|Eleventh day of Advent|
(Common name, Mallard)
|Eleventh day of Advent|
Not unlike a platypus, but ya know…
Visual illusions, such as the rabbit-duck (shown below) and café wall are fascinating because they remind us of the discrepancy between perception and reality. But our knowledge of such illusions has been largely limited to studying humans.
That is now changing. There is mounting evidence that other animals can fall prey to the same illusions. Understanding whether these illusions arise in different brains could help us understand how evolution shapes visual perception.
For neuroscientists and psychologists, illusions not only reveal how visual scenes are interpreted and mentally reconstructed, they also highlight constraints in our perception. They can take hundreds of different forms and can affect our perception of size, motion, colour, brightness, 3D form and much more.
Artists, architects and designers have used illusions for centuries to distort our perception. Some of the most common types of illusory percepts are those that affect the impression of size, length, or distance. For example, Ancient Greek architects designed columns for buildings so that they tapered and narrowed towards the top, creating the impression of a taller building when viewed from the ground. This type of illusion is called forced perspective, commonly used in ornamental gardens and stage design to make scenes appear larger or smaller.
As visual processing needs to be both rapid and generally accurate, the brain constantly uses shortcuts and makes assumptions about the world that can, in some cases, be misleading. For example, the brain uses assumptions and the visual information surrounding an object (such as light level and presence of shadows) to adjust the perception of colour accordingly.
Known as colour constancy, this perceptual process can be illustrated by the illusion of the coloured tiles. Both squares with asterisks are of the same colour, but the square on top of the cube in direct light appears brown whereas the square on the side in shadow appears orange, because the brain adjusts colour perception based on light conditions.
These illusions are the result of visual processes shaped by evolution. Using that process may have been once beneficial (or still is), but it also allows our brains to be tricked. If it happens to humans, then it might happen to other animals too. And, if animals are tricked by the same illusions, then perhaps revealing why a different evolutionary path leads to the same visual process might help us understand why evolution favours this development.
The idea that animal colouration might appear illusory was raised more than 100 years ago by American artist and naturalist Abbott Thayer and his son Gerald. Thayer was aware of the “optical tricks” used by artists and he argued that animal colouration could similarly create special effects, allowing animals with gaudy colouration to apparently become invisible.
In a recent review of animal illusions (and other sensory forms of manipulation), we found evidence in support of Thayer’s original ideas. Although the evidence is only recently emerging, it seems, like humans, animals can perceive and create a range of visual illusions.
Animals use visual signals (such as their colour patterns) for many purposes, including finding a mate and avoiding being eaten. Illusions can play a role in many of these scenarios.
Great bowerbirds could be the ultimate illusory artists. For example, their males construct forced perspective illusions to make them more attractive to mates. Similar to Greek architects, this illusion may affect the female’s perception of size.
Animals may also change their perceived size by changing their social surroundings. Female fiddler crabs prefer to mate with large-clawed males. When a male has two smaller clawed males on either side of him he is more attractive to a female (because he looks relatively larger) than if he was surrounded by two larger clawed males.
This effect is known as the Ebbinghaus illusion, and suggests that males may easily manipulate their perceived attractiveness by surrounding themselves with less attractive rivals. However, there is not yet any evidence that male fiddler crabs actively move to court near smaller males.
We still know very little about how non-human animals process visual information so the perceptual effects of many illusions remains untested. There is variation among species in terms of how illusions are perceived, highlighting that every species occupies its own unique perceptual world with different sets of rules and constraints. But the 19th Century physiologist Johannes Purkinje was onto something when he said: “Deceptions of the senses are the truths of perception.”
In the past 50 years, scientists have become aware that the sensory abilities of animals can be radically different from our own. Visual illusions (and those in the non-visual senses) are a crucial tool for determining what perceptual assumptions animals make about the world around them.
Laura Kelley is a research fellow at the University of Cambridge and Jennifer Kelley is a Research Associate at the University of Western Australia. They are the co-authors of the paper ‘Animal visual illusion and confusion: the importance of a perceptual perspective‘, published in the journal Behavioural Ecology.
Bringing together significant work on all aspects of the subject, Behavioral Ecology is broad-based and covers both empirical and theoretical approaches. Studies on the whole range of behaving organisms, including plants, invertebrates, vertebrates, and humans, are welcomed.
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Image credit: Duck-Rabbit illusion, by Jastrow, J. (1899). Public domain via Wikimedia Commons.<
The post Animals could help reveal why humans fall for illusions appeared first on OUPblog.
Something on the drawing board. It’s fun to take a pic and distort it!Add a Comment
Friday night, Halloween night, it rained for the first time in, like, forever!
It was miraculous and life affirming!
It was marvelous!
Was looking forward to more precipitation, but nooooooo. The sun shone mockingly back at me today.
Maybe tomorrow we’ll get some “fowl” weather.
What is SkADaMo? Check it out here.
During a walk by the water yesterday, I stopped to watch the various birds search for their evening grub. A tall, slim heron, was idling along in the shallow waters on his own, while nearby were ducks and gulls in pairs or groups. And the ducks and gulls were often intermingled with each other. So I imagined what the plight of this heron would be if he were to join in. He would certainly have some struggles to interact, as he towered at least a foot above the other birds. And so I figured it might be a lonely experience, to be in the midst of a group where you towered over everyone else.Add a Comment
4 Stars Pobble’s Way Simon Van Booy Wendy Edelson 32 Pages Ages: 4 to 8 Inside Jacket: Pobble’s evening walk with Daddy is a magical adventure in which branches wear sleeves of snow and mushrooms become frog umbrellas. When Pobble’s mitten—small and pink and as soft as a bunny’s chin—is lost on the path, woodland animals gather to discuss [...]Add a Comment
4 Stars Chasing Watermelons Kevin White Rex White 32 Pages Ages: 3 to 6 ……………… Press Release: When Duck opens a crate of watermelons for a watermelon feast, they begin to roll. Duck chases after them. One by one, Duck invites Goat, Pig, Chicken, and Cow to join the chase by promising, “If you help, [...]Add a Comment
“Eliminate all other factors, and the one which remains must be the truth,” Sherlock Holmes has said about his method of detective work. In Sylvan Dell’s new picture book, Deductive Detective, our hero Detective Duck shows that he’s learned from the best! He dons his best deerstalker hat, his much-too-big magnifying glass, and solves the case of the missing cake with the same methods the pros use!
That is, a style of logical thinking called “deductive reasoning.” In deductive reasoning, someone finds an answer they’re looking for by first finding out what the answer isn’t. When Detective Duck examines the clues and finds out which of his friends couldn’t have stolen the cake, it leads him closer to what really happened!
Of course, you don’t need a weird hat and a magnifying glass to use deductive reasoning. These methods come in handy every day! If you lose a toy, for example (or car keys), you may make your search easier by determining where the item isn’t.
“Oh yeah,” you may say, “I didn’t bring it to my friend’s house; I wasn’t holding it when I walked to the living room, or landed on the moon. I wouldn’t have brought it to my parents’ room or under the ocean or into Mordor.” By deciding where you shouldn’t look, you now have a better idea of where you should.
This kind of logic process happens throughout the day, sometimes without you even being aware of it; you might say your brain is always on the case as much as any detective!
Apply deductive reasoning the next time you’re in the bookstore: subtract the books that don’t meet the highest educational standards, offer pages of activities and facts, offer online supplements, are fun to look at and fun to read! You’ll be left with books by Sylvan Dell like The Deductive Detective!
To all the mothers out there of every species, have a wonderful day!
The post Happy Mother’s Day! appeared first on .Add a Comment
2. However, if you need to be bailed out, a bunny is the first critter you should call.
3. Bears will sink your boat.
My little Newton the lamb has hit the big time in South Africa! This week I received these pictures of a new pre-school with my Newton as their mascot! It’s great fun to see the children wearing Newton t-shirts. Way to go Newton!
In anticipation of yet another upcoming move (just a short, local move this time), I started designing a postcard to send out once we're settled at our new address:
I think I'm setting myself up for a serious challenge with all the ripples in the water those little ducklings can't help but generate. But for the opportunity to illustrate ducklings in all their irresistable cuteness, hopefully the challenge will be worth it!
Our final moving date is just a little over a week away and there's still a lot to do. I need to put in change of addresses with various places, set up phone and internet service at our new home, and gather up a bunch more book boxes for our substantial library. But, I do, at least, have my painting all finished and ready to be made into postcards:
I think I'm probably going to post this one for sale on my Etsy shop, but I think it might be best to hang on to it until my postcards are finalized. So, if you're interested, check my shop in maybe three or four weeks. I'll update here with a direct link too when it's available.
This is the alleyway leading to the almost hidden entrance of one of the highest rated duck restaurants in Beijing. The inside looks much like you would expect of a place you enter from an alley, but the food is so very very good!Add a Comment
When I was in elementary school… a gazillion years ago, we used to do this drill called “duck and cover.” You’d be in class, minding your own business, when a scary, air-raidy sounding alarm would go off. You were then expected to drop down to the floor, crawl under your desk and cover your head with your hands. This was a drill designed to protect you against a nuclear attack.
You heard me.
A nuclear attack. Duck and Cover. Mmmm hmmmm.
I guess they figured it was an easier position to be in to kiss your tookus good-bye.
Anywho, this here is a kinder, gentler, sillier take on the theme… probably just as effective too.
Right up until the moment Iggy remembered her intense fear of water, she quite enjoyed her day spent stalking ducks.
A duck walks into a bar, approaches the counter and orders a sandwich. He says to the bartender, "Listen, I'm a bricklayer on the construction site nearby. The work will last for some time and I'll be coming here every day around lunchtime for a sandwich. How about a discount?"
The bartender, shocked as he has never encountered a talking duck before, agrees to give the duck a small discount for his daily sandwiches.
The duck takes his sandwich, pays, thanks the bartender and goes out.
The bartender immediately calls his friend who owns a circus:
"Listen, there's a talking duck coming to my bar. Come tomorrow around lunchtime, you gotta see this for yourself!"'
So the next day the circus owner waits in the bar. Sure enough, the duck goes in, jumps on the barstool and orders a sandwich.
The circus manager overcomes his awe and says:
"Hello sir, I'm a circus owner and I want to offer you a job. I can give you whatever money you want, plus a company car, a cell phone, best hotels. Really, whatever you want!"
The duck considers his offer for a moment and says:
"So you're a circus owner, right?"
"And your circus is one of those big tents, right?"
"With a sandy arena in the middle?"
"And with rows of seats around?"
"So what the heck do you need a bricklayer for?"
My dad sent me this joke last week. I just couldn't resist illustrating the duck.Add a Comment
July 1, 2012…. Happy Mid Year!
This is exactly the midpoint of this year. Most of us only make New Year’s Resolutions; or really attend to projects at their beginning point; or only have great starts to their races –
but Puppicasso knows that the hinge of everything lies in survival of getting through the bend of the middle.
To that he asks me, “What’s your mid-year resolution?” He never waits for my response to any question since he has other needs at present, always at present.
Those needs take us to the outside, and that’s where we see them, the unexpected guests…
ducks in the alley in the Valley.
I have seen ducks walking around before, but never in the civilized wild, only in parks or in Memphis at the Peabody Hotel, but never casually strolling. And indeed never in an alley.
So Puppi and I follow the pair of ducks to the midpoint of the alley, I think they got wind of us, so as not to disturb their unique path, we turned back around and ventured elsewhere for his business, which included the usual mischief of barking at Shadow and finding a compost heap to do a quick face rub in.
By the time we got back, the ducks were at the top of the alley again, where we found them the first time.
Maybe they are in purgatory, but more likely they are at their midpoint. Puppicasso says that I can give myself a break at my midpoint – I don’t have to meet my New Year’s goal, simply start a Mid-year one.
Thanks Puppi, I needed that do-over.