After a study of the brain researchers have concluded that women have two pathways to sexual pleasure.
Researchers from Rutgers University in New Jersey used brain scanners to look at which parts of a woman's brain become active when they are aroused.
They found one of the 'pathways' is activated when a woman is alone and fantasising, while the other gets charged when she is physically stimulated by a lover, reports the Daily Mail.
The research team, led by Barry Komisaruk from Rutgers, analysed MRI scans of women reaching climax to investigate the role of imagination and 'top-down control' in triggering a physiological response.
They found heightened activity in more than 30 parts of the brain, including the prefrontal cortex, an area which controls functions such as decision-making, controlling urges and imagination.
In contrast, when scientists observed women being stimulated by a partner, they found that the same brain region had 'switched off' during orgasm.
"It is possible there is a difference between someone trying to mentalise sexual stimulation as opposed to receiving it from a partner," said Janniko Georgiadis of the University of Groningen in Holland.
This suggests that an orgasm is achieved with a partner when the woman 'lets go' and reaches an 'altered state of consciousness'.
The study also concludes that an inability to do this may prevent women from reaching their climax.
The study has been published in the New Scientist.