For the 40 percent of women who’ve had one, an orgasm in a dream is often more intense that one in real life. And it’s not just a dream — a nocturnal orgasm is a real physiological phenomenon. The dreamer awakens to the same pulsing sensations she’d have during an orgasm from masturbation or sex. Her heart rate surges, her breathing deepens, her vaginal blood flow increases. Her orgasm might even be so fierce that she cramps up as she transitions from dream to reality.

Why?

A few studies shed some light:

1. During REM, the relative pulse pressure in the vagina increases. This also happens to a man’s penis, resulting in nocturnal emissions and morning erections. The content of the dream doesn’t appear to affect genital pulse — after all, it increases every time you sleep — but the physical sensation may influence your dreams (no one knows for sure). At the same time, the parts of the brain that inhibit orgasm, particularity the prefrontal cortex and amygdala, are offline when you’re asleep. (Readers of BLONDES might recall that the left amygdala, associated with anxiety, and the prefrontal correct are quiet during orgasm.)

2. Female orgasm can result from brain activity alone — “no hands.” Evidence of this comes from the research of Beverley Whipple, who studied women who reach orgasm via “self-induced imagery” (i.e. fantasy) alone. Volunteers’ blood pressure, heart rate, pupil size, pain threshold, and so on increase as they reach climax, their hands nowhere near their genitals.

As speculated by Whipple ( see also her research on paralyzed women), a “hands-off” orgasm may channel the vagus nerve, which is like a livewire that extends from the brain to the cervix via the heart, lungs, and other organs. Not every orgasm strums it — but, like hitting the right chord, a vagus nerve climax is said to be richer and more fulfilling. Some women think they can even feel it surge through their bodies from their brainstems. (See previous blog about asphyxiophiliacs.) It’s interesting: Vagus nerve activity might be one reason why so many women say their nocturnal orgasms are so much stronger than their diurnal ones.

Only in their dreams….