I think no SDR’s are directly translatable anyways without the minimum context. Let’s think about the old famous question, that even kids ask:
“Do we really see the same colors?”. The answer is both yes and no.
Yes - because that is how the language works. We have been exposed to the same objects and grew up associating them with the same words. When invoking the words, we invoke from memory the experiences that were imprinted by the same objects, so for all practical purposes, they are the same colors.
No - because, despite our identical physiologies in retinal receptors, the birth of ‘color’ is in the brain, and it is extremely unlikely that a certain color will produce exactly the same neuronal activations in 2 different brains. I assume there is a great deal of (systematic) randomness in the way information flows.
First, I think the optical nerve pathway performs some “hashing” due to the way the tissue has grown. Second, the neuronal activity itself has a chaotic component. Yes, once the representation of color in a given brain has formed it will stay that way, but the exact way it forms the first time is unpredictable due to the chaotic dynamics which make the system very sensitive to both minute variations in current input and to past context (bias). And yes, the activation will happen in the same visual areas of the cortex, but I am talking about the fine granularity SDR.
My point is that if you take from each brain the ‘blue’ SDR’s, the topological overlap between brains will be minimal. While the SDR’s are logically identical, they are hashed differently. “De-hashing” happens automatically through speech, and that is how 2 brains can agree they both see blue. But if we want to, let’s say, read an SDR from brain 1 and implant it into brain 2 by external (artificial) means, we need to know the hashing functions to perform the translation - and that might be a very difficult task. This issue might have implications to mind uploading.
I do not have evidence for the differences at fine granularity and if that is not so, please correct me. But we know at least that cortical neurons are not hardwired to color - a study on monkeys found that although their retinas have no ‘red’ receptors, after a gene mutation that converted some receptors to ‘red’ they started recognizing red objects.
Now, if we consider the conscious experience as a mystical soul possessing intelligence (which is a valid point of view, I’m not trying to put it down) then we can keep wondering about the question and especially about what is it exactly that we might “see” different in the same color?