- [host Joe Hanson] For hundreds of years,
we've been paying good money to scare ourselves.
Why?
What is happening to our brains on these rides
that makes us keep strapping in generation after generation?
[Margee screaming]
And how do roller coaster engineers
make us feel like we might plummet to our death
without, you know, actually plummeting to our death?
Turns out being scared might actually be good for you.
[Margee screaming] [roller coaster wheels clacking]
[wind blowing]
- [Margee] We're basically shutting down our thinking brain
and feeling just that primal instinct of, "Oh my gosh,
I'm gonna die."
- [Joe] That's Dr. Margee Kerr.
She wrote the book on fear, literally.
- [Margee] When we're on a thrill ride,
our sympathetic nervous system,
which is the system responsible for fight or flight mode
is basically fully activated
and a whole cascade of chemicals are released in our brain,
throughout our body.
- [Joe] Dr. Kerr spent over a decade researching fear.
She's traveled the world
putting herself at objectively terrifying situations
to better understand it,
like this walk around the ledge of 116 story tower.
- No hands. - No hands?
[Margee screaming] Nice!
- [Joe] I'll pass.
But one of her favorite ways to elicit fear quickly
is on a roller coaster.
- [Margee] I've been roller coasters for over 30 years
and I remember pretty much all of them.
- [Joe] Part of that is that
one of the chemicals released
when you ride a coaster, dopamine,
has a memory boosting effect.
- [Margee] Anytime our body
is in a heightened state of stress, whenever we're afraid,
we're going to work really hard
to encode every detail into our memory,
because it's important
that we remember the things that scare us
so that we can avoid them later.
- [Joe] One thing that we all remember
from amusement parks is the scream.
- [Margee] There are very few places
that it's okay to scream at the top of your lungs,
and it's too bad because screaming
can actually make you feel better.
[children screaming]
Studies have shown that when we scream,
we increase our range of vision,
we have faster eye movements
and even a heightened sense of smell
because we're breathing more rapidly through our nose.
- [Joe] And having a yell is especially good fun
when you know you're on a safe ride.
Roller coasters have actually been around
since the 17th century.
These old-timey coasters were lower tech,
but significantly more thrilling
without all the, you know, safety rigmarole
that we have these days.
- [Margee] The history roller coasters
can be traced all the way back
to something called the Russian ice slides.
They were constructed out of wood and then covered in ice.
People would grab something and go sledding down it.
- [Joe] Apparently, Catherine the Great herself
was a fan of the Russian ice slides.
Adding to the excitement
was the fact that you might actually perish on your ride.
You might say it's a real slippery slope.
I'll see myself out.
Luckily, these days
you're far more likely to be struck by a bolt of lightning
than to get injured on a roller coaster,
and that's because of the meticulous work
of roller coaster engineers like Donnelley Williams.
- [Donnelly] Roller coasters in all attractions
are very safe.
- [Joe] That's Donnelly now in Vancouver, Canada,
where he designs and develops rides.
- [Donnelly] The testing and the safety wrapped around that
is the first thing and the last thing
on every designer and engineer's mind.
- [Joe] Donnelly designs rides
that are shipped all over the world.
- [Donnelly] We have rides in California and Orlando,
Japan, China, Abu Dhabi,
France, Dubai, and even Singapore.
- [Joe] He's being a little modest.
Donnelley and his team designed some of the best loved rides
in the whole world,
like the Incredible Hulk at Orlando Studios,
Big Thunder Mountain at Disneyland,
and Harry Potter and the Forbidden Journey.
Donnelly and his colleagues
are responsible for the control system.
- [Donnelly] The control system tells the ride to go,
tells the right to stop,
is constantly checking to see the position of the ride,
are they going too fast?
Are they going too slow?
It's the brains of the ride.
- [Joe] Donnelly and his team have to plan
for every kind of body that might be on a ride
and every kind of thing that body might do on the ride.
- [Donnelly] You have to make sure that
you can keep people safe
even though they themselves may try to do something unsafe.
We will do something called a hazard analysis,
where we basically look at a ride
and think about every single way that a person could be hurt
and how can we mitigate that risk.
- [Joe] But your body doesn't know it's safe,
at least maybe not right away.
- [Margee] Your body is trying
to quickly assess in milliseconds,
if you're safe or if you're really in danger.
Your sympathetic nervous system
is driving all of this big chemical reaction
and a big part of that is being driven by the amygdala.
The amygdala is very deep inside the brain
and it's responsible for a lot of emotional regulation.
The amygdala is working as kind of a control center,
that's push more chemicals out into the body
or let's bring it back and slow it down.
Within a second you are reminded that you're actually safe.
The parasympathetic is coming in
to just tamp down the threat response a little bit.
- [Joe] The chemicals released
when the parasympathetic takes over,
endorphins like dopamine, serotonin,
endocannabanoids and oxytocin,
they all feel really good.
- [Margee] And what's left on a thrill ride
is that feeling of thrill and euphoria.
[wind whooshing] [Margee screaming]
- [Joe] But then there's the stomach drop.
When you're plummeting down a hill
or flipping a loop on a coaster,
your stomach actually does move in your body.
We kind of think of our body as one solid mass,
but it's not that at all.
The force of gravity keeps our organs
in roughly the same place when we're in our day-to-day life.
But during the drop of a roller coaster,
our organs fall with the rest of us and feel weightless.
And that sensation is deeply unsettling.
Why, you ask.
- [Margee] Our construction of reality
is based on a predictive system.
We're constantly anticipating what's about to happen next
so that we can be prepared.
- [Joe] One part of that system
is the vestibular system,
and it's located way down deep in our inner ear.
The vestibular system supplies data on balance
to inform these predictions so we stay upright.
[suspenseful music]
- Thrill rides like roller coasters
are disrupting this entire system
primarily through disrupting our proprioception
or where our body is in space.
Roller coasters basically just confuse the hell out of us.
- [Joe] You may have heard acceleration
described in terms of g-force.
That g is for gravity.
- [Donnelly] The g-forces that are applied to the guests
on all rides
is defined nationally by a standard ASTM.
- [Joe] That's the American Society
for Testing and Materials.
- [Donnelly] The F24 Committee
on Amusement Rides and Devices
figure out what is too much or too little
to apply to guests.
- [Joe] Most people can handle between four and six gs.
Some other people like fighter pilots deal with nine gs,
but only for a few seconds tops.
Sustained periods of g-force
can pull blood away from the brain inducing g-LOC,
or gravity induced loss of consciousness.
In other words, you pass out.
Exciting but not conducive to enjoying a ride.
- [Donnelly] Well, our goal when designing rides
is to help the guest to be scared and then overcome it.
You can overcome little fears
and that can help you build up to big fears.
- [Margee] When you choose to do something scary,
when you choose to push yourself,
you gain a sense of confidence
that makes everyday challenges seem not as hard.
The type of research that we're doing,
it's not just for fun,
we are aiming to use our findings to help improve treatments
for things like social anxiety or general anxiety
and a whole range of phobias.
- [Joe] So there you go: roller coasters,
one part thrill, one part self care.
[gentle synth music]
♪