Intuitively, we recognize that emotional connection touches the heart. We talk about how thinking of someone can warm our hearts. The symbol of the heart is synonymous with the calm, safe feeling we get when are close to people we love. But is this more than a figure of speech?
Scientists have been asking this question for a long time. In 1872, Charles Darwin observed that the heart and the brain are connected:
. . .when the heart is affected it reacts on the brain; and the state of the brain again reacts through the pneumo-gastric [vagus] nerve on the heart; so that under any excitement there will be much mutual action and reaction between these, the two most important organs of the body.
-Charles Darwin, The Expression of Emotions in Man and Animals
The vagus nerve connects the brain to vital organs throughout the body. It plays a major role in many physiological functions, including heart rate and the workings of the digestive tract. The vagus nerve transmits signals from the brain to the body, but the vast majority of information flows the other way – from the body to the brain.
Over the past 25 years, research has provided new insight into how the body affects behavior and emotions, and vice versa. In mammals, two branches of the vagus nerve have evolved, each supporting different functions and behaviors.
The Polyvagal Theory
The Polyvagal Theory, developed by Dr. Stephen Porges, proposes that the evolution of the autonomic nervous system in mammals is a major component of social behavior. According to Porges, when we feel safe, our body is primed for growth and restoration. The nerves and muscles involved in eye contact, facial expression, listening and tone of voice are also primed and ready to go. We are ready to relate.
But when we face challenges – such as the need to conserve energy, or feeling unsafe – that system can be overridden by another evolutionary coping mechanism; our “lizard brain” takes over to conserve energy and even behavioral shutdown. Polyvagal theory predicts that when our bodies are in this state of feeling threatened, it changes how we perceive social interactions. Instead of seeing someone approaching us as a friendly gesture we are more likely to see them as threatening, and respond with aggression or often, withdrawal.
So when our bodies go into survival mode, perceiving threats everywhere so we can’t connect with others, what can be done to change that? How can we get back to a physiological state that supports social engagement and emotional connection? Nurture Science Program research suggests that we can’t do it alone. We need to be in relationship with each other.
The Calming Cycle Theory
The Calming Cycle Theory, developed by Martha G. Welch MD and Robert Ludwig, adds a new element to the understanding of how our bodies affect our behaviors and emotions – the power of relationships. Calming Cycle Theory proposes that early emotional behavior is shaped by visceral co-conditioning of, and emotional connection between, mother and infant that is initiated during pregnancy and continues after birth. Physical and emotional co-regulation between mother and child condition autonomic calming responses, helping child and mother soothe each other.
If closeness and co-regulation are interrupted, mother and child can no longer calm each other. This leads to adverse conditioning. Instead of relaxing when they are together, they might avoid physical contact and withdraw emotionally as well. Emotional connection between two individuals, and the associated physical calming, is necessary for healthy child development and is a cornerstone for life-long health.
A randomized control trial of Family Nurture Intervention in the NICU has shown that supporting emotional connection between mothers and infants can have significant short and long-term benefits for both mother and baby. These findings led Nurture Science Program researchers to the hypothesis that it would also lead to better autonomic regulation early in life.
New Findings: Emotional Connection Touches the Heart
To test this hypothesis, babies in the NICU who were born prematurely were randomly assigned to two groups. While a full term baby is born at 40 weeks, all of these babies were born between 26 and 34 weeks. One group of preterm babies received standard care in the NICU. The other group received Family Nurture Intervention, in addition to standard care. For both groups, when the babies were about 35 weeks electrocardiograms (ECG) were monitored for about an hour while the baby was sleeping. Another ECG was done when the babies were about 41 weeks old.
The preterm babies who received Family Nurture Intervention showed more rapid maturation of autonomic nervous system regulation, more specifically, a heart rate marker of the vagal system that is inextricably linked to prosocial behavior. These findings, a collaboration between Dr. Porges, Dr. Welch, and their research teams, are published in the Journal of Developmental Psychobiology. They show that Family Nurture Intervention could have long-term benefits for physical health, in addition to cognition, learning, behavior and social development.
A New Theory of Change
These findings bring together the Polyvagal Theory and Calming Cycle Theory to better explain how our bodies are affected by our experiences in our relationships. They also provide a new way of understanding how Family Nurture Intervention in the NICU could lead to life-long benefits for preterm infants.
These findings demonstrate that our emotional relationships – the emotional connection established and strengthened through Family Nurture Intervention in the NICU – affect physiological function. In these preterm babies, emotional connection affected the functioning of their autonomic nervous system. So our relationships aren’t just pro-social. They are pro-health. Our relationships really do touch our hearts.