The Sexual Allure of Chanel No. 5

Does olfactory stimulation influence sexual responsiveness in humans? More specifically, does the scent of a woman's perfume produce sexual arousal in men? If so, what are the neural correlates of this response? The answers, of course, are of great interest to the manufacturers of perfumes and fragrances, a $5 billion retail industry.

A group of Korean researchers (Huh et al., 2008) conducted a small fMRI study in 8 male subjects to examine these questions. What was the arousing fragrance, need you ask?¹ According to MTV3.fi [as far as I can tell, since the article is in Finnish], it appears that the researchers used iconic perfume Chanel No. 5 as their olfactory stimulus:

Osa naisista käyttää hajuvettä oman itsensä vuoksi. On yksinkertaisesti miellyttävää tuoksua hyvälle. Toisaalta tietoisuus siitä, että on hyvätuoksuinen, lisää itsetuntoa. Hajusteilla pyritään tekemään myös positiivinen vaikutus vastakkaiseen sukupuoleen. Onko hajusteilla kuitenkaan moista voimaa, vai onko niiden teho lähinnä plasebon luokkaa? Vaikuttavatko hajusteet ainoastaan käyttäjänsä mielikuviin, vai onko niillä todellista tehoa? Moisiin kysymyksiin halusivat saada selon muun muassa korealaisen Chonnamin yliopiston tutkijat Joon Huh ja Kwangsung Park.

Tutkimukseen osallistui kahdeksan 20–35-vuotiasta miestä. He haistoivat kaksi kertaa 30 sekunnin ajan naisten hajuvettä. Haisteluiden välillä oli 30 sekunnin mittainen tauko. Haistelusessioiden jälkeen koehenkilöiden aivoista otettiin magneettikuvat, jotta nähtäisiin, mitkä aivojen kohdat reagoivat hajuveden haistamiseen. Magneettikuvauksen jälkeen miesten tuli listata mielipiteensä hajuveden voimakkuudesta ja siitä, miten hajuvesi vaikutti heihin seksuaalisesti. Testissä käytetty hajuvesi oli muuten Chanel No. 5 joten nyt näemme, onko esimerkiksi Marilyn Monroen suosimasta tuoksusta mihinkään.

The fMRI study used a block design of alternating 30 sec intervals of olfactory stimulation and rest (Huh et al., 2008) . After the scanning session, subjects rated their perceived sexual arousal and the odor's intensity. Two of the eight subjects reported "strong" sexual arousal, three reported "moderate" sexual arousal, and three were presumably not aroused while smelling Chanel No. 5. The imaging results demonstrated that

The common brain areas activated in response to the odor stimulus in all eight subjects included the insula, the inferior and middle frontal gyrus, and the hypothalamus. The median [sic] cingulate gyrus, thalamus, angular gyrus, lingual gyrus, and cerebellar cortex were activated in subjects who had moderate or strong sexual arousal response.

Huh, so why were portions of the parietal and occipital lobes activated by an olfactory stimulus? I don't know the authors' interpretation, but one speculation for the latter is that the perfume might have triggered some visual associations, perhaps with an ad campaign or a specific person.

However, these results are very preliminary, given the small number of subjects (and the paltry numbers at each level of sexual arousal).

Who funded this research? IDK yet. But interestingly, Korea is a leader in olfactory branding:

Presidential Candidate Lures In Voters with Great Korea Perfume

In Korea, presidential front-runner Lee Myung Bak must have a keen nose and believe in the powers of olfaction like no other since his campaign staff has decided to implement a very unusual strategy for "branding" the candidate's image. Drawing on marketing experience and department-stores' olfactory branding of which Korea is an early practitioner, the idea has been taken a step further by attempting to associate feelings of "hope, victory, passion" with a perfume called Great Korea that was secretly sprayed at public gatherings and will be again sprayed when voters enter the polling booths. ...

The semi-covert operation called "The Perfume of the President" has a Big-Brother flavor to it and seemed not long ago to be safely relegated to the realm of science-fiction but its has been conducted for real since the beginnings of the presidential campaign and will be ultimately tested on December 19, 2007 when voters make their ways to the voting urns. Lee Myung-Bak has already a 30-point advance in the polls.

Maybe the next fMRI study will examine the brain activity elicited by Great Korea perfume...

Footnote

¹ I didn't have access to the entire article in the Journal of Sexual Medicine and was therefore reliant on other sources.

Reference

Huh J, Park K, Hwang IS, Jung SI, Kim H-J, Chung T-W, Jeong G-W. (2008). Brain activation areas of sexual arousal with olfactory stimulation in men: A preliminary study using functional MRI. J Sex Med., in press.

Introduction. There have been extensive studies evaluating the functional neuroanatomy of the brain during visual sexual stimulation. However, little data exist concerning the role of olfactory stimulation in human sexuality.
Aim. This preliminary study intended to elucidate the brain areas responding to an olfactory sexual stimulus using functional magnetic resonance imaging (fMRI).
Methods. Eight healthy right-handed heterosexual male volunteers (20–35 years of age), having normal olfaction and no brain diseases, were recruited. During fMRI, a women's perfume was given as an olfactory sexual stimulant in an alternating block design with a 30-second stimulation period followed by a 30-second rest. After the fMRI sessions, the participants provided ratings for both the odorant's intensity and perceived arousal.
Main Outcome Measures. The study subjects rated the odorant stimulation and perceived sexual arousal response by Likert-type rating scales. Brain activation maps were made by blood oxygenation level-dependent (BOLD)-based fMRI with an echo-planar imaging pulse sequence.
Results. Two out of eight subjects experienced "strong" sexual arousal, and three subjects experienced "moderate" arousal during olfactory stimulation, resulting in a mean score of 2.25 on a 4-point scale. The common brain areas activated in response to the odor stimulus in all eight subjects included the insula, the inferior and middle frontal gyrus, and the hypothalamus. The median cingulate gyrus, thalamus, angular gyrus, lingual gyrus, and cerebellar cortex were activated in subjects who had moderate or strong sexual arousal response.
Conclusion. Olfactory stimulation with women's perfume produces the activation of specific brain areas in men. The brain areas activated differed according to the degree of perceived sexual arousal response. Further studies are needed to elucidate brain activation response according to the different kinds and intensities of olfactory stimulation.