Thursday, May 10, 2007

I don't mind; it doesn't matter

It's a standard trope in the kind of movies they used to show on Saturday afternoons: two people exchanging minds. In cartoons, it's usually done with electrified hemispheric caps; live- action films tend to go with a modified cross-fade. It brings up the problem of personal identity.
What is being transferred in a mind-switch is something non-material. But memories (including skills and habits) are encoded in the physical structures of the brain. So the transferred mind would not remember ever having been in a separate body. I may be swapping minds every day, and not noticing, because my memories always tell me, whatever body I am in, that I have always been in this body.
I think there would be a difference that is noticeable over time. I think that the transferred mind experiences qualia, and also makes free choices that are not causally determined by what is in the brain. These choices include moral choices. A good person would not become evil just because they suddenly have new evil memories and habits.
It might take some time for this change to show up, because of the force of habits. The difference may be subtle. The mind would not know that a switch had occured, but looking back at its (adopted) memory, it would find itself unable to understand why it had acted the way it did. It would be very much like what we describe when we say someone has "experienced a change of heart."
It could also be that the mind would literally "see the world differently." (This is the inverted spectrum argument.) The mind would not realize that the memories were inconsistent with the present perception because when it pulled up a memory of green grass to compare, the memory would cause the mind to experience its current green qualia rather than the other mind's green qualia.
After we die, our memories and skills would be left behind to decay along with the physical matter of the brain (barring divine intervention.) Those things are part of our bodies, not our eternal being. Believers in reincarnation should not expect to retain memories of past lives.


David said...

I've never liked the inverted spectrum theory because photons of light have a given energy and the way they interact with mater is dependent upon that energy. The energy of the photon is the same for everyone it cannot change for one person and not another.

D said...

That's true, and it may invalidate the inverted spectrum argument at some level. But we don't understand at what point in the brain the experience of color is created, so we don't know whether that experience is different, even though the signals coming from the rods and the cones are the same.
In fact, I doubt that generating experience is even something that can be said to happen in the brain. I'd love to discuss it further with you if you want.

D said...

To clarify: the causes of experience are in the brain, but the effects-- the color experiences themselves-- are not.