hey Vsauce Michael here and a
hemispherectomy is a surgical procedure
in which half of a person's brain is
removed it's usually only ever done on
very very young patients because their
brains are still plastic enough that the
remaining half will take on the
functions of the half that was removed
and it's usually done because a young
child or a baby is having seizures and
removing the part where the seizures
occur is the only solution but here's my
question if you can live with half a
brain what if I were to take two empty
skulls and take one half of your brain
and plop it into one body and the other
half and put it in another body which
person would be you I mean you are you
you are conscious you are aware of what
is happening to you from the perspective
of yourself like think of it this way
if you just stare at something and kind
of feel what it feels like to be you it
feels a little bit like you're a thing
inside a body looking out through the
eyeballs and nobody else on earth will
ever see the world from that position
this awareness of your own experiences
the awareness that you are having them
the awareness that you are having your
own thoughts makes up what we call
consciousness but if I were to take your
brain and split it into two and put it
into two different people would both of
them be new people who were conscious
well one of the best places to start
when defining consciousness
understanding it is to begin with things
that we agree are not conscious for
instance
burbot cleverbot comm is an amazing
website where a computer program will
respond to your questions really
cleverly but only because it is
programmed to do so we wouldn't consider
it conscious because it doesn't have a
sense of itself it doesn't feel anything
it doesn't have its own inner life it's
just a program that responds
automatically to my inputs now I know
that I am NOT like clever but I know
that I feel things and that I have a
sense of myself I have intentions but
how do I know that you do for that
matter how do I know that everybody else
that I meet is like me how do I know
that they're not just little smart
versions of cleverbot who know exactly
what to automatically say now what I'm
asking is incredibly philosophical but
it is a very famous and important
question I'm basically asking if it's
possible for something to exist as a
philosophical zombie that's right a
thing that reacts and responds and acts
just like a normal human but yet doesn't
actually feel anything it doesn't know
that it's having its own thoughts it
just automatically responds like a robot
in the appropriate way now what's
amazing and heavy about this question is
that science doesn't have an answer and
it's not even clear that science will
ever have an answer let alone an
approach to finding that answer about
all we have is the psychology of
disorders of consciousness let's begin
with Anna signo Xia a common example of
Anna said Noah in psychology classes is
a patient who has say lost the ability
to move their left hand when asked to
raise their right hand they'll say yeah
no problem there you go
but then when asked to raise their left
hand they'll say okay yeah sure no
problem
but not moving and when asked why they
didn't move their left hand instead of
reporting that they can't
they'll confabulate some excuse for
instance oh I didn't feel like it
Anton Babinski syndrome is even more
dramatic patients with this syndrome are
cortically blind they cannot see
anything but they deny being blind if
you ask them a question for instance how
many fingers am i holding up they will
make a guess but if they're wrong
they'll explain their inaccuracy with an
excuse for instance oh well I don't have
my glasses people who exhibit anise
Ignacio tend to be the victims of stroke
and there's some disconnect between what
they're really experiencing and their
conscious awareness of it they don't
know that they can't see because the
part of their brain that monitors visual
input isn't telling the brain anything
it's not even telling the brain that
there is no visual input which means
that the parts of their brain
responsible for answering questions or
greeting speech has to completely create
a confabulated response despite the fact
that we've been able to study patients
with aniseed nausea we still have no
idea how to solve our original problem
in fact all we've managed to come up
with our more impossible questions about
identity questions that are so
befuddling the best you can do with them
is to answer them yourself according to
what you believe here's another one it's
called the swamp man imagine that I'm
walking around in a swamp and then all
of a sudden I get struck by a bolt of
lightning and my entire body is burned
to a crisp dissolved into smithereens
but at the very same moment a second
bolt of lightning strikes nearby and it
causes a bunch of atoms and molecules to
all arrange themselves into the exact
same configuration that my body used to
have making a second Michael is does
that mean would that be me and here's an
even better one imagine that a surgeon
came in and he started removing cells
from me and from you replacing them it
exactly one at a time replacing my cells
into your body in your cells into my
body at what point would I officially
have become you no one on earth has the
definitive answers to these questions
but you know what we do have a lean back
that's right
I've made a playlist of some of my
favorite clips from all over YouTube of
psychology experiments and illusions and
all sorts of fun stuff that deal with
consciousness all you have to do is
click the link at the top of this
video's description and then lean back
and let the automatic playlist do the
work for you I'll see you over there and
as always thanks for watching
hey Kevin any new YouTube messages
actually yes I just got this message
over at Vsauce - from a user who doesn't
create videos but he organizes them in
his own playlists yeah yeah that's
excellent cuz there's so many videos on
YouTube we need people to help organize
them especially by type imagine a
channel of playlists ranging from cool
songs to listen to when it rains or best
explosions ever exactly if you make a
playlist that you think is really cool
and full of stuff that we should know
about send it to Michael at Vsauce comm
and will feature the ones we really like
because you have made YouTube a better
more organized place and after all
Vsauce is kind of like a carpool lane
we're all gonna get to the cool stuff
faster because we're traveling together
where did you get that