Well, no, but with things like this you sort of tend to assume that the basic structure of everyone's brain is pretty much the same, so it only takes n=1 to stu

Well, no, but with things like this you sort of tend to assume that the basic structure of everyone's brain is pretty much the same, so it only takes n=1 to stuff that you can pretty safely extrapolate to everyone. It would be a different matter if we expected an array of different brain mechanisms at the information-pathway level. Compare to how we do probably expect variation at, like, reasoning and emotional levels, maybe.