Three classes of odorants were used: (1) Alcohol Odors (AO) were each subject’s two most frequently consumed alcoholic beverages, and were represented by the actual alcoholic drinks as “bubbled” (rendered volatile by passing an airstream through the liquid) in two of the olfactometer’s vials, (2) Non-Appetitive Odors (NApO; Grass and Leather International Flavors & Fragrances, Union Beach, NJ) to serve as control stimulation, and (3) Appetitive Control Odors (ApCO; hot chocolate and grape juice, McCormick & Company, Inc., Hunt Valley, MD) to serve as a second baseline reference that, like the AO, represented something comestible. Small, porous polyethylene discs (0.475 inches in diameter, 0.250 inches in thickness; Porex®, Fairburn, GA) were used to absorb the NApO and ApCO odorants, and then placed at the bottom of a glass vial, over which the olfactometer airstream passed before being delivered to the subject. After completing the imaging session, subjects left the scanner room and rated the intensity, pleasantness, and representativeness of the odors that were delivered during scanning on a linear 9-point visual analog scale.
