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.

Science Finds a Better Way to Calculate 'Dog Years'

thegoodphoto/iStock via Getty Images
thegoodphoto/iStock via Getty Images

Anyone who has ever owned a pet is likely familiar with the concept of “dog years,” which suggests that one year for a dog is like seven years for a human. Using this conversion metric, a 2-year-old dog is akin to a high school freshman, while a 10-year-old dog is ready for an assisted living facility.

If that seems rather arbitrary, that’s because it is. But now, researchers at the University of San California, San Diego have come to a more data-based measurement on dog aging through DNA.

The paper, published on the preprint server bioRxiv, based the finding on DNA methylation, a process in which molecules called methyl groups attach themselves to DNA and serve as an indicator of aging. Generally speaking, the older living beings get, the faster the rate of methylation. In the study, 104 Labrador retrievers were examined, with subjects ranging from 1 month to 16 years old. The results of their DNA methylation were compared to human profiles. While the rate of methylation tracked closely between the two—young and old dogs had similar rates to young and old people—adolescent and mature dogs experienced more accelerated aging.

Their recommended formula for comparing dog and human aging? Multiply the natural logarithm of a dog’s age by 16, then add 31. Or, just use this calculator. Users will see that a 2-year-old dog, for example, wouldn’t be the canine equivalent of a 14-year-old. It would be equivalent to 42 human years old and should probably start putting money into a 401(k). But because methylation slows considerably in mid-life, a 5-year-old dog is approximately a 57-year-old human, while a 6-year-old dog is nearing 60 in human years—a minor difference. Things level out as the dog gets much older, with a 10-year-old dog nearing a 70-year-old human.

Different breeds age at different rates, so the formula might not necessarily apply to other dog breeds—only Labs were studied. The work is awaiting peer review, but it does offer a promising glimpse into how our furry companions grow older.

[h/t Live Science]

Sssspectacular: Tree Snakes in Australia Can Actually Jump

sirichai_raksue/iStock via Getty Images
sirichai_raksue/iStock via Getty Images

Ophidiophobia, or fear of snakes, is common among humans. We avoid snakes in the wild, have nightmares about snakes at night, and recoil at snakes on television. We might even be born with the aversion. When researchers showed babies photos of snakes and spiders, their tiny pupils dilated, indicating an arousal response to these ancestral threats.

If you really want to scare a baby, show them footage of an Australian tree snake. Thanks to researchers at Virginia Tech, we now know these non-venomous snakes of the genus Dendrelaphis can become airborne, propelling themselves around treetops like sentient Silly String.

That’s Dendrelaphis pictus, which was caught zipping through the air in 2010. After looking at footage previously filmed by her advisor Jake Socha, Virginia Tech Ph.D. candidate Michelle Graham headed for Australia and built a kind of American Ninja Warrior course for snakes out of PVC piping and tree branches. Graham observed that the snakes tend to spot their landing target, then spring upward. The momentum gets them across gaps that would otherwise not be practical to cross.

Graham next plans to investigate why snakes feel compelled to jump. They might feel a need to escape, or continue moving, or do it because they can. Two scientific papers due in 2020 could provide answers.

Dendrelaphis isn’t the only kind of snake with propulsive capabilities. The Chrysopelea genus includes five species found in Southeast Asia and China, among other places, that can glide through the air.

[h/t National Geographic]

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