How Loud Is a Touch?

Fundamentally, humans are governed by laws of nature 🔊

We've spent centuries quantifying symbolic human communications, while the thing that really matters in communication - skin-to-skin contact - has so far slipped under our epistemic radar. Given Sergey's interest in correcting this injustice and Laura's biology and information theory prowess (not to mention her otherworldly attractiveness), a research question is born - Exactly how many bits are transferred from Sergey to Laura via touch?

Our yard-stick is not the peripheral nerve, but Laura's conscious self. That means we have to consider not only skin receptors but also:

1. Attention filter. Most spikes never get airtime in awareness.
2. State delta. Moving a contact point from elbow→forearm carries less news than elbow→heel.
3. Surprise & distraction. If Sergey was to, say, parachute in to hug Laura, it would be considerably more surprising than if they had been hanging out for a while, thus giving our intrepid researchers an information boost.

1 · Cutaneous spike trains

Laura's skin is packed with four flavours of mechanoreceptors. Microneurography suggests each fires off up to ~200 bits·s^-1 about indentation, vibration, and slip. Multiply by how many receptors Sergey manages to squish and how long he lingers:

Area cm² × density × rate bits/s × duration s →

2 · Episodic & emotional resonance

The touch evokes memory snippets averaging  bits each, boosted by an emotional salience gain of ×.

3 · What we still don't know

Receptor codes are charted; subjective gating is not. We lack:

• Real-time measurements of touch-evoked attention shifts.
• Good priors on state delta weighting across the body map.
• Interaction terms between multisensory distraction and surprise.

Verdict: the numbers above are sandbox speculations. We really haven't scratched the surface of this problem, so Sergey and Laura should feel urgency to gather empirical data. For science.

Key refs: Johansson & Vallbo 1979 · Goodwin et al. 2009 · Dunbar 2024 · Gardner et al. 2012 · Brady et al. 2008 · Cahill & McGaugh 1998