Conditioning of stimuli with nonzero initial value

In five experiments, rats received conditioning of either moderately attractive or moderately aversive flavors using either a strongly negative lithium chloride (LiCl) or a strongly positive Polycose as the reinforcer. In each case, testing was done with a compound of the two moderately valued stimuli to determine the amount of associative change produced by the pairing. In both within-subject and between-subjects designs, the amount of associative change was greater for a signal whose moderate value was opposite in valence from that of the reinforcer. This suggests that, like learned stimulus value, inherent stimulus value can modulate further associative learning.