The traditional problem in mind/brain interaction arises from a dualistic view that sees the brain as material and the mind as immaterial. This is often derided as the "ghost in the machine" model of Rene Descartes. The difficulty stems from an inability to explain how an immaterial object, like the mind, can move through a material object, the brain, yet manipulate it like a poltergiest that can go through walls but at the same time grasp a vase and fling it across a room. If it goes through solid objects how can a ghost hold a vase?
This has lead many materialists to assert the "mind" is just a physical process in the brain. By assuming a model such as this dualism is avoided because the mind and brain are both thought of as essentially the same.
I agree with that principle but I don't think it is materialistic but idealistic (my reasons for this can be found in my essay "The Paradox Of Nothingness" which can be found here: http://www.positivedeism.com/phpbb2/viewtopic.php?t=2699 ).
I think the mind arises from the brain as an epiphenomenon. Basically consciousness begins as a linear concept, manifested as a simple stimulus/response behavior, but as it matures it makes associations and connections that allow it to close like a straight line that is made to bend back on itself making a circle (that is it observes itself and thus becomes self-referential).
This self awareness will cause the mind to rise above the "plane" that defines the brain. Think of a flat plane (representing the brain) intersected by a sphere (representing the mind). Where they intersect there will be an area common to both in the form of a ring. Only that which is possible in both the plane and the sphere can occur within this ring so in effect this causes the brain to act as a filter which limits our awareness to that which is supplied by the senses. Therefore all observed behavior, which is confined to the plane, must be explainable by the so called "material" processes of that plane (this is why I doubt the possibility of things like ESP).
But since they are both concepts they constitute a single multi-dimensional structure and likewise avoid the problems of dualism. And they can interact because a disturbance in one portion of it will cause a similar disturbance in the other, and vice-versa, in the area of the ring. It is this effect that I think holds the key to mind/brain interaction.
There are stuctures in the neuron called ion channels that control the flow of molecules across the cell membrane. These molecules will cause the neuron to depolarize and fire.
Ion channels occupy a unique size range. They are small enough to be susceptable to quantum influences yet big enough to initiate actions at the macroscopic level. So in effect what I think happens is this; there is a certain very low probability that a given ion channel will open but when intersected the probability increases to a near certainty. Since all ion channels in a given cell will be thus intersected they will all open and they will cause the cell to fire. So basically mind/brain interaction can be reduced to nothing more than the addition of probabilities. If the resulting sum is great enough the chances are an action will occur.
This mechanism would allow the senses to inform the mind and the mind to control the body. And as the interaction is essentially vibrational, experiances accumulated over the course of time will create a unique "vibrational signature" for each individual.
Patterns of sensations conveyed by the brain will induce complimentary patterns of probability waves (or vibrations) in the mind. Since the process is reciprocal when presented with a choice the mind could simply "scroll" through possible responses, pick one, lock on, and through the resonance thus established reinforce the complimentary pattern in the brain (which we percieve as specific neural circuits) and cause an action. And because these decisions arises in the mind it not only suggests we have free will it explains how it works.
Self awareness then would be a function of the geometry of the mind, that is it bends back on itself. And awareness of the world could be thought of as how that structure vibrates. This is consistent with the wave nature of matter as described by modern physics because particles (such as those which compose the atoms the brain is made of) are essentially vibrating bits of energy governed by probability.
This is probably an evolutionary mechanism that allowed early man to defend himself against the fangs and claws of predators like lions or tigars. Being able to construct mental models of possible scenarios from which to choose from and thier consequences would enhance thier chances of survival.
As an open concept the brain will someday deteriorate and die but this model suggests that as a closed concept the mind may be able to hold itself in existence after the "physical" death of the body. For if God exists and holds Itself in existence because It can say, "I am" then it follows we may be able to do likewise because we can also say, "I am". If this is true then once the bonds that tie the mind to the brain are cut it will continue on without it- forever.
I would not call this "life after death", though. Life is a biological function and death is the permanent cessation of that function. This is better termed a continuation of consciousness.
But since we all come from the same "reason for being" (that is the Prime Observer) all of these free minds will be connected to each other and thus be able to communicate by "sensing" each others vibrational signature. However this can only happen after they are liberated. Just think of a free mind as a bubble in a cluster of bubbles.
It also suggests that after liberation these free minds act as secondary observers and as such may be just as responsable for holding the world in existence as the Prime Observer. In idealism the world must be observed but it doesn't matter by who.
I have to say this model was inspired by a new model of consciousness called orchestrated objective reduction that was developed by the physicist Roger Penrose and the physician Stuart Hameroff. But there are significant differences between them. Unfortunately those differences are far too complex to be elaborated on here.
Nor is thier anyway to test it empirically since our senses are confined to the plane. So no matter how sophisticated her instruments a researcher will only see nerve cells firing because that is the only part of the structure that intersects the plane. But in my opinion the argument (with the support of the essay I referred to earlier) makes it the most reasonable model I am aware of.
Anyway thats my take on it for what its worth.