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Nirva Institute · Bottom-Up Healing · Science

The Neuroscience of Body-First Change

Interoception, predictive processing, and the ascending pathways.

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The Nirva InstitutePublished 2026≈ 8 min read

Bottom-up healing rests on a specific claim: that the nervous system organizes experience upward from body to mind, and that skilful physiological input can move a person’s state faster than cognitive insight alone. This claim is well supported by two converging literatures — the interoceptive pathways from viscera to insular cortex, and the predictive-processing account of how the brain interprets internal signals.

§ 1

Ascending signals: the body’s route to the mind

Interoception — the sensing of internal bodily state — travels through vagal afferents and the spinothalamic tract to the anterior insular cortex, which A. D. Craig identified as the hub through which visceral signals become subjective feeling.9,10,11

Contemporary reviews describe interoception as a broad ecosystem influencing emotion, attention, learning, decision-making, and self-continuity — not just a sixth sense but the substrate of experience itself.12,91,92

§ 2

Predictive processing and the priority of the body

Predictive-processing frameworks describe the brain as continuously generating best-guess interpretations of incoming signals, updating only when mismatch is large.1,2,6

Because interoceptive priors are updated slowly and metabolically expensive to revise, a change in physiological input often reaches the interpreting mind faster than a change in thought reaches the body.7

§ 3

Autonomic state as prior

When autonomic tone shifts — slower breathing, warmer periphery, softer jaw — the brain reads a different landscape and generates a different prediction. This is the mechanism by which bottom-up work reaches material cognition alone cannot.26,19,27

§ 4

Why this matters clinically

For nervous systems that have long been in chronic activation, insight has often already arrived; physiology has not caught up. The neuroscience of ascending signals explains why body-first practice is not a supplement to change but, for many, the missing ingredient.37,39,117

Foundational NSI Concepts

The pillar ideas this article rests on

Cornerstone

Bottom-Up Healing

Term

Interoception

Term

Predictive Processing

Cornerstone

What Is Nervous System Intelligence?

Scientific References

Primary literature

AMA numeric style. Citation numbers are unified across the Nirva Life ecosystem — the same number refers to the same reference across every library article. Full registry is anchored in the Cornerstone Paper.

  1. 1.Friston K. The free-energy principle: a unified brain theory? Nat Rev Neurosci. 2010;11(2):127-138. PubMed ↗
  2. 2.Clark A. Whatever next? Predictive brains, situated agents, and the future of cognitive science. Behav Brain Sci. 2013;36(3):181-204. PubMed ↗
  3. 6.Ficco L, Mancuso L, Manuello J, et al. Disentangling predictive processing in the brain: a meta-analytic study in favour of a predictive network. Sci Rep. 2023;13(1):3512. PubMed ↗
  4. 7.Millidge B, Seth A, Buckley CL. Predictive coding: a theoretical and experimental review. Neurosci Biobehav Rev. 2024. PubMed ↗
  5. 9.Craig AD. How do you feel? Interoception: the sense of the physiological condition of the body. Nat Rev Neurosci. 2002;3(8):655-666. PubMed ↗
  6. 10.Craig AD. How do you feel — now? The anterior insula and human awareness. Nat Rev Neurosci. 2009;10(1):59-70. PubMed ↗
  7. 11.Critchley HD, Wiens S, Rotshtein P, Öhman A, Dolan RJ. Neural systems supporting interoceptive awareness. Nat Neurosci. 2004;7(2):189-195. PubMed ↗
  8. 12.Quigley KS, Kanoski S, Grill WM, Barrett LF, Tsakiris M. Functions of interoception: from energy regulation to experience of the self. Trends Neurosci. 2021;44(1):29-38. PubMed ↗
  9. 19.Thayer JF, Åhs F, Fredrikson M, Sollers JJ, Wager TD. A meta-analysis of heart rate variability and neuroimaging studies: implications for heart rate variability as a marker of stress and health. Neurosci Biobehav Rev. 2012;36(2):747-756. PubMed ↗
  10. 26.Porges SW. The Polyvagal Theory: Neurophysiological Foundations of Emotions, Attachment, Communication, and Self-Regulation. W.W. Norton; 2011. PubMed ↗
  11. 27.McCraty R, Shaffer F. Heart rate variability: new perspectives on physiological mechanisms, assessment of self-regulatory capacity, and health risk. Glob Adv Health Med. 2015;4(1):46-61. PubMed ↗
  12. 37.van der Kolk B. The Body Keeps the Score: Brain, Mind, and Body in the Healing of Trauma. Viking; 2014. PubMed ↗
  13. 39.Neurobiology and Treatment of Posttraumatic Stress Disorder. 2024. PubMed ↗
  14. 91.Khalsa SS, Adolphs R, Cameron OG, et al. Interoception and mental health: a roadmap. Biol Psychiatry Cogn Neurosci Neuroimaging. 2018;3(6):501-513. PubMed ↗
  15. 92.Petzschner FH, Garfinkel SN, Paulus MP, Koch C, Khalsa SS. Computational models of interoception and body regulation. Trends Neurosci. 2021;44(1):63-76. PubMed ↗
  16. 117.Somatic and body-based interventions for trauma: a systematic review of clinical trials. 2025. PubMed ↗

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