VOICE OVER: Putting a mouse in a maze can tell you a lot.
Researchers have been using puzzles like these for over a century
to study how rodents’ brains help them get around their environments.
But what if you want to study the human brain?
Putting humans in a giant maze is pretty impractical,
but neuroscientists have been working on replicating rodent studies in humans.
And they do it using virtual reality.
COREY: There’s a whiteboard right there, then there’s a door.
SHAMINI: Oh no, I got a sad face! I failed.
VOICE OVER: So is virtual reality the future of neuroscientific research?
SHAMINI: To find out I’m going to be navigating my way to some virtual labs,
trying out some VR technology,
and experiencing the world of a virtual lab rat.
SHAMINI, V/O: The first location on my journey is here at the Norwegian University of Science and Technology
where neuroscientists have been trying to understand the strategies people use
to find their way around.
Tobias Navarro Schröder has promised to show me one of their virtual mazes.
TOBIAS: Tobias, nice to meet you. SHAMINI: Tobias, great.
TOBIAS: Here we research spatial navigation and memory and we use this
omnidirectional treadmill with a head-mounted display.
Wanna give it a go?
SHAMINI: Yeah sure.
TOBIAS: So what you’re gonna do is called an object-location memory task.
There will be objects on the ground so try to remember
where they are.
SHAMINI: Ooh! TOBIAS: Ok.
SHAMINI: OK
SHAMINI, V/O: I’ll be honest, it’s not what I imagined a maze would look like,
though I did feel a little like a lab rat.
And this is actually the kind of puzzle rats are given in modern tests.
TOBIAS: A lot of the recent work is done in circular or square environments, basically just a box.
TOBIAS: Ok, now you are asked to put back the oil barrel.
SHAMINI: Oh I don’t remember. Um...
Oh no, I got a sad face! I failed. So will it tell me…
oh I was completely wrong.
TOBIAS: You probably were on the exact opposite side so it was not random what you did.
SHAMINI: Why am I doing this in VR like a computer game and not just in the real world?
TOBIAS: It’s always the same time of day in this world.
We can make these objects disappear and appear magically on the spot,
so we have high control over the type of things you are experiencing.
And we can have a large number of people go through this exact experience.
SHAMINI: Let me press the top button… (gasps) I got a...
TOBIAS: Much better smiley! SHAMINI: I got a medium face!
TOBIAS: Medium, this is actually pretty close.
SHAMINI, V/O: My successes and, rather more frequent, failures
help Tobias see how I’m approaching the task.
But if we’re going to see what’s going on inside my brain,
we need a very different piece of kit:
An MRI scanner.
This time I can’t move at all, and the virtual maze appears on a small screen.
It’s obviously not as realistic an experience,
but now Tobias can see which brain areas are lighting up.
Doing this experiment on different people and comparing the results
can reveal differences in which brain areas they're using.
SHAMINI: So what are then the disadvantages of the fact that it is VR and not a real experience?
TOBIAS: One of the big disadvantages is that you only have vision. You only see the world.
And in the case of the scanner your body and head are fixed.
So that’s very different from everyday life.
SHAMINI, V/O: Virtual reality gives you complete control over an environment,
and that’s a big attraction for researchers.
But they also want those environments to be as realistic as possible.
The closer to reality the virtual world is, the closer the brain’s behaviour
will be to how it acts in the real world.
I found the omnidirectional treadmill pretty immersive,
but it’s impossible to use at the same time as an MRI scanner.
But there is a way around this problem.
A way to peer inside brains while they’re exploring virtual worlds.
SHAMINI: Hi NANTHIA: Come on in, hi.
SHAMINI: Hi, Shamini. NANTHIA: Hi, Nanthia, nice to meet you.
SHAMINI: Good to meet you hi, so ok this is… NANTHIA: This is the room. Virtual reality room.
SHAMINI: What are we going to be doing in here today?
NANTHIA: So this is Corey. She has graciously volunteered her time to do the study
and she’s very special in that she has a system implanted in her brain
that can actually record brain activity.
It’s actually for epilepsy, for preventing seizures,
but we can actually look at the activity, look at the brain data
in a part of the brain called the hippocampus
which is very important for memory and spatial navigation.
COREY: I’m having to remember where trigger point one, two, three and four were
and then they have me go to like five red. It’s like Yahtzee or, or, um... what’s that thing where you…
Twister! It’s like Twister!
SHAMINI, V/O: Just like in Tobias’s experiment, Corey finds herself in a very simple type of maze.
COREY: There’s like a supply closet right there,
then there’s a door.
And the cylinder that I’m supposed to go into is right... here.
NANTHIA: So this is the first time we can record deep brain signals
while somebody's actually moving around.
We’ve never been able to do that in a human being before.
So she can learn things, she can interact with people, she can do all sorts of things,
so this is the beginning of many, many studies to come, to look at what’s happening in the brain
at exact moments of naturalistic behaviours and real life activities.
SHAMINI, V/O: There aren’t many participants like Corey available for studies,
and it’s possible that the brains of people with epilepsy might have differences from an average brain.
But there is still an advantage to being able to measure brain signals
during the immersive simulation.
NANTHIA: We are seeing that there are properties of these brain waves
that do react differently depending on what the person is doing.
SHAMINI: So it’s really important then that the participants are actually doing something,
they are actually like walking at a particular speed or whatever,
so that you can see what’s happening during that.
NANTHIA: Yeah, it’s important that they’re doing something and that we can actually
monitor what they’re doing very precisely,
and that’s why we have all this room and this set up and complicated equipment.
SHAMINI: So the VR, you can control it carefully.
So, you know, for a scientist all your variables are controlled which is great
but is there not a disadvantage in that it’s still sort of
a clearly artificial world, is that a problem?
NANTHIA: I mean definitely we want it to be really a replica of the real world
and I think the VR field, the technology itself is still evolving.
But you know, yes, it’s not quite the real world, right,
it’s still a virtual rendition of the real world.
SHAMINI, V/O: But is Virtual Reality realistic enough for our brains to act like they do in the real world?
To find the answer, researchers need to compare real and virtual worlds
but there hasn’t been much research on this yet - at least not in humans.
Another lab, round the corner from Nanthia’s, has been asking this question
though they use more conventional lab rats…
MAYANK: So come on in here. So this is the set up
and we are going to go in there and look at what's going on.
So that’s Athena, that’s her rat. SHAMINI: Hi.
MAYANK: So we are going to put the rat in this virtual reality
where he has to figure out where he is, using only vision.
SHAMINI: So it looks like this rat is on a giant beach ball.
MAYANK: He’s on a giant floating ball, that every step he takes the world changes accordingly.
So it’s like a bigger than iMAX.
He's totally surrounded by that in every direction all the way up to his feet
so he sees his own shadow.
And you’re going to do that and you’ll see how compelling it looks for yourself.
SHAMINI: Oh right, ok great, I’ll give it a try.
MAYANK: So we’re going to pretend that your hand is the rat, right.
SHAMINI: So I’m walking and I can see, look, ok I’m getting closer to this wall.
MAYANK: Everything is coming, yeah, things are coming towards you,
and you’ve still not got any reward.
SHAMINI: And when you’ve got a rat and you’re doing the experiment
you’re actually recording their brain signals live?
MAYANK: Brain signals. That’s exactly right.
You’ll have to hurry up because if you don’t find it quickly enough it’ll be time out.
SHAMINI: Oh. Oh no. Oh man.
MAYANK: 'Cause you know rat finds its reward in about 3 seconds.
SHAMINI: Oh! Oh I found it! I found it! MAYANK: You did it!
SHAMINI: I don’t really know where I am though…
MAYANK: Virtual reality allows the brain to make a map using only vision.
Now we are going to see how the brain makes map in the real world
where all the senses are telling you where you are, not just vision.
SHAMINI: Wait a second. This looks familiar.
MAYANK: So this is the real world version of the virtual maze.
SHAMINI: So the floor pattern is the same, the walls are the same.
MAYANK: Exactly. The walls have the same patterns.
And the rat has to now run around in this maze
and we can measure the activity of the same neurons,
in the real and virtual world. So we can compare now,
whether the neurons, the map of the space the neurons made in the real world
looks exactly the same as virtual reality or not.
SHAMINI, V/O: During these experiments, electrodes in the rats brains
measure the activity in a brain area called the hippocampus.
Previous work has suggested that the neurons in the hippocampus
create a kind of mental map
that represents the spaces the rats are exploring.
SHAMINI: So in the experiment that we’ve just seen you’ve gone to a lot of trouble
to make sure that the virtual world and the real world are identical.
So there’s no external sound, there’s no air moving, and it looks exactly the same.
So you would expect then that the brain recordings that you get
from the rats in those two places should be the same, right?
MAYANK: That’s exactly what we expected. But what we found could not be more different.
First thing we noticed is that 60% of the hippocampus shut down in virtual reality.
And when we saw this, the first time that happened we thought, wait a minute,
maybe something went wrong with his brain, maybe the electrodes got damaged.
So we put him back in the real world, nope, the neurons are still there.
Then we said alright, what about the remaining 40% of neurons,
are their maps as good as the real world or better?
Once again, major surprise,
that the maps of these neurons were completely corrupted.
SHAMINI: So even though the mouse looked like it was doing exactly the same thing and it
knows where it’s going, somehow the brain just wasn’t reacting in the same way.
Why would that be?
MAYANK: We think that what happens in virtual reality, is that different senses
are not saying the same thing to the rat.
When the rat takes one step in virtual world,
his feet are telling him yep I’m putting in a lot of effort, I’m moving.
Whereas his guts are telling no, you’re not going anywhere.
His head is telling him, nope, I don’t feel any wind coming in.
SHAMINI: And does this apply to human VR studies as well, when you have people walking around
with electrodes in their head, or even just on a treadmill?
MAYANK: There is merit to simplify the real world and say, I’m going to forget about
these four things in the real world and I’m going to focus only on vision.
If on the other hand our goal is to say, I want to understand
how the hippocampus works in natural conditions,
then the only thing to do is the natural condition.
So in my opinion we need to do not just the real world, not just virtual reality, but both.
In the same subjects.
SHAMINI, V/O: As virtual reality research continues to grow,
the question of accuracy is only going to get more important.
It’s not yet clear whether humans show the same unusual brain patterns in VR
as Mayank’s rats do,
or how significant that might be for different research questions.
And we don’t know how immersive a computer simulation has to be
before our brains will react naturally.
But the researchers I spoke to on my journey all agreed that,
despite ongoing questions,
VR technology isn’t going anywhere.
SHAMINI: Oh! TOBIAS: Look at that
SHAMINI: I got a happy smiley. TOBIAS: That's actually really difficult to get.
SHAMINI: That's amazing.