Dear Dr. Behavior -- I went to the state fair in St. Paul last summer and ate three triple-decker pistachio ice cream cones, then went in the livestock barn, then ate four brats with sauerkraut and went on the tilt-a-whirl, then ate five cotton candies and went to machinery hill, and then I ate several bags of mini-donuts and went bungy jumping. Then when I got home, I was sick. I associated getting sick with the cotton candy. Why didn't I associate getting sick with everything else I ate, or with machinery hill? Why did I associate getting sick with just one thing, and why cotton candy? -- Just a typical day on The Midway.

Dear Midway -- Dr. Behavior is impressed that you made it home before you got sick. When we show Taste Aversion Learning, we tend to associate it with just one thing, and that one thing would be something we ate, not a place or some other non-gustatory CS. We are prepared to associate getting sick with something we ate. Also, while we should associate getting sick with the most recent thing we ate, according to the temporal contiguity theory of conditioning, we don't necessarily. What we do associate getting sick with is the most unique (in terms of our individual past history) thing we had eaten. Unique could be a few things -- one obvious one is the distinctiveness of the flavor; another is experience. Which one you would associate with getting sick might be different from what someone else would. I would probably associate the sauerkraut, since it has the most distinctive flavor (at least I think it does). But being the good Stearns County boy that you are, you have eaten lots of brats with sauerkraut in the past, so the cotton candy is most distinctive, so you associate cotton candy with getting sick. Martin Seligmann, one of the pioneer researchers in taste aversion learning, has called this selectivity of association the Sauce Bernaisse Phenomenon. As he was conducting research on taste aversion learning, he recalled that he once became ill after eating a steak that had this sauce on it, and he did not associate the steak with getting sick, only the sauce. Again, evoluntionarily speaking, it would make sense for organisms to be selected for associating uniqueness with getting sick, since the unique food would most likely be the one that made the organism sick. -- Dr. B.