An important dimension of interoception is inherent motion. Inherent motion refers to involuntary motion generated by the body’s physiological processes. These processes support homeostasis and are essential to Integrated Embodiment.
Inherent motion is detected by specialised free-nerve endings called mechanoreceptors, these are embedded throughout the connective tissue of the entire body.
Mechanoreceptors and other free-nerve endings transmit information to the brain through slow conducting C-fibres. Proprioceptive information is conducted by much faster fibres. Proprioceptive and interoceptive information is processed by totally different areas of the brain. Interoceptive free-nerve endings vastly outnumber proprioceptive endings in muscular tissue (7 to 1). This indicates the substantial bandwidth of neurological activity that is dedicated to homeostasis (including inherent motion) as opposed to voluntary movement.
Free nerve fibres transmitting interoceptive information from the entire body, project to the main homeostatic sites in the brainstem. There are further projections to the insular cortex. It has been proposed that the insula-cingulate network integrates sensory reception, interoception, cognitive load and conscious feelings with motivation and action – to maintain homeostasis.
Inherent motion is an expression of affective tonality – encompassing homeostasis and overall physiological coherence. These aspects of affective tonality can be experienced through interoception.
FEATURED IMAGE:
A.D. Craig. Interoception: the sense of the physiological condition of the body (2003).