Showing posts with label sex science. Show all posts
Showing posts with label sex science. Show all posts

Saturday, March 22, 2008

What is the cause of sexual problems?


Most cases there is not just one cause for a sexual problem; there are often several causes. It is important to look at the problem from three different points of view, namely physical causes, psychological causes and social causes.
Physical causes are anomalies of the body that cause sexual problems. Examples of this are disorders in hormonal regulation as a result of certain medicines that cause a reduced interest in making love, irritations of the vagina that cause pain when making love or certain operations on the genitals.

Psychological factors are feelings, thoughts and perceptions that cause sexual problems. This may be negative feelings for the partner or shame for one's own body, unpleasant events of the past, and also fears and restraints related to sex.

Social factors may be values and standards that you have received in your education, traumatic events or the behavior of the partner. Certain stress factors e.g.: unemployment, a bad financial situation, little knowledge of the body and family quarrels can influence the sexual perception.

Sunday, March 16, 2008

Sex: The science of sexual

Psychologists are gaining new insights into sexual arousal with the help of innovative research methods.
Men and women experience sexual arousal very differently, not only physiologically but psychologically, according to researchers who are studying arousal using an array of new and refined methods.

Those methods are making it possible for researchers to understand the causes of real-world problems, such as sexual dysfunction and high-risk sexual behavior (see pages 54 and 58). But they are also giving researchers the means to explore basic questions about the nature of sexual arousal and how its different components--such as physiological arousal and subjective experience--are related to each other.

"It's easier to get funding for research that focuses on, let's say, AIDS-related sexual behaviors, than for research on the very fundamental question of what sexual motivation and sexual arousal really are," says Erick Janssen, PhD, a psychologist at the Kinsey Institute for Research in Sex, Gender and Reproduction at Indiana University. "But in the long run, those basic questions have to be answered before we can move on to explain other, related behaviors."

Cognition and arousal

One active area of research concerns cognitive factors that influence sexual arousal. In the mid-1980s, Boston University psychologist David Barlow, PhD, and his colleagues conducted a series of studies to examine the relationship between anxiety and sexual arousal. They found that men with and without sexual problems reacted very differently to anxiety-inducing threats of mild electric shock.

Men who reported having no trouble getting and maintaining erections, says Barlow, "would believe that they were going to get shocked if they didn't get aroused, so they would focus on the erotic scene." The result was that the threat of shock actually increased sexual arousal. But men who had sexual problems responded to the threat of shock very differently, says Barlow. "Their attention would be so focused on the negative outcomes that they wouldn't be able to process the erotic cues," he explains.

Since those initial studies, Barlow and his collaborators have been trying to tease apart the factors that distinguish men with and without sexual problems. One of the key differences, he says, is that men with sexual arousal problems tend to be less aware of how aroused they are.

Another difference has to do with how men react to instances when they can't become aroused, says Barlow. "Males who are able to get aroused fairly easily seem unfazed by occasions where they can't get aroused," he notes. "They tend to attribute it to benign external events--it was something they ate, or they're not getting enough sleep--not as characteristics of themselves." In contrast, men with arousal problems tend to do just the opposite, thinking of every instance of difficulty as a sign of a long-term internal problem, either physiological or psychological, he says.

At the Kinsey Institute, Janssen and John Bancroft, MD, the institute's director, have been developing a theoretical model and a set of measurement tools that define sexual arousal as the product of excitatory and inhibitory tendencies. Last year, they published papers in the Journal of Sex Research (Vol. 39, No. 2) describing the Sexual Inhibition and Sexual Excitation Scale--a new questionnaire that measures individual differences in the tendency to become sexually inhibited and excited.

Early research on the model suggests that while a single factor accounts for all of the variation among men in their tendency to become sexually excited (SES), there are two inhibitory factors--one that represents inhibition due to the threat of performance failure (SIS1) and one that represents inhibition due to the threat of such performance consequences as an unwanted pregnancy or a sexually transmitted disease (SIS2).

One implication is that people with different levels of SES, SIS1 and SIS2 will respond differently to different kinds of stimuli, says Janssen. In one study, for instance, Janssen, Bancroft and their collaborators found that people who scored highly on SIS2 were less likely to be aroused by erotic films that included threatening stimuli than people with low SIS2 scores.

"We believe that people who are high in inhibition-proneness are more vulnerable to developing sexual problems, whereas those who are low are more likely to engage in high-risk sexual behavior," says Janssen.

Physiological and subjective arousal

For most of the history of research on sexual arousal, studies involving women have been much rarer than studies involving men. Recently, however, the gap has started to narrow due to the work of psychologists such as Cindy Meston, PhD, of the University of Texas at Austin, Julia Heiman, PhD, of the University of Washington, and Ellen Laan, PhD, of the University of Amsterdam. Janssen and his colleagues at the Kinsey Institute have also begun studying female arousal.

One of the most interesting results to come out of that work, researchers say, is that there are significant differences between men and women in the relationship between physiological and subjective arousal.

"What we find in research in males is there's a very high correlation between their erectile response and how aroused they say they are," says Meston. "But in women we get low, if any correlations."

In addition to being interesting from a scientific standpoint, the sex difference could also have important implications for the treatment of female sexual dysfunction, says Meston. Researchers have not yet been able to pinpoint the source of the difference, she says, but some progress has been made.

Several explanations that once seemed likely candidates have been eliminated in recent years. One of them is the idea that women are less likely than men to talk honestly about their sexuality because of sexual taboos. But Meston says she sees no evidence of reticence in the women who volunteer for her studies.

Another possibility is that erotic films might evoke negative emotions in women, which could mask their arousal. But Laan and her collaborators at the University of Amsterdam have found no evidence that such reactions can account for the physiology-experience gap.

Meston and others suspect that the difference probably has something to do with the fact that male genital arousal is simply easier to notice than female genital arousal. Men also seem to be more attentive than women to all kinds of physiological signals, not just sexual ones, says Janssen.

An open question is whether the resulting sex differences in the relationship between physiological and subjective arousal are permanent, or whether they can be changed through training. Meston says her lab is currently conducting a study to find that out.

Saturday, January 12, 2008

I love you ?How to tell love from lust

sponsored by 24hoursnews
I love you.
Means what ?
Love appears to be a more evolved behaviour than lust, according to new research that has mapped the brain's centres of love, lust and attachment.

The authors of the study believe that lust is quite different from love.

"[Love] requires more sophisticated behaviours, reward and memory systems than other mammals," says lead author Dr Lucy Brown, a neurologist at the Albert Einstein College of Medicine in New York.

"It is present to some degree in other primates that are close to us in brain development."

She says humans have evolved three distinct brain systems for mating and reproduction: the sex drive, romantic love and attachment to a long-term partner.

Brown and her colleagues took magnetic resonance images, or pictures of brain activity, of 17 young men and women who described themselves as being "newly and madly in love."

The researchers compared the MRI data with earlier studies on male penile girth responses to photographs of women, other studies on how the brains of men and women activate when individuals view people they find to be attractive or unattractive, and data on both human and animal couples that have been together for a long time.

The findings will be published in the July issue of the Journal of Neurophysiology.

Left versus right brain

The researchers discovered that early stage romantic love feelings are located mainly on the right side at the base of the brain, or the ventral midbrain, and in the middle of the brain, the caudate nucleus.

Long-term attachment, on the other hand, appears to be centred in the front and base of the brain, or the ventral putamen and the pallidum.

Feelings related to lust and sexual arousal occupy different areas, mostly located on the left-hand side of the brain.

The area of overlap seems to mostly involve visual information, but for romantic love to set in, it takes more than just a lustful pang and a pretty face.

Lust is good but love is better

Lust obviously can lead to procreation, which ensures the survival of a species, but the scientists believe love is better for humans in the long-term.

"Simple lust may be necessary in extremely difficult survival circumstances when there is no time for romance," Brown says.

"It is known that people in very dangerous and threatening situations can suddenly find themselves lusty for each other, even though they are strangers.

However, under safe circumstances within a stable society, romantic love and attachment may be the best and more efficient way to continue species survival."

Brown and her team believe that "love at first sight" is a real phenomenon, but they say other non-visual aspects of a person, such as mannerisms, voice, personality and social status, usually must come into play if lust is to evolve into love.

The researchers suggest "love at first sight" and the obsessive goal-driven aspects of early love are both evolved behaviours that speed up mating and provide a better chance for successful reproduction.

"Rather than get up the energy to go to a different bar every night and maybe be successful in finding a different person every night, sticking to the same person, being able to have sex without spending time on the search may increase chances for pregnancy," Brown says.

Crazy for you?

Dr Donatella Marazziti, a University of Pisa scientist who has also studied the brain and biochemical activity of people in love, agrees with the findings.

Marazziti says she isn't not surprised by the neural basis for "love at first sight," since, according to her theory, "love is a basic emotion, which would use the system of the basic emotions and, as such, it is sudden and unpredictable."

Marazziti also says that romantic lovers are a bit "crazy," since they can experience chemical imbalances within the brain.

Mental health experts have linked somewhat similar imbalances to depression, anxiety and obsessive-compulsive disorders.

Friday, October 26, 2007

Worms offer clues to human sexuality : Sexual Orientation Hard-Wired in Worm Brains



Sponsor : www.lustnews.blogspot.com Sexual orientation seems to be wired into the brains of nematode worms, and tweaking this sexual wiring can result in worms attracted to members of the same sex.Biologists at the University of Utah have engineered worms that are attracted to worms of the same sex, bolstering evidence that sexual orientation may be hard-wired in the brain.


"The conclusion is that sexual attraction is wired into brain circuits common to both sexes of worms," said researcher Erik Jorgensen, scientific director of the Brain Institute at the University of Utah and an investigator with the Howard Hughes Medical Institute.


The blue spot on the left contains sexual attractants from nematode worms that are hermaphrodites, or have male and female organs. The other spot does not. (Courtesy of the University of Utah )




While the study involved only worms, Jorgensen and his colleagues considered how the results shed light on sexual attraction throughout the animal kingdom.

"We cannot say what this means for human sexual orientation, but it raises the possibility that sexual preference is wired in the brain," Jorgensen said. "Humans are subject to evolutionary forces just like worms. It seems possible that if sexual orientation is genetically wired in worms, it would be in people too."


Sensual scents


While most nematode worms (Caenorhabditis elegans) are hermaphrodites, having both male and female sex organs, one in 500 nematodes is a true male.


The hermaphrodites are essentially females," said lead study author Jamie White, a member of Jorgensen's lab. "It just turns out they make a little bit of sperm during development that they store to fertilize their own eggs."


The ability to reproduce without a mate is crucial for the slender worms, which reside in the soil, where it's hit or miss as to whether they come across a sporadic bacteria bloom - a meal.


This way, when a lone worm spots such a feast, it doesn't have to wait around for a mate to take advantage of the nutrition and reproduce.


Male nematodes, however, must seek out a mate in order to reproduce.


Since like all nematodes the males lack eyes, they sniff out sex-attractant odors called pheromones to find potential mates.


This olfactory obligation could explain why males have a nervous system that includes eight sensory neurons (out of 383 total nerve cells) that aid in pheromone detection.


Female nematodes, however, only have four of these sensory neurons, general sensory neurons which they use for finding food and other sweet-smelling substances.


Sex change


Jorgensen and his colleagues were interested in finding out how the nervous system, which is directed by genetics, affected the sexual behaviors of the worms.


The researchers activated the so-called "fem-3" gene in the brains of hermaphrodite worms.


The gene is responsible for the development of male-specific features of cells in the body and nervous system, but the scientists only switched on those in the worms' brain cells.


"The body cells are expressing the genes it normally would in the hermaphrodite," White told LiveScience. "The neurons themselves - we flipped this genetic switch to turn them into male."


Before the brain-sex change, the hermaphrodites showed no interest in the pheromones of other hermaphrodites - members of their own sex.


The genetically altered hermaphrodites (or transgender ones), however, crawled toward the same-sex scents.


Most of the transgender worms still lacked the male-specific sensory neurons, even though the fem-3 gene was activated.


White suggests they relied on the four general sensory neurons for pheromone sniffing.


The study is detailed online today in the journal Current Biology.




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Saturday, October 20, 2007

Way to overcome lust for sex .


To experience God's grace, we must first recognize our need. (See "How can I tell if I'm getting addicted to sex or pornography?") We must turn to him and others for help. That's not easy. Perhaps you realize that you have a problem but still believe you can handle it alone. Guys hate to admit defeat. We don't want to ask for help.


You Can't Overpower Your Lust


The apostle Paul understood our predicament. He told the Romans, "I have the desire to do what is good, but I cannot carry it out. For what I do is not the good I want to do; no, the evil I do not want to do-this I keep on doing" (Romans 7:18-19).


I'm not suggesting that Paul struggled with compulsive sexual behavior, but he did struggle with sin-just like the rest of us. And like the rest of us, he would make up his mind not to commit a certain sin ever again. Did he succeed? No way! Now, if the apostle Paul couldn't overpower his sin, why should you and I think we can?


Even in a world free of erotic images, men don't control their lust. My oldest son called me last week from Pakistan. In that country men and women never hang out together. And women are covered with clothing from their head to their feet. Yet my son said he met a guy who offered to introduce him to some prostitutes.


If men in a country like that can't control their lust, how can we? From the moment we get up in the morning until we climb between the sheets at night, we're bombarded with erotic images and messages.


Suppose you made up your mind you were going to make it through one day without lusting after a woman. On your way to work your eyes are drawn to the bikini-clad model greeting you from a billboard. A few moments later as you stop at an intersection, you aren't able to keep from noticing the attractively dressed young woman crossing the street.


At work a friend brags about the gorgeous babe he bedded the night before. As you order lunch, the waitress with the short skirt winks at you and smiles. When you get back to the office, a coworker eagerly shows you his favorite erotic image on the Internet.


On your way home you stop at the grocery store and catch yourself gazing at the seminude models that adorn the magazines by the checkout counter.


When you finally get home, you plop down in an easy chair and flip on the TV. As you channel surf, you're exposed to more of the female anatomy than I found in the pages of Playboy when I was a kid.


With the high level of erotic stimulation you face on a daily basis, do you believe you can bridle your lust alone? I remember a friend once telling me (and he said this with a straight face), "I'll never have a problem with sexual lust."


I looked at him and said, "You're absolutely amazing. If that's true, you're stronger than Samson, godlier that David, and wiser than Solomon."


I'll never forget his response. He sat down and stared at me for a half minute without uttering a word. And then he said, "I never though of it like that."


I'll guarantee you, if Samson, David, and Solomon were here, they'd all say, "You can't defeat your lust alone!"


You Can't Reform Your Lust


"OK," you may be thinking, "maybe I can't beat it. But I can make myself better. I can reform my lust."


I frequently talk with new Christians who think that becoming a follower of Christ means the lust problem is solved. It's as though they think Jesus waved some sort of magic wand over them and-presto!-their sinful nature was transformed. Their lust was gone.


When they discover that their problem with lust seems even worse than before, they decide they'll study the Bible and pray more. Much to their surprise, that doesn't seem to solve the problem, either.


Listen to Paul's words. In Romans 7:10-11 he said, "The very command that was supposed to guide me into life was cleverly used to trip me up, throwing me headlong."[1]


As sinful human beings, our lustful appetites are so evil, they'll use God's good commands to tempt us. Like a rod stirring up dirt that has settled to the bottom of a jar of water, so God's law excites our lust. Forbidden things are more exciting. Women who are off-limits take on a greater appeal. God says don't and our lust says do. God says do and our lust says don't.


Trying to reform our lust is like trying to make a dog into a person. For thirteen years a buff-colored cocker spaniel named Pumpkin graced our family. Over those years I taught Pumpkin all kinds of tricks. She obeyed the common commands like sit, lie down, and roll over. I also trained her to jump through a hoop, close a door, sit on her hind legs, and fall over as though dead when I shot her with an imaginary gun.


Yet in spite of all my training, I couldn't keep Pumpkin from acting like a dog. She always did doggy things. She ate things people tried not to step in. She sniffed other dogs in places only dogs sniff. She went to the bathroom in public. No matter how well I trained Pumpkin, she was still a dog.


Similarly, your sinful propensity doesn't reform when you enter a church. It doesn't change when you come to faith in Christ. You can go to church, read your Bible, pray daily, and even lead a ministry without reforming your sinful nature. Paul said, "I know that nothing good lives in me, that is, in my sinful nature" (Romans 7:18).


When we fall under the domination of our sinful nature, we're capable of doing anything evil, whether we're believers or not. When controlled by our lust, we can no more do good than a dog can talk.


Yet when dealing with their lust, men sometimes think they can reform it. They deny its evil power.


You may grow as a Christian. You may become more like Christ in your spiritual nature. But in the flesh, in your sinful nature, you're no better than the day you trusted Christ. And because your lust is driven by sin, you can't reform it.


You Can't Starve Your Lust


One of the problems I have with a lot of recovery programs is that their primary emphasis is on abstinence. They think the key to defeating an addiction is to stop the behavior. Now, please don't misunderstand me. We can't control any addiction unless we stop acting out. But if that's all we do, it won't work. We'll simply change addictions. For example, our lust will transfer from sex to alcohol. And if we stop drinking, it will move on to shopping or work or gambling.


It's impossible to starve our lust to death. Until the day we're with the Lord, we'll struggle with sin. A number of years ago I read a poem that describes the struggle and defeat we experience when we fight against our lust alone. W It's entitled "The Yipiyuk" (by Shel Silverstein).



In the swamplands long ago,
Where the weeds and mudglumps grow,
A Yipiyuk bit on my toe…
Exactly why I do not know.
I kicked and cried and hollered "Oh!"
The Yipiyuk would not let go.
I whispered to him soft and low.
The Yipiyuk would not let go.
Yes, that was sixteen years ago,
And the Yipiyuk still won't let go.
The snow may fall, the winds may blow.
The Yipiyuk will not let go.
I drag him 'round each place I go,
And now my child at last you know
exactly why I walk so slow.

Like the Yipiyuk, your sinful nature will resist letting go. For a while you may ignore it. Later you may insist it doesn't really have a hold on you. But if you hope to break its power, you must first realize it's there and admit you don't have the power to dislodge it.


Hopefully, you'll tire of fighting a losing battle. Paul did. In desperation he cried out, "Oh, what a terrible predicament I'm in! Who will free me from … this deadly lower nature?" (Romans 7:24 LB).


If someone as spiritually together as Paul realized he was fighting a losing battle, isn't it time for you to do the same thing? I know giving up isn't easy. But it's a step you must take if you're going to find lasting freedom.


You may now begin to see your powerlessness to overcome your lust, and sense your need for God's help.




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