The Mona Lisa Does Not Actually Cause the ‘Mona Lisa Effect’

Wikimedia Commons // Public Domain
Wikimedia Commons // Public Domain

Do you ever feel like you’re being watched? By a certain Leonardo da Vinci painting, perhaps? Scientists call it the Mona Lisa effect: the sense that the eyes of a figure in a painting or photograph are following you as you move around the room. But according to a new study in the journal i-Perception, the eyes in the Mona Lisa painting don’t actually fit the criteria.

The Mona Lisa effect is real—scholars have documented the phenomenon for nearly 2000 years. The effect doesn’t just depend on the direction of the painted figure’s gaze. The figure’s head position in the painting and the slant of the picture itself create specific geometric conditions in space, distorting the viewer’s perception of the painted person’s stare. The sensation can occur no matter where the viewer is in relation to the portrait.

Until now, according to researchers at Bielefeld University in Germany, no one had tested the effect on the Mona Lisa itself. Gernot Horstmann and Sebastian Loth, members of the university’s Cluster of Excellence Cognitive Interaction Technology, designed a study in which 24 participants viewed 15 different sections of the Mona Lisa painting on a monitor. A simple ruler was placed in front of the monitor, and each viewer marked the spot where they thought the gaze landed on the ruler, which indicated its angle.

An angle of zero meant a straight-at-the-viewer look. A slightly sideward gaze toward the viewer’s ear, corresponding to a 5-degree angle, would still prompt the sense of being watched. "But as the angle increases, you would not have the impression of being looked at,” Horstmann said in a statement.

After analyzing about 2000 assessments from participants, the researchers found that viewers felt the gaze of Leonardo da Vinci’s masterpiece to be at an angle of 15.4 degrees—looking off to their right-hand side, rather than directly at them.

“It is clear that the term Mona Lisa effect is nothing but a misnomer,” Horstmann said. But even though this particular phenomenon has been demystified, people's obsession with the painting will surely continue.

A Simple Skin Swab Could Soon Identify People at Risk for Parkinson's

iStock.com/stevanovicigor
iStock.com/stevanovicigor

More than 200 years have passed since physician James Parkinson first identified the degenerative neurological disorder that bears his name. Over five million people worldwide suffer from Parkinson’s disease, a neurological condition characterized by muscle tremors and other symptoms. Diagnosis is based on those symptoms rather than blood tests, brain imaging, or any other laboratory evidence.

Now, science may be close to a simple and non-invasive method for diagnosing the disease based on a waxy substance called sebum, which people secrete through their skin. And it’s thanks to a woman with the unique ability to sniff out differences in the sebum of those with Parkinson's—years before a diagnosis can be made.

The Guardian describes how researchers at the University of Manchester partnered with a nurse named Joy Milne, a "super smeller" who can detect a unique odor emanating from Parkinson's patients that is unnoticeable to most people. Working with Tilo Kunath, a neurobiologist at Edinburgh University, Milne and the researchers pinpointed the strongest odor coming from the patients' upper backs, where sebum-emitting pores are concentrated.

For a new study in the journal ACS Central Science, the researchers analyzed skin swabs from 64 Parkinson's and non-Parkinson's subjects and found that three substances—eicosane, hippuric acid, and octadecanal—were present in higher concentrations in the Parkinson’s patients. One substance, perillic aldehyde, was lower. Milne confirmed that these swabs bore the distinct, musky odor associated with Parkinson’s patients.

Researchers also found no difference between patients who took drugs to control symptoms and those who did not, meaning that drug metabolites had no influence on the odor or compounds.

The next step will be to swab a a much larger cohort of Parkinson’s patients and healthy volunteers to see if the results are consistent and reliable. If these compounds are able to accurately identify Parkinson’s, researchers are optimistic that it could lead to earlier diagnosis and more effective interventions.

[h/t The Guardian]

World’s Oldest Stored Sperm Has Produced Some Healthy Baby Sheep

A stock photo of a lamb
A stock photo of a lamb
iStock.com/ananaline

It’s not every day that you stumble across a 50-year-old batch of frozen sheep sperm. So when Australian researchers rediscovered a wriggly little time capsule that had been left behind by an earlier researcher, they did the obvious: they tried to create some lambs. As Smithsonian reports, they pulled it off, too.

The semen, which came from several prize rams, had been frozen in 1968 by Dr. Steve Salamon, a sheep researcher from the University of Sydney. After bringing the sample out of storage, researchers thawed it out and conducted a few lab tests. They determined that its viability and DNA integrity were still intact, so they decided to put it to the ultimate test: Would it get a sheep pregnant? The sperm was artificially inseminated into 56 Merino ewes, and lo and behold, 34 of them became pregnant and gave birth to healthy lambs.

Of course, this experiment wasn’t just for fun. They wanted to test whether decades-old sperm—frozen in liquid nitrogen at -320°F—would still be viable for breeding purposes. Remarkably, the older sperm had a slightly higher pregnancy rate (61 percent) than sheep sperm that had been frozen for 12 months and used to impregnate ewes in a different experiment (in that case, the success rate was 59 percent).

“We believe this is the oldest viable stored semen of any species in the world and definitely the oldest sperm used to produce offspring,” researcher Dr. Jessica Rickard said in a statement.

Researchers say this experiment also lets them assess the genetic progress of selective breeding over the last five decades. “In that time, we’ve been trying to make better, more productive sheep [for the wool industry],” associate professor Simon de Graaf said. “This gives us a resource to benchmark and compare.”

[h/t Smithsonian]

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