Individuals rated odourant stimulation and perceived sexual arousal. They also had functional MRI scans taken during the experiment. The results showed that olfactory stimulation with women's perfume produces activation of specific brain areas associated with sexual arousal in men.[10] Another study found that homosexual men displayed similar hypothalamic activation to that of heterosexual women when smelling a testosterone derivate present in male sweat, suggesting that sexual orientation plays a role in how humans experience olfactory sexual stimulation.[11]