Re: Searle: Is the Brain a Digital Computer?

From: Hunt Catherine (
Date: Tue Mar 06 2001 - 13:52:08 GMT

> 2. Is the mind a computer program?
> 3. Can the operations of the brain be simulated on a digital computer?
> I think 2 can be decisively answered in the negative. Since programs are
> defined purely formally or syntactically and since minds have an intrinsic
> mental content, it follows immediately that the program by itself cannot
> constitute the mind.

> Salcedo:
> I think we can only decisively state that the mind is not a computer
> program if we consider the definition of program as it is now known
> today: a group of commands, symbols, that have a defined meaning and
> stand for some kind of operations on the computer.
> 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. But what if the mind itself, the thing we call
> consciousness, is nothing but reactions to some more complex set of
> procedures or operations, that can actually be defined formally and
> described in some analogous way to computer programs, syntactically?
> Then, the mind could be considered a computer program and computers
> would be able to evolve to a true state of artificial intelligence.
> Artificial because it would still be organic-based and intelligence for it
> would mimic the functioning of the brain/mind.

I agree with the comments from both Searle and Salcedo. I have already
argued myself that it is not possible to simulate the human mind with a
computer program. If you can simulate the human mind exactly then, surely
the simulation is a mind? If indeed consiousness is merely a set of
reactions to a complex set of procedures or operations then Salcedo is
arguing that there is a possibility that it could be defined syntactically
by a computer. I would argue that although the mind can be seen as a set
of reactions to procedures or applications, the mind is also specific to
the person that it belongs. By this I mean that unlike a computer making
calculations and producing what we perceive to be correct answers,
different minds produce different results. As an analogy, if one person
sees a spider on the ground, their reaction might be to stamp on it
without a second thought. Another person might see a spider on the ground
and do their best to avoid squashing it. The two outcomes are perceived as
correct by different sets of people. There are probably an infinite number
of situations in which humans react differently. So how could the mind be
represented as a computer program if there are no definitive rules for

> So the answer to the second question is obviously "No".

> Salcedo:
> 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 agree, following my previous argument and the comments from Salcedo. I
wonder if scientific theory will ever be able to understand the human
brain. Unless there is a complete comprehension of the mind, I doubt that
we will ever get near to simulating the human mind with a computer

> Salcedo:
> We have to be careful when considering question 3. When asking if we
> can actually simulate brain operations on a digital computer, we have
> to remind ourselves that a simulation is not by itself a complete
> representation of what it simulates.
> The brain performs mathematical operations, which can be obviously
> defined on a digital computer with no difficulty at all.

Searle believes that it is possible to simulate brain operations on a
digital computer. Salcedo reminds us that a simulation is not a complete
representation of what is being simulated. I agree with Salcedo, that
identical mathematical operations can be performed by the digital computer
and the mind - 1+1=2 for instance. A digital computer can run a program
that reacts to bright light by protecting itself in some way in the same
way that a human might either shut or squint the eyes to block out the
light. But this is not simulating the complete human mind, just a mere
subset of functions.

> Salcedo:
> How can we actually compare internal representations between something
> that, for now, is completely nonconscious as a computer program, and
> something that can either be done consciously/unconsciously by a human
> brain?
> 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?
> Can we actually generalise the human brain to one human brain as we can
> with a mechanical computer? If we took several mechanical computers
> that were found to have the same internal processes as the human brain,
> would we then get different results from the mechanical computers as we
> would if checking what different people would think or do in the same
> situation/input?
> Would the computers show different personalities, different ways of
> thinking?

I completely agree with Salcedo on these points. I am myself arguing the
fact that human minds work in different ways. Some minds might be similar,
but I would imagine that is highly unlikely that two minds are identical
in every way. The mind is unique to an individual, so how can there be a
simulation of the human mind? Which human mind? Mine, Searle's,
Also, Salcedo comments that the mind works in different ways and identical
internal processes might produce different outcomes. On the other hand,
differing internal processes might produce the same outcomes with a number
of people. How would it be possible to model this with a computer
simuation? I argue that it would be impossible.

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

What is a 'Cartesian soul'?

> Salcedo:
> Again, the 0s and 1s dont have a physical existence. If this is the
> human computer program, then isnt mind non-physical? What is and what
> is not meta-physical? If the mind cant be physically described, can it
> actually be considered computational?
> The thing is, what we think can only be known to us and cant ever be
> fully transcribed to a physical existence. Why do we think? It just
> happened. Its intrinsic to our nature. It belongs to us. But how? How
> can it be intrinsic to our characteristic, if at the same time it
> doesnt belong to its physical nature?
> This is by far the main debate between science and philosophy.
> Philosophers believe in the meta-physical mind, something that belongs
> to us but doesnt at the same time. Something intrinsic to us, because
> we are born with it, but at the same time extrinsic to us, because its
> not intrinsically written down to other humans.

How does Searle come to the conclusion that there are 0's and 1's flowing
through the brain. Indeed, there may be 0's and 1's if that is
specifically what we are thinking about, as well as 2's, 3's.. But the 0's
and 1's are just a syntactic representation of what is really going on in
there and if we are having to liken what goes on in the human mind to
something else in order to explain it, then surely we do not have enough
knowledge to simulate it?

> Salcedo:
> In my opinion, the only pattern one could associate with brain
> processes in a human being, thus helping predict action/reaction pairs
> would be the personality concept. A person tends to react in the same
> way that is defined by its personality. But what exactly is
> personality? There is no way to physically describe it and, as such, to
> explain the events that are processed in the brain. And were back in
> the same hole.

I agree with bot Searle and Salcedo. I think that cognition is not
understood well enough to explain reactions to external stimuli and
internal processes and operations. Personality - whatever it is -
definitely shapes the outcome of individual mind processes. So if we do
not know what personality is, then as Salcedo states, 'we are back in the
same hole'. We do not understand the mind, so we cannot simulate it with a
digital computer.

> 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.

> Salcedo:
> 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. The brain is completely interconnected to all other human
> senses at the same time, and as Searle describes it is not only a
> biological set of processes, but it also has intrinsic characteristics
> and processes that happen both consciously and unconsciously at the
> same time.
> Again, calling the brain an information processing unit would be a way
> too large abstraction, and wouldnt help at all in understanding how
> brain functions can be correctly modelled on a mechanical computer.

Searle and Salcedo both assert that it is false to say that the brain is
an information processing device. To a certain extent, I disagree with
this assertion. The brain does process information. We react to external
stimuli and we do this by assessing the information given in terms of the
state of the environment and react accordingly. If this is not information
processing, then what is? However, I do think that it is wrong to see the
brain as 'just an information processing device'. I think that is what
Searle and Salcedo are doing.
Another point I will make is the reference made by Salcedo to the brain
being completely interconnected to all other human senses at the same
time. During lectures we have explored the idea of the brain being
stripped of all external organs, such as the skin and the eyes etc. and
the possibility that it will still function as a brain, and I just
wondered where that idea fitted in with Salcedo's commnents. As I
understand, he is making the assumption that in order to function as a
brain, it has to be connected to two arms, two legs, eyes that work,
tastebuds that work.. What happens in the case of a blind person, or
someone who has lost their sense of taste or smell. Is Salcedo suggesting
that their brains cannot function because they are not connected to all
their human senses?

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