After orgasm, activity in the hypothalamus and nucleus accumbens gradually calms down. Illustration: Corbis
Scientists have used brain scan images to create the world's first movie of the female brain as it approaches, experiences and recovers from an orgasm. The animation reveals the steady buildup of activity in the brain as disparate regions flicker into life and then come together in a crescendo of activity before gently settling back down again.
To make the animation, researchers monitored a woman's brain as she lay in a functional magnetic resonance imaging (fMRI) scanner and stimulated herself. The research will help scientists to understand how the brain conducts the symphony of activity that leads to sexual climax in a woman.
By studying people who have orgasms, Professor Barry Komisaruk, a psychologist at Rutgers University in New Jersey and his team hope to uncover what goes wrong in both men and women who cannot reach sexual climax.
The animation was compiled from sequential brain scans of Nan Wise, a 54-year-old PhD student and sex therapist in Komisaruk's lab. "It's my dissertation," Wise told the Guardian. "I'm committed to it."
fMRI images of a woman's brain as she experiences an orgasm. Oxygen levels in the blood correspond to the activity of different brain regions and are represented here on a spectrum from dark red (lowest) to yellow/white (highest). Twenty snapshots of the data have been taken from a 12-minute sequence during which she approaches orgasm, achieves orgasm and then enters a refractory period. Video: TheVisualMD.com
The five-minute movie shows how activity changes across 80 separate regions of the brain in snapshots taken every two seconds. The animation uses a "hot metal" colour scale that begins at dark red and progresses through orange and yellow to white at the highest levels of activity.
"The general aim of this research is to understand how the orgasm builds up from genital stimulation and what parts of the brain become recruited and finally build up into an orgasm," said Prof Komisaruk, who presented the work at the Society for Neuroscience annual meeting in Washington DC on Monday. The work has yet to be published in a peer-reviewed journal.
As the animation plays, activity first builds up in the genital area of the sensory cortex, a response to being touched in that region. Activity then spreads to the limbic system, a collection of brain structures involved in emotions and long-term memory.
As the orgasm arrives, activity shoots up in two parts of the brain called the cerebellum and the frontal cortex, perhaps because of greater muscle tension. During orgasm, activity reaches a peak in the hypothalamus, which releases a chemical called oxytocin that causes pleasurable sensations and stimulates the uterus to contract. Activity also peaks in the nucleus accumbens, an area linked to reward and pleasure.
After orgasm, the activity in all these regions gradually calms down.
"It's a beautiful system in which to study the brain's connectivity," Komisaruk said. "We expect that this movie, a dynamic representation of the gradual buildup of brain activity to a climax, followed by resolution, will facilitate our understanding of pathological conditions such as anorgasmia by emphasising where in the brain the sequential process breaks down."
In a new technique being developed by Komisaruk, people inside the scanner can see their own brain activity on a screen almost instantaneously. Through this "neurobiofeedback", Komisaruk speculates that people might be able to learn how to change their brain activity, a feat that could perhaps help treat a broad range of conditions, such as anxiety, depression and pain.
"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," he said.