In the world of manual therapy, somatics, and trauma work, we often focus on what we can objectively feel and observe—muscle tension, postural patterns, movement restrictions, and visible responses to touch. Yet beneath these observable phenomena lies a profound system that may hold the key to deeper healing: interoception, our ability to sense and interpret signals from inside our body.

Beyond the Sixth Sense

Interoception has been called our "eighth sense" (after the traditional five plus proprioception and vestibular sense), but it might be better understood as our most fundamental sensing system. It encompasses our awareness of heartbeat, breath, digestion, pain, temperature, muscle tension, pleasure, and emotional states as they manifest in the body.

Unlike proprioception (which tells us where our body is in space) or exteroception (which connects us to the outside world), interoception is our internal monitoring system—the continuous stream of data from our organs, tissues, and physiological processes that informs our most basic sense of self.

Neuroscientist A.D. Craig describes the anterior insula—a key brain region for interoceptive processing—as creating "a representation of the sentient self at one moment of time," suggesting that our very sense of being arises from this internal sensing system.

Wired to Feel: The Neuroscience of Interoception and Embodiment

Explore the neural mechanisms behind internal body awareness and discover how interoception influences emotion, decision-making, trauma, and social connection.

The Neuroscience of Internal Awareness

Recent advances in neuroscience have revealed the remarkable complexity of interoceptive processing. Signals from throughout the body travel primarily via two pathways: the lamina I spinothalamocortical tract and vagal afferents. These pathways converge in brainstem nuclei before projecting to the thalamus and ultimately to cortical regions—particularly the insula and anterior cingulate cortex.

The insula processes these signals along a posterior-to-anterior gradient, transforming raw physiological data into increasingly complex representations that ultimately contribute to emotional awareness, decision-making, and our sense of embodied self.

What makes this system particularly fascinating is its bidirectional nature. While bottom-up signals from the body inform our brain, top-down predictions from the brain simultaneously shape how we experience these signals. This predictive processing framework helps explain why our perception of internal states can be both remarkably accurate and surprisingly malleable.

When Interoception Goes Awry

For many individuals, interoceptive processing has been disrupted. Trauma, particularly, can profoundly alter this system in seemingly contradictory ways.

Some trauma survivors develop hypersensitivity to certain internal signals—a racing heart triggers immediate panic as the brain predicts threat. Others experience interoceptive numbing, a protective disconnection from body sensations associated with overwhelming experiences. Many oscillate between these extremes, their internal sensing system no longer providing reliable data for navigating the world.

Chronic pain conditions similarly involve interoceptive disruption. Research by Lorimer Moseley and others suggests that pain persistence may partly result from altered interoceptive predictions—the brain continues to predict tissue damage even when none exists, generating very real pain experiences.

Even common mental health conditions like anxiety and depression show distinctive interoceptive patterns. Anxiety typically involves heightened sensitivity to cardiac and respiratory signals, while depression often features blunted interoceptive accuracy across multiple systems.

Interoception: The Foundation of Behavior and Decision-Making

What many don't realize is how profoundly interoception shapes our everyday choices and behaviors. The influential somatic marker hypothesis proposed by neuroscientist Antonio Damasio suggests that emotions—which arise largely from interoceptive signals—are not obstacles to good decision-making but essential guides.

When we make choices, from what to eat for lunch to major life decisions, our bodies generate subtle physiological responses to different options. These "somatic markers" provide crucial data about potential outcomes based on past experiences. People with damage to brain regions that process these signals make objectively poorer decisions despite intact logical reasoning abilities.

Research using the Iowa Gambling Task demonstrates this vividly. Participants with normal interoceptive processing begin making advantageous choices before they can consciously explain why, guided by bodily signals like subtle changes in heart rate or skin conductance. Their bodies "know" the right choice before their conscious minds do.

Even our impulsivity and self-regulation capacity may be interoceptively mediated. Research suggests that poor interoceptive accuracy correlates with difficulty delaying gratification and resisting temptation—potentially explaining why some people struggle more with habits like overeating or substance use. The body's signals about future rewards and punishments become harder to access or interpret accurately.

Moral Judgments: The Embodied Foundation of Ethics

Perhaps most surprisingly, interoception appears central to our moral judgments. Studies show that manipulating people's bodily states—inducing disgust through bitter tastes or unpleasant odors—can make their moral judgments more severe. Conversely, blocking awareness of visceral signals can alter moral decision-making.

The influential theory of moral foundations suggests that moral intuitions arise from embodied experiences first, with rational justification following afterward. When we say something is "wrong," we're often reporting on a bodily sensation of wrongness that precedes our logical analysis.

This has profound implications for understanding moral disagreements and ethical development.

Different interoceptive sensitivities may partly explain why people have such diverse moral reactions to identical situations. Our ethics are literally embodied—feelings of rightness and wrongness that originate in the body's response to situations.

Distress Tolerance: When Internal Sensations Become Unbearable

Central to many psychological difficulties is interoceptive distress tolerance—our capacity to stay present with uncomfortable internal sensations without resorting to avoidance strategies.

This skill has far-reaching implications for well-being and behavior.

Addiction provides a clear example. Substances and behaviors that become addictive often work by either numbing uncomfortable bodily sensations or producing pleasurable ones. The inability to tolerate the bodily sensations of craving, anxiety, or emotional pain drives continued use despite negative consequences. Recovery, then, necessarily involves developing greater capacity to be with difficult body states without immediate escape.

Similarly, trauma responses often center around intolerable bodily sensations. Flashbacks are not merely mental memories but full-body re-experiences of sensations associated with the traumatic event. Avoidance behaviors that define PTSD are frequently attempts to prevent these overwhelming bodily states.

Research on borderline personality disorder and self-harm further illustrates this connection.

Self-injurious behaviors often function to modulate unbearable internal sensations when other regulation strategies fail. The temporary relief comes from shifting interoceptive experience, not from the injury itself.

Building distress tolerance is thus not simply a psychological skill but a somatic one—expanding the window of tolerable internal experience so that difficult sensations no longer trigger automatic avoidance responses. This capacity underlies everything from emotional regulation to impulse control to our ability to persist through challenges.

Bodywork as Interoceptive Modulation

This understanding transforms how we view manual therapy and bodywork, which works through interoceptive pathways—changing how the brain perceives and interprets signals from the body.

Touch has privileged access to interoceptive processing. The slow-conducting C-tactile fibers activated by gentle, appropriate touch connect directly to interoceptive brain regions, potentially bypassing cognitive defenses. This makes bodywork a powerful entry point for those with disrupted internal awareness.

Different forms of bodywork modulate interoception in distinct ways:

Rhythmic, predictable touch (as in certain massage techniques) can downregulate threatening interoceptive signals, helping hypervigilant systems recalibrate.

Novel, attentive touch can illuminate "blind spots" in body awareness, bringing previously unconscious areas back into conscious perception.

Supportive, containing touch can create safety that allows exploration of previously overwhelming sensations.

Myofascial techniques may work partly by creating novel interoceptive experiences that challenge existing predictive models. When one experiences a feeling of a tissue “releasing”, this may be driven by a revision of how that area is represented in interoceptive awareness.

Most importantly, effective bodywork creates an interoceptively safe environment where clients can begin to explore internal sensations with curiosity rather than fear. This shift from automatic reactivity to conscious awareness may be the most therapeutic element of hands-on work.

Final Thoughts

As our understanding of interoception expands, it promises to bridge historical divides between "physical" and "psychological" approaches to healing. The body's internal sensing system reveals itself as neither purely physical nor purely mental—but rather the fundamental matrix from which both emerge.

This interoceptive lens allows us to see how conditions previously considered separately— chronic pain, trauma responses, addiction, emotional disorders—may share common mechanisms in altered internal awareness. It suggests that developing healthy relationships with our bodily signals isn't merely supplemental to psychological health but foundational to it.

Author

Dr. Mark Olson holds an M.A. in Education and a Ph.D. in Neuroscience from the University of Illinois, specializing in Cognitive and Behavioral Neuropsychology and Neuroanatomy. His research focused on memory, attention, eye movements, and aesthetic preferences. Dr. Olson is also a NARM® practitioner, aquatic therapist, and published author on chronic pain and trauma-informed care. He offers a variety of courses at Dr-Olson.com that provide neuroscientific insights into the human experience and relational skill training for professionals and curious laypersons.

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