Via Neuroskeptic, a new paper in Brain and Cognition investigates the maximum affect Heisenbergian quantum uncertainty could have on synapses
Wildly waving toward the quantum world has been one major defense for dualist theories of mind – which posit that the mind is not reducible to the brain. It’s also the last line of defense (just above “magic”) for many people who wish to retain some notion of a soul.
As many have insisted must be the case, the numbers reveal that the Heisenberg uncertainty has no affect:
I conclude that Heisenbergian uncertainty is too small to affect synaptic function, and that amplification by chaos or by other means does not provide a solution to this problem. Furthermore, even if Heisenbergian effects did modify brain functioning, the changes would be swamped by those due to thermal noise. Cells and neural circuits have powerful noise-resistance mechanisms, that are adequate protection against thermal noise and must therefore be more than sufficient to buffer against Heisenbergian effects. Other forms of quantum indeterminism must be considered, because these can be much greater than Heisenbergian uncertainty, but these have not so far been shown to play a role in the brain.
This is unsurprising for anyone who recognizes the scale at which nerve cells interact – several orders of magnitude larger than the quantum world. But it’s good to see people investigating this assumption.
Read “Neuroscience, quanitum indeterminism and the Cartesian Soul” by PG Clarke.