Sit up and smell the roses better: olfactory sensitivity to phenyl ethyl alcohol is dependent on body position.

Previous studies have demonstrated that body position can alter auditory sensitivity. Here we demonstrate for the first time that olfactory sensitivity for the commonly used odor phenyl ethyl alcohol (PEA) (rose odor) is also dependent on body position. By using successive dilutions presented in a staircase protocol, we determined olfactory thresholds for PEA in 36 healthy participants (18 women) in both an upright and a supine position. Participants had a significantly greater olfactory sensitivity when tested in an upright than a supine position, with no significant differences between the sexes. This preliminary study sets the stage for further work on the interaction between olfactory functions and our biology. The implications for olfactory neuroimaging studies are discussed.