Re: Searle: Is the Brain a Digital Computer?

From: Marinho Francis-Oladipo (
Date: Tue Mar 27 2001 - 18:53:49 BST

>> 2. Is the mind a computer program?
>> 3. ....
>> So the answer to the second question is obviously "No".

>It is obviously No as we currently dont yet understand how the brain
>actually works. Scientific theory keeps evolving and correcting itself,
>and this is not a proven statement.

I may be being pedantic but Salcedo has already stated that the mind works
similarly to a computer program BUT with the added capacity of an awareness.

>Human beings do have this capacity, but we have always to consider that
>there is also a mental content, a consciousness, or whatever it might
>be called.

Firstly, is the mind considered to be different from the brain? They seem
to me to be used interchangeably by Salcedo. If they are different, and
the brain is the human part that is responsible for the program-like
computations, then i would agree that the mind is not a computer program
because then it would be the mind that supposedly has this extra ability
that cannot be displayed by a computer program. If however, as suggested,
they are one and the same, then i don't think that it is right to say
that the mind is not a computer program. I think it would be more
appropriate to say that the mind is not JUST a computer program, instead
it is a computer program with whatever Salcedo refers to as consciousness.
Searle's investigation starts off by trying to establish the distinction
between the brain and the mind. He accepts that the mind has an element of
a program about it but like Salcedo is hasty to renounce it from being a
computer program.

>> We try to discover the programs being implemented in the brain by
>>programming computers to implement the same programs. We do this in turn
>>by getting the mechanical computer to match the performance of the human
>>computer (i.e. To pass the Turing Test) and then getting the
>>psychologists to look for evidence that the internal processes are the
>>same in the two types of computer.

>If different people think in different ways, and therefore have
>completely different outcomes even while having exactly the same
>internal processes, how can we actually say that the computer mirrors
>the brain computer?

What are internal processes? Taking the processes in a human brain, are
they the receptors taking in data, performing a computation and producing
an output? Or are these processes much deeper? Consider the test where an
individual is presented with an abstract picture and asked to name the
first thing they think of as a consequence. The results of such an
experiment on different individuals will yield answers of all sorts.
These answers could be as a result of the mental state of the candidate,
they could be restricted to images previously encountered or they could
be from the candidates imagination visualising features that are not
immediately apparent to others.
Salcedo suggests that it could be wrong to compare internal processes
due to the fact that humans with the same internal processes think
differently. This may be true, but whether or not they think differently,
the fact of the matter is that they think, and different thinking does
not make one human necessarily intelligent and another stupid.
The mere fact that each individual, given the same circumstances would
react differently could suggest that even though at face value, the same
internal processes are at play, further below the surface maybe they are
not so identical.
As a result of the above, is there a need to be able to generalise the
human brain? If one brain can be mirrored by a mechanical computer and that
brain is considered to display intelligence then surely the main objective
has been met.

>>The idea is that unless you believe in the existence of immortal
>>Cartesian souls, you must believe that the brain is a computer.

I agree with Salcedo's point with reference to this. Looking at it from
another point of view, Searle seems to be implying that if you only believe
in physically, algorithmically explainable things, then your logical
thinking means that you also believe that the brain is just implementing
algorithms. What of the case where an unbeliever of the supernatural world
experiences a supernatural event? He or she may still not believe in the
supernatural after the event but the mere fact that an unexplainable thing
happened could leave them thinking that there is more to the brain.

>From yet another standpoint, what if i don't believe in the supernatural,
but i believe that i am more intelligent than any computer? I would
therefore disagree with Searle because to believe that i am more
intelligent than any computer, i have to believe that no computer can
mirror my brain, and from Turing and Church, if my brain were a computer,
then it would be able to be mirrored.

>> The upshot of this part of the discussion is that in the sense of
>> "information" used in cognitive science it is simply false to say that
>>the brain is an information processing device.

>I agree with Searle on this 100%. In my opinion, considering the brain
>to be just an information processing device, would be comparing it to
>the information processing that goes on in a mechanical computer system.

I agree with both Searle and Salcedo on this point. Just as a simulation of
a plane can do everything that a plane does apart from actually, physically
fly, so also a simulation of the brain could also do everything the brain
does except actually think. There is however the argument that says if it
acts like it's thinking, then surely there is no point in trying to say it
is not thinking. If the flying case is considered however, then a simulation
is just going through the motions of flight without actually doing it. If
the simulation actually flew, then it would no longer be a simulation of a
plane. It would instead be a plane. With a plane, you want
to get in and be able to get out at a different destination. With a brain
the thought process doesn't appear to be physical and hence there doesn't
seem to be as much difficulty in accepting a simulation of the thought
although it is important to note that it is still not really thinking.

Francis Oladipo Marinho

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