Notes:
As I said the objections against this model are strong. It seems to be extremely speculative and actually imossible, Rather than the 25 milliseconds that is required for this model theoretical calculations show that the quantum suerposition can only exist for 10 -12 seconds at most. Proponents of the Penrose-Hameroff school calculate of course using differnt assumptions about brain structures and properties that the pure states might exist for at least 10-4 seconds.
This is an incredibl.e difference in theoretical prediction and that is due because too many assumptions have to be made in order to do these calculations.
Rather than theoretical predictions one would like to see empirical measurmennts. Is that possible?
Yes there is a method that is routinely used to measure the duration of quantum states.
It is called photon echo and uses two pulses of a laser. The first to induce the state, the scond to probe the state. If the state still exists the probe will result in an emission of photons of the same wavelength that were used to induce the state. By manipulationg the time between the pulses one can test at what duration no echo is observed anymore. That duration is the quantum decoherence time.