The Illusion of Now
everything you’re experiencing
right here right now took place half a
second ago
what’s more you couldn’t be anywhere
other than
right here right now
and to expand on that idea and to
justify if you like
i’m now going to explore with you three
different ideas
okay the first of those ideas is that
our experiences of the world
are our best interpretations of what’s
out there
the second idea is that those best
interpretations
are the product of unconscious processes
that take around
half a second to complete and thirdly
choice is an illusion and our decisions
to act
are in reality our experiences
of unconscious processes that happened
and have already determined
our behaviors before i get into
exploring these questions
or these ideas in some detail i’d like
to just
go have a reality check there’s no
light or sound inside our heads
inside our heads is a dark and silent
space
what there is inside our heads is 80
billion neurons
these 80 billion neurons are each
individually connected
on average to 7 000
of their colleagues so that means
there’s approximately
560 trillion connections
in our brains so-called synapses
and this 560 trillion synapses
are organized in such a way that we have
specialist regions
in our brains connected by neural
pathways
some of these neural pathways are
microscopic just a few neurons thick
and other ones are fibers as thick as
our fingers that connect the major
regions of the brain
and all of these connections and all of
these specialist regions make up what we
call today
the human connectome if it’s if you like
it’s the ordnance survey map of our
brain
and it’s the pattern of activity in our
connect homes
that is actually giving us our
experience of what’s happening
right here right now
so with reality check out the way let’s
look at our first
uh idea your experiences of the world
are your individual best estimates of
what’s actually out there
now there’s over the last 20 years or so
there’s been a growing body of evidence
that fully supports this idea
but the scope of this talk isn’t going
to allow me to
go too deep into that and there’s some
pretty complex ideas in there as well
but what this talk will do is allow me
to do a couple of simple demonstrations
so please enjoy right firstly i would
like those members of the audience that
have a birthday
that begins with an even number to close
your eyes
and to keep them closed until further
notice
those of you with your eyes open i’d
like you to take a look at the following
image
right so those with eyes closed please
open them
and now we’re going to reverse the
process those of you with birthdays on
an odd number please close your eyes now
until further notice
and those of you with your eyes open
take a look at this image
right everybody with their eyes open
again now please
i’m now going to present an image and
i’d like you to make a note of the first
thing you
you see in this image
now some of you the first thing you’re
going to see in this image is a face
a face with spectacles others of you are
going to see a rat
or a mouse so what’s that about because
what we’ve done
here is we’ve created an audience in
which some people are seeing
a face and some people are seeing a
mouse or a rat
so you’re all making different
interpretations of what’s out there
now this demonstration is based on a
1960s study by bergelski and olampe
their so-called ratman experiment
and as you can see from the two images
what they found
significantly was that people had been
primed with a picture of a face
saw a face and those that had been
primed with a picture of a rat
saw a rat and this is what’s called
so-called
cognitive priming so this is my
initial demonstration to say to you that
what you’re seeing is your best
interpretation of what’s out there
and in this instance it’s based on an
earlier experience you had
so we can all be seeing something
different
now it’s not only cognitive priming that
establishes
what our interpretations are of what’s
out there
look at these next two images
so as i look at these images the image
on the left
is labeled a i see as the happier of the
two faces
um i’m guessing many of you would share
that the one on the left looks the
happier one
for other people the one on the right
labeled b
is going to be the happier face for
others you may
see not a happy or a sad face but you
may see two sarcastic faces or you may
see something
entirely different but uh the point i
make here is again
we’re interpreting the moods or the
emotions on faces
differently now what might be causing
this there’s no cognitive priming going
on this time around
but as i look at it and i think you know
face a is the happier face
maybe that’s got something to do with
the fact that my left eye
is my leading eye it may be something to
do with the fact that
i’m right-handed and that may be genetic
alternatively it may be something to do
with being brought up in a culture
where i i read from left to right
there’s many things in there that could
be influencing this but the point i want
you to take away from this part of the
talk
is that we’re all interpreting the world
according to our own
best interpretations idea number two
these best interpretations are the
result
of unconscious processes that take
around half a second
to complete so can i go back to the
reality check for a moment
there’s no light or sound inside our
heads
what there is is 80 billion neurons 560
trillion
synapses or connections
and there’s also chemistry and biology
there’s also anatomy and physiology
so that’s what’s going on in here
creating for me
this multi-colored
multi-sensory three-dimensional universe
that i’ve got in my head
is being created by just these things
no light i sound in my head regardless
of what it feels like
so what is going on here
well as i start to look out at the world
and i can just see the river thames
outside there
what’s happening is my eyes are
receiving various wavelengths of light
those wavelengths of light are being
coded into electrical signals
by the neurons the neurons are passing
on signals to other neurons
electrical signals going to my brain
in addition what i’m hearing is
picked up from pressure waves in the air
and those pressure waves through the
mechanisms in my ears
are being converted into electrical
signals
that are being passed onto other sig
onto other neurons
and ultimately into my brain
and these signals are all creating what
i’m going to call the primary processing
and this primary processing for my
visual system is turning those
electrical impulses
into colors and shades
and shapes primary processing processing
the inputs
from the outside for my ears much the
same sort of thing
it’s tone it’s volume um
it’s intonation of a voice
these are all the things that are coming
into my brain to my auditory cortex
primary processing
and i argue that primary processing
takes a finite amount of time
and i think it’s going to be taking
around 150 milliseconds
those primary processes then become the
inputs
into the secondary processes and this is
where the journey starts to get really
interesting
because the primary processes are now
being put together
with the stored knowledge i’ve already
got
so for example as i look out the window
and i see the particular shapes of a
river
i’ve got experiences of rivers in fact
i’ve got experience of that particular
river the river thames
i got memories about it from when i was
young i’ve got memories about it from a
few years ago when i was with my
children going along to greenwich
all of these memories are coming in to
meet in this secondary processing
something that’s helping me to interpret
what’s out there i interpret a river
my knowledge of rivers comes to bear
that particular river
my memories from my episodic memory come
to bear
so all this top-down processing goes on
it gets even more interesting yet again
when we talk about my auditory
processing
because not only am i hearing sounds but
i’m also
interpreting these sounds into words the
words
have to be built into sentences i have
to understand the grammar
from previous learning and that grammar
and the syntax has meaning for me
if you talk to me about new york i’ve
got memories of new york that have
meaning for me it’s not just the word
new york so all of this
processing is taking i’m going to argue
another 150 milliseconds
then even more magic happens because all
of that processing
then gets broadcast to my whole brain
into what’s called the global workspace
and it’s at this point that my conscious
awareness
and my interpretations of what’s
happening start to become life for me
now that’s pretty amazing now
auditory processing takes a certain
amount of time
visual processing takes a certain amount
of time
and they don’t take the same amount of
time so why is it that i don’t
experience the world like
a desynchronized and unsynchronized
video i don’t experience
that i experience everything lined up
beautifully
what’s more i don’t experience
everything as if it happened half a
second ago
i experienced it as if it happened now
so all of these processes are being
synchronized
within processes underneath the global
workspace
and being backdated so that i’m
experiencing this here and now
one more bit and this is the real magic
for me
not only have i created this entire
world out there
inside my head my own virtual reality my
own
super high definition movie but i’m also
creating
the main character in that movie
that’s the character i call myself and
i’m guessing it’s the same for you guys
but i can’t be absolutely sure of that
the third idea
choice is an illusion and
our experiences of decisions
are more realistically our experiences
of unconscious processes
that have already determined our
behaviors
here we see daniel libit as a young
scientist
uh in the early early 1980s i was
originally a microbiologist
i stumbled across this paper and
i’m going to just read you the title
time of conscious intention to act
in relation to onset of cerebral
activity
is the second part the unconscious
initiation
of a freely voluntary act now that
intrigued me that caught my attention
the
unconscious initiation of a freely
voluntary act
now there’s a contradiction in there
isn’t there a freely
voluntary act with an unconscious
initiation so i read the paper
absolutely fascinating what libit did is
a series of experiments
in which he asked people to listen to a
tone
wire up their heads wide up their
fingers wide up everything
and when they had a rare tone they had
to twitch their finger
and from the knowledge of the areas of
the brain that were active at different
points in time
and doing this experiment thousand doing
this demonstration thousands of times
he was able to average out and work out
what was going on in the brain
now if we call time zero the point at
which
a finger is twitched 550
milliseconds before that point there was
activity detected in the motor cortex
in other words the motor cortex was
initiating
that act 550 milliseconds before it
actually became a reality
350 milliseconds later
that part of the brain that is
associated with our conscious awareness
started to come into action 200
milliseconds later the action happened
so what’s this saying it’s not saying i
think
and then i do it’s saying i do and then
i think
and then it happens this is the
so-called user illusion
now libya got quite uncomfortable with
this idea and he did lots of other
experiments where it wasn’t about
responding to a single um to a single
sound
but rather his subjects were asked to
just whenever they wanted to twitch
their finger
same measurements done and some really
interesting stuff it was a lot more than
half a second
before the action that the readiness
potential was being created
in the motor cortex so
he then tried to do some other
experiments as he got older
and what he introduced the idea of was
free won’t
the idea that whilst we might not have
free will
we do have free won’t in other words i
don’t have to do
what my motor cortex has directed me to
do
but i’ve got a problem with that because
surely if i’m making a decision
to not do something that’s already
started that decision decision itself
had to start at a point earlier on
and as biological psychologists would
say
everything psychological is at first
biological
so libit’s extra experiments weren’t
able to convince me
but i’m approaching the end now we’ve
covered the three ideas so i’d just like
to leave something with you
if it’s true that our experiences of the
world
are our individual best estimates of
what’s out there
and those interpretations of what’s out
there
are the result of unconscious processes
that take
half a second to complete
and the choice is a free will and in
fact
our decisions are in reality our
experience of unconscious processes that
have already determined our behaviors
how could we be anywhere other than
right here
right now thank you