Clue to attraction that is sexual in lesbian brain


Clue to attraction that is sexual in lesbian brain

Lesbian and women that are heterosexual differently to certain individual odours, a brain-scanning research has found. The homosexual ladies revealed brain that is similar to heterosexual guys once they inhaled specific chemical compounds, that might be pheromones, the scientists state.

“But our research can’t answer questions of cause and effect, ” cautions lead researcher Ivanka Savic during the Karolinska Institute in Stockholm, Sweden. “We can’t state perhaps the distinctions are due to pre-existing variations in their minds, or if past intimate experiences have conditioned their minds to react differently. ”

Savic and her peers asked 12 lesbian ladies and 12 heterosexual ladies to breathe focused samples of two steroids: EST, which can be produced from oestrogen and discovered within the urine of expectant mothers; and plus, that is produced from progesterone and discovered in men’s armpit sweat.

Positron emission tomography (animal) scans revealed which areas of the women’s brains answered to every chemical. Once the heterosexual females smelled AND their brains showed activity into the anterior hypothalamus, an area associated with mind considered to process intimate cues. But EST just produced activity when you look at the olfactory area of the minds, the area that processes smells.


The lesbians, but, just revealed task into the region that is olfactory odour they smelled.

Intimate choice

The scientists conclude that these “pheromone-like stimuli” create various reactions when you look at the anterior hypothalamus of females of various intimate orientations, and therefore their research supports the concept that the anterior hypothalamus plays a part in sexual choice.

The pattern of task into the minds of lesbians both for chemical compounds ended up being comparable – though perhaps perhaps not identical – to your pattern for heterosexual guys. In-may 2005, the exact same team revealed that the minds of heterosexual ladies and homosexual males reacted in identical methods once they smelled either plus or EST.

Nevertheless, George Preti and Charles Wysocki, that have done associated research in the Monell Chemical Senses Center in Philadelphia, Pennsylvania, United States, involve some criticisms for the study that is new. They told New Scientist that the researchers that are swedish past an acceptable limit by implying that the 2 chemicals they utilized are pheromone-like. “Although they’re calling them putative pheromones, here really is not any strong proof in the biomedical literary works why these compounds are pheromones, ” Wysocki claims. In reality, professionals debate whether individual intercourse pheromones occur after all. Humans do have other forms of pheromones: chemical substances we discharge once we are frightened, or that enable a mother to recognize her infant by odor, or that cause female roommates’ menstrual cycles to synchronise.

Inconclusive proof

Circumstantial proof implies that people likewise have intercourse pheromones and thus researchers into the field are available to the likelihood, Savic states. But up to now, Wysocki records, no research has conclusively shown the presence of pheromones that influence people’s sexual behavior.

Minimal is known about EST, the chemical produced by oestrogen. Evidence that the 2nd, progesterone-derived substance may be an intercourse pheromone is more powerful, Savic claims. But that it is also present in the sweat of women, making its role as a sexual attractant for heterosexual women uncertain while it is found in men’s sweat, Preti notes.

He additionally highlights that the scientists used the purified, crystalline types of those two chemical substances, making them roughly a million times more concentrated than when they’re produced obviously because of the human anatomy. Better levels will often cause not simply a more powerful reaction, but a totally various one.

Savic admits that it was an issue and states she along with her peers aspire to execute a study that is future natural concentrations regarding the chemical substances. The scientists agree that mapping these differences in brain activity between heterosexual and homosexual women is an important step towards understanding how sexual orientation manifests in the brain despite these issues.

The paper seems within the edition that is online of procedures for the National Academy of Sciences.

Journal reference: PNAS (DOI: 10.1073/pnas. 0600331103)