system
Given the following post, respond as if you're commenting on Reddit:
human
Chinese Room Argument Applied To Human Brains

Why doesn't the chinese room argument apply to biological brains, in particular human brains?   

The obvious rejoinder is that human brains are not symbolic, but I don't think that works.  If you have a human brain, it is 'just' made up of neurons performing computational tasks (aside:  we know that the computations are way more complicated than McCulloch-Pitts models, but assume that it's not some Penrosian quantuum calculation).  Does that mean that an analog brain consisting of neuron-like units would 'understand'?   

Alternately, if you replace the neurons, one-by-one, in a human brain with synthetic units, does it stop 'understanding'? (immediately?  at some point?  when all neurons are replaced?)

And if the synthetic units themselves use symbolic computation internally, would that affect it?   (Or if the neuron replacement was actually a person computing the in-out relationship?)

Finally, if you replaced a cluster of neurons (a microcolumn, for example) with a single larger computational unit, would the human-machine hybrid still 'understand'? 

It seems to me that the Chinese room argument is vulnerable to an argument from the other side, that if the CR does not 'understand', then people don't either.  

I can only assume that this argument has been made better by real philosophers, but I can't find a discussion.  Can someone point me to it?
gpt
Searle's Chinese Room is not presented as an argument against thinking machines. As Searle likes to say: human brains are machines that think. So we KNOW machines can think. It's an argument that syntax (symbol) manipulation alone does not get you semantics (understanding/meaning). Today's computers are algorithmic. All they do is manipulate symbols. The CRA shows that a machine that works solely by manipulating symbols can't get you semantics. Since we know that the brain gets us semantics, we can infer that it does not work solely through algorithmic manipulation of syntax.