BY Franklyn Sills

The Fulcrum, Issue 96 Summer 2025

Having discussed babies’ neurology as present time social beings in the previous article, part 3 addresses the role of the stress response and autonomic strategies for survival.

STRESS RESPONSE BASICS

The autonomic nervous system is part of our repertoire of survival mechanisms, constantly operating beneath our conscious awareness and can become strongly engaged and sensitised in a baby’s birth experience. Practitioners need to be able to recognise the various signs of activation and respond appropriately. Autonomic functions are deeply embedded in our neurophysiology. If we feel threatened, the intelligence of our system immediately invokes a series of responses to address the situation, initiating a cascade of neuroendocrine-immune changes that we experience as physical and emotional shifts. Normally the system shifts back to a baseline state after the danger is passed but, if the threat is overwhelming, the system can become fixated at a particular phase of the autonomic cycle, constantly sensing danger even when none is present. These autonomic issues can be at the root of many health problems.

The autonomic nervous system evolved over the entire history of life forms and three distinct aspects have been identified. Conventional anatomy and physiology commonly recognises only two of these – the sympathetic and parasympathetic nervous systems – but, as introduced in part 2, Stephen Porges PhD has explored a third aspect, the social engagement system. This newer orientation is extremely important in understanding human stress responses and defensive tendencies.¹

The social engagement system is evolutionally the newest and most sophisticated autonomic function – manifesting in babies via instinctual maternal bonding strategies. Babies know how to recognise mom both visually and aurally, how to find mom’s breast and elicit her attention and affection (via oxytocin and endorphin inducement). The social engagement system coordinates babies’ orienting response when they seek mom’s attention – neck muscles, eye movement, inner ear muscles, vocalisation and facial expression are all coordinated by the nuclei of the social engagement system.

If the social engagement strategies do not work, babies will turn to their older autonomic layer, the sympathetic nervous system, best known as the locus of fight-or-flight capabilities.

It is common to hear angry cries coupled with physical motions when a baby’s needs are not being met. Babies can express anger and fear but their real effective usage of this layer is minimal, since they are physically incapable of either fight or flight. However, the neurochemistry of fight-flight – cortisol, adrenaline, norepinephrine and related neurotransmitters – is still activated even if physical action is not possible and protective tensions of muscles and connective tissues inevitably arise.

Assuming failure of the sympathetic nervous system to solve the problem, the autonomic nervous system has one card left to play, the parasympathetic response. This is the evolutionary oldest layer of the system, present in simple, relatively immobile organisms. Babies have a tendency to deploy parasympathetic freeze and dissociation responses in overwhelming experiences as they cannot fully engage fight or flight to protect.² The parasympathetic response is to “play possum” – to engage freezing and immobilising strategies – in hopes that the danger will pass on its own. In infants, dissociation, freezing responses and withdrawal are primary examples of this response. Traumatised babies may thus sleep a lot or be very quiet and slow in orientation. They may be sensed to make poor contact, have bonding or attachment issues or to be very distant or listless.

The autonomic system is designed to deal with ordinary novelties and threats and generally functions quite well to keep us alive and operational. However, extreme circumstances can overwhelm the capacity of the autonomic system. Overwhelm is the distinctive point at which novelty and stress become trauma. When the system is overwhelmed and has inadequate resources to cope with the event, stress nuclei may become sensitised and stuck in the protective response. They continue to cycle the need to protect but cannot complete the intention. This is the ground for the emergence of a whole spectrum of developmental trauma and post-traumatic stress symptoms and is the key factor in traumatisation.

Generally, babies’ autonomic nervous system experience is underestimated or unrecognised in modern health care. I am convinced that simple awareness of autonomic effects of various birthing and infant-care events would have a huge benefit for our society and world.

BABIES’ AUTONOMIC STRATEGIES

Let’s go through these stages in relation to a baby’s experience in more detail. The social engagement system is the baby’s first orientation in getting its needs met. It will seek caregivers’ attention and express its needs via voice, motion and facial expressions. Unfortunately, this level is frequently overridden by routine birthing procedures and much more so by events arising from major medical interventions. Babies need and expect  protection from pain and nurturance from their mothers. But if mom is in pain and anaesthetised, her capacity for meeting her baby is at least compromised and the baby’s capacity for meeting mom can be equally reduced because the anaesthesia is fed to the baby through the umbilical cord.

If the baby is immediately removed from the mom for cleaning and examination, the needed  bonding contact with mom may be interrupted. If painful pressures, suctions, surgeries or  injections are given without sensitivity, the need for protection and safety is at least undermined. All of these may be experienced as a betrayal of the bonding and attachment process at the time of birth. It may even be experienced as a devastating abandonment by caregivers. When this occurs, the social nervous system and its orientation to safety, contact and nurturance may be overwhelmed. Once non-protection and non-connection are experienced at a social autonomic level, the baby’s response to current novelty and stress may bypass the social engagement system to immediately activate the sympathetic nervous system. This is a survival ploy based on the experience of overridden needs and lack of security. Perhaps this is a root source of childhood attention deficit and hyperactivity issues.

The sympathetic system in babies lacks muscular coordination and strength to implement survival intentions. Neurochemistry is present but there is little chance for actual fulfilment. In session work, sympathetic nervous system issues in babies commonly present as hypertonic  or tense tissues, sleeplessness, extended inconsolable crying and similar excited states. The infant’s cries may seem anxious and angry.

Limbic emotions commonly co-arise with the sympathetic response. In overwhelming  experience, the amygdala – the baby’s limbic sentry for sensory and environmental danger and novelty – will co-arise with sympathetic arousal and generate feelings of fear and anger – all oriented to survival. Fight-flight responses thus have direct resonance with anger  and fear and – in the extreme – rage and terror. These states – expressed as tensions and  autonomic and emotional activation – are clearly sensed as they arise in baby sessions. As  they arise, the practitioner must have patience, presence and empathy for the little one’s  process.

The parasympathetic state is the default strategy of last resort for the baby. Unable to make contact, unable to move, the baby deals with perceived threat – intrusion, absence of mom, physical pain and so on – by entering a dissociative and immobilised state. In sessions this can present as non-contact – a sense of withdrawal and distance – inability to orient, hypotonic tissues, excessive sleeping, inability to move the head and similar placid states. Ironically, these babies may be identified as “good” babies and indeed the neurochemistry of parasympathetic response (serotonin, dopamine, endorphins) is generally pleasurable in the short term. If the baby is stuck in a parasympathetic protective response, its ability to orient to mom and to get needs met via the social nervous system are severely challenged. In the extreme, a fixated parasympathetic state is dangerous because metabolic function slows down to the point where the heart-lung supply of oxygen-rich blood to the brain is too low. I wonder if parasympathetic shock may be a factor in sudden infant death syndrome?

Parasympathetic-overwhelmed children are commonly not recognised as having problems until later in life. They may appear as quiet babies who sleep a lot and give no trouble and if they do not like your contact they are likely to just turn away instead of crying. But later they may have learning difficulties and in adult life may have issues such as chronic fatigue, endogenous depression (atypical depression) and states of low energy and low motivation. This may also be a factor in the development of autistic states. Adults stuck in cycling a parasympathetic protective response tend to collapse under stress and can sleep for weeks on end in response to stressful or threatening life experiences.

The remarkable endurance of pre- and perinatal stress has been well established by Emerson, Castellino, Chamberlain, Verny and others. A trauma schema – when the person responds in the present as though their trauma is still happening – may become a habitual way of responding to threat and may strongly shape the person’s experience of everyday life. Under stress, the child or adult begins to live in trauma time – again living as though the threat is still present – and the ability to respond to current stress is greatly diminished. Researchers have proposed that an autonomic set point or adapted default strategy can be instilled semi-permanently so that the individual habitually goes to sympathetic or parasympathetic strategies instead of having the full autonomic repertoire available. Studies have shown that early trauma can be the root of later childhood dissociative and attention deficit disorders.³ My experience is that the inherent potential for a full spectrum of autonomic responses, including a full return to social engagement system strategies, is never lost. Healing modalities – such as craniosacral therapy, mindfulness-based therapies, pre- and perinatal therapies and trauma resolution work – have great potential for healing the resonances and fixity of traumatic cycling and its repercussions in our mind-body system.

In part 4 of On Meeting Infants, Franklyn Sills discusses the importance of therapeutic intentions in the context of an infant’s resources.

References
1. Porges, S.W. (2011) The Polyvagal Theory: Neurophysiological Foundations of Emotions, Attachment, Communication, and Self-regulation, W. W. Norton & Co.
2, 3. Perry & Pollard, (1998) Homeostasis, Stress, Trauma, and Adaptation, A neuro-developmental view of Childhood Trauma, Child and Adolescent Psychiatric Clinics of North America, Volume 7, Number 1 January 1998, 31-51

The opinions expressed in this article are those of the author and do not necessarily reflect the viewpoints of the CSTA.