Image via flickr
I always found it strange that Yonge Street is technically the centre of our city. It’s the dividing line between East and West – and in school they always told us proudly that it’s the longest street in the world. But for a road with that kind of credibility, it’s a surprisingly seedy place.
When you’re downtown on Yonge Street – between, say, Queen to the south and Bloor to the north – you’ve got enough head shops and basement stores selling fake IDs to supply years’ worth of illegal activity. If you spent your (hopefully not too awkward) adolescence in Toronto, you probably remember getting your Alberta or New Brunswick licence on Yonge, amid unfriendly tattoo parlours and gaudy tourist shops. And on the way, you’d pass Zanzibar or the Brass Rail – these weird multi-story buildings with big signs, which promised “totally nude female interactive dancing” or, perhaps more optimistically: “the girls never stop.”
Downtown Yonge Street is what comes to mind when I think about sex in this city. I remember gazing at the sassy bikini-clad ladies postered on the front of the Brass Rail as a kid, totally curious about what it was like inside, and always wondering whether I’d catch sight of someone actually going in. I always wondered what exactly they do in there. These days, I wonder what exactly is going on in their brains.
Our brains have a very specific, and not to mention fascinating, reaction to sex. There’s a lot going on before, during, and after sex, involving over thirty brain areas and a whack of hormones. At orgasm, for example, both men and women release the hormone oxytocin – a chemical that induces feelings of emotional bonding. So that post-coital cuddle is actually a natural biological reaction resulting from your oxytocin rush.
And oxytocin doesn’t only work its magic in humans. When you pet your dog, the oxytocin levels in your blood rise – both in you and your dog – increasing emotional bonding. In the prairie vole, too, oxytocin is a critical chemical released in the female brain that makes them monogamous with their partners. In the male brain, the neurotransmitter vasopressin is responsible for monogamous bonding. What’s interesting is that in a related rodent – the non-monogamous meadow vole – if you genetically engineer males to be more sensitive to vasopressin, they’ll actually form close pairs with their female partners. Essentially, they become monogamous because of a chemical.
But back to humans. At climax, apart from the hormones released, you see some very specific parts of the brain come into play. Building up to orgasm, you’ve revved up your somatosensory cortex (the grey matter that lets you feel stuff), and you’ve activated brain regions associated with memory, pleasure, and pain. The orgasm itself is a pain-killer. At orgasm, the anterior cingulate cortex (ACC) becomes strongly activated, and it’s an area that modulates pain and stress reactions. In fact, stimulating the ACC electrically tends to increase your cardiovascular activity– increasing blood pressure, heart rate, and other normal reactions to stress. Orgasms are generally not too stressful (one would hope), but our physiological reactions to stress happen to match our reaction to orgasm pretty damn well, and the ACC explains that.
But how do neuroscientists study orgasm in the first place? In general, they’ll have participants lie in an fMRI scanner (a machine that measures blood flow to different brain regions over time), while they either stimulate themselves or have a partner stimulate them. What’s interesting is that there are some discrepancies in the brain signatures between auto-erotic and partner-stimulated orgasm.
For example, the prefrontal cortex (the PFC; the forward-most part of your brain, and the area that deals with things like decision-making, personality, and self-awareness) lights up strongly at orgasm – but it seems this is the case only when participants stimulate themselves. Neuroscientist Dr. Barry Komisaruk believes this could be because the PFC is involved in the fantasizing, which many participants use to, uh, get themselves off.
As far as sex goes, it seems the PFC is also related to hypersexuality in men. That is, when men had lesions to their PFC, they got a lot hornier. Some researchers think that “turning off” the PFC is what leads to a sense of abandonment in sex. And in fact, scientists from the Netherlands have found that in participants who had their partners stimulate them while in the scanner, their PFC was actually deactivated.
Researchers are still wondering how the PFC, fantasies, and loss of control all add up when it comes to sex. When fantasies are involved, does the concentration required make it harder to feel that sense of abandonment? Or given the size of the PFC (it’s pretty big), could different parts of it be lighting up in specific ways to allow for the full experience?
Anyway, just something to think about next time you’re walking past the lit-up sign at Zanzibar on Yonge Street.