Can we conflate it with high functioning autism if we consider Star trek's Spock to be the ultimate rationalist?

No. Spock is an awful rationalist. He a) doesn't acknowledge his emotions when they exist b) repeatedly makes probability estimates of things being very unlikely that turn out to be wrong c) claims that actors are acting irrationally when they aren't (or when they just disagree with his values). In fact, Spock is the original Straw Vulcan (which incidentally lists many more problems with Spock).