This picture was described in Scott Aaronson's essay The Ghost in the Quantum Turing Machine in 2013, and claims that human free will is related to our choices being caused by (and/or causing) quantum bits from the initial state of the universe that first have macroscopic effects inside our brains, where all other observers must have purely Knightian uncertainty over such bits[*]. For it to be plausible, a few facts have to be true about human brain biology and cosmic background radiation:
- "Quantum uncertainty—for example, in the opening and closing of sodium-ion channels—can not only get chaotically amplified by brainactivity, but can do so “surgically” and on “reasonable” timescales."
- All photons that impinge on human brains have quantum states that could not "be altered, maintaining a spacetime history consistent with the laws of physics, without also altering classical degrees of freedom in the photons’ causal past".
Have these questions been studied in the intervening years, and what have the results been? Note that the plausibility of the picture has been discussed before on LW, and I'm not interested in further discussing whether a priori it seems at all promising to link free will and Knightian uncertainty.
[*] This is a poor summary, I recommend reading the paper if you have time.