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Pigeons are… smarter than they look.
Admittedly, that’s not a super high bar to clear.
But you may have heard that these supposed birdbrains are so smart, they can actually
read.
Is that true?
The main study behind this claim was published in 2016, and it looked at orthographic processing,
which is the ability to visually recognize what a given word looks like. And it found
that pigeons can do that.
But despite a slew of news stories suggesting that pigeons can read or kind of read, this
research didn’t show that pigeons can actually read, like, at all.
Here’s what it did show.
Researchers put eighteen pigeons through a training regimen designed to teach them to
distinguish four-letter words from four-letter strings of gibberish.
It was a follow-up to a similar 2012 study on baboons, which showed that non-human primates
have the ability to recognize words as visually-distinct shapes.
But baboons are still primates, like us.
So the real question was, can anything that’s not a primate do this?
The pigeon researchers drew four-letter words from a pool of 308 words previously used in
the baboon study.
A screen in front of each pigeon displayed words and non-words one at a time, along with
a small star.
If the sequence of letters on the screen was a real word, the pigeons were supposed to
peck the word.
If it was a jumble of letters, they were supposed to peck the star.
If they were right, they got a treat.
If not, they got to try again until they got it right and got their treat.
The researchers taught the pigeons one word at a time until they could reliably recognize
it.
Then, once they mastered that word, the researchers introduced another one, while also quizzing
them on older words to keep their memories fresh.
After a grueling 8 months, the researchers identified the top four word-learners.
These feathered savants had learned to recognize anywhere from eight to twenty-three words.
These word-pecking prodigies then continued their training, after which the sharpest pigeon
of the bunch eventually learned to distinguish /fifty-eight/ words.
But they didn’t just learn to distinguish words from non-words.
To the researchers’ surprise, the pigeons could also tell the difference between words
they knew and mixed-up versions of those words -- like V-E-R-Y vs. V-R-E-Y.
This so-called transposed letter effect is considered a hallmark of orthographic processing.
This means that not only can pigeons recognize words from non-words, they also grasp the
statistical properties of letters and their distribution within words -- like, where the
letters are supposed to go.
Which is impressive, but it’s not the whole deal when it comes to reading.
Along with orthographic processing, reading involves several other systems working in
tandem.
As human kids learn how to talk and read, they learn how sounds correspond to spoken
and written words. That’s known as phonological processing.
Semantic processing is how we get to the meaning of words.
It’s what our brains use to conceptualize, say, the word “water” as that refreshing
liquid that we crave when we’re thirsty.
There’s also syntactic processing, which involves the position and arrangement of words
in relation to each other, and morphological processing, which deals with the smallest
meaningful bits of words.
Pigeons haven’t been shown to engage in, yeah, any of those additional processes that
are crucial to actually reading.
But just because pigeons can’t be taught to appreciate Shakespeare — or fanfic depending
on what you’re into — doesn’t mean that the study’s findings aren’t exciting or
important.
This pigeon study gives us new insight into fundamental questions about the origins of
reading and language.
Like, there’s a region of our brain called the visual word form area that activates when
we read.
But humans have only been reading for 5000 years.
That’s way too recent for a special, reading-specific part of our brain to have evolved,
so scientists hypothesize it must have started out doing something else.
Pigeons’ brain architecture and visual systems are distinctly different from human brains,
yet they’re capable of what seems to be a similar kind of orthographic processing.
That means that visual systems that aren’t genetically or physically similar to humans’
can somehow use the brain wiring that helps animals recognize objects and pictures to
also recognize words and word structure.
And that provides a clue that our own reading-specific brain center could actually have an older
function in recognizing visual information --
something pigeon brains can do, too, even though they’re so different.
So perhaps we just co-opted that function for reading, in what’s known as the neuronal
recycling hypothesis.
Maybe they can’t read, but these pigeons -- and their birdbrains -- have a lot to teach
us.
Thanks for watching this episode of SciShow, which is produced by Complexly.
We produce over a dozen channels, including Nature League, which recently celebrated its
first birthday.
Host Brit Garner explores life on Earth and questions what we think we know about the
natural world.
Each week she strives to critically examine the relationship between humans and the other
species that share this planet -- like pigeons.
For a taste of what you can expect, we’ve linked to their “Best of” playlist in
the description below.
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