I got a really interesting question from a reader today in response to something I said in my two- part blog Real Self Soothing. Here’s her question.
Hi – really enjoying these posts on the myth of self soothing. I am unclear however as to why the vagal brake would be off during breast feeding? The way I see it, nursing is a time of security not threat (such as being chased by a wild animal). But you stated that nursing “places demand on newborn’s resources” and because of that the vagal break is turned off? Can you clarify this issue for me? Thanks!
Here’s my answer:
It does seem counter-intuitive that the sense of security that nursing can provide would be associated with the body responding in the way it does when responding to a threat. I don’t claim have a full understanding of all the workings of the vagus nerve, but, based on my reading of the work of Dr. Stephen Porges (and others), and with the help of a quick e-mail correspondence with Dr. Porges, I can make a couple of points.
First, helping us respond to threats is by allowing an increased heart rate is no means the only thing the vagal “brake” (as it’s sometimes called for brevity’s sake) does. It helps us manage other sorts of demands on our resources as well. And those demands are different for a newborn than an adult, or even a 6-month-old. Actually it’s not breastfeeding per se, but rather sucking itself, at a breast or bottle, that places metabolic demands on a newborn’s resources. So the vagus would enable an increased heart rate during bottle feeding too. This is completely normal given how neurologically immature human babies are at birth. It is important to clarify that this stops happening as the baby matures. At some point — I don’t know exactly when, and, most likely it varies from baby to baby – the infant’s physiological and neurological development progresses to the point where its brain and body would sense that the vagal brake no longer needs to come off during sucking. This working of the vagus nerve is one part of how the body is designed to help the newborn adjust to the demands of being out in the world instead of in the womb where everything the fetus needs comes directing from the mother’s body. In other words, the baby develops the physiological capacity to suck without the support of an increased heart rate. Interestingly, Dr. Porges told me that with preemies, the vagal brake comes off during sucking, but it doesn’t go back on when he baby is finished (or at least it stays off for longer, presumably it goes back on at some point). That’s because preemies are less physiologically mature and they have to work harder to suck and recover from the effort of sucking. Because of their greater physiolocial immaturity they also need need more medical support (and as much bodily contact as they can get) to manage being out in the world.
But breastfeeding does appear to play a role in helping the vagal system (for lack of a better word) to “learn” how to operate the way it should in a broader sense. Dr. Porges describes the the removal and re-instating of the vagal brake during sucking as a wonderful “neural exercise” for a newborn. He says this ability to remove and reinstate the vagal brake gradually helps the baby develop the neural pathways and enable it to calm even after major disruptions (upsets). That doesn’t mean the baby is calming entirely on his own without help from a caregiver (although that might happen sometimes). What it means is that the baby’s brain and body have the ability to work with (so to speak) the caregiver who is trying to comfort the baby with body contact, movement, soothing sounds or whatever.
And, as many people know from experience, babies differ quite markedly in how easily they can calm down or be calmed. As I’ve posted before, some babies are born with more efficient vagal regulation (meaning the vagal brake works better in helping the baby stay in and/or return to a state of calm). Lots of research has shown this. And it’s probably one, but by no means the only, explanation for why some babies are fussier than others.
Dr. Porges told me he was working on a paper based on his research that found that babies who are extremely fussy and difficult tend to have inefficient vagal regulation, meaning the operation of the vagus nerve (including its brake function), doesn’t work as well as it does in unfussy, calmer babies. This helps explain why some babies are so much harder to soothe than others. It’s not anybody’s fault, they were born that way, and they need even more external regulation from caregivers than other babies. However, Porges and his team found that at age 6 months this relationship between inefficient vagal regulation and fussiness was seen only in bottle fed babies. The breastfed babies were still fussy, but they showed efficient vagal regulation, which is undoubtedly good for them in the longer term, even if they remain fussy in the short term. The bottle fed babies who were fussy still had inefficient vagal regulation. What’s interesting is that non fussy babies had efficient vagal regulation whether they were bottle fed or breastfed. I don’t think that necessarily means that fussy bottle fed babies can never ever achieve efficient vagal regulation, although it may take longer and require a little more ongoing responsive, sensitive care from their parents. But it does support the idea that there is something about breastfeeding that helps the baby physiologically in ways that go beyond nutritrion (as many breastfeeding proponents have been saying for years).
Dr. Porges also says that the muscles (and nerves) involved in early feeding behavior help develop the facial muscles and nerve pathways that are involved in social behaviour such as smiling, and the ability to engage in responsive social communication with a caregiver. Obviously bottle fed babies develop these abilities as well, but it seems that breastfeeding – in addition to being the way babies were designed to be fed – is also part of the way babies were designed to develop social abilities. Does that help?
*For any bottle feeding mother or father (including gay men whose parenting partner is another man) who happens to read this and feels yet another a stab of guilt, remember that human babies are also designed to be adaptable and resilient. They have the capacity to survive and thrive in all sorts of circumstances. The love, care and responsiveness your baby gets from you (and dad, other mom, other dad, grandparents and other people) are the most important things in terms of helping your baby’s social engagement system to develop. And loving physical contact, eye contact and soft vocalizations that parents provide if they hold the baby while giving a bottle would definitely help “teach” the vagal brake to work properly.
The challenge for the parents of the fussier, harder to calm babies (I know what it’s like, we had one!), is to accept that you are probably going to have to put more work into calming than parents of other babies (or even your own other babies). And try to remember that there is research that strongly suggests that, even when it seems like your efforts are doing much to calm the baby in the moment, you are undoubtedly helping her over the long term.