Sexual Chemosensory Cues
Wen Zhou & Denise Chen speculated that if humans produce and respond to sweat pheromones, then a woman should respond to a guy’s sweat when sexually aroused differently than she does to his normal sweat.
The researchers asked 20 heterosexual guys to put pads in their armpits as they watched pornographic videos and became aroused (verified by electrodes). Later, they collected the sweat they produced when they weren’t aroused. (See “Encoding Human Sexual Chemosensory Cues in the Orbitofrontal and Fusiform Cortices“)
The researchers then recruited 19 women to smell the men’s pads while undergoing (fMRI) brain scans. The sexual sweat, but not the normal sweat, activated the right orbitofrontal cortex and the right fusiform cortex, brain areas that help us recognize emotions and perceive things, respectively. Both regions are in the right hemisphere, which is generally involved in smell, social response, and emotion.