The theory I most comfortably espouse posits the brain as an antenna receiving and transmitting signals into and from the Field. If one takes a physical perspective, this could be an EM (electromagnetic) field. Even the quantum physicists though now refer to what underlies our sensed reality as a more esoteric sort of field: the quantum field. We could paint the quantum field as the cloud of all possibilities, where imagination waits for the light of conscious awareness to call this, that, or the other into being.
A recent article in Aeon by Johnjoe McFadden (real name) describes the brain as an antenna within what the author calls the cemi (conscious electromagnetic information) field theory of the brain. I've ported it into Outline.com's annotator as well. Johnjoe claims that he has spent the last 20 years publishing about brain wifi, or the cemi field. I will want to read some more of his work; he is an elegant writer to boot.
In Quantum Evolution Johnjoe claims that evolution is willful. I've also surmised this and spouted it about willy-nilly. Would love to read what he came up with to support it.