First, disagreements aside, thank you for taking the time to respond. I am genuinely interested in trying to understand more about the topic (for my own personal benefit if nothing else) and that is harder to do in a vacuum if there is no discussion. Also, I do apologize if I mix up terms in a way that hampers discussion.
Mind-brain devolves to brain = magic if we must accept that the brain is special in some way that makes it immune to analysis. If it is not, then it is functionally identical to and scientifically indistinguishable from a biological implementation of the Chinese Room with a critical modification (the removal of the arbitrary requirement that all input to the CR be reduced to symbols). The Other Minds response highlights this problem well, and Searle's response that the the assumption that other people are conscious is necessarily axiomatic is either a strong indication that his definition of consciousness irrelevant to science (faith in the consciousness of others (or even the self) is a not a falsifiable position) or begging the question. Note that I did not say that his meaning is unimportant (it could still be the most important question ultimately facing any intelligent existence), but it is simply outside of the scope of science. The third option is to fall back on the broader symbol grounding issue as you seem to be doing.
The core of the argument is that you can't get semantic content from purely syntactic content. Ultimately, it's an attack on computationalism, and a damn good one.
That statement just raises the Connectionist argument that the validity of the CR thought experiment depends upon the false premise that all computation is necessarily syntactic. Searle specifies as axiomatic to the CR argument that any program must be symbolic, and further implies that any programmable computer must therefore only be capable of symbolic manipulation, and as such the CR argument a priori limits the scope of the problem to the syntactic. As such, the CR does not simulate the overall physical reality of, e.g., the propagation of pressure waves and the subsequent audio-neural transduction (hearing Cantonese) or the EM-neural transduction (seeing Chinese characters on a page). This then limits the interaction of the system with the outer world as occurring through a filter stripping that interaction of all a-symbolic and sub-symbolic components. We can contrast this with the experience of a native Cantonese speaker, for whom hearing spoken Cantonese or seeing pinyin characters on a page is a fundamentally non-symbolic interaction that only becomes symbolic after being processed by the brain. The original CR is therefore fundamentally flawed in its conception or inconsistent in its premise that the CR can perform in a manner identical to a real intelligence while stipulating conditions that are impossible to impose on, e.g., a human intelligence. Even the CR-inside-a-mind modification later articulated by Searle exhibits this flaw as Searle’s consciousness still filters and strips all non-syntactic input before passing it to the internalized CR.
To paraphrase parts of the Connectionist argument, the view that all computation as identical to manipulation of meaningless syntactic constructs is an observer-dependent interpretation that unjustifiably excludes the physical reality of the computer system, which has structure and properties independent of our choice to view the cascade of physical interactions as manipulation of symbols. In short, a la his wordstar-on-the-wall argument, Searle is correct in asserting that a program in the abstract is a collection of symbols that has no inherent meaning, but it is incorrect in asserting that a physical system responding to inputs that we perceive to be a program is identical to that abstract concept, and that because the one of many real inputs into the system to which we assign meaning is symbolic to us, that the system’s response is necessarily and only symbolic.
In any case, Neural net modeling, which was the original topic of this discussion, is essentially focused on studying non-syntactic computation. If the response to this is that it is still flawed because ANNs are mostly implemented on digital (and therefore nominally symbolic) computational systems, then, even ignoring the point of the larger system above, this objection reduces to a simple implementation technology issue as opposed to a fundamental constraint of ANNs as an ANN is not necessarily limited to implementation on nominally digital platforms. If implementation on digital logic is found to be fundamentally limiting for some as-yet unknown reason, then that can be addressed via moving to analog, quantum, or biochemical systems (which, taken to the extreme, could simply be an artificially constructed human brain).
In essence, while I agree that the cognitive model of the mind processing symbols to which we assign meaning is flawed, it is incorrect to assert that computation is necessarily limited to this model. In that view, the CR only addresses a very narrow class of AI based on the reality/interaction -> symbol -> meaning cognitive model, where the mind's interaction with reality is mediated by a purely symbolic interface, as opposed to the connectionist model of reality/interaction -> a-symbolic sensory input -> meaning -> symbol where symbols are only created as a result of assignment of meaning, and then later inserted into the cognitive process as useful filters or abstractions that allows the mind to more quickly/efficiently deal with inputs. This model of the cognitive process rejects Searle's CR as valid as in this context the CR argument's premise begs the question by imposing the restriction that symbols must be specified before meaning is assigned (i.e., they are not symbols to the CR, but are in fact someone else's symbols), and the more subtle inference that the system must ultimately respond to each symbol as a hypothetical native Chinese speaking conversation partner (or otherwise immediately pass the Turing test as applied by a Chinese speaker) in order to qualify as being conscious. In order to do so with a foreign set of symbols that have not been internalized by the consciousness means it must either fail the Turing test or to simply get inside (or alternatively internalize) the Chinese Room and process symbols via complex lookup. As passing the Turing test is a premise of the CR, then we are left with the latter scenario whereby even an assumed consciousness, being forced to work with symbols created by someone else to which it has not developed or assigned any meaning, must simply respond to inputs mechanically based on the rules it has been supplied a premise of the though experiment. In other words, even if a consciousness does exist, it cannot simultaneously understand Chinese and satisfy the other premises due to the conditions imposed by the thought experiment, so the possibilities of the CR are a consciousness that does not understand Chinese, or a lack of consciousness and simple mechanical symbol processing. The conclusion of the CR argument is therefore a recursive and inevitable outcome of the combination of the reality -> symbol -> meaning cognitive model and the conditions of the experiment.