Inclusion Criteria (primary premature ejaculation subjects):
* patients' age varied from 18 to 45 years；
* patients met the 2014 International Society for Sexual Medicine (ISSM) definition criteria for PPE；
* patients had a stable, heterosexual relationship with a single sexually active female partner for at least 6 months and with at least two sexual intercourses a week and kept stable during the study period;
* Patients with premature ejaculation lasting longer than 6 months；
* patients were identified if their scores were higher than 9 on the Chinese version of Premature Ejaculation Diagnostic Tool (PEDT);
* patients had no history of any previous therapies for PE or had recently stopped the therapies for at least 3 months
* patients had fully informed consent, signed informed consent form
Inclusion Criteria (Non-premature ejaculation subjects):
* Men between the ages of 18-45 years were included according to an age difference of \<3 years between each patient and the primary premature ejaculation group, and if more than one volunteer was eligible at the same time, the one with the closest age was selected；
* Patient does not meet the 2014 International Society for Sexual Medicine (ISSM) criteria for defining premature ejaculation；
* patients had a stable, heterosexual relationship with a single sexually active female partner for at least 6 months and with at least two sexual intercourses a week and kept stable during the study period;
* patients had fully informed consent, signed informed consent form；
Exclusion Criteria:
* patients were diagnosed with secondary PE, variable PE, and subjective PE;
* patients were using medications for endocrinological, metabolic, chronic systemic, or psychiatric diseases;
* patients were abusing alcohol or illegal drugs；
* patients were diagnosed with erectile dysfunction (ED) if their scores were \<21 on the abridged five-item International Index of Erectile Function (IIEF-5)
* patients were diagnosed with sexual hormone abnormalities, hyperthyroidism, hypothyroidism, Peyronie's disease, prostatitis, urethritis, or urinary tract infection;
* patients with head injuries that prevent them from completing near-infrared light brain function imaging
* Patients with severe schizophrenia, anxiety, depression or other neurological symptoms or poor compliance
