Evidence for inhibitory associations between the unique elements of two compound flavours

In each of two experiments, rats were pre-exposed to two flavoured solution s, saline-lemon and sucrose-lemon. For group ALT, trials with one solution alternated with trials with the other. Group BLK received all trials with o ne solution in a block, before any trials with the other. An associative th eory suggests that the alternating, but not the blocked, schedule would est ablish an inhibitory association between sucrose and saline. To provide a r etardation test of this inhibition, some animals in each group were then gi ven a single pairing of saline and sucrose, experienced sodium depletion, a nd were finally tested for their consumption of sucrose. Sodium depletion i ncreased consumption of sucrose more in group BLK than in group ALT. In gro ups given no saline-sucrose pairing, sodium depletion had only a small effe ct on sucrose consumption, which was the same in both groups. After multipl e pairings of saline and sucrose, sodium depletion had an equally large eff ect on sucrose consumption in both ALT and BLK groups. These results imply that alternating pre-exposure to two compound solutions does establish an i nhibitory association between their unique elements, and thus provide suppo rt for an associative theory of perceptual learning.