In the realm of brain studies there’s a fairly reductionist view that argues that our consciousness and subjective experience is firmly rooted in our physical brains. The idea goes that we have these incredibly complex interactions between tens of billions of neurons and out of that arises our experience of being alive. Most authors I’ve read on the topic freely concede the exact nature of how consciousness arises from this is a mystery but it seems pretty clear that our self corresponds to our neural tissue. Simply consider that someone can have a brain stroke and they become a different person — they can no longer speak or form memories or control their anger. The soul seems to exist in physical form (or more accurately, it doesn’t exist at all.)
I’m pretty sympathetic to this view. But the book “The Mind’s I” has a thought experiment that does challenge this view. First let’s consider a brain in its ideal form. It’s sitting there, neurons firing, creating thoughts. Now let’s imagine an incredible surgery where you go in and separate apart every single neuron and place each one in its own chemical bath to keep it alive. (This is, or course, impossible.) You then attach electronic signaling/receiving devices so each neuron can communicate with whatever neurons to which it was “attached” (e.g. shared a synapse with) before. So, basically, even though the neurons are now separate, their signaling is exactly the same as it was in the whole brain. Can we still envision a mind rising out of all this?
Well, I dunno… maybe…
But it gets worse. Instead of putting little signaling/receiving devices on each neuron, attach little zappers that that simply fire different amounts of electricity. Now separate these neurons by hundreds of miles. Then fire of each of the zappers so that the neurons fire the exact way the would if the brain’s owner was thinking of a cat. (There’s no signaling going on, just neurons firing in the same order as if they were receiving signals.) Would some entity somewhere suddenly think of a cat?
It seems unlikely doesn’t it? But the individual neurons in all these cases are behaving exactly the same. So this would seem to dispel the possibility of a purely reductionist (e.g. it’s all in the tissue) model of consciousness.
I just stumbled on some general theories that address this issue. They are “Electromagnetic theories of consciousness.” (Link goes to wiki page about it.) The idea is that when you have a bunch of neurons in a brain they are, because of their electrical activity, creating an electromagnetic field. And somehow this field is consciousness. The field is not only created by the brain’s neurons, it affects them as well, so the field and brain effectively pass signals back and forth. The wiki page has details.
The starting point for McFadden and Pockett’s theory is the fact that every time a neuron fires to generate an action potential, and a postsynaptic potential in the next neuron down the line, it also generates a disturbance in the surrounding electromagnetic field. McFadden has proposed that the brain’s electromagnetic field creates a representation of the information in the neurons. Studies undertaken towards the end of the 20th century are argued to have shown that conscious experience correlates not with the number of neurons firing, but with the synchrony of that firing.[9] McFadden views the brain’s electromagnetic field as arising from the induced EM field of neurons. The synchronous firing of neurons is, in this theory, argued to amplify the influence of the brain’s EM field fluctuations to a much greater extent than would be possible with the unsynchronized firing of neurons.
McFadden thinks that the EM field could influence the brain in a number of ways. Redistribution of ions could modulate neuronal activity, given that voltage-gated ion channels are a key element in the progress of axon spikes. Neuronal firing is argued to be sensitive to the variation of as little as one millivolt across the cell membrane, or the involvement of a single extra ion channel. Transcranial magnetic stimulation is similarly argued to have demonstrated that weak EM fields can influence brain activity.[citation needed]
McFadden proposes that the digital information from neurons is integrated to form a conscious electromagnetic information (cemi) field in the brain. Consciousness is suggested to be the component of this field that is transmitted back to neurons, and communicates its state externally. Thoughts are viewed as electromagnetic representations of neuronal information, and the experience of free will in our choice of actions is argued to be our subjective experience of the cemi field acting on our neurons.
I’m not agreeing with this (frankly, I still don’t really understand what electromagnetic fields are) but it does address the problems with the reductionist view.