Decremental carryover effects of sucrose ingestion in the negative anticipatory contrast procedure in rats.

To test for retrospective effects of sucrose ingestion in the anticipatory contrast procedure, 4 experiments examined intake of an initial 0.15% saccharin solution as a function of the unsignaled interspersing of days in which the 2nd solution was 32% sucrose or 0.15% saccharin. In Experiment 1, rats that received alternating saccharin-saccharin days and saccharin-sucrose days drank less saccharin on saccharin-only days, and on both days they drank less saccharin than a control group that received saccharin only. In Experiment 2, rats that received randomized saccharin-saccharin and saccharin-sucrose days drank less saccharin if, and only if, a sucrose day preceded. Experiments 3 and 4 used double and quadruple alternation of saccharin and sucrose days to examine persistence of the effects of a sucrose day. The results highlighted a retrospective carryover effect of sucrose that reduced intake of the initial saccharin solution and apparently was based on sucrose memories persisting over days.