Page 102 - Foundations of Cognitive Psychology : Core Readings

Minds, Brains, and Programs 103

states at all; it is simply moving about as a result of its electrical wiring and its
program. And furthermore, by instantiating the program I have no intentional
states of the relevant type. All I do is follow formal instructions about manip-
ulating formal-symbols.

5.3 The Brain Simulator Reply (Berkeley and M.I.T.)

‘‘Suppose we design a program that doesn’t represent information that we have
about the world, such as the information in Schank’s scripts, but simulates
the actual sequence of neuron firings at the synapses of the brain of a native
Chinese speaker when he understands stories in Chinese and gives answers to
them. The machine takes in Chinese stories and questions about them as input,
it simulates the formal structure of actual Chinese brains in processing these
stories, and it gives out Chinese answers as outputs. We can even imagine that
the machine operates, not with a single serial program, but with a whole set of
programs operating in parallel, in the manner that actual human brains pre-
sumably operate when they process natural language. Now surely in such a
case we would have to say that the machine understood the stories; and if we
refuse to say that, wouldn’t we also have to deny that native Chinese speakers
understood the stories?At the level of the synapses, what would or could be
different about the program of the computer and the program of the Chinese
brain?’’
Before countering this reply I want to digress to note that it is an odd reply
for any partisan of artificial intelligence (or functionalism, etc.) to make: I
thought the whole idea of strong AI is that we don’t need to know how the
brain works to know how the mind works. The basic hypothesis, or so I had
supposed, was that there is a level of mental operations consisting of compu-
tational processes over formal elements that constitute the essence of the men-
tal and can be realized in all sorts of different brain processes, in the same way
that any computer program can be realized in different computer hardwares:
on the assumptions of strong AI, the mind is to the brain as the program is to
thehardware, and thuswecan understand themindwithout doingneuro-
physiology. If we had to know how the brain worked to do AI, we wouldn’t
bother with AI. However, even getting this close to the operation of the brain is
still not sufficient to produce understanding. To see this, imagine that instead
of a monolingual man in a room shuffling symbols we have the man operate
an elaborate set of water pipes with valves connecting them. When the man
receives the Chinese symbols, he looks up in the program, written in English,
which valves he has to turn on and off. Each water connection corresponds to
a synapse in the Chinese brain, and the whole system is rigged up so that
after doing all the right firings, that is after turning on all the right faucets, the
Chinese answers pop out at the output end of the series of pipes.
Now where is the understanding in this system?It takes Chinese as input, it
simulates the formal structure of the synapses of the Chinese brain, and it gives
Chinese as output. But the man certainly doesn’t understand Chinese, and nei-
ther do the water pipes, and if we are tempted to adopt what I think is the ab-
surd view that somehow the conjunction of man and water pipes understands,