Male subjects who could not perceive the pheromone 5a-androst-16-en-3-one, produced similar orbitofrontal changes on PET compared with perceptible phenylethyl alcohol (rose).
BACKGROUND
The aim of this study was to evaluate in how far cerebral blood flow changes in male subjects when exposed to a pheromone that they cannot consciously smell.


METHODS
We used a boar taint steroid (5a-Androst-16-en-3-one), which is similar to human axillary sweat but could not be detected by the human volunteers who participated in this study.


RESULTS
The pheromone produced activation of the orbitofrontal and frontal cortex in comparison to a baseline condition. The same regions were activated when the subjects smelled a rose-like odour.


CONCLUSIONS
This study shows that a pheromone, which is not consciously detected, can evoke a response in the brain that is similar to a detectable odour.
Treyer
Valerie
V
PET Center, Division of Nuclear Medicine, University Hospital, CH-8091 Zürich, Switzerland. Valerie.Treyer@usz.ch
Koch
Heinz
H
Briner
Hans Rudolf
HR
Jones
Nick S
NS
Buck
Alfred
A
Simmen
Daniel B
DB
D000328:Adult; D000737:Androstenols; D000818:Animals; D002540:Cerebral Cortex / Q000098:blood supply*; D002560:Cerebrovascular Circulation; D006801:Humans; D008297:Male; D009812:Odorants; D009830:Olfactory Bulb / Q000098:blood supply*; D010626:Phenylethyl Alcohol; D010675:Pheromones; D013552:Swine; D014055:Tomography, Emission-Computed
D000737:Androstenols; D010675:Pheromones; D010626:Phenylethyl Alcohol