Value transfer across odor stimuli using probability of reinforcement in the rat.

In a series of experiments value transfer across odor stimuli using probability of reinforcement was demonstrated in rats. Rats were trained with the following pairs of simple simultaneous discriminations A(100) B(0) and C(50) D(0) where the letter represents a particular scent mixed with sand presented in a cup and the number in parentheses represents the probability of reinforcement given that the rats dug to the bottom of the cup. In test, the rats were confronted with a choice between the B and D stimuli and (in experiments 2 and 3) the rats preferred to dig in the B stimulus providing evidence for value transfer using procedures similar to those that have been used in the pigeon literature.