[ExI] Wernicke's aphasia and the CRA.

[Stathis Papaioannou]

2009/12/12 Gordon Swobe <gts_2000 at yahoo.com>:

>> No, I mean that if you replace the brain a neuron at a time
>> by electronic analogues that function the same, i.e. same
>> output for same input so that the neurons yet to be replaced
>> respond in the same way, then the resulting brain will not only
>> display the same behaviour but will also have the same consciousness.
>
> How will you know this?

Searle believes that consciousness is a special property of brains,
and that although it may be possible (if technically difficult) to
simulate the behaviour of a neuron electronically, the artificial
neuron will lack qualia.

Suppose we replace some of the neurons in your visual cortex. The
artificial neurons will behave just the same as the original neurons,
sending the appropriate signals to their neighbours, which in turn
send signals to their neighbours so that all of the biological parts
of your brain behave the same as if the replacement had not been made.
The experimenters confirm this by taking readings from neurons in
different parts of your brain before and after the replacement, and
finding that they are unchanged. Your motor cortex will therefore send
signals to your vocal cords and you will declare that the page of
writing put in front of you looks exactly the same as it did before,
and to prove it you correctly read out what it says.

However, if Searle is right all is not well, because you have just
gone blind! Your vision has undergone zombification: you behave as if
you can see, but you lack visual qualia. So either you are blind
without noticing that you are blind, which makes a mockery of the idea
of consciousness, or you do notice that you are blind but can't do
anything about it, locked into behaving normally while struggling in
vain to communicate your terror. The latter nightmarish scenario would
mean that you are doing your thinking with your immaterial soul, since
your brain activity would be the same as if nothing unusual had
happened.


-- 
Stathis Papaioannou