Posts Tagged ‘fmri’
Women’s Emotional Tears Are a Turnoff for Men, Suggesting a Chemical Compound At Work
Although men were unable to smell the difference between real tears and a saline solution, they had decidedly different reactions to each. Men who sniffed real tears became less sexually aroused by photographs of women than those who sniffed saline. Just to be sure skin was not the culprit, the researchers dripped saline down women’s cheeks, to the same effect: Only real, fresh-cried tears turned men off.
The researchers, from the Weizmann Institute of Science and Edith Wolfson Medical Center in Israel, actually . They expected tears’ chemical signals to trigger empathy or sadness, but that didn’t happen; they did, however, dampen men’s sexual desire. Some researchers believe this phenomenon evolved to protect emotionally vulnerable women from male aggression, while others believe it’s evidence of a heretofore unknown human pheromone, .
To capture tears, two donor women ages 30 and 31 watched sad movies by themselves and placed vials beneath their eyes to collect teardrops. The researchers needed fresh tears no more than two hours old, so the women watched weepies like “Terms of Endearment,” “My Sister’s Keeper” and “When a Man Loves a Woman,” the Times reports. Their tears were collected 1 milliliter at a time and deposited onto small pads that were attached beneath men's noses, so they could continuously sniff the sadness.
Then 24 men, whose mean age was 27, were shown emotionally ambiguous photographs of women and asked to rate the faces’ sadness and their attractiveness. The faces appeared less sexually attractive after sniffing real tears, according to the study.
The researchers also learned the men experienced a drop in testosterone. Then, the men sniffed tears and watched a sad movie while in a functional MRI machine, which showed reduced activity in the brain regions associated with arousal.
Other bodily fluids, like sweat, are known to contain chemical signals that influence others’ emotions or behaviors, so it makes sense that tears would have a similar effect, the researchers say. The next step is to study the emotional tears of children and men — potentially explaining the lachrymose nature of the new .
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According to New Study, fMRI Brain Scans May Predict Your Behavior Better Than You Can
In a study published last week, they showed neural signals can predict future behavior more accurately than people's own best guesses. This has for everything from advertisers, who would very much like to anticipate what you'll do, to educators, who could predict how much knowledge students will actually retain.
The researchers studied brain activity of people who watched public-service announcements about the importance of wearing sunscreen. They focused on two brain regions, the medial prefrontal cortex and the precuneus, which are both associated with self-awareness. The subjects -- mostly UCLA students -- were asked how they felt about sunscreen and how likely they were to use it. The researchers gave the subjects sunscreen to be sure they'd have access to it.
A week later, the participants reported how much sunscreen they actually used. About half had been able to accurately predict their behavior.
The neuroscientists developed a model that compared the subjects' brain activity to their own predictions, and found the model was accurate 75 percent of the time. In other words, it was more accurate than the students' own ability to predict how they would act. The findings were published last week in the .
Matthew Lieberman, a UCLA psychology and psychiatry professor who led the study, said people are not very good judges of what they will actually do.
"Many people 'decide' to do things but then don't do them," he says.
The study involved a small sample size -- just 20 students -- and more work needs to be done to understand the disconnect between your intentions and your actions. But the study could pave the way for neurologically informed marketing, education and even public health campaigns, UCLA says.
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Brooklyn Lawyer to Enter Brain Scan as Court Evidence for Client’s Veracity
The case could represent a legal precedent for sorting out truth from falsehood in a court of law
The lawyer, David Levin, represents a woman who claims that she no longer received good assignments from a temp agency after she complained of sexual harassment at a job site. A coworker at the temp agency claimed he heard a supervisor say the woman should not be placed on jobs because of the complaint.
That prompted Levin to have the coworker undergo a functional magnetic-resonance imaging (fMRI) brain scan by the company Cephos, which claims to provide scientific validation of whether someone is telling the truth. Now the proposed evidence will test the New York standards for scientific evidence in courts -- known as the Frye standard -- which typically requires the evidence to be considered reliable among the broader scientific community.
Both Cephos and another company called No Lie MRI have marketed their brain scans as lie detectors since 2007. They report accuracy rates from 75 percent to 98 percent under lab conditions, but many neuroscientists remain skeptical of, or outright opposed to, using brain scan technology in court.
We reported earlier on a Cephos-funded fMRI study at the University of Texas Southwestern Medical Center, which tested people who participated in a mock crime within the experiment. The test caught guilty parties, but also who were telling the truth.
Last year, an Illinois court allowed an expert to describe the fMRI brain scan of man accused of murdering a 10-year-old-girl. But that was presented as evidence of the man's mental illness during the sentencing phase of the trial, whereas the new Brooklyn case would be a legal first for determining truth-telling.
We'll be sure to keep an eye on whether this battleground between science and the law translates into wider use of brain scans or not. If it does pass muster with the Frye standard, expect even more debate over the use of in the future.
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Brain Scans Predict Who Benefits from Electrode Implants in Their Heads
fMRI helps scientists see interconnected brain networks and understand why happiness is a warm electrode
A new fMRI study showed that deep brain stimulation treatments seem to work by affecting a whole networked array of brain regions. Scientists focused on the subgenual region of the brain that tends to become hyperactive in people suffering from depression.
Patients whose condition improved because of the electrodes in their heads seemed to have a connection between the subgenual region and a part of their prefrontal cortex. By contrast, patients who did not benefit from DBS treatment had a connection between the subgenual region and the amygdale -- a part of the brain related to fear and other emotions.
The study, conducted at Emory University in Atlanta, may do more than just offer treatment to more people -- it has helped further our relatively paltry understanding of some of the brain's most complex internal processes.
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