10/28/2024
HOLD YOUR BABIES
Hold your babies, people!! Preferably up, as far as the child is concerned... and much to the dismay of tired parents around the world who are exasperated at an infant’s insistence at holding them standing.
A study by Esposito et al. (2013), published in the Journal of Current Biology, demonstrated for the first time that the calming response to parents holding them is a coordinated set of central, motor, and cardiac regulations and is a conserved component of parent-infant interactions in mammals.
Using electrocardiograms (ECG) to monitor twelve healthy human infants’ heartbeats, along with their behaviour and vocalisations, they recorded mother-infant pairs during behavioural tasks that consisted of the child lying in a crib, being held by the mother who was sitting on a chair ( ), or being held by the mother who was walking continuously ( ).
The researchers found a sustained elevation of heart interbeat intervals due to carrying in awake infants could not be explained by any known cardiac vagal reflex, including the orienting reflex (brief period of heart rate deceleration by mild sensory stimulus), suggesting that carrying evokes a sustained heart rate reduction in concert with the rapid behavioural changes in human infants via a novel mechanism.
The researchers furthermore found that in mouse pups, carrying induced calming responses similar to those in human infants, even though maternal carrying methods differed. This draws parallels between the carrying-induced state evoked in human babies and other mammalian young such as cats or squirrels who adopt a still, compact posture with their hind legs drawn up when maternally carried. The reduced mobility, reduced distress vocalisations, and reduced heart rate appears to be adaptive.
The calming responses evoked by carrying are thought to be an evolutionary measure to increase the survival probability of the infant in cases of emergency escape by the mother and child, and so ultimately works to strengthen the mother-infant relationship. There is adaptive value in this behaviour in carer-infant relationships and, as a consequence, infant survival.
The study found that the effects of carrying on the infant’s parasympathetic nervous system were significant, and it provides a scientific understanding of this physiological infant response that could be beneficial for parents and early childhood educators to understand.
Considering the physiological response of the infant when being carried may lead to greater parent and carer patience, reduced frustration and an increased appreciation of age-old parenting techniques such as and parenting.
https://www.cell.com/curre.../fulltext/S0960-9822(13)00343-6
Reference:
Infant Calming Responses during Maternal Carrying in Humans and Mice
Esposito, Gianluca et al.
Current Biology, Volume 23, Issue 9, 739 - 745
Highlights
• Maternal carrying reduces crying, body movement, and heart rate of infants
• In mice, a similar set of calming responses is observed during carrying
• Mouse calming response requires proprioception and somatosensation
• The calming responses in infants function to increase maternal carrying efficacy
Summary
Background
Mother-infant bonding is the earliest and most critical social relationship of mammalian infants. To promote this bond, infants have innate behaviors to seek maternal proximity and protest upon separation via communication with the mother vocally and through body movement. However, the physiological mechanisms regulating these infant behaviors remain largely undefined.
Results
Here we show a novel set of infant cooperative responses during maternal carrying. Infants under 6 months of age carried by a walking mother immediately stopped voluntary movement and crying and exhibited a rapid heart rate decrease, compared with holding by a sitting mother. Furthermore, we identified strikingly similar responses in mouse pups as defined by immobility and diminished ultrasonic vocalizations and heart rate. Using pharmacologic and genetic interventions in mouse pups, we identified the upstream and downstream neural systems regulating the calming response. Somatosensory and proprioceptive input signaling are required for induction, and parasympathetic and cerebellar functions mediate cardiac and motor output, respectively. The loss of the calming response hindered maternal rescue of the pups, suggesting a functional significance for the identified calming response.
Conclusions
Our study has demonstrated for the first time that the infant calming response to maternal carrying is a coordinated set of central, motor, and cardiac regulations and is a conserved component of mammalian mother-infant interactions. Our findings provide evidence for and have the potential to impact current parenting theory and practice, since unsoothable crying is the major risk factor for child abuse.
Photo📷 Credit: Neurochild Community
