Walking the halls of one of the world’s great art museums, it’s easy to regard familiar classic paintings as eternal and unchanging. But this is not the case. Paintings are a mix not only of color but of chemistry—and chemistry changes. In some of Vincent van Gogh’s works, the striking, sunny yellows have faded and turned brownish, robbing the Dutch master’s art of some of its trademark intensity. So a European team of scientists decided to find out exactly what was happening on those canvases.
Using sophisticated X-ray machines, they discovered the chemical reaction to blame — one never before observed in paint. Ironically, van Gogh’s decision to use a lighter shade of yellow paint mixed with white is responsible for the unintended darkening, according to a study published online Monday in the journal Analytical Chemistry. [Los Angeles Times]
Vincent loved yellow. In particular, he loved chrome yellow, a 19th century invention that shone brighter than previously available hues of paint. Art preservationists have known that the lead-based paint fades under intense sunlight, so they’ve done what they can to keep van Goghs and similar works out of intense light. What’s curious about his paintings, however, is that some yellows have faded while others have not.
When you’re nature’s ideal killing machine, perhaps color vision is merely an unnecessary affection. New research argues that sharks could be completely colorblind.
An Australian team led by Nathan Scott Hart investigated 17 shark species, peeking at the structure of their rod and cone photoreceptor cells in the retina. Human eyes come with red, green, and blue cone variations, allowing us to see in color. But not shark eyes. They appear to have just one kind of cone.
“Our study shows that contrast against the background, rather than color per se, may be more important for object detection by sharks,” Hart said. [CNN]
That, Hart says, may explain the common wisdom that sharks love yellow (and therefore you ought to avoid sunny swimsuits). It may be the reflective quality of yellow that catches a shark’s eye, not the hue itself.
“Bright yellow is supposed to be attractive to some sharks, presumably because it appears to the sharks as a very bright target against the water,” said Dr Hart. “So perhaps it is best to avoid those fluoro-yellow shorts next time you are in the surf.” [BBC News]
When researcher Julian Asher goes to the symphony, he gets a sensory extravaganza. “When I hear a violin, I see something like a rich red wine,” says Asher…. “A cello is more like honey” [New Scientist]. Asher has a condition called synesthesia in which sensory information gets mixed in the brain; in Asher’s particular form, auditory-visual synesthesia, sounds cause him to see colors. Now, a study led by Asher may have uncovered the genetic source of the condition, which synesthetes say can be both a blessing and a curse.
The researchers collected DNA samples from 196 people who had auditory-visual synesthesia running in their families, they explain in the American Journal of Human Genetics [subscription required]. Asher expected to find a single gene associated with the condition, but scanning the genomes revealed that it was linked to four distinct regions, on chromosomes 2, 5, 6, and 12.
The region that was most strongly linked to synesthesia was an area on chromosome 2 that has also been strongly linked to autism. That doesn’t mean that the two conditions are related, per se, explained Ed Hubbard, a cognitive neuroscientist…. Instead, the common gene or genes are likely “more generally involved in how the brain gets built.” The study also pulled out a region on chromosome 6 that contains genes linked to dyslexia — especially interesting, “seeing as phonemes [the units of sound in language] and letters are two of the strongest synesthetic triggers,” Asher said [The Scientist].
When you need to brainstorm ideas for a big project, get yourself to a room that’s painted blue. But when it’s time to proofread the final product, find a red room. Those are the implications of a fascinating new study that measured the effect that colors have on cognition. Researchers found that red can make people’s work more accurate, and blue can make people more creative [The New York Times]. Since people associate red with danger, it primes them to proceed with more caution and diligence, Zhu reasons, while blue’s oceanic connotations put them in a more adventurous mood.
Researcher Juliet Zhu decided to tackle the topic because previous studies had come up with inconsistent findings. Some studies had found that red enhances cognition, for example, while other studies suggest the opposite. Zhu suspected this might be because the work didn’t pay enough attention to which types of cognition were being affected. Red might enhance performance on some tasks, she reasoned, while impairing performance on others [ScienceNOW Daily News].