of consonant‐vowel syllables, predicted contingent maternal responding. Vocalizations directed at objects also facilitated increased responsiveness. The responses mothers exhibited, such as sensitive speech and vocal imitation, are known to facilitate vocal learning and development. Infants, by influencing the behavior of their caregivers with their babbling, create social interactions that facilitate their own communicative development.

 
more » « less
NSF-PAR ID:
10048303
Author(s) / Creator(s):
 ;  ;  
Publisher / Repository:
Wiley-Blackwell
Date Published:
Journal Name:
Developmental Science
Volume:
21
Issue:
5
ISSN:
1363-755X
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Abstract

    Infants’ prelinguistic vocalizations reliably organize vocal turn‐taking with social partners, creating opportunities for learning to produce the sound patterns of the ambient language. This social feedback loop supporting early vocal learning is well‐documented, but its developmental origins have yet to be addressed. When do infants learn that their non‐cry vocalizations influence others? To test developmental changes in infant vocal learning, we assessed the vocalizations of 2‐ and 5‐month‐old infants in a still‐face interaction with an unfamiliar adult. During the still‐face, infants who have learned the social efficacy of vocalizing increase their babbling rate. In addition, to assess the expectations for social responsiveness that infants build from their everyday experience, we recorded caregiver responsiveness to their infants’ vocalizations during unstructured play. During the still‐face, only 5‐month‐old infants showed an increase in vocalizing (a vocal extinction burst) indicating that they had learned to expect adult responses to their vocalizations. Caregiver responsiveness predicted the magnitude of the vocal extinction burst for 5‐month‐olds. Because 5‐month‐olds show a vocal extinction burst with unfamiliar adults, they must have generalized the social efficacy of their vocalizations beyond their familiar caregiver. Caregiver responsiveness to infant vocalizations during unstructured play was similar for 2‐ and 5‐month‐olds. Infants thus learn the social efficacy of their vocalizations between 2 and 5 months of age. During this time, infants build associations between their own non‐cry sounds and the reactions of adults, which allows learning of the instrumental value of vocalizing.

     
    more » « less
  2. Abstract

    Turn‐taking interactions are foundational to the development of social, communicative, and cognitive skills. In infants, vocal turn‐taking experience is predictive of infants' socioemotional and language development. However, different forms of turn‐taking interactions may have different effects on infant vocalizing. It is presently unknown how caregiver vocal, non‐vocal and multimodal responses to infant vocalizations compare in extending caregiver‐infant vocal turn‐taking bouts. In bouts that begin with an infant vocalization, responses that maintain versus change the communicative modality may differentially affect the likelihood of further infant vocalizing. No studies have examined how caregiver response modalities that either matched or differed from the infant acoustic (vocal) modality might affect the temporal structure of vocal turn‐taking beyond the initial serve‐and‐return exchanges. We video‐recorded free‐play sessions of 51 caregivers with their 9‐month‐old infants. Caregivers responded to babbling most often with vocalizations. In turn, caregiver vocal responses were significantly more likely to elicit subsequent infant babbling. Bouts following an initial caregiver vocal response contained significantly more turns than those following a non‐vocal or multimodal response. Thus prelinguistic turn‐taking is sensitive to the modality of caregivers' responses. Future research should investigate if such sensitivity is grounded in attentional constraints, which may influence the structure of turn‐taking interactions.

     
    more » « less
  3. null (Ed.)
    Abstract Background How the brain develops accurate models of the external world and generates appropriate behavioral responses is a vital question of widespread multidisciplinary interest. It is increasingly understood that brain signal variability—posited to enhance perception, facilitate flexible cognitive representations, and improve behavioral outcomes—plays an important role in neural and cognitive development. The ability to perceive, interpret, and respond to complex and dynamic social information is particularly critical for the development of adaptive learning and behavior. Social perception relies on oxytocin-regulated neural networks that emerge early in development. Methods We tested the hypothesis that individual differences in the endogenous oxytocinergic system early in life may influence social behavioral outcomes by regulating variability in brain signaling during social perception. In study 1, 55 infants provided a saliva sample at 5 months of age for analysis of individual differences in the oxytocinergic system and underwent electroencephalography (EEG) while listening to human vocalizations at 8 months of age for the assessment of brain signal variability. Infant behavior was assessed via parental report. In study 2, 60 infants provided a saliva sample and underwent EEG while viewing faces and objects and listening to human speech and water sounds at 4 months of age. Infant behavior was assessed via parental report and eye tracking. Results We show in two independent infant samples that increased brain signal entropy during social perception is in part explained by an epigenetic modification to the oxytocin receptor gene ( OXTR ) and accounts for significant individual differences in social behavior in the first year of life. These results are measure-, context-, and modality-specific: entropy, not standard deviation, links OXTR methylation and infant behavior; entropy evoked during social perception specifically explains social behavior only; and only entropy evoked during social auditory perception predicts infant vocalization behavior. Conclusions Demonstrating these associations in infancy is critical for elucidating the neurobiological mechanisms accounting for individual differences in cognition and behavior relevant to neurodevelopmental disorders. Our results suggest that an epigenetic modification to the oxytocin receptor gene and brain signal entropy are useful indicators of social development and may hold potential diagnostic, therapeutic, and prognostic value. 
    more » « less
  4. Coleman, Melissa J. (Ed.)
    Although male vocalizations during opposite- sex interaction have been heavily studied as sexually selected signals, the understanding of the roles of female vocal signals produced in this context is more limited. During intersexual interactions between mice, males produce a majority of ultrasonic vocalizations (USVs), while females produce a majority of human-audible squeaks, also called broadband vocalizations (BBVs). BBVs may be produced in conjunction with defensive aggression, making it difficult to assess whether males respond to BBVs themselves. To assess the direct effect of BBVs on male behavior, we used a split-cage paradigm in which high rates of male USVs were elicited by female presence on the other side of a barrier, but which precluded extensive male-female contact and the spontaneous production of BBVs. In this paradigm, playback of female BBVs decreased USV production, which recovered after the playback period. Trials in which female vocalizations were prevented by the use of female bedding alone or of anesthetized females as stimuli also showed a decrease in response to BBV playback. No non-vocal behaviors declined during playback, although digging behavior increased. Similar to BBVs, WNs also robustly suppressed USV production, albeit to a significantly larger extent. USVs suppression had two distinct temporal components. When grouped in 5-second bins, USVs interleaved with bursts of stimulus BBVs. USV suppression also adapted to BBV playback on the order of minutes. Adaptation occurred more rapidly in males that were housed individually as opposed to socially for a week prior to testing, suggesting that the adaptation trajectory is sensitive to social experience. These findings suggest the possibility that vocal interaction between male and female mice, with males suppressing USVs in response to BBVs, may influence the dynamics of communicative behavior. 
    more » « less
  5. Abstract

    Caregiver responsiveness and presence of secondary attachments play a crucial role in children's socio‐cognitive and emotional development, but little is known of their effect on the development of non‐human primates. Here we present the results of a 16‐month behavioral study conducted on 22 wild infant olive baboons (Papio anubis)at the Uaso Ngiro Baboon Project, Kenya. This is the first study to examine the effects of maternal responsiveness and secondary attachments on the development of infant social behavior in a wild primate species that does not breed cooperatively. The data track maternal responsiveness and the rates of two behavioral indicators of infant social competence—orienting toward interactions and social play—over the course of the first year of life. Maternal responsiveness decreased as infants grew older, while infant orientation toward interactions and play behavior increased. Infants with poorly responsive mothers were more likely to have secondary attachments, and infants with secondary attachments to siblings oriented more frequently to social interactions than those with secondary attachments to adult/subadult males or with no secondary attachments. These findings indicate that variation in maternal responsiveness and presence of secondary attachments can influence the development of social competence in olive baboon infants.

     
    more » « less