As a researcher who helped to identify the G-spot and female ejaculation, Dr Beverly Whipple transformed how we understand women, sex and pleasure.

“With my life and my research I have focused on validating the pleasurable, sensual, and sexual experiences that women report,” she tells The Independent.

Dr Whipple started her career decades ago as a nurse, teaching women how to perform kegel exercises to strengthen their pelvic floor muscles and prevent them from going under the knife too treat urinary incontinence. But some women, she found, had very strong pelvic floor muslces but reported that they only lost fluid through the urethra – or the pee hole - during sexual activity. And that is how she discovered that women can ejaculate.

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“The fluid was like watered down fat-free milk, it was about a teaspoon or about 3 to 5cml in volume, and it tasted sweet and it didn’t look or smell like urine,” she explained. This lead her to the research of scientist Ernst Gräfenberg, who in the Fifties described how a sensitive area inside the vagina produced a fluid when it was stimulated. A study of 400 different women looking for an area of sensitivity found that all of them had a sensitive area between 11 o’clock and 1 o’clock at the top of the vagina which swells when a woman is aroused.

Stimulating this area seemed to trigger the fluid in women who thought they were incontinent, but had full control of their bladders. That area is, of course, what is now known as the G-spot. The The G-Spot and Other Recent Discoveries About Human Sexuality book based on that research was revolutionary, and changed what we know about female sexuality and anatomy. The 1982 text, co-authored by researchers Alice Kahn Ladas and John D Perry, since become a classic published in 22 languages.

Recalling when she appeared on TV to discuss her findings, she says: “We talked about this sensitive area and the female ejaculation and I got 5,000 letters from women thanking me for helping them feel normal.”

The Independent spoke to Dr Whipple about what her decades of work into sexual health have revealed about women’s bodies.

Orgasms can block pain

Working with psychologist Dr Barry Komisaruk at Rutgers University, Dr Whipple found that orgasms double a woman’s pain thresholds. In a further study they discovered that during labour, the baby passes through the birth canal and past the g-spot causing sensitivity to pain to drop. Without this, they believe, childbirth might be even more painful.

Asked what defines an orgasm, Dr Whipple explains: “The definition of orgasm is what a woman says is an orgasm. When we measure orgasms we see a signifcant increase in heart rate, blood pressure, diameter of the pupil, and in pain thresholds. Those are the major physiological measurements that we have made."

Women can reach orgasms using their imaginations

While writing a book about women and HIV infections in the 1980s, Dr Whipple was invited to join the faculty at Rutgers College in New York where she aws given a large grant to build a human physiology laboratory to continue her research.

There, she investigated reports that some women could reach orgasm using their imaginations by not being touched. Researchers tested this by measuring the size of women’s pupils, blood pressure and heart rate during orgasm from their imagination and from being stimulated manually in the G-spot. MRA scans later proved that the same areas of the brain are activated.

“We can also see in the brain what area women are stimulating because in the pre-frontal cortex you can tell if they're stimulating the clitoris, the vagina, the cervix or a nipple,” she says.

Women can reach orgasms from any erogenous zones

Working with sex therapist Gina Ogden, Dr Whipple pieced together what they coined the extra-genital matrix. This maps out the 15 types of touch across 35 body parts that can lead to orgasm, from the vagina to the nipple.

But most people don’t find them because it takes longer than clitoral or vaginal stimulation, Dr Whipple explains.

"The whole point is to help women to realise that what they find pleasurable, sensually and sexually is what they should enjoy and not feel that they have to fit into one model of only one way to respond. We have to give women the permission to enjoy what they enjoy. It is all very individual and it's all normal," she stresses.

Blended orgasms exist

By exploring the extra-genital matrix, women can experience what Dr Whipple describes as ‘blended orgasms’.

“Women can have stimulation of more than one area of the body at the same time, and experience orgasm where you are stimulating more than one nerve pathway. That might involve clitoral and vaginal stimulation," she says.

Sex doesn't have to be "goal-orientated"

“When I talk about sexual experiences and goal orientated I use the analogy of the stair case, where each step leads to the next step,” explains Dr Whipple.

“It starts with a touch, a kiss, and the penetration of the vagina is the top step. If people who are goal orientated don’t reach that top step don’t feel very good about the whole process.

“Whereas, I look at the analogy of the circle where any behaviour on the perimeter of that circle, whether its holding hands cuddling kissing oral sex whatever, is it an end in itself and it doesn't have to lead to something else.

Dr Whipple argues that by moving away from an vaginal orgasm being the main focus of sex, different types of pleasure can be appreciate on an equal footing.

"When you use the words 'reach' or 'achieve' you’re setting up orgasm as a goal, if you use 'experience' it happens but it doesn't have to be the goal.