Figure 2.
Schematic drawing of the PET procedure: First, under endoscopic control, the patch was placed either on the VNO (VNO occluded) or on the lateral nasal wall (VNO open). Then, after injection of H2O15, subjects were instructed to sniff for 3 s, during which the odor (CON, AND or, in the baseline condition, a blank) was presented by holding a bottle under their nose. Then subjects were instructed to exhale for 5 s, after which the next stimulation cycle began. The whole stimulation period lasted 60 s. After this, subjects rated the odors with regard to intensity, pleasantness, and familiarity.