I don’t think you can directly compare brain voltage to Landauer limit, because brains operate chemically, so we also care about differences in chemical potential (e.g. of sodium vs potassium, which are importantly segregated across cell membranes even though both have the same charge). To really illustrate this, we might imagine information-processing biology that uses no electrical charges, only signalling via gradients of electrically-neutral chemicals. I think this raises the total potential relative to Landauer and cuts down the amount of molecules we should estimate as transported per signal.
Neuron computation is electro-chemical through voltage gated ion channels. If the voltage is at or below the Landauer voltage, then ion motion through the gate is pure noise. As the voltage climbs above the Landauer limit, you start to get meaningful probabilistic state transitions (error rate below 50%) in reasonable time; you can then implement analog computation using many such unreliable carriers reducing error/noise through central limit binomial.
‘Pure’ chemical computation is protein machinery. Biology evolved voltage based signaling for high speed longer distance communication/computation.
This was super interesting.
I don’t think you can directly compare brain voltage to Landauer limit, because brains operate chemically, so we also care about differences in chemical potential (e.g. of sodium vs potassium, which are importantly segregated across cell membranes even though both have the same charge). To really illustrate this, we might imagine information-processing biology that uses no electrical charges, only signalling via gradients of electrically-neutral chemicals. I think this raises the total potential relative to Landauer and cuts down the amount of molecules we should estimate as transported per signal.
Neuron computation is electro-chemical through voltage gated ion channels. If the voltage is at or below the Landauer voltage, then ion motion through the gate is pure noise. As the voltage climbs above the Landauer limit, you start to get meaningful probabilistic state transitions (error rate below 50%) in reasonable time; you can then implement analog computation using many such unreliable carriers reducing error/noise through central limit binomial.
‘Pure’ chemical computation is protein machinery. Biology evolved voltage based signaling for high speed longer distance communication/computation.