The vomeronasal organ (sex nose), which detects pheromones, the scent essential for mating, is the only sense with a direct link to the limbic system. Nonsexual smell organs reach the limbic system only after they’re passed through the higher centers. Thus, they are under greater control. (Howard, Pierce J., PhD. The Owner’s Manual for the Brain. p 712-713. GA: Bard Press, 1994, 2000.)