I believe that the brain evolved while excluding significant external EM fields. By paying attention to the timing of signal components picked up by different antennas, an array of antennas can focus on a selected area to the exclusion of others, and a similar process may be used by the current carriers of the brain as they propagate and receive internally-generated EM energy.
I think that consciousness is dependent on the degree of effective complexity in the neural wiring, and I think that free will is what consciousness has during free time, when no ideal or pressing mental pursuit is apparent.