Neural and Physiological Synchrony in Mother-Infant Dyads

• In Event: Innovations in the Developmental Study of Biobehavioral Synchrony

Abstract

Bio-behavioral synchrony has been proposed to be an essential aspect of caregiver-child interactions, shaping the development of attachment as well as cognitive and social skills of the child (Atzil et al., 2018). Interpersonal synchronization of brain activity, physiology and behavior has been separately documented in child-caregiver dyads. However, it remains unclear how the three levels of synchrony are related to one another. Here, we examine mother-infant dyads in both interactive and non-interactive contexts in order to test under which circumstances neural and physiological synchrony between mother and infant occur. We hypothesize that both neural synchrony and physiological synchrony should be enhanced in interactive contexts as compared to non-interactive contexts.
We tested 4- to 6-month-old infants and their mother (N=69 dyads) in three conditions. Mother and infant were either seated next to one another without physical contact or the infant sat on the mother's lap as both were watching a calm aquarium video on a tablet (distal watching and proximate watching conditions). Next, mother and infant engaged in a 5-minute long free play without toys while both were seated face-to-face (interactive free play condition; as depicted in Figure 1). We assessed neural synchrony through dual functional near-infrared spectroscopy (fNIRS) measurements in 22 channels, which were located over bilateral inferior frontal and medial prefrontal regions. Wavelet transform coherence was used to calculate neural synchrony in the same channels of both participants. Additionally, we assessed physiological synchrony through respiratory sinus arrythmia (RSA) estimates acquired through electrocardiography and subsequent processing (Authors, under review). Physiological synchrony was estimated with Cross-Recurrence Quantification Analysis.
Preliminary findings reveal a significant increase in neural synchrony during free play in comparison to the non-interactive watching conditions, t>4.12, p<.0001 (see Figure 2). Furthermore, neural synchrony during the proximal watching condition was significantly increased as compared to the distal watching condition, t>2.38, p<.045. Next, we found higher physiological synchrony during the interactive free play vs. the non-interactive conditions, t>4.99, p<.001. The results indicate that both neural and physiological synchrony were enhanced in the interactive face-to-face free play situation in which mother and infant were able to respond to each other. However, only neural synchrony was increased in the non-interactive but proximal compared to the distal watching condition. The micro-adjustments of bodily contact as well as the perception of heart rhythms and respiration, might be related to why mother and infant showed neural synchronization during this condition. The findings thus indicate that neural and physiological synchrony might arise in partly similar contexts for the mother-infant dyad but diverge in their functionality.
We will further report analyses of behavioral synchrony as well as social touch measures which are currently underway. We will discuss these results in the context of variables affecting bio-behavioral synchronization and the functional significance of neural and physiological synchrony in early caregiver-child interactions.

Authors

• Trinh Nguyen, Istituto Italiano di Tecnologia (IIT)
  Presenting Author

• Drew Abney, University of Georgia
  Non-Presenting Author

• Bennett I Bertenthal, Indiana University - Bloomington
  Non-Presenting Author

• Stefanie Hoehl, University of Vienna
  Non-Presenting Author