Can simultaneous incentive contrast be produced by the pharmacological effects of alcohol?

Three groups, each consisting of 10 female albino rats, were run in an experiment that tested for simultaneous incentive contrast effects by varying the alcohol content of fluids consumed prior to conditioning trials. All groups received five food pellets as reward in the runway. One control group drank an alcoholic fluid, and the second control group drank a nonalcoholic fluid. The experimental group drank the alcoholic fluid on some days and the nonalcoholic fluid on alternate days. Comparison of the appropriate experimental and control conditions revealed no positive contrast effect and only a marginal negative contrast effect in goal speeds.