Simultaneous incentive contrast effects with alcoholic and nonalcoholic beverages as the discriminanda for reward magnitude

Alcoholic and nonalcoholic beverages consumed by 40 female Sprague-Dawley rats prior to runway conditioning trials served as cues for reward magnitude. Learning under the alcoholic (but not the nonalcoholic) cue condition appeared to be state dependent. Under both conditions, a simple effect for reward magnitude occurred, but positive and negative incentive contrast effects occurred under only the alcoholic condition. The symmetrical contrast effects seem consistent with the view that alcohol enhances positive states rather than reduces negative ones.