Conditioned drinking and its failure to extinguish: Avoidance, preparedness, or functional autonomy?

When a compound CS of a white box and 1-hr water deprivation were paired with the UCS of thirst caused by NaCl-procaine injections, male albino Sprague-Dawley rats increased drinking in the presence of the CS. Such conditioned drinking was under stimulus control and showed no sign of extinction across 55 sessions of unreinforced exposure to the CS. Preventing drinking in the presence of the CS produced a small but significant reduction of conditioned drinking. Drinking conditioned without the water deprivation element of the CS, rapidly extinguished. Ss seemed prepared to associate mild water deprivation with strong thirst. (18 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved).