The Role of Affectionate Caregiver Touch in Early Neurodevelopment and Parent-Infant Interactional Synchrony.

Sofia Carozza,Victoria Leong

doi:10.3389/fnins.2020.613378

Sofia Carozza, Victoria Leong

Open Access

https://doi.org/10.3389/fnins.2020.613378

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Abstract

Though rarely included in studies of parent–infant interactions, affectionate touch plays a unique and vital role in infant development. Previous studies in human and rodent models have established that early and consistent affectionate touch from a caregiver confers wide-ranging and holistic benefits for infant psychosocial and neurophysiological development. We begin with an introduction to the neurophysiological pathways for the positive effects of touch. Then, we provide a brief review of how affectionate touch tunes the development of infant somatosensory, autonomic (stress regulation), and immune systems. Affective touch also plays a foundational role in the establishment of social affiliative bonds and early psychosocial behavior. These touch-related bonding effects are known to be mediated primarily by the oxytocin system, but touch also activates mesocorticolimbic dopamine and endogenous opioid systems which aid the development of social cognitive processes such as social learning and reward processing. We conclude by proposing a unique role for affectionate touch as an essential pathway to establishing and maintaining parent-infant interactional synchrony at behavioral and neural levels. The limitations of the current understanding of affectionate touch in infant development point to fruitful avenues for future research.

Highlights

Interactions with a parent provide the foundation for infant cognitive and socioemotional development (Raby et al, 2015; Mermelshtine and Barnes, 2016)
Gentle caregiver stroking— but not other forms of touch—enables 4-month-old infants to recognize faces with an averted gaze, though they typically attend only to faces with a direct gaze (Della Longa et al, 2019). These changes may be mediated by the maturation of the social brain, as frequent maternal touch is associated with greater activity and connectivity of cortical regions implicated in social processing (Brauer et al, 2016)
While touch has yet to be isolated in studies of parent–infant neural synchrony, it appears probable that, like the ostensive cues of gaze and speech, touch leads to the phase reset and entrainment of neural oscillations

Summary

INTRODUCTION

Interactions with a parent provide the foundation for infant cognitive and socioemotional development (Raby et al, 2015; Mermelshtine and Barnes, 2016). While rodents do not form attachments as such, SSC with the dam—together with her olfactory cues— are signals of maternal care, and rats deprived of tactile and olfactory stimulation in infancy show impaired maternal behavior themselves in later life (Melo et al, 2006; Kojima et al, 2012) Both SSC and KMC appear to increase peripheral oxytocin levels in human infants, when measured with enzyme immunoassay (Vittner et al, 2018; Hardin et al, 2020). Gentle caregiver stroking— but not other forms of touch—enables 4-month-old infants to recognize faces with an averted gaze, though they typically attend only to faces with a direct gaze (Della Longa et al, 2019) These changes may be mediated by the maturation of the social brain, as frequent maternal touch is associated with greater activity and connectivity of cortical regions implicated in social processing (Brauer et al, 2016). Affectionate touch appears to promote the development of neural circuits involved in social forms of learning, as well as motivation and reward processing

A ROLE FOR TOUCH IN PARENT–INFANT INTERACTIONAL SYNCHRONY

CONCLUSION AND FUTURE DIRECTIONS