Nervous System Terminology

A few “Must Know” Terms for Understanding
Nervous System Function 


“Regulation is the term used to describe our ability to manage our emotional state, to calm ourselves during times of heightened emotion when we become fearful, deeply sad, angry, or frustrated.

Regulation is a learned process, one we integrate into our own lives by observing others and, importantly, through the attachment phases with early caregivers.


Infants are unable to regulate their emotions independently. They feel strongly and express those emotions in the moment without regard for what may be socially appropriate or convenient. Their emotional responses are instinctual and unregulated. Physiologically speaking, moments of intense emotion activate the reptilian part of the brain, the first part of the brain to develop in utero. This is the root of our autonomic nervous system– the origin of the fight or flight response which affects blood pressure, heart rate, breathing rate, body temperature, digestion, metabolism, and multiple other bodily functions. This neurological response is powerful and easily triggered when threats are perceived which is why it’s so important for parents to step in and help children literally “calm their nerves“ during times of distress.


Parents and caregivers play a crucial role in helping in children soothe  intense emotions, and these interactions between parent and child will shape the child’s ability or inability to regulate his own emotions later in life. This process is called co-regulation because the parent steps in as a mentor and external source of soothing when a child feels distressed.

This process of co-regulation creates a foundation for neurosequential development for the child (Allen Schore, 1994). In other words, once this co-regulation pattern is formed, the child can grow in productive, healthy, and predictable ways towards emotional maturity. This isn’t purely about feeling a “better” emotion, but about regulating our level of arousal when the autonomic nervous system is activated, and about regulating our affect in the company of others.

Self-Regulation: The Primary Task of Development

Dr. Allen Schore (2001) sees the transfer of regulation from external– that is, relying on others– to internal, developing the capacity to self-regulate as the primary task of early development.

This ability to move toward internal regulation is critical to our ability as humans to process our environment and distinguish between real and perceived threats, allowing us to develop impulse control and self control. Self-regulatory capacity is one of the protective factors affiliated with the development of resilience.

Self-regulation also enables us to form relationships and aligns with the social norms of our group. Regulation is not only about regulating the physiology of the autonomic nervous system. It’s about regulating levels of arousal, and eventually being able to regulate our affect.

It’s important to emphasize the fact that co-regulation involves mutual interaction between the caregiver and the child. The child’s alarm signals the parent who may also become alarmed but who steps in to perform a nurturing function. A child’s transition to a more settled state will in turn influence the caregivers state. Therefore the co-regulation process is about the ability of the caretaker to understand the infants needs, and the caregiver’s willingness to provide comfort and to allow back-and-forth interaction–– the attachment dance between parent and child.

This process of co-regulation sets the stage for critical physiological processes, including the maintenance of homeostasis which is physiological equilibrium. We use co-regulation and self-regulation constantly, and both support the development of higher level thinking. In relationships, co-regulation helps us maintain more effective self- regulation.” (All of the above excerpted from Kathy Kain and Stephen Tyrell’s Nurturing Resilience.)

Travel your INNER landscape for learning!


“Interoception is the process by which we notice our internal state. We evaluate a combination of sensations and perceptions of physical processes to assess our interior milieu and decipher what it’s telling us about what we are feeling, how we are, and even who we are. This includes our perception of physiological processes such as heart rate, the digestive process, sensations of the skin, and any other internally experienced sensation of our own bodies.

Using our valuations of the sources of vital information, we take action, make meaning, make predictions like predicting our own illness by feeling the initial sensations associated with the onset of a cold, and make judgments about who we are and how we are; are we hungry, are we safe, are we loved?

Interoception is the infant’s sixth sense (Porges,1993).

Interoception forms an individual’s experience of self and environment– both internal and  external.

Interoception provides a significant portion of the information we use to form our experience of self and our view of the self in relation to others.

Interoception provides a large portion of the self communication we use to assess whether or not we are safe or unsafe and whether an external event or person is pleasurable, exciting, or threatening.

Interoception develops in context including our social context which provides a significant amount of feedback which we use to calibrate our interceptive perception and interpretation.

Interoception can be easily influenced including by something as simple as our mood when we are asked to rate our pain levels: positive emotion increases our tolerance for pain, and negative emotion decreases our tolerance for pain.

The interoceptive system is meant to inform us and give us a predictive assessment of our internal and external environments, but it can mislead us if the system develops without congruent context and feedback. In other words, our markers for perception and meaning-making may be overly-sensitive or tuned to signals that don’t provide the most reliable information or points of reference, thus making a judgment may be off-base and therefore lead to false conclusions (Demasio, 2000).

Information gathered via interoception tends to be experienced as factual, not evaluative, because it comes from what many of us call “inner knowing” or “gut feeling.”

(Part of a clinician’s job is to support clients in changing and revising their interoceptive “conversations“ with themselves.)

Interoception remains plastic, that is, it’s possible to help clients change their interoceptive vocabulary and conduct more nuanced assessments of their inner world, resulting in more helpful self-conversations.

People use their interoceptive experiences to inform their behavior and make meaning about themselves and their relationship with others.” (all of the above excerpted from Kain & Tyrell’s Nurturing Resilience, p. 26-29).

Traveling the Outer Landscapes for Learning!

Exteroception: Our exteroception systems help us pay attention to our external environments and aggregates information from a combination of sources.

Exteroception contributes to:

our perception of safety and lack of safety,

is influenced by day-to-day experiences,

contributes to our predictive assessments of experience,

contributes to meaning-making about our experiences, and

develops in the context of environmental and social factors.

It aggregates information from a combination of sources and helps us make sense of the outside world rather than the interior world of the body and the psyche.

Paying Attention Systems

Exteroceptive sensory systems are sight, hearing, taste, smell, and touch,  what we might call the “paying attention” systems. To develop in a healthy way, our exteroceptive systems need appropriate stimuli and feedback, and we need our care providers to help us make sense of what we perceive. We, again, rely on our social group to help us place our different perceptions in context to arrive at understanding.

There are additional sources of information that contribute to our overall assessment of our internal and external environments: the vestibular or balance system; the proprioceptive system, which tells us where different parts of our body are in relation to each other and how fast they are moving; temperature perception; vibration perception; and pain perception.

It’s often difficult to clearly differentiate between information that originates outside the self and information that originates within our sensory systems.

Our sensory systems develop to produce perceptions of our environment but they’re not always accurate and they are strongly influenced by environmental factors including trauma.” (Kathy Kain and Steven Terrell, Nurturing Resilience, North Atlantic Books, 2018)

Safety & Stress
In Mind AND Body 

“It’s important to remember that we cannot exclusively use cognitive processes when assessing our safety. Rather, our body’s holistic response tells us whether or not we are safe.

We can certainly evaluate our external environment with conscious thought, but our responses to that information will provide the bulk of the information we use to determine whether we are in fact safe.

Our methods and processes for attending to the outside world, just as with interoception, are altered by stress physiology.

Even a completely healthy perceptive system when operating under stress can provide distorted information about the surrounding environment.

One of the key influences during stress physiology is the sympathetic nervous system, which prepares us for activity, including threat response. It increases our heart rate and breathing and sends messages to our muscles to prepare for action. It also makes subtle adjustments that are more difficult to notice such as changing our hearing and vision and bringing an overall height and focus to perception of the external environment.

When under the influence of stress physiology, we literally hear differently, specifically our middle ear muscles change.

The ability to perceive content is also altered during times of stress, and we are less able to make sense of what we hear when we switch into a constant state of vigilance (Porges, p. 31).”

Your Body Guard or Safety System

“Neuroception is a term coined by Stephen Porges who summarizes it in this way:
Neuroception describes how neural circuits distinguish whether situation or people are safe, dangerous, or life-threatening.’

He also describes neuroception as ‘a dynamic an interactive process whereby we respond to cues about safety and threat, while simultaneously transmitting similar cues in our social interactions.’

Interoception and exteroception both inform neuroception.

When we have a healthy, well-developed safety system, our interoceptive and exteroception set of systems will work in an integrated fashion to help us differentiate information and determine when we are safe and when we are not. Likewise, our social systems will have helped us experience a felt sense of safety and security in our relationships, which reinforces our ability to perceive safety and experience a sense of belonging and security.”

Faulty Neuroception

“Neuroception refers specifically to the neurophysiological processes involved in the perception of safety and threat, what Porges refers to as the neural platforms that support certain categories of behavior. Porges differentiates the physiological processes from the behaviors themselves. This is important to understand as clinicians working with clients whose perception systems may be inaccurately signaling them false threats. That perceived lack of safety may internally trigger the behaviors of threat response, even if there is no legitimate threat to respond to. This can create a self-fulfilling process whereby others in the social interactions react to those threat behaviors with their own, and the client’s felt sense of lack of safety becomes reality, further justifying his initial reaction.

For example, the client may respond to a perceived sense of threat by behaving aggressively toward the other person in the interaction. That person in turn responds with their own aggression, because they now feel attacked, confirming the client’s experience of threat.

If we respond only as though behaviors need to be addressed, we will miss a very important source of support for clients: to help them develop a more accurate neuroceptive system and better calibrate their experience of their environment and social interactions.”

Understanding our physiological drivers for behavior

“In the attachment and bonding process, we learn on many different levels: socially, behaviorally, and physiologically. Because so much of our behavior is based on underlying neurophysiological processes, Porges has for a long time argued for a better understanding of the physiological  drivers for behavior, even when working primarily from the psychological perspective.

The development of neuroception can be influenced by trauma and altered profoundly by developmental trauma. Clients who lack a safety map are primarily tuned to danger and have a limited ability to recognize safety, either within their interoceptive self-communication or in the perception of their external environments. Once the scales are tipped, the frame of reference can become radically altered. If we are tuned toward danger, we will certainly find it, and if we discard or otherwise ignore information that indicates we are safe or we don’t know how to perceive safety in the first place, we will certainly have a difficult time recognizing it. This is faulty neuroception.”

Healthy Neuroception

“Healthy neuroception enables us to differentiate between safety and threat. Neuroception is about the detection of both, but to properly make the distinction between the two, we need:

1. reliable access to a sense of safety
2. care providers who help us regulate our responses and understand environmental cues contextually
3. coherent feedback from our social group about how we are to categorize our experiences.

Together the 3 elements for the development of necessary and healthy neural platforms neurophysiologically help us differentiate between safety and threat.

Healthy Neuroception develops in the context of healthy social engagement.

Our social group provides a great deal of information about what is safe and not safe. People in our social group: family, friends, and peers help us learn by modeling various responses and ways of sorting the information we receive. The goal is to develop a more well-rounded neuroception system, one that also provides information about the felt sense of safety and not overly attuned to threat.

(all of the above excerpted from Kathy Kain and Steven Terrell, Nurturing Resilience, North Atlantic Books, 2018)

Additional Terms

Attachment: a psychological construct reflecting a strong emotional bond between two individuals, such as the relationship between a mother and child. The features of safety manifested in the social engagement system enable attachment to occur. Prosodic voices, positive facial expressions, and welcoming gestures trigger through neuroception feelings of safety and trust that spontaneously emerge when the social engagement system is activated.

Biological Imperative: the needs of living organisms required to perpetuate their existence (i.e. survival, territorialism, fitness, reproduction).

Connectedness: Polyvagal Theory refers to the social connectedness that define trusting relationships that humans have with others as a biological imperative. Humans can also feel connected to their pets, which are usually other mammals with reciprocal social engagement systems.

(Definitions taken from Porges, Pocketguide to Polyvagal Theory, 2017, p.9).


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