User:Rai S G Bari/sandbox

= Pupillometry and Sexual Interest =

Sexual Interest
Sexual urge is characterised as the experience of sexual considerations, imaginations, and the desire to take part in sexual activities. Researches carried out on the topic revealed that women report low sexual desire because women have weaker biological urge to engage in sexual activities. On the other hand, men report to have elevated sexual urges in terms of frequent repetition of sexual thoughts and desired frequency of sex. This difference in sexual desire can be explained by the hormonal differences between the two genders as men have elevated levels of testosterones

Sex stimulating hormones i.e. estrogen and androgen, trigger the sexual desire by stimulating the brain and peripheral organs. The social elements also play important part in the expression of sexual desires by the two genders.

Sexual Orientation
Alfred Kinsey (1948) was the first researcher to recognise the diversity of sexual orientation. He stated that sexual orientation is not a dichotomous category i.e. homosexuality and heterosexuality but a diverse complex system that encompasses sexual identity, sexual appeal and sexual conduct of an individual. He conducted a survey in which he asked the participants to rate their sexual attraction on a scale from zero to six in which zero indicated complete attraction to individuals of the other gender, and six symbolised complete attraction to same-gender individuals. According to him, by using this survey individuals can also recognise their sexual identity and sexual conduct.

Genders Anatomy
A visible evidence of a man’s arousal is his erection. Although women show clitoral erection as a result of arousal, but it is not as visible as that of men. Since most of the women are unaware of their physical response and arousal, this also affects subjective understanding of sexual desire. Researches state that awareness of sexual arousal impacts sexual desires. Women who were told to focus on their vaginal lubrication while watching pornography reported arousal out much more than the women who were not given this instruction. Women who are not aware of their physical response to arousal depend on their partners to become aroused.

Brain Differences
Brain stimulation as a result of sexual arousal is similar for both genders. The only difference occurs in the hypothalamus of both genders, the area that activates in women during sexual arousal is ventromedial hypothalamus and medial pre-optic area in men’s hypothalamus. Similarly, hypothalamus and amygdala activate more in men than women as a sexual response. Anatomical brain differences also lead to different sexual orientations. A researcher found out that anterior part of hypothalamus of a gay man resembles more to that of a woman however it was later discovered that this study was carried exclusively on patients who had died of AIDS.

Hormones
Testosterone is also known as the sex hormones. It defines the level of sexual arousal in both genders. A survey stated that castrated male primates stop getting sexual arousal but after given artificial testosterones regained their sex drive. As women have low levels of testosterones, it explains their low sexual drive. But endocrine system is much more complicated in human beings to come to this simple conclusion. It could be that women generate testosterones so efficiently that they need lower levels to generate the same levels of sex drive. A few researchers share belief that low levels of testosterones in men are linked to homosexuality, however research does not support this prognosis see

Methods to Measure Sexual Interest
Physiological response to sexual arousal is usually measured in laboratory by conducting tests on heart rate, pupil dilation, galvanic skin response and genital response of individuals. Usually participants are exposed to erotic stimuli and changes in their genitals are measured. As laboratory testing involves invasive techniques to measure sexual arousal, researchers resort to self-reporting methods of sexual arousal measurement. Before opting for self-reporting methods, it is essential to know if the selected method produces results in accordance with the measurement results of laboratory testing. Though these methods have been widely employed but they suffer from credibility issues because of social desirability responding, when measuring genital arousal, it is also possible to suppress true responses. For this reason, researchers have tried to explore other measures to report sexual arousal that are less inclined to subjective manipulations such as the pictorial modified Stroop tasks, choice reaction time tasks, and viewing-time paradigms.

Pictorial Modified Stroop Task
In this task, participants are asked to recall the colour of stimuli overlooking the content or nature of it, as the stimuli may be sexual in nature the details may not be kept in mind.

Choice Reaction Time
It is a method in which the participants are asked to locate the dot on a rather sexually stimulating picture.

Implicit Association Task
The Implicit Association Test (IAT) is a method where participants are asked to categorise the stimuli using two buttons. In this test, each button is assigned a attribute category and a concept category. If the participant will find any relationship between those categories, and are required to categorise the stimuli, eventually, they would experience facilitation effect. There was a study conducted on the prisoners who committed sexual offences against children, they were given the IAT Task to categorise the child or adult vs sexy or not sexy. Inmates were quicker to respond when the stimuli were categorised as Child/Sexy and for the adults Adult/Not Sexy.

Viewing Time
In this method, individuals interests and motivations regarding sexual desire are measured. The participants are showed a series of two figures sexual in nature. The participant is asked to select one from each set. The researcher measures time that the individual spends on each figure and conclude his sexual interests and aspirations.

Limitations
Despite the advantages of the methods discussed above, there are some limitations such as controlling your actions and fixation behaviour is also vulnerable to top-down control. Participants can divert their attention from target to somewhere else which can affect the results. This limitation can be tackled by a non-invasive technology, widely used for the research purpose called Eye-Tracking.

Pupillometry
Pupillometry is an alternative eye-tracking measure that is more sensitive and not under the control of top-down control. Considering the previous methods and their susceptibility to manipulations, it is critical to investigate the method that may be less vulnerable to control. One possible measure for that has gotten just enough consideration is pupillary reaction. This method is reliable enough because the dilation of pupil is out of deliberate control of a person. When used for the assessment of sexual interests or arousal the individual will have no way to conceal his sexual aspirations. The only concern with this method is that to what extent pupillary responses assess the sexual interests and whether this measure can help distinguish between interests in adult and child targets.

Researches carried out on the subject revealed that pupils dilate after encountering sexual stimuli especially to the preferred sexual stimuli. However, these studies used fairly simple techniques for measuring changes in pupil size. A researcher measured the diameter of pupil size of 10 males including five homosexuals and five heterosexuals from video clip of their eyes, which was recorded when the participants viewed the pictures of nude adult men and women. The results showed the dilated pupils of five heterosexual men while viewing pictures of nude women and 4 out of 5 homosexual males showed dilated pupils while looking at the pictures of men. Although these findings were compelling enough but no further research was carried out until recently. In the recent study, participants were shown sexually explicit videos while the dilation of their pupil size was recorded. The findings supported earlier researches closely; as recorded before, the pupils of homosexual men and women dilated to footage of the same sex, while pupils of bisexual men and women dilated to both sexes. The pupils of heterosexual men dilated to the opposite sex, but heterosexual women displayed equal pupil sizes to both sexes. Another experiment supported these findings by showing association between pupil dilation and genital arousal, which supports the conclusion that pupillary responses reflect sexual interest. This study however opted for another way to support the findings of prior surveys and researches. The participants were showed explicit sexual video and their pupillary responses and genital arousal were measured. The results showed high concordance between the both genders, however, just like the earlier researches, this association was weak in heterosexual women.