The researchers presented their findings at the Society for Neuroscience Annual Meeting, 2011, Washington D.C.
The video footage shows how brain activity develops during the crescendo period, the orgasm itself, and the recovery period. It shows how unrelated brain regions come to life, reach a climax of activity, and then settling back down again.
Lead researcher, Professor Barry Komisaruk, said:
"We're looking at the sequence of brain regions that get recruited at increasing intensity leading up to orgasm. It's such a compelling behavioral and sensory phenomenon with so many implications and so little understanding."
Nan Wise, 54, a sex therapist, who is a Rutgers PhD candidate, reached orgasm by self-stimulation. The researchers explained that every part of her brain was activated when she reached orgasm.
"When I first started grad school in '80s, we didn't have these methods. Now we can study how the brain is recruiting these regions to create the big bang of orgasm. Secondary to an epileptic seizure, there's no bigger brain networking event. It's a fantastic opportunity to examine the connectivity of the brain. Theoretically, it's going be helpful to know how things work. I think the caveat is understanding that sexuality is very complex."
In an interview with The Guardian newspaper, UK, Wise said, "It's my dissertation. I'm committed to it."
Prof. Komisaruk said they aim to find out what goes wrong in individuals of both sexes who fail to reach sexual orgasm.
The movie animation - consisting of a series of snapshots taken two seconds apart - shows how 80 different brain regions (40 on each laterality) respond. It uses colors to represent oxygen utilization levels in the brain, displayed on a spectrum from dark red, progressing to orange, yellow and finally white (highest level of activity). When orgasm is reached, nearly the entire brain becomes an illuminated yellow/white.
Early on in the movie, the genital area of the sensory cortex becomes active first - what the researchers say is a response to being touched in the genital area. Then the limbic system comes into action - this part of the brain is involved in long-term memory and emotions.
When the orgasm is about to arrive, the cerebellum and the frontal cortex become much more active - Komisaruk says this is due to muscle tension.
Activity reaches a peak in the hypothalamus during orgasm - oxytocin is released, a pleasure-inducing chemical that makes the uterus contract. The nucleus accumbens, a region in the brain linked to pleasure and reward, also becomes very active.
After the orgasm subsides, so does activity in all the stimulated brain regions.
Komisaruk has developed a technique whereby the individual being scanned can see his/her own brain activity on a monitor, providing neurofeedback. The team aims to help people learn how to alter their brain activity, and perhaps eventually improve their symptoms related to pain, depression and anxiety.
"We're using orgasm as a way of producing pleasure. If we can learn how to activate the pleasure regions of the brain then that could have wider applications."
Written by Christian Nordqvist