I've got a sort of "mind-reading" system involving interpretation of electric fields/impulses in the brain, basically an advanced BCI (brain-computer interface), but the key point of this system is that it's used across species, with this mind-reading being accessible across species and thus brain waves/brain fields almost being a sort of "universal language" in this regard. Now obviously every species would have different ways of perceiving some things in the world, so Species X would not have the same neural code for a color that they see differently from us, but the patterns in Species X's brain activity and in humans' brain activity would be the same for a color that we both can see in the same way; or perhaps, if both cultures have similar enough concepts of "shoes" with the same meaning, when thinking of a shoe the neural code representing the concept would be the same (or close).

How feasible is it to suggest, as this system does, that even across different planets the neural code representing info/input as electricity would be the same? Is there an infinite range of possibilities for it, or is there more or less only one "system" for representing sensory data through electricity when branching out over the course of evolution and natural selection from foundations of "input vs no input"? Or, basically: could I use a human's communication BCI on an alien?

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    $\begingroup$ It doesn't even work across different individuals of the same species. The interconnections between the neurons in the brain are not specified by the genetic code, they are developmental feature. They happen how they happen, both before birth and in life. You will not have two different individuals firing the same neurons when they read the phrase "convergent neural code". Even the same individual at different moments in their life will fire different neurons, for example because they have learned calculus and the word convergent has acquired new denotations and connotations. $\endgroup$
    – AlexP
    Sep 5, 2023 at 13:46
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    $\begingroup$ Not even all humans share functionally identical brain organization: eg. brain of someone with ADHD is wired a bit differently than a neurotypical brain, obviously not much but enough to be noticeable in brain scans. additudemag.com/… $\endgroup$ Sep 5, 2023 at 14:43
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    $\begingroup$ @JaniMiettinen You don't even need brain disorders. No two people have the exact same neural representation, for the same reason no two artificial neural networks (each trained from scratch) have the same weights, even if they have exactly the same connectivity. $\endgroup$
    – causative
    Sep 5, 2023 at 19:19

2 Answers 2


It is not feasible at all to suppose that when comparing a human's neurology to the physical and chemical processes that produce an alien's thought processes that they will in any way be similar. Where terrestrial animals use a sodium-gate depolarisation system for the operation of their neurons, an alien being might, for example, use a photo-emitter/waveguide/photoreceptor system for signal transmission, which is obviously so completely different that absolutely nothing is similar between the two. The alien system I've described here doesn't use electricity at all.

Since I can concieve of a system that doesn't use electricity, the answer is that it is not feasible. QED.

If we assume that the alien being does have an electrical-based process for transmitting signals, it still doesn't make sense to say that the encoding will be the same as a human's for equivalent stimuli. Signals on human nerves are based on frequency of pulses, not necessarily individual pulses. An alien 'neurology' may potentially invert the frequency concept with reduced rather than increased frequency being the 'signal', or it may literally use single pulses rather than trains of pulses.

Since I can concieve of a way that an alien's 'brain' might use electrical signals in a different way, again, it is not feasible to suggest that the two species systems are comparable or compatible. QED again.


the key point of this system is that it's used across species, with this mind-reading being accessible across species and thus brain waves/brain fields almost being a sort of "universal language" in this regard.

If you want this to be a feature of your setting, it's pretty much necessary that your various humans and aliens have a common origin. This implies that they were planted on their various home planets by some highly advanced species. This is a common SF trope, usually going by some name like "The Precursors" (warning: TV Tropes link).

You also have to ignore the problem that among humans, the development of the nervous system is only controlled in very general terms by genetics, implying that your BCI system would be specific to an individual. If you're doing either retro-SF or quite "soft" SF, this should not be a problem.


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