In the study of individual differences in sexual response and the role of sexual fantasy in sexual arousal, people have increasingly recognized the important role of psychological activities in human sexual behavior4. Wenxue Li et al. 5 also proposed that due to the physiological and psychological characteristics of disabled people different from ordinary people, it is generally believed that the sexual problems encountered by disabled people are far more complex than those of healthy people. The problems often involve many aspects such as ethics, morality, physiology, psychology and society. The deaf are often difficult to obtain the most full sexual experience due to their own hearing and speech communication barriers. It is found that the higher the disability level of deaf, the lower the sexual satisfaction. Vision is very important for sexual feeling and behavior. Whether congenital blindness or acquired blindness, lack of sensory impulse from the eyes can affect sexual activities6,7. Many scholars have conducted research on sex related diseases for men and women with normal vision, but there is little research on the sexual behavior of the blind1,8,9. Therefore, combined with the particularity of blind men, we conducted a survey on the sexual behavior characteristics of the blind, such as the stimulation of sexual arousal, the understanding of sexual partners' beauty and access to sexual knowledge.
The marriage age and the age of first sexual behavior of blind males are generally late, which is closely related to the social environment. Due to physical defects, they are often hindered in finding lover or marriage objects. In the sexual behavior experience, including the age of first experiencing sexual behavior is later than that of normal people, and the frequency of sexual behavior is less, and even some people have no sexual behavior experience. In the experience of sexual behavior, blind people, like normal people, often achieve orgasm and obtain satisfactory sexual pleasure.
Studies support that in daily life, it is generally believed that men respond more strongly to visual sexual stimuli than women, and men are more exposed to all kinds of pornographic networks, magazines, newspapers and periodicals than women7. With the opening of today's social culture and the tolerance of people's sexual concepts, the sexual behavior of people in various groups in society is not only related to the happiness of individuals and families, but also may affect the stability of the whole society. With the continuous progress of society, the continuous improvement of artificial intelligence, the improvement of the living standards of the blind, all sectors of society including the government also continue to improve their economic status, psychological status, self-care ability. This survey concluded that the blind males' access to sexual knowledge mainly comes from the voice of mobile phone (self-media), radio and television, and peer communication. Unfortunately, there is little or no work on sexual education for the blind in China.
In sexual cognition, the visual sensory organ has become the first important channel for human beings to receive sexual information. Among all sensations, the development of human visual perception is the fastest and most sufficient7. After losing sight, the blind have to turn to other senses, including hearing, touch, taste, smell and proprioception, in order to better obtain the information of the surrounding environment. It is generally believed that other senses of the blind may become unusually sharp7. This study shows that the blind people's understanding of the sexual partners' beauty is mainly reflected in gentle and pleasant voice, delicate and smooth skin, sexy and stylish figure, heterosexual and attractive body fragrance. From the above results, it can be seen that blind males' understanding of the sexual partners' beauty is mainly reflected in hearing, touch and smell. This is similar to the idea put forward by Wu Jianhui that the blind who lose visual input gradually form their own behavioral ability in line with their own characteristics in their interaction with the surrounding environment10. Behind its sensitive hearing and touch, the plasticity of the central nervous system has changed to adapt to the unique sensory world of the blind. It is also consistent with Song Yiqi that the lack of experience of blind students' visual channel leads to the generation of special representation mechanism through tactile channel compensation, which proves that it is consistent with the hypothesis of perceptual symbol theory11.
Sexual arousal in normal people is an emotional state produced by the processing of external sexual stimulation, such as visual and auditory sexual stimuli and sexual caress, and internal sexual stimulation, such as sexual fantasy4. Sexual arousal consists of physiological, psychological and cognitive components. Physiological sexual arousal includes cardiovascular system, such as changes in heart rate, blood pressure and respiration, and genital response, such as male penile erection and female vaginal congestion. Psychological sexual arousal refers to the emotional and emotional state generated by sexual arousal, while cognitive sexual arousal includes interactive components such as attention, evaluation, classification, motivation and behavioral response to sexual stimulation1,7,9. Whether there are differences in sexual psychology and sexual cognition between blind males, especially congenital blind males, and normal people, the stimulating state of sexual arousal should be reflected. Therefore, we conducted a questionnaire survey on the stimulating factors of blind males' sexual arousal, and concluded that the stimulating performance of blind males' sexual arousal was 40.7% to hear gentle and pleasant sounds, 44.4% to touch delicate and smooth skin, 53.7% to touch sexy and stylish body, and 22.2% to feel happy. From the data analysis, it can be seen that the stimulation of blind sexual arousal is mainly reflected in hearing gentle and pleasant sounds, touching delicate and smooth skin, touching sexy and stylish body, but the pleasant mood also has a significant impact. This is also consistent with several studies that put forward that sexual arousal refers to an emotional state generated by an individual when processing external ,such as visual and tactile stimulation, or internal such as fantasy7,12,13. Similar to other emotions, sexual arousal has obvious antecedent stimulation and expression patterns as the basis for the regulation of sexual reproduction behavior. Sexual arousal consists of physiological changes, emotional expression and motivational behavior.