The notable outcome of this experiment was the dramatic difference between control and experimental rats in goal speeds on the denatonium trials.
1990, Experiment 2), the following relations were established between odors and goal events: R odor signaled absence of water; N odor signaled water; and A odor signaled aversively conditioned denatonium saccharide.
If the odor deposited on denatonium trials was different from that deposited on non rewarded trials, then the rats should show discriminative responding of fast approach in the presence of N odor and slow approach in the presence of A odor.
In three experiments, Batsell (1989), using the technique schematized in Figure 2, consistently found denatonium introduced into a runway goal box could substantially suppress approach speed of subsequent rats.
Rats serving as odor donors were first given aversive conditioning to denatonium and then runway discrimination training to reward, nonreward, and denatonium goal events in the manner described above for the Batsell et al.
In the present experiment, three groups of rats were given 10-min access to 10 ml of denatonium prior to injection with LiCI Group DEN received only the denatonium taste in the water, Group A-DEN received denatonium in the presence of A odor, and Group AL-DEN received denatonium in the presence of a 1% almond odor.