Effects of expectancies of different reward magnitudes in transfer from noncontingent pairings to instrumental performance

In two experiments, rats received noncontingent pairings of two stimuli with food reward, one paired with small reward and the other with large reward, and received bar press training with large reward or with small reward. When the noncontingent stimuli (NS) were presented for test during subsequent rewarded bar pressing and during early extinction of bar pressing, responding for each group was faster in the presence of the NS which was paired with the same reward magnitude that group received in bar press training than to the NS which had been paired with a different reward magnitude. As extinction progressed, all groups responded more slowly in the presence of the NS which had been paired with the large reward than in the presence of the NS which had been paired with small reward. These results were interpreted as indicating that responding in the presence of an NS depends on: (i) whether the reward expectancy elicited by the NS has been conditioned to the instrumental response, and (ii) the relationship between the reward expected in the presence of the NS and that received in test.