INVESTIGATION OF THE DEVALUATION INTERPRETATION OF ANTICIPATORY NEGATIVE CONTRAST

Rats suppress intake of an acceptable substance (e.g., 0.15% saccharin ) when it is followed by a preferred substance (e.g., 32% sucrose) in once per day pairings. The role of a learned devaluation of the initia l solution in suppressed intake (anticipatory negative contrast) was i nvestigated. The findings included the following: (a) Flavors or odors as within-subject cues precluded the occurrence of anticipatory contr ast, conditioning flavor and odor preferences instead, which appeared to antagonize suppressed intake. (b) Anticipatory contrast was obtaine d when within-subject context cues, temporal alternation cues, or drin king-spout cues were used. (c) Preference tests conducted with the spo ut cues showed that devaluation of the initial substance was not neces sary for the occurrence of negative anticipatory contrast.