vu before okay a good number of you this
is in line with Survey Research which
suggests that roughly two-thirds of
people report experiencing deja vu at
some time or other in their lives deja
vu is generally defined as a feeling of
having experienced the current situation
before
despite realizing that this is actually
new so for example maybe you’re visiting
the Louvre in Paris for the very first
time in your life yet you’re plagued
with this mysterious feeling that you’ve
been in that exact place before my goal
has been to scientifically understand
deja vu why does it happen what is its
underlying basis for how many of you is
this definition here incomplete for how
many of you is deja vu accompanied by a
feeling of knowing what will happen next
okay a good number of you you’re not
alone
a lot of people claim that when they
experience deja vu it’s accompanied by a
feeling of knowing what’s going to
happen next
including in survey research I became
interested in this aspect of deja vu
when I began getting contacted by random
people who had come across my research
and contacted me to tell me that this is
their a personal experience with deja vu
and to ask me if I have any explanation
for why this occurs one man in
particular called me because he’d had a
jarring experience it was so jarring
this feeling of knowing what would
happen next that he couldn’t stop
thinking about it and so he called me to
tell me about this experience he’d gone
on a hunting trip for the first time
he’d never been on this particular trip
before and he felt like he had done this
before as he was boarding the plane he
felt like he’d done this exact thing
before he felt he had sat in that very
seat on that very plane before he felt
that those very passengers surrounding
him were there before and they were
wearing those same clothes and he also
felt he knew that the flight attendant
was about
approach him and not only that but he
knew what she was going to say the
situation bothered him so much it was so
jarring that he began researching deja
vu on the internet to try to find
answers and that was how he found me in
my talk today
besides my research on deja vu and what
it suggests about deja vu I have three
larger points that I’d like to make one
is that deja vu can be studied
scientifically the second is that even
the sense of premonition can be studied
scientifically and finally don’t
underestimate the power of science for
discovering how things work there have
been many proposed causes of deja vu put
forward over the years all of them
challenging to investigate
scientifically these range from the idea
that deja vu may be the result of
spontaneous brain activity I like to
call this the glitch in the matrix idea
to the idea that deja vu results from a
nun recalled memory so for example maybe
upon visiting the Louvre for the first
time the reason you experience deja vu
is because you’re failing to recall the
fact that you saw those same scenes in
the movie The Da Vinci Code years ago
and that’s responsible for this feeling
of deja vu II my goal was to
experimentally investigate this
particular hypothesis the Unruh called
memory hypothesis which no one had ever
done before but there were some hints in
Survey Research that were supportive of
this general hypothesis for example
survey research suggests that people who
report having deja deja vu more
frequently tend to travel more and to
watch more movies and this is consistent
with the Unruh called memory hypothesis
because people who travel more and who
watch more movies have more potential
memories in their to serve as sources of
deja vu my starting point for
investigating the Unruh called memory
hypothesis of deja vu was a very
specific theory that had been put
forward 80 years ago but never
scientifically tested it is the idea
that deja vu might be driven by a nun
recalled memory
for a situation that spatially resembles
the current situation that you’re in so
for example maybe you’re crossing the
street in panel B here for the first
time in your life and you have a sense
of deja vu that sense of deja vu may be
driven by the fact that you previously
experienced a very similar scene such as
the one shown in panel a it has a very
similar spatial layout and that may be
responsible for the feeling of deja vu
the reason this particular hypothesis
the spatial resemblance hypothesis had
never been scientifically tested is very
likely because scientists have largely
assumed that deja vu is too rare in
occurrence in real life to be
investigated experimentally or to
duplicate in a laboratory setting I
wondered if this was actually true
there’s a very similar type of
subjective phenomenon that you may be
familiar with it’s called the tip of the
tongue experience the tip of the tongue
experience is when you feel as though a
word is right there on the tip of your
tongue about to be recalled and you
can’t quite access it researchers have
been studying tip of the tongue
experiences for many decades and the way
that they do this is to create
circumstances in the laboratory that are
hypothesized to produce tip of the
tongue experiences and then to have
people self-report and when they’re
experiencing tip of the tongue and when
they’re not in order to test these
hypotheses I wondered if the same
approach could be taken with deja vu so
for example why couldn’t we create the
type of spatial resemblance that’s shown
here in this figure in a laboratory
setting and have people self-report and
when they’re experiencing deja vu in
order to test this hypothesis that
spatial resemblance can produce deja vu
in the absence of recall of the source
and this is what we did we used virtual
reality we used virtual reality to
create spatial resemblance among
different scenes and different
experiences within the context of an
experiment and we asked participants in
this experiment to self-report and when
they were experiencing deja vu this is
an example of how we created spatial
resemblance this is a bird’s-eye view of
an aquarium in panel
which Maps spatially onto a reception
area shown here in panel C this is the
first-person perspective of the aquarium
and the first-person perspective of the
reception area here are some other
examples in alley that spatially
resembles a hallway a courtyard that
spatially resembles a museum a prison
that spatially resembles storefronts a
bowling alley that spatially resembles a
subway station a bedroom that spatially
resembles a clothing store so
participants would be immersed in a
large number of scenes in the first
phase of the experiment such as the
bowling alley or the aquarium or the
bedroom and then later on in the second
phase of the experiment they would be
immersed in new scenes some of which
spatially resembled older scenes that
they had been immersed in previously and
our primary question was whether when
immersed in a scene such as this
clothing store here when people fail to
recall anything specific so this
clothing scene maps on spatially to the
bedroom scene that you saw earlier if
the person fails to recall that are they
more likely to report experiencing deja
vu when there is this spacial
resemblance than when there is no such
spatial resemblance and it turns out
that they are participants show a higher
probability of reporting experiencing
deja vu for scenes that spatially
resemble earlier experienced but Unruh
called scenes then for scenes that do
not we next asked well if if deja vu can
be driven by a nun recalled memory can
it occur because we actually did
experience this very thing before but we
forgot to investigate this we use the
same paradigm but we added a new twist
some of the time in the second phase of
the experiment we had our participants
immersed in the same exact scene that
they had been in earlier so for example
maybe the person would be immersed in
the bedroom scene they were in that
exact scene some time earlier in the
experiment our our interest was in those
instances in which people forgot they’re
saying this is a new scene I was never
in this scene before I don’t recognize
it when people are in the exact same
scene and they forgot that they were
actually in this earlier are they likely
to report
experiencing deja vu it turns out that
they are in fact they’re even more
likely to report experiencing deja vu in
these cases than in cases in which the
scene merely spatially resembles an
earlier scene this suggests that the
more similar an experience is to one in
memory that we’re failing to recall the
more likely it is that we’ll have a deja
vu experience this also suggests that
maybe sometimes we experience deja vu
because we did do this very thing before
and we simply forgot I want to turn now
to that very aspect of deja vu that I
mentioned toward the beginning of this
talk the feeling of prediction many
people claim that when they experience
deja vu it’s accompanied by a feeling of
knowing what will happen next I wanted
to find a way to experimentally
investigate this no one had ever done it
before what we came up with to to
experimentally investigate this idea was
we thought why not use the scenes that
we’d used in these previous studies and
try to create a dynamically unfolding
situation in which we could examine the
possibility of prediction so for example
participants would view video this time
of a particular navigational path
through a scene so it could dynamically
unfold in that way so in this bird’s-eye
view of the aquarium
perhaps the navigational path might look
something like this ending in a leftward
turn then later on in the experiment
when when when presented with video in
this spatially resembling room such as
the reception area the video follows the
same navigational path but it stops
short of that final turn our question
was could people show predictive ability
that’s based in memory so in other words
could that unruhe called memory of the
aquarium from earlier drive not only an
increased likelihood of deja vu with
that reception area but could it drive
an ability to predict what the direction
of that next turn should be we found
three things in this study that are of
interest the first was that deja vu was
more likely when scenes did space
chillie resemble earlier scenes than
when they did not that wasn’t surprising
it replicates these other studies that
I’ve already shown here however they did
not show any predictive ability people
could not predict whether the next turn
should be left or right however they did
feel like they could predict when they
were experiencing deja vu they felt
strongly that they could predict the
direction of the next turn people gave
ratings of their sense of knowing what
the direction of the next turn should be
and those ratings were much higher
during reported deja vu states than
reported non deja vu states we call this
the deja vu illusion it appears that
deja vu states bias people to think that
they know what will happen next
even when they don’t so I’d like to to
to remind you of these three main points
that I wanted to make here that deja vu
can be studied scientifically that even
the sense of premonition can be studied
scientifically and don’t underestimate
the power of science for discovering how
things work I’d like to end with a quote
by the famous computer scientist Alan
Kay the best way to predict the future
is to invent it no matter how familiar a
situation might seem or no matter how
strongly you might feel that you know
exactly how this is going to go or
exactly how this situation is going to
unfold our experiences don’t just unfold
before us in a predetermined manner our
actions and our choices can change the
you
[Applause] [Music]