Three Parts of the Autonomic Nervous System based on the work of
Stephen Porges, PhD.-A PolyVagal Perspective
This article is based on a 4 day Advanced Cranial Workshop I
attended October 24-27th 2013 in NYC with Katherine Ukleja DO, BCST
, The Vagus
and Emotional Expression.
Many of you have heard of the Autonomic Nervous System (ANS),
the part of the peripheral nervous system that acts as the control center of
the body. This system is largely involuntary and controls functions like heart
rate, digestion, respiratory rate, and urination. Well, it has recently been
discovered that the ANS contains an additional component, the Social Nervous System.
This new addition to our body’s control center allows us to read the
environment and respond to threats appropriately.
There are two branches of the ANS, the parasympathetic and
the sympathetic. These two divisions typically work in opposition to each
other. The parasympathetic branch is known to promote a “rest and digest”
response and is responsible for slowing down our bodily functions, such as
heart rate, with the exception of digestion, which is enhanced by increased
peristalsis, or muscular contractions, in the gut. On the other side, there is
the sympathetic nervous system, which plays the role of the “fight or flight”
response. This division increases the body’s energy output, through increased
heart rate and respiratory rate, and inhibits peristalsis, thereby inhibiting
digestion.
The newest addition to the ANS, the Social Nervous System
introduced above, is a new branch of the vagus nerve and is technically called
the Ventral Vagal Complex (VVC). This division operates in response to safety
and is responsible for self-expression, orientation (turning our neck and
head), listening, speaking, calling/asking for help, and communicating in
general.
The vagus, the nerve that travels from our brain to our gut,
allows us to be in touch with what’s happening inside our bodies. This
communication between the brain an the gut is called interoception, or as Stephen Porges puts it, our “6th
sense, what we call ‘gut feelings’ or instincts.” Not only do the nerves in our
gut communicate with processing centers in the brain, they also communicate
with the heart (our emotions) and the motor branches of the face and throat to
regulate self-expression. This is why your heart aches when you’re emotionally
hurt and why your facial expressions display what you’re emotionally feeling.
These nerves play more of a role in psychological feelings
than was previously acknowledged. The gut is stimulated by external stimuli,
which it then relays to the brain to be integrated. This area in the brain is
the key brain area for empathy and is responsible for awareness of feelings and
emotions from the body. The information it receives either stimulates or inhibits
the release of certain hormones and neurotransmitters; this regulation is
called negative feedback.
Have you ever wondered how instincts work? These reflexes
stem from neuroception, the sensory
arm of the social nervous system. This is how we are able to detect safety or
threat. For instance, our ability to read faces is a survival function that
allows us to differentiate between friend or foe. Since the VVC communicates
via nerves to the face, throat, and heart, it is adaptive in that it permits us
to listen, signal for help, get more oxygen to the brain, and modulate heart
rate. In addition to survival adaptations, this part of our nervous system
plays a role in our ability to feel empathy and happiness by allowing us to
assess another’s emotional state and connect with others.
Your facial expressions are of extreme significance; they
are the link between exteroception and interoception. As a baby, this and
crying was your only form of communicating with your parents in order to convey
your needs. Since babies solely rely on their caregivers for survival, the acts
of crying, fussing, smiling, etc. are extremely essential for their needs to be
adequately met. The less these needs are met by caregivers, the slower the
child is to fully develop and self-regulate. When the baby’s needs are not
attended to, she will experience stress, which will eventually stimulate
cortisol, a stress hormone, release from the adrenals. A build up of this
stress hormone is not only detrimental to the child’s health, it can
psychologically blunt their emotional development and cause them to be
avoidant, making no eye contact and being withdrawn from human contact. This
inability to show emotion will persist well into the child’s life and cause
social anxiety, as well as health issues, such as an increased risk for heart
disease.
Another important part of proper development of the social
nervous system is the ability to feel empathy, which gives us a sense of
connection and belonging, and is the basis of human bonds. A child with an underdeveloped social nervous
system may grow up to be isolated and depressed, or even become aggressive. An
impaired social nervous system results in misinterpretation of safety or
threat. It also results in a weakened interoceptive “6th sense,”
which will damage the ability to tune into our inside feelings, inhibiting us
from feeling pleasure or pain.
The work of Biodynamic
CranioSacral therapy is interactive; it permits you to get to know your own
material through your own body, or your sensations and feelings. This will
allow you to meet the history of another human being from a neutral place,
holding them with presence and lightness. It will allow your inherent treatment
plan to emerge, primary respiration to ensue, and their nervous system to come
into balance.
