Breaking News: Fish Confused by Optical Illusions

Despite the sarcastic title, this work is pretty neat. In a recent Scientific Reports paper (open access, yay!), researchers from the University of Padua in Italy found that fish pretty much see the world as we do, as least when talking about motion illusions. If you’ve spent time as a child, you’re probably familiar with optical illusions (personally, I was obsessed with Magic Eye books; maybe I shouldn’t say was). Motion illusions are a type of optical illusion that make the brain perceive motion from a static image (see picture below).

illusion

Their version of the classic Rotating Snakes illusion, abbreviated RSI in the paper because all academic papers need more abbreviations.

Why fish? It turns out that fish don’t have a visual cortex like humans and other mammals. We know fish can see (they need to to hunt and escape predators) but we don’t know exactly what they see. We do know they see changes in light, but can they see texture and contrast and form? In mammals, this additional sight comes from our visual cortex. If fish do get additional visual information, then they must do so in a manner completely distinct from us. That’s why fish were chosen: to see if they perceive an illusion that arises in mammals from our visual cortex.

To find out this interesting piece of scientific information, they crammed a fish tank between two computer monitors. On one monitor was the RSI (the allure of abbreviations has not yet left me). The other monitor had a static version of the image, only subtly different, without the motion illusion. The fish were trained to spot motion to get a food reward (tasty, tasty brine shrimps).

After all was said and done, 18 out of 24 fish were confused (that’s 75%). They thought the illusion was real and tried to get their food reward (their… just desserts). This compares fairly well with the percentage of humans who can see the illusion (that’s 84%).

The experiment didn’t explain how fish, with their lack of visual cortex, saw the motion. If anything it threw more questions into the mix, which I think is a good thing. The object of a good scientific paper shouldn’t be to answer all the questions but to ask more… unless you’re trying for a Theory of Everything (the answer to it all, the mack daddy of theories, the big ToE).

I, for one, welcome our new robot overlords.

Robert Platt from Northwestern has used a new technology created by Edward Adelson from MIT to make a robot that plugs in USBs. This is more difficult than it sounds (unless you’ve had experience with fourth-dimensional USBs, then it’s exactly as difficult as it sounds). If the robot is not pre-programmed, like these on-the-fly USB pluggers, their external sensors must be highly precise—a centimeter off and your drink will get cold without your USB drink warmer. Or worse. Your pet rock may not charge.

usb-joke

In the unspoken scientific agreement to make robots increasingly human, the sensor system relies on vision. One side of the robot’s rubber gripper is coated with metallic paint. The rest of the gripper is surrounded by a translucent box. Each side of the box emits a different-colored light. When the robot grips, the sides light up depending on how the gel inside of the box deformed. By using computer algorithms that monitor the color and intensity of the light, the three-dimensional structure of the gripped surface can be “seen”. This system worked well. The robot was able to find a dangling USB plug, grab it, and plug it into the port.

The more important discovery here is that the robot can insert the USB correctly on the first try. Technology has truly passed our human limitations.

I’m like a rat. I only fly away.

A decade ago, scientists at the University of Florida taught a Petri dish rat brain to fly a flight simulator. They grew a culture of 25,000 rat neurons and, using 60 electrodes, hooked it up to a common desktop computer. At first, the neurons were simply scattered in the dish, but they quickly started to form connections. “You see one extend a process, pull it back, extend it out – and it may do that a couple of times, just sampling who’s next to it, until over time the connectivity starts to establish itself,” Thomas DeMarse, the lead biomedical engineer of the work, described in a ScienceDaily release. When the neural network was joined to the computer, more connections formed as the “brain” learned to control the simulated F-22. Eventually, the “brain” could control the pitch and roll of the aircraft in a variety of conditions, including hurricane-force winds.

flightsim

Would a Petri dish brain get motion sickness?

According to the release, “As living computers, they may someday be used to fly small unmanned airplanes or handle tasks that are dangerous for humans, such as search-and-rescue missions or bomb damage assessments.” A prescient statement for a time before drones (or at least before the public knew). Who knows, maybe the next generation of war will be fought by rat brains.

(For anyone who doesn’t understand the title of this post, I thought I’d bring back some early 2000s references. Remember this?)

Hemp: Not Just for Granola-Eating Hippies

Hemp is back, man, and more energizing than ever. David Mitlin, then at the University of Alberta and now at Clarkson University, has developed a method for making supercapacitors out of hemp that is not only much cheaper than graphene (the cream of the crop as far as organic conductors go), but also outperformed standard devices by nearly 200%.

In a press release from the American Chemical Society, Mitlin gives the best quote possible on his research: “We’ve pretty much figured out the secret sauce of it. The trick is to really understand the structure of a starter material and to tune how it’s processed to give you what would rightfully be called amazing properties.” Right on.

hemp

The American Society of Mechanical Engineers is down with hemp.

To make the supercapacitors, his group heated hemp waste at 180 °C (~350 °F) for a day to get a nice char going, then blasted it at 800 °C (~1470 °F) with a little potassium hydroxide. That final burn turned the char into carbon nanosheets (as so nicely depicted in the above picture from the American Society of Mechanical Engineers). The hemp precursor left a lasting impression on the nanosheets, giving them the unique molecular structure that Mitlin claims is key to his device performance. The sheets were riddled with holes 2–5 nanometers in diameter, making nice paths for charges to move in and out.

Yury Gogotsi, materials scientist at Drexel University, in a comment to Chemical & Engineering News, says that scaling up the process may be difficult (read: costly), what with the high temperatures and day-long heating process.

But that’s just, like, his opinion, man.

Froggy Style

City frogs like to look for mates in the gutter, according to a report in the Journal of Zoology. Researchers in Taipei found that male tree frogs were congregating in storm drains. It turns out that the structures amplify their mating calls by about 4 decibels, which could help to attract the ladies. The verdict is still out on whether this technique works, but I suspect frogs aren’t too picky about the setting of their romantic trysts.

treefrog

Our little buddy desperately calls for a mate.

Read a bunch of articles on the paper here: Nature News, Live Science (which got picked up by Mother Nature Network and for some reason The Christian Science Monitor), CityLab (complete with “Sexy Sewer Mix” recording) and News Tonight Africa.

That Spider Looks Like Shit

Bird shit, to be specific. In a sad-for-you but funny-for-me play by evolution, the Cyclosa ginnaga orb-web spider has somehow learned to fashion its nest so, when sitting in it, the spider looks like bird poop. This is, like most evolutionary advances, done in an effort to avoid predators (thankfully, these spiders don’t dress up like poop to find a mate). To predators such as ants and wasps, the color of the spider’s body and its web decorations are indistinguishable from each other and from bird dukes. A group in Taiwan published these findings in a recent issue of Scientific Reports (which is open-source, hooray).

(a) Our spider friend pretending to be poop and (b) a reference in case you don't know what bird poop looks like.

(a) Our spider friend pretending to be poop and (b) a reference in case you don’t know what bird poop looks like.

 

In the paper, the authors noted  that many have pointed out that the spider looks like shit, but no one has ever done a scientific experiment to confirm this “hypothesis”.  So they gathered up 10 spiders and waited for them to spin their webs. Then they measured the specific wavelengths of light emitted by the spider’s bodies, their webs, and, of course, bird turd for comparison. Using a computer program to analyze the emitted patterns, they found that bees and wasps couldn’t distinguish between the spider and its web—it all looked like one big blob to them. What’s more, they couldn’t distinguish the spider-web blob from a pile of bird dinks either.

Then, they went out in the wild and decided to color some of the webs black so that the spiders could no longer hide. In short: “When the color signal of decoration silk is altered the predator attack rate increased significantly,” I-Min Tso, an ecologist at Tunghai University and co-author of the paper, told Smithsonian Magazine. The spiders not only needed to blend in with their web, but the entire setup had to blend in with the background, the forest. Black was just too obvious of a disguise.

Oddly enough, “it’s really not all that uncommon. Several other spiders, like Bolas spiders, also use this disguise,” Cornell University arachnologist Linda Rayor, who was not involved in this study, told National Geographic.

So the next time you think you look like shit, remember our little friend C. ginnaga and realize you don’t look so bad after all.

Journal of Proteomics Gets Weird

Harry Belafonte and the secret proteome of coconut milk sounds like a bad detective novel from the 50s (maybe even a radio show). Really, it’s the title of a January 2012 paper in the Journal of Proteomics. After the title, the abstract calms down a bit. They talk about mapping the proteome (proteins expressed by a genome) of coconut milk. Their reason for doing this pain staking work is to create a starting point to discover the proteins responsible for the beneficial health effects often attributed to coconut milk.

And then there’s the graphical abstract:

Image

And their wonderful caption: “Here is your coconut woman, as perhaps envisioned by Harry Belafonte. For its proteome, though, have a look at the report inside!”

They also have a list of highlights about coconut milk.

  • The beverage promoted by Harry Belafonte since at least 1957!
  • A most nutritious beverage in vogue in the Caribbean and all over the world.
  • A grand total of 307 unique gene products detected.
  • Now you know what is the proteome in your Mocha Coconut or Coconut Crème Cappuccino or even in your Piña colada.

In the introduction they even have a recipe for a Batida de Côco coctail (“coconut milk is mixed with sugar and cachaça”). The paper then goes on to talk about proteomics and gel electrophoresis and mass spectrometry, but, man, did they really put some effort into making their work “interesting.”