FEATURE INTERVIEWABOVE LEFT Elisa on board
the Vomit CometABOVE RIGHT On firmer
ground at Royal Holloway,
University of Londonteams are onboard at the same time, and
experiments can vary from the biological
sciences to physics.
During these flights, the plane follows the
trajectory of a parabola. It alternates between
rises and descents, at a 45° angle of inclination.
Each parabola starts with a ‘pull-up’ acceleration
phase in which the gravitational load is double
Earth’s gravity, what we call hypergravity or 2g.
The pilots then let the aircraft drop into ‘free-
fall’. This phase generates weightlessness (0g).
Then pilots perform a ‘pull-out’ acceleration, in
which gravity is again double. Each phase lasts
for approximately 20 seconds.
During the flight we’ll have many parabolas,
around 15 or 16, so the flight itself lasts for two
or three hours. It’s a long period of time, but the
experiment can only last 20 seconds because of
the short exposure to microgravity.CAN YOU ACHIEVE ANYTHING IN JUST
20 SECONDS?!
It’s complicated, but it’s doable. The experiment
needs to be well designed, precise, and
controlled. We have to make sure that the
experiment is perfect before take-off. Then it’s
kind of a dance, a choreography of people doing
stuff for the experiment in those 20 seconds, in
approximately 1.5m^2 of space, and while
floating. So, it’s challenging. It’s far from the
comfort of the lab, but the experience of
weightlessness itself is already a nice reward!
WHAT DOES IT FEEL LIKE?
Weightlessness is the best thing ever. It’s awe
and freedom. Movements are with no effort, no
physical constraints, floating. It’s an amazing
experience. But, let me be honest: it is not easy.
I mentioned before space motion sickness and
we get it during parabolic flights. We normally
have some medication, but there is sickness
and disorientation.
WHAT EFFECT HAVE YOU FOUND THAT GRAVITY
HAS ON COGNITION?
My research group and I are interested in how
gravity influences human perception and
decision making. For instance, we wanted to see
whether decision making is optimal when
gravity is no longer our usual 1g acceleration.
We did that in the lab, actually, by asking
people to say a random number. You are going to
say, ‘How is this related?’ Well, [when you say a
series of random numbers] you either you go
with the same option, generating ‘stereotype
behaviour’. For instance I’d keep saying ‘two’,
‘two’, ‘two’. Or you shift from one number to
another, kind of generating ‘optimal behaviour’.
So more options, more novel behaviour. Now,
when we think about adaptations to the
environment, we want to have a trade-off
between stereotype and novel. We don’t always
want to go for the same choice, we don’t always
want to go for a different choice.
This sort of random number generation task
can give us some indexes of how willing and
exploring people are in an environment. We did
this with participants being upright, in line with
the orientation of gravity, or lying down flat, a
posture incongruent to gravity. This simple
manipulation allowed us to alter the
physiological processing of gravity, leading to
very different gravitational information reaching
our brain. The vestibular organs immediately
detect ‘I’m not aligned with gravity’.
We found that, while lying down, people were
producing more stereotyped responses. This
tells us that participants were not using an
optimal strategy to solve the task and that their
decision-making was affected by altered gravity.
Now, this is a lab experiment. But imagine that
you are on Mars. You need to decide whether to
explore or to stay put. Maybe exploring is risky,
but you need to do it, and if you don’t move, you
don’t explore, this might be a problem.
Our lab manipulation is basically telling us,
look, people might not take the right decision