> If your visual cortex is replaced by an electronic device that
> produces the appropriate outputs at its borders, the rest of your
> brain will respond normally.

This is just an assumption. I guess that at present one cannot prove or disprove it. Let me quote an opposite assumption from Jeffrey Gray (p. 232, section 15.5 Consciousness in a brain slice?)

"Might it be the case that, if one put a slice of V4 in a dish in this way, it could continue to sustain colour qualia? Functionalists have a clear answer to this question: no, because a slice of V4, disconnected from its normal visual inputs and motor outputs, cannot discharge the functions associated with the experience of colour. But, if we had a theory that started, not from function, but from brain tissue, maybe it would give a different answer. Alas, no such theory is to hand. Worse, even one had been proposed, there is no known way of detecting qualia in a brain slice!".


On 13.08.2011 05:18 Stathis Papaioannou said the following:
On Fri, Aug 12, 2011 at 3:22 PM, meekerdb<meeke...@verizon.net>

John Searle claims to be a physicalist but he believes that if
part of your brain is replaced by a functionally identical
computer chip your behaviour will remain the same but your
consciousness will fade away. Incidentally, Searle accepts that
there is no problem in principle with making such a zombie chip.
However, this is not possible under a physicalist theory as
defined above. If the computer chip has the same I/O behaviour as
the volume of tissue it replaces, the brain that does the

And what part would that be?  The homunculus in the Cartesian
theater.  I don't think functionalism entails that there is some
"noticing" neuron in the brain.  If functionalism is correct,
"noticing" must be distributed.

Noticing is distributed, but the parts of the brain are
interconnected. Visual perception occurs in the visual cortex, then
the information may be sent to the limbic system causing an
emotional reaction to what is seen and the language centre allowing
you to describe what you see, and on to the motor cortex leading to
muscle contraction in the limbs. If something changes in your visual
cortex then all these other areas in the brain receive different
inputs, and so produce different outputs. You feel different and you
behave differently, and that constitutes noticing that there has been
a change.

If your visual cortex is replaced by an electronic device that
produces the appropriate outputs at its borders, the rest of your
brain will respond normally. You will watch a film, understand the
story and be able to describe it afterwards, have the appropriate
emotional responses, and so on. In other words as far as the qualia
in the rest of your brain go there is no difference. Now, is it
possible that your actual visual qualia have disappeared and you just
can't notice? If you think this is possible, how can you be sure that
didn't go blind last Tuesday and just haven't noticed? If you are
actually blind in this strange way what have you lost?

cannot tell that anything has changed. Only if consciousness is
disconnected from brain activity, due for example to an
immaterial soul, could the subject notice a change even though
his brain is responding normally. The conclusion is that IF the
replacement is functionally identical THEN the consciousness is
also preserved,

But the question is what "functionally identical" means.  Can it
mean only the same input/output or must it be similar inside at
some lower level.  If you specify the same input/output for all
possible input sequences, including "environmental" ones, then I
agree that your argument goes through.  But failing that, it seems
to me the consciousness that is within or due to the AI hemisphere
can be different AND noticed in that hemisphere.

It can be noticed separately in that hemisphere but if it is not
communicated it will be a separate consciousness. If my liver
suddenly gained self-awareness that would not necessarily mean that I
(the person generated by my brain) would share in it or vice versa.

Your argument seems to assume that consciousness is localized and
must be outside the AI part, but that would lead to philosophical
zombies when you replaced the whole brain and there was no

No, because the argument shows that the replaced part must
contribute normally to the consciousness of the whole, due to the
conceptual difficulty with partial zombies - being blind without
knowing you are blind.

You received this message because you are subscribed to the Google Groups 
"Everything List" group.
To post to this group, send email to everything-list@googlegroups.com.
To unsubscribe from this group, send email to 
For more options, visit this group at 

Reply via email to