Double drive learning in rats without previous selective reinforcement

Can rats which have never been selectively satiated by food or water respond appropriately by choosing the relevant reward when they are made hungry or thirsty ? A group of 21 rats was put on a diet of wet mash and trained both hungry and thirsty in a T-maze with water on one side and food on the other. 8 out of 10 of the animals which were made thirsty on the test-run chose correctly in spite of an established preference for the other reward. Only 1 out of the 11 animals made hungry chose correctly. Possible explanations of this result are examined.