3 Big Things We Learned About the Brain in 2019


We’ve learned a lot about how the human
brain works, but there are still new discoveries and mysteries each year. And this past year was no exception. From internal compasses, to mysterious sniffers,
to brain-washing — no, not like that — here are three ways the brain surprised us in 2019. [ ♪INTRO ] First, in March, scientists published evidence
in the journal eNeuro that humans may be able to sense Earth’s magnetic field. We know an internal compass exists in a lot
of animals, like migratory birds and sea turtles, and we’ve suspected it might be present
in humans, too. But no one had been able to provide solid
evidence for that — so last year, scientists took another run at the problem. They asked a group of about 30 volunteers
to — one-at-a-time — climb into a special, room-sized device designed to block the Earth’s
magnetic field. The device had two main components: an external
Faraday cage, which blocks magnetic fields, and internal coils that could create an artificial
magnetic field — one the scientists could control. So basically, the only magnetic fields the
participants experienced were the ones for the experiment. In the study, the test subjects sat in a wooden
chair in the center of the room, in the dark, while the scientists manipulated their artificial
magnetic field. They turned it this way and that way as if
the person was turning around. Kind of like virtual reality, but for magnetism. Meanwhile, an EEG machine monitored the volunteers’
brain activity — specifically, their alpha waves, which are seen when someone is awake,
but resting. Then, the scientists combined all the participants’
data sets and analyzed them. They found that certain changes in the artificial
magnetic field appeared to trigger changes in the participants’ alpha waves. It was as if the brain suddenly noticed an
abrupt change, suggesting there really is something in our brains that can sense magnetism. That said, the scientists don’t know what
that mechanism is, if it does exist. They suggested it could have something to
do with magnetite crystals: iron compounds we’ve found in other animals that can function
like biological magnets. Where these might be located in our brains…
we don’t know. But one way or another, this study was still
really helpful for the field, and it will be interesting to explore this more in the
future. Next, moving from “things we’re trying
to find” to “things that are missing”! In November, scientists announced in the journal
Neuron that they’d found people who could smell without olfactory bulbs. Our olfactory bulbs are located just above
the nasal cavity, and they’re a part of our brain responsible for receiving and processing
nerve signals from our noses. Basically, they allow you to smell stuff. Except… maybe that’s not the whole story. Last year, a group of scientists, working
on a completely different study, were using MRI brain scans to look at the olfactory bulbs
of volunteers. And they found something unusual: a 29-year
old woman without olfactory bulbs. Not having these things isn’t unheard of,
but what was confusing is that the woman said she could smell just fine. And this wasn’t a one-off case. As the researchers were building a control
group for their study, they found another woman who also could smell without olfactory
bulbs. And tests backed up these claims. With the exception of one type of fruity-smelling
chemical, the women had normal senses of smell. But how? Well, we don’t know yet. The scientists weren’t able to detect any
other differences in their brains, compared to the control group. So maybe this is an example of just how the
brain can adapt when some structure is missing. Or… maybe not. Other scientists have pointed out that it’s
possible there may be something there that just didn’t show up on the MRI. Maybe the women had really small olfactory
bulbs. In any case, something is going on. And also? There’s a final twist in this mystery, too. After scientists combed through a database
of about a thousand people’s brain scans, they suggested this condition — whatever
it is — might be associated with being female and being left-handed. Based on that database, they estimated that
about 1 in every 200 women, and maybe 1 in every 25 left-handed women, might be mystery
sniffers. Admittedly, it does sound like a bit of a
stretch, given how small their sample size was. And we definitely need more data about it. But the authors, at least, think there’s
a correlation here. So if they’re right, maybe there’s something
even cooler to be found this year. Finally, from sniffers to sleepers! Also in November, researchers announced in
the journal Science that our bodies may naturally kind of “wash” our brains while we sleep. See, like I said earlier… not that kind
of brain-washing. Although you’re not awake to experience
it, a lot is going on in your brain while you sleep, including changes to brain waves
and blood flow. But scientists have also detected changes
in the amount of cerebrospinal fluid, also called CSF. It’s a clear, colorless fluid that surrounds,
cushions, and protects the brain, and it can also carry things like antibodies. In this new study, though, the scientists
wanted to know exactly what the CSF was doing. So they used MRI and EEG machines to watch
what was happening in 13 people’s brains during dreamless sleep. And they found something pretty cool. They discovered that CSF seems to flow in
and out of the brain in waves, about one every 20 seconds. This happened more-or-less in sync with certain
brain waves and opposite cycles of blood flow. As the blood goes in, the CSF goes out, and
vice versa. The scientists think these waves of fluid
might be important for maintaining our brain’s health, and they might even be a missing link
in how we understand sleep. For instance, as your sleeping brain is solidifying
memories or doing whatever else, it looks like waves of CSF might help flush out toxic,
memory-impairing proteins or other waste. So now, the scientists think investigating
how CSF flow changes could be a way into studying conditions associated with sleep, like insomnia. At the end of the day, our brains are super
weird. They seem to go through a wash cycle, might have bits we haven’t found yet, and might
not need all the bits they do have! But for as strange as they are, they’re
absolutely fascinating. And the more we learn about them, the more
we’ll understand a big part of what makes us who we are. Thanks for watching this episode of SciShow
Psych! If you want to help us make more content like
this in the New Year, you can head over to patreon.com/scishow. Our patrons are an amazing community of people
who love to learn, and they’re the ones who voted for us to create SciShow Psych in
the first place. So, to all our current patrons, thank you! This show literally wouldn’t exist without
you. Happy new year! [ ♪OUTRO ]

73 thoughts on “3 Big Things We Learned About the Brain in 2019

  1. Well, you know, we also have taste buds in our asses. So why no olfactory bulbs?
    I mean, it's a possibility.

  2. It might be outside the scope of this video but I think it will be interesting to see what comes out of the discovery of the woman who had a genetic mutation which protected her from Alzheimer's. Heard of it from a New York Times article in November.

  3. Who ever is reading this , just remember that you are good at what you love and you will make your dreams come true

    My dream is to be a big youtuber

  4. Is Mr. Brown a new host? I haven't seen him before, but he joins the host lineup quite nicely. (I confess that I don't watch every video. He might have hosted for months.)

    Right on.

  5. There "is" new mysteries? Please, no. A little careful scripting, a few do-overs, would help maintain the credibility of the show. It's more than worth it.

  6. Smelling without olfactory balls is cool,but seeing without eyes(like Tom Campbell,Frank Elaridi)is cooler.
    Could you do a vid about it?

  7. 4:30– That's not new, back in 2015 or 2016, it was observed that when we sleep, our neurons physically shrink which makes it easier for CSF to flush out the brain's metabolic waste. They've been theorizing this as one of the reasons we sleep and also that a lack of sleep puts one at risk for degenerative diseases like Alzheimer's. The 2019 study just added more proof of this.

  8. You are currently processing light through your optical nerves in your brain to read a sentence written by the expression of another brain on a video where a brain processed and expressed what information other brains have learned about brains…..

  9. Excellent presenter. Very clear way of speaking unlike most of your Female presenters who speak in a gibberish accent. Please make him do more.

  10. What really pulled my attention was the deliberate and slow speech of Anthony. All of the other anchors are fast speakers so if someone is learning to speak English too, they might have a tough time.

  11. The brain's "wash cycle" starts itself periodically.
    And that is where we get sleepiness and Circadian Rhythm.
    I think.

  12. 1. our brain uses electrical signals to function, so why is it so weird that a magnetic field did some changes in it?
    2. the women probably had really small olfactory bulbs….
    3. the fact that the brain is brain-washing itself during sleep is not surprising. we have known for a long time now that the brain is doing some kind of maintenance during sleep…..

  13. There are two well known facts…. moving magnetic fields generate electricity in a conductor, and… the brain uses (aka conducts) electricity. All the study did was to generate a moving magnetic field and measure its effect on an electrical conductor. DUH!!!

  14. Reproducibility crisis.
    Most papers that were published have never been replicated, and those that were could not produce the original results in a flurry of scientific integrity tests.
    It seems there has been a lot of motivated research, motivated questions, motivated reasoning, lax peer review, and applause by colleagues, institutions and the profession, because the results were alligning with their biases.
    All the Canon in sociology, psychology and education are suspect.
    Maybe that is why there seems to be a pile up of problems rather than a resolution of problems in these fields.

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