After carefully reading your last reply, it's definitely you...
That is the disagreement in a nutshell. I say that brain states are necessary but insufficient for meaning. I'll leave my position aside for now. It ought be openly stated here that I'm assuming you're referring to all types/kinds of meaning. In other words, I'm assuming that you're claiming that all senses of the term "meaning" are exhausted and/or covered by your assertion that "meaning is a brain state", and "there are no non-mental/non-brain-state constituents for meaning"....There are no non-mental/non-brain-state constituents for meaning...
If that were so, then it wouldn't pose any problem at all to replace the term "meaning" with "brain state" in each and every utterance which includes the term "meaning", and after doing so the utterance wouldn't lose any meaning, or should I say, the utterance wouldn't lose any brain state.
That can't be right. Using your own claims and applying this method we get the following...
So for one, if we were to claim that the signals we receive from our visual or auditory nerves were necessarily semantic, we'd have to be able to account for how we could read or listen to something, so that we're aware of the words as words or sounds as sounds, yet attach no brain state(meaning) to it.
Instead, a brain state(meaning) is something that our brains can do (but something they don't always do) once we've received visual and auditory signals (and not only, of course, but that's our example).
Actually, as sounds we make, or marks we make on paper or computer screens, etc., they have no brain state(meaning). Brain states (meaning) are(is) only assigned by individuals thinking about as much.