Microneurography

Enters the wiki through Quigley et al. (2021), and it is worth a page for one reason: it is the wiki’s only method that measures human interoceptive signalling at the nerve.

Everything else here is a proxy at some remove. Heartbeat counting measures a judgment about a signal. Skin conductance measures one sympathetic effector. ERPs measure cortex. Microneurography measures the traffic.

Why it matters, and why it doesn’t (yet)

The catch is anatomical and is the same catch that shapes the entire literature. The method reaches “peripheral nerves that lie close to the skin’s surface.” Interoceptive afferents are mostly visceral, thin, unmyelinated and diffusely arrayed — deep and inaccessible. So the method that could in principle settle the field’s measurement problem is, for most interoceptive modalities, unusable.

Two developments make it relevant anyway:

C-tactile afferents. CT fibres share the morphology of interoceptive afferents but live in hairy skin, and can be recorded microneurographically in humans (Ackerley et al. 2014; McGlone et al. 2014). This is the technical half of the affective-touch proposal: if CT afferents are functionally interoceptive, then microneurography plus a controlled brush gives an interoceptive channel that can be both recorded and stimulated in healthy awake people — converting a correlational literature into an experimental one.

The human vagus. Quigley et al.’s closing paragraph names “recording from the vagus nerve in humans” (Ottaviani et al. 2020, ultrasound-guided microneurography) alongside VNS and affective-touch manipulation as the techniques that may open interoceptive processes to human study. The wiki’s vagal material — immune-to-brain signalling, the microbiota interface, gut-hippocampal priming, VNS as therapy, and polyvagal-theory’s contested claims — is entirely inferential about what the human vagus is actually carrying. This is the method that could stop it being inferential.

Status in the wiki

Recorded as a capability, not as an evidence base. No study in raw/ uses it. It is here because the wiki’s standing complaint is that interoception cannot be manipulated in humans, and this is the one entry on the short list of things that might change that.