Can orally consumed calories condition preferences for relatively unacceptable tastes?

A reverse-order differential conditioning procedure adapted from Boakes and Lubart (1988) was employed in an attempt to condition preferences to relat ively unacceptable tastes in rats. Rats received 10 mi of a calorific reinf orcer, which after a short delay was followed by one taste cue, either citr ic acid or sucrose octaacetate (both were mixed in water), and 10 mi of wat er followed by the other taste cue. During subsequent two-bottle tests, the se animals failed to show a preference for the taste that had been paired w ith the calorific reinforcer relative to the taste that had been paired wit h water. When the same reverse-order procedure was employed using taste cue s which were mixed in saccharin rather than water, rats acquired a signific ant preference for the CS+ mixture regardless of whether they were water re stricted or not. These results suggest that without the presence of sacchar in in the CS solutions, rats do not acquire conditioned preferences for rel atively unacceptable tastes. (C) 2000 Academic Press.