[♩INTRO]
When you were a kid, you probably learned to talk by imitating others.
Like, after hearing people say “Bye bye!” enough times,
you finally learned to make those sounds yourself
to the delight of everyone around you.
But what if there were another way?
What if someone could shine a light on your brain,
and you’d suddenly know the foundations of language?
Well, that sounds kind of ridiculous, but that’s basically what researchers did
in a study published last week in the journal Science.
But...with birds.
They showed that songbirds could learn parts of their courtship song
after having it beamed into their brains.
And while this method will probably never catch on in humans,
it could help us understand how we learn to speak in the first place.
Now, at first, this research might seem bizarre...maybe even a little bit absurd,
but the goal was actually pretty simple: The researchers wanted to know
what pathway in the brain is needed to learn something through imitation.
This work is still in the early stages, so instead of experimenting on humans,
the study used male zebra finches.
These are small, pretty cute birds that learn their songs
by listening to and imitating older birds.
Past research has suggested that at least some of this process
is affected by a pathway between two of their brain regions:
the NIf, and the higher vocal center, or HVC.
But it hasn’t been totally clear how the pathway is involved
so that’s what this team wanted to figure out.
One of the best ways to see what something does is to manipulate it.
So this team investigated if stimulating those neural pathways
in baby birds would implant the memory of a song.
Which, I guess makes sense.
But is still totally bananas!
When the birds were only about a month old, the researchers used a type of genetic
engineering to make some of their brain cells activate in response to light.
Then, they raised the animals away from adult birds to make sure they weren’t
getting any singing lessons outside of the experiment.
As the animals grew, researchers simulated song-tutoring by shining
a type of blue light directly into their brains at different intervals,
which excited those neurons-of-interest in the NIf.
From the brain’s perspective, there wasn’t much difference between this
and getting an input from an actual bird.
So when the test animals reached adulthood, they had a pretty good idea what their
song should sound like, even though they’d never imitated a real animal.
Admittedly, there were some differences, so the researchers say these implanted
memories guide learning, as opposed to being virtual sheet music.
But since the goal was to figure out the HVC’s job,
those results were pretty awesome.
And also slightly upsetting.
Like, I’m a little worried about memory implantation.
And of course, there are more questions to answer here, too.
For instance, another experiment in this paper demonstrated that the HVC pathway
is necessary when a bird is learning a song, but not afterward.
And it’s not clear which part of the brain takes over next.
Studies like this are great for animal biology,
but this type of research could someday apply to humans, too.
There’s no guarantee that we will someday be shining light on our brains
especially considering those two brain regions in finches don’t exist in humans.
But this work will likely prompt future experiments that show how social interactions
help us imitate sounds.
And that could be really helpful in places like speech therapy.
In other news, scientists recently got their hands on some cool new tech and used it
to study human embryos and fetuses.
They published their results last week in the journal Development,
and what they found was pretty amazing.
The team announced the discovery of new muscles present
in fetuses that disappear before birth.
And they propose this could teach us more about, of all things, our own evolution.
Now, scientists have been researching human development for more than
a hundred years, so the fact that fetuses have muscles that adults don’t isn’t new.
But this study used a combination of 3-D imaging techniques to show us
that process in the highest resolution yet.
That helped scientists update our general body of information,
but naturally, the team also carried out a huge analysis of the new data.
Because like, what else do you do with a mountain of shiny new info?
The team was trying to figure out when in development certain muscles
form or split off from each other.
And in the process, they found entire muscles
that form in the hands and feet but disappear before birth.
One set of muscles in the hands, called the dorsometacarpales,
was especially interesting.
According to the paper, it typically shows up by about seven weeks after conception
and fuses with other muscles by about thirteen weeks.
If it stuck around, the scientists hypothesize it might be involved in the forearm,
or it could act like the extra muscles in our thumbs, which give us more dexterity.
These guys.
But the coolest part isn’t necessarily what the muscle would do.
The amazing thing is that, while we rarely see this as a separate muscle
in adult humans, it does appear in other animals, like lizards.
Did you think I was going to say monkeys?
No. Lizards!
That’s another piece of evidence that we once shared
a common ancestor with that group.
The team suggests this muscle disappeared from our adult, mammalian ancestors
around the time we split off from reptiles.
So, roughly two hundred and fifty million years ago.
And although it isn’t clear why it still appears in fetuses, it’s really cool that it does.
Getting to draw these kinds of evolutionary connections is a big reason
these scientists were interested in studying disappearing structures.
And with tools like this new hi-def imaging technology at our disposal,
it’s exciting to imagine what we’ll see next.
Speaking of new things, I have an exciting announcement!
SciShow is produced by Complexly, a video production company that tries to make
content to help people understand ourselves, each other, and the universe.
And we’re about to try a new thing.
We’re launching our very first pilot season!
Which sounds like such a ridiculous idea to me, but we’re doing it!
From October 15th to the 31st, we’re going to debut
three new YouTube channels with three episodes each.
They’re called History Pop, Stories Retold, and Hashed Out,
and you can find more about each of them in the links in the description.
At the end of October, we’re going to see how the world responded to each channel,
how we felt about them, and figure out which to keep producing.
So we’d love it if you check them out and if you tell us what you think!
Again, check out the description to learn more,
and we’ll have some new shows starting for you next week!
[♩OUTRO]