The whole River storyline is intentionally left hazy and mysterious, but I believe it is at least strongly implied that her psychic-like talents are created, not augmented. She was a genius and prodigy before the Alliance got ahold of her, but this manifested as an ability to learn things instantly, not as any sort of mind-reading. And as far as I recall, we never meet anyone else who is supposed to be psychic.
ETA: In the episode "Objects in Space", at one point the characters discuss River's abilities. When the subject of mind-reading is brought up, Wash asks, "Is that even possible?" So it seems definite that as far as the characters know, there are no natural psychics in their universe.