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{♫Intro♫}
There may be nothing in science that’s more mysterious than the brain, and sometimes,
neuroscientists get stuck trying to figure out what’s going on up there.
Fortunately, they’ve got some backup coming from their friends in physics.
Physicists don’t usually have the answers neuroscientists are looking for, but sometimes
they’ve got the next best thing: new tools to find them.
So, here are three exciting tools that might just help unlock the secrets of our brains.
The first comes from what may be the last place you’d think to look: astronomy.
In astronomy, one big problem for telescopes on the ground is the fact that the earth’s
atmosphere distorts light passing through it.
To correct for this, some new telescopes actually change the shape of their mirrors up to thousands
of times a second to help undistort the light that hits them.
The result is a huge amount of extra detail that you’d normally only be able to get
from a telescope out in space.
But now, similar technology is being deployed not for telescopes, but in microscopy.
Granted, there’s not usually a lot of atmosphere between the lens of a microscope and its subject,
but there’s often something even more problematic: living tissue.
Living tissue can also, of course, distort light, and if a researcher wants to image,
say, the brain cells of a living creature, they can’t exactly cut out all the stuff
in their way.
In the past, that’s meant settling for a blurry, low-res view, but this new method,
called adaptive optics, is starting to change things.
It’s not as simple as just borrowing the same tech that is used in astronomy, since
we don’t understand how light interacts with different layers of living tissue as
well as we understand its interaction with air.
But for small structures that aren’t too deep, adaptive optics are already enabling
views that are dramatically sharper. And microscope companies are starting to offer
kits that let researchers add this technology to their microscopes.
As it becomes more affordable, it will open the door to a whole new realm of biology.
Particle physicists are getting involved in the brain game, too.
Recently, a team of physicists and neuroscientists have been working together to improve something
you might be more familiar with here: EEGs.
The EEG, or electroencephalogram, is a super important tool for diagnosing things like
epilepsy, stroke, and brain tumors.
Basically, it listens to traffic in the brain, using electrodes on the scalp to pick up the
signals that brain cells use to communicate. But EEGs don’t just listen; they can also
be used to stimulate brain cells directly by running electricity the other way—through
the electrodes and into the brain.
The problem is, today, EEGs can be used to listen to the brain or stimulate it, but not
both. Why? Well, it takes the strength of, like,
six or seven AA batteries to stimulate the brain,
but the signals the brain produces itself are around a million times weaker than that.
Current EEGs don’t have that huge range of sensitivity, so researchers can’t just
stimulate the brain and immediately measure its response.
Being able to do that would be really valuable, though, because it would show the link between
activity in one region and a response in another—which could help them understand and treat certain
conditions.
That is where particle physicists come in. That whole problem of detecting a super-faint
signal in the middle of really strong ones… that’s exactly what particle physicists
do all the time.
So a team of researchers—from both physics and neuroscience—got together. They took
an off-the-shelf EEG system that could detect the brain’s faint signals and added some
electronics. The final product alternates between listening to the brain and applying
stimulation.
In true scientific fashion, they tested the first prototype on themselves.
And it seems to work! This first version can only send a basic signal and listen for any
response, but the team is already working to expand that.
So, don’t look for this at your doctor’s office anytime soon, but now that we know
the principle works, it seems like it’s only a matter of time.
Finally, here’s a question you probably never expected to hear: What if we made an
earthquake in the brain? A... brainquake?
Well, someone actually asked that question — in the hopes of finding a better way of
imaging deep inside the brain.
Today, doctors currently have two options: They can stick you in an MRI machine or use
an X-ray machine to conduct a CT scan.
There are downsides to both of those methods, though, so some researchers have been exploring
a third way to peer inside: ultrasounds. Ultrasound imaging creates vibrations in the
body that reflect off our organs and back to a special sensor that turn them into an
image.
They work really well for seeing inside things like the uterus, so naturally, people have
tried using them to image the brain.
The problem is, the hard, round shape of our skulls causes the vibrations to bounce around
in complicated ways, which produces an image that just doesn’t look like much.
But this result happens to be a lot like what happens when seismic waves from an earthquake
reflect around inside of our planet.
And, that is a problem physicists have been working on for a long time.
To create a picture of what’s inside the Earth, geophysicists don’t start with a
blank slate—they start with a rough model approximating what’s inside. Then, they
gradually tune their model based on real-world seismic data.
Starting out with a basic sketch helps them weed out the data points that are way off
so their final image is cleaner. And now, researchers are trying to apply those
same techniques to create ultrasound images of our brains
They’re starting with models and then using those vibrations to fine-tune those models
to see things more clearly.
They’ve only tried it with simulated brains so far, but the approach seems to be working!
And, if it can get turned into an actual product, the benefits could be enormous.
An ultrasound scanner for your brain could be small enough for ambulances to carry, enabling
EMTs to diagnose things like strokes before a patient even gets to the hospital. Which
could be huge.
Today, a lot of the world’s most important problems are in medicine, and fortunately,
biologists aren’t in this alone! With the help of a friendly neighborhood physicist,
our brains can all end up healthier and happier.
If you want to learn more about creative techniques that can help us better understand human nature,
you might like the book “Social Physics,” which is available on Blinkist.
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{♫Outro♫}