Interdependencies between vocal behaviour and interpersonal arousal coupling in caregiver-infant dyads

Abstract

We currently understand little about how autonomic arousal influences early vocal development. To examine this, we used wearable microphones and autonomic sensors to collect multimodal naturalistic datasets from 12-month-olds and their caregivers. We observed that clusters of vocalisations occurred during elevated infant and caregiver arousal, but the relationship is stronger in infants than caregivers. Caregivers show greater functional flexibility, and their vocal production is more influenced by the infant’s arousal than their own. Negative affect vocalisations occur following reduced arousal stability and lead to increased child-caregiver arousal coupling, and decreased infant arousal. Positive vocalisations also occur at elevated arousal, but lead to increases in arousal, and elicit more parental speech. Our results point to important bi-directional associations between vocalisations and arousal regulation across caregiver-infant dyads.

Preverbal infants produce more protophones with artificial objects compared to natural objects

“…Specifically, infant vocal activity increases during interactions with traditional toys compared to electronic and feedback toys 13 , 23 , 24 , suggesting that the former may promote protophone production and benefit later language skills and outcomes. Such increased protophone production linked to specific toys has previously been explained by a distinctive attentional or arousal state of the infants 25 , 26 . It is, however, possible that an overall frequent occurrence of protophones is linked more to artificial objects, where toys are especially designed to engage children 27 .…”

Vocalization and physiological hyperarousal in infant–caregiver dyads where the caregiver has elevated anxiety

“…Taken together, results from arousal contagion studies with parent-infant dyads suggest that ostensive cues, such as touch and gaze, can facilitate the transmission of physiological arousal from one partner to another during social interaction (Waters et al, 2017). Very little, however, is known about the role of speech in arousal contagion, despite the importance of the auditory modality in communication between parent and infant Wass et al, 2021;Zhang & Ghazanfar, 2020). This is particularly true when the infant is out of reach and not directly controllable, a potentially stressinducing context that becomes increasingly common as the infant develops.…”

Infant vocalizations elicit simplified speech in childcare

“…From the infant's perspective, adults' contingent responses appear to both facilitate infant attention (Masek et al., 2021) and come at a time when infants are signaling their own attention by vocalizing (Wass et al., 2021). Wass et al.…”

“…Wass et al. (2021) found that infants are more likely to vocalize at points of peaks arousal. Further, contingent input causes infants to produce more advanced or speech‐like vocalizations (Goldstein et al., 2003; Miller & Gros‐Louis, 2013).…”

“…For example, 11‐month‐old infants who hear an object label following a silent bout of joint attention are unsuccessful in learning novel labels; however, infants who hear the label immediately after producing an object‐directed vocalization do learn (Goldstein et al., 2010). Contingent labeling after babbling may enhance learning because the vocalization stimulates a level of arousal that facilitates infant attention (Wass et al., 2021).…”