"Wanting" what was never "liked"

Work from Berridge and collaborators shows in rat experiments that pathways in the ventral pallidum that fire when a cue to a previously liked stimulus (such as sucrose) is presented - but do not fire with a cue of the previously "disliked" taste of intense salt - can suddenly become activated if the salt cue is encountered in a never-before-experienced state of physiological salt depletion. This means that dynamic recomputation of cue-triggered "wanting" signals can occur in real time at the moment of cue re-encounter by combining a previously learned Pavlovian associations with novel physiological information about a current state of specific appetite.