THE EFFECTS OF ISOLATION-REARING ON SUCROSE CONSUMPTION IN RATS

Three experiments examined the hypothesis that social isolation of wea nling rats potentiates hedonic processes by examining the consumption of sucrose solutions. In the first experiment no differences in consum ption were found between socially reared rats and isolation-reared rat s allowed to consume sucrose in a familiar test apparatus. In a second experiment socially-reared rats and isolation-reared rats were food a nd water deprived. Again, no differences in consumption were found. Ln a third experiment socially reared and isolation-reared rats were all owed to consume sucrose presented in either an ascending or descending order of concentration. When given sucrose in an ascending order of p resentation isolation-reared rats consumed significantly more sucrose than socially reared rats. This suggests that isolation-rearing increa sed the effects of positive contrast, and is consistent with other obs ervations of increased incentive motivation in isolates. (C) Elsevier Science Inc.