Lifelong premature ejaculation (LPE) is a common male sexual dysfunction with a high prevalence in global. Up to now, the etiology of LPE remains unclear. In recent years, dapoxetine, a highly potent serotonin-transporter inhibitor, has been used for treating premature ejaculation. However, the underlying mechanism of dapoxetine was unknown. Recently, with widespread use of neuroimaging techniques, like positron emission tomography and magnetic resonance imaging (MRI) in basic science, researchers can acquire human data on cerebral base of human sexual behavior, not only in normal subjects but also in patients with sexual dysfunction. Therefore, in order to further understand the biological mechanism of LPE and the brain targets of dapoxetine, the present study would investigate the brain changes of LPE and the effect of dapoxetine on brain activation by using MRI technology.

Inclusion Criteria:

• right-handed male Chinese volunteers
• intravaginal ejaculatory latency time within 1 min
• premature ejaculation diagnostic tool score >11 for patients, but <5 for each control.
• patients who never received dapoxetine hydrochloride or other SSRI drugs

Exclusion Criteria:

• smokers
• had medical，neurological or psychiatric disorders
• had alcohol, nicotine, or drug abuse
• received any treatment at least 2 weeks before the experiment