Re: Qualia and the Galactic Loony Bin
Fri, 18 Jun 1999 22:12:27 -0700

Damien Broderick, <>, writes:
> At 06:56 PM 18/06/99 -0700, Hal wrote:
> >Either all possible mental states are existing all the time
> >just due to random neural firings in disconnected brains all over the
> >world, or else these carefully planned stimulations, which were designed
> >to mimic actual neural patterns in a conscious brain, were not actually
> >producing any mental states.
> >
> >So, what do you think?
> Obviously the latter, since connectivity of the neurons is absent.

As I said, I shortened the tale somewhat. The original story gave reasons for not believing connectivity to be important:

Initially, the brain is just stimulated from the outside. It is intact and all its neurons are connected. The eyeball neurons are not attached to eyes, but are stimulated directly to produce visual scenes, etc. Presumably there would be agreement that this would produce conscious experiences.

Then, the brain is accidentally split in half along the corpus callosum. However, undaunted, the project continues, with each half of the brain being stimulated not only at its input neurons as before, but also on the incoming fibers of the corpus callosum. Stimulus units provide the signals which would have come in from the other half of the brain. (This would appear to require that either the stimulation being provided is a playback of previously recorded brain activity, or that the stimulus unit simulates the entire opposite half of the brain. For simplicity let us assume the first alternative.)

We now have our two brain halves firing in exactly the same pattern as before. The two halves "can't tell" that the signals coming in are not actually coming from the rest of brain but rather that they are artificially applied. The patterns are exactly the same as before. So we should presumably conclude that we are again creating conscious experiences, despite the break in connectivity.

If this step is accepted, we merely repeat it, with the brain being quartered, then divided into progressivelly smaller steps, until we reach the point where we have the individual neurons. At each point the units are stimulated appropriately so they fire exactly as they did when they were part of the whole brain. If splitting the brain once retained consciousness, then going all the way to the neuron should do so as well.