A psychic bond was a long held belief among Vulcans that thoughts, feelings and images could be shared with another after they mated. In December 2154, T'Pol told Charles Tucker III that, as a result of their becoming intimate a year previously, they shared a psychic bond which explained why they saw each other in daydreams they had. The bond also made Tucker immune to the effects of Orion slave girls Enterprise NX-01 was carrying on board at the time due to T'Pol's Vulcan physiology. (ENT: "Affliction", "Bound")