Episode Transcript
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Speaker 1 (00:00):
I think we're alone now. It doesn't seem to be
anyone around. I think we're all now. The beating of
my okay, hello, I didn't hear you come in. Maybe not, huh,
you stealthy listener have arrived nearly undetected at the underground
(00:20):
headquarters of Deeply Human, the show about why you do
what you do. I'm your host, Deessa, but I gotta
say you have picked quite the moment to home in
on our encrypted signal and tunnel into the office. We
are in the midst of an investigation into some of
the most mystical, disorienting experiences a person can have, and
(00:40):
the brain science that's involved might help explain big important
chunks of being human, stuff like religion and creativity. So
you'll forgive me if I have to gently tape you
to your chair until we're finished. Security in the podcast
sector has gotten pretty intense. Okay, music is up. There
(01:01):
we go, and we're off this time a Deeply Human.
We're heading into the science of perception to discover why
we're so eager to find signs of life in our surroundings,
eager enough to see faces in the clouds or tweak
out when the house creeks at night, even when you
were alone, why might you sometimes feel like someone's with you?
(01:24):
To find out, we begin with a story beneath the
surface of the ocean. I was diving in a cave
known beautifully as the Mermaids Layer. That's researchers Stephanie s Faba,
who studies the rock and microbiology of underwater caves known
(01:46):
in the Bahamas as blue holes. She took a life
changing dive. I swam in and the water felt amazing.
It was perfect temperature. When you go into these underwater caves,
you have to lay down a guideline. If you don't
have this guidelining back out to the entrance, then you
may not find your way back out and you will
(02:08):
die in the cave. Stephanie is a big deal, recognized
around the world as a top diver, and her work
is dangerous. Rob my late husband, had died a few
months before in a diving accident, and he and I
had always worked in that cave. Stephanie describes Rob as
the love of her life, and her grief was still
(02:30):
very fresh. This was her first dive since its death,
and the whole time she's in the cave, she's sort
of subconsciously expecting him to swim along and check in
like he used to do when they dove together. And
then I went with the mainline further into the cave,
quite pleased with what I had found. And then I
(02:51):
turned my head to look for my guideline and realized
that I had lost contact with it and also visual
with it, and it all came together at me suddenly
at once that you know, Rob wasn't there to help me,
and now I was in deep, deep trouble. I didn't
know where it was, and I was trying very hard.
(03:13):
You know, at that moment, you hear your heart beat
in your ear. I mean it literally is thumping like crazy.
And I looked at my air supply. I had probably
maybe fifteen minutes left, and I think at that point
I became angry, really angry at myself for being so stupid,
and then I got really angry at Rob for not
(03:35):
being there. And then I heard something in my head
that Rob always said to me, and I kind of
thought it was kind of a cool phrase, except there
believe you can believe you can't either way, you're right.
(03:57):
It was an interesting feeling because it was like he
was there Stephanie is one of many adventurers who have
reported experiences like this, a feeling of presence during a
moment of crisis. Sailors, prisoners of war, astronauts and aviators,
(04:18):
and distress have made similar reports. To understand why all
these people suddenly perceive a mysterious presence and sometimes hear
them too, we have to start with how we perceive
our own bodies. So I right now I am someone
or something that is embodied. I occupy a volume of
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space that is my body. I have a sense of
ownership about my body, my arms and leg and indeed
my entire body feels like my own. Batman in possession
of his own arms and legs is a nil Anto Swami.
He's a science journalist and a research fellow at M
I T. And although I think I get it pretty
(05:03):
chill during our conversation, I've been a fan for a minute.
When we think about where ourselves are really located, you know,
we don't even if it feels like our whole body
is ours, Our sense of consciousness doesn't seem like it's
headquartered in our knees or in our hips. Where does
the self live within the body, That center of awareness.
(05:25):
It really recites in our heads. We we have the
sense that we are somewhere right behind our eyes actually,
and that turns out is also something that the brain
works really hard to position the center of awareness in
that place. But our brains are not foolproof, and sometimes
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that center of awareness gets displaced, which can make for
an out of body experience. People will say that, oh,
I'm observing myself lying on the bed, but I am
somewhere near the ceiling. It's very clear now from experiments
done in labs and from just the study of the brain,
that this is an illusion that nothing actually leaves the body.
(06:09):
But it's certainly the case that people definitely have this experience.
They reported as being a very strong experience, a very
strong sensation beneath the water line of consciousness. Our brains
work really hard to create a smooth, consistent perception of
the world in our place within it. Let's say you
(06:30):
go for a solo jog. Well, your brain has to
compensate for the bouncing of your visual field so that
you don't get motion sick, just piloting your own body
through the park, and it's constantly integrating signals from the
outside world. Birds song, a whiff of diesel exhaust with
(06:51):
signals coming from inside your body. I have to be
my right knee is doing that clicking thing again. But
sometimes the signals get miscategorized, and signals from inside I
perceived just coming from outside, and that can get really
really spooky, like someone's knees clicking, And if it's not mine,
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then who's someone else's be here? You know, It's like
I've accepted I'm in trouble, I've screwed up, I'm probably
gonna die. So back to Stephanie. She's lost, she's running
out of air, and suddenly she gets this sense that
she has company, that her late husband Rob is with her.
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I mean, I could hear his voice so clearly. I
didn't feel alarm. And when I kind of just settled
down from that and it was almost accepting my situation,
I looked up and I saw what I thought was
a little piece of line, a white line that it
almost looks like the cables that you have your earpieces on.
(07:59):
And it turned out to be the guideline, the main line,
and I got on it, went out and just remembered
sitting there really so glad to see the yellow sunlight
and saying, don't you ever do that again. Stephanie eventually
(08:20):
launched a foundation in Rob's honor, and she actually still dives,
which I think we can all agree makes her both dedicated,
professional and tough as nails. Experiences like Stephanie's are rare.
I've never heard the term feeling of presence before, and
maybe you hadn't either, but you probably have heard of
the phantom limb phenomenon, where someone who's had a body
(08:42):
part amputated still reports sensation in that missing arm or foot.
No a science journalist, he told me that a neuroscientist
named Olaf Blanket explains the feeling of presence as the
full body compliment off a phantom limb. So the way
that you can and experience a limb that doesn't exist,
(09:04):
you can literally experience a body that doesn't exist, and
this is kind of a disruption and aberration off the
mapping mechanisms in the brain. The brain maintains a map
of the body, its components, and their positions in space,
and in the case of phantom limb, this map hasn't
been updated to reflect a new reality. In a case
(09:24):
of feeling of presence, the map of the body is
shifted outside of the body completely. Okay, now is the
time to grab your special occasion clipboard because we are
heading into the lab and my duct taped friend is
gonna get weird. We're about to speak to a senior
(09:44):
scientist from the Laboratory of Cognitive Neuroscience at the Swiss
Institute of Technology, a guy named Julio Renu. An experiment
conducted at Julio's lab was able to induce a feeling
of presence by sending a little electrical current through a
read of the brain that integrates sensory signals. If the
patient was standing, the present was felt asked standing, and
(10:08):
if the patient was seating, the president was felt as sitting.
So this is actually led to the idea that what
was going on is really the misattribution of one's own signals.
So there was basically the patient was misattributing her own
signals to the presence. So here's this idea again, that
a feeling of presence can be caused by the brain
(10:28):
miscategorizing internal bodily signals as external like if it's not
my body that I'm feeling, there must be another body nearby.
For research types like Julio, the big question is, Okay,
how can you test that idea? You have to somehow
confuse people into thinking that sensations coming from inside them
were coming from outside, and then find out if any
(10:51):
of them had a feeling of presence. But how do
you confuse people about their own bodies in a lab?
The answer here as if so often the case with
life's hard questions. There's robots. Basically, we use a tour
robotic system, one in front of you that you were
asked to operate with your hands, and then one on
(11:11):
the back that was replicating the movements that you were
performing with your hands. So I'm in your lab, I'm
manipulating something with my hands. Right, It's a joystick. It's
a kind of a fancy joystick. What is happening is that,
basically there is a robotic carm that is touching you
according to the movement that you perform to the joystick
(11:32):
that we just mentioned. Okay, so if I pushed the
joystick forward like I'm getting poked in the back, is
exactly that. It's real time. It's real time exactly, and
you're got to be poking yourself and when there is
perfect synchrony between the tooth, you feel like you're actually
poking yourself, and that's normal. You know you're in control
of what you're doing. Everything is fine. Whereas if we
(11:55):
add a delay between what you do and what you
receive on the back, this start feeling that he's actually
somebody else doing this. On first listen, adding a delay
into the system might seem like a small thing, like
so what if I push forward on my joystick and
there's a little lag before I get my poke in
the back? Who's in a rush to get a poke
in the back? But that lag is the detail on
(12:17):
which the whole experiment hinges. Like imagine you're walking alone
at night. You pass under a stream lamp and you
can see your shadow walking beside you. But then she
misses a step and now her footfalls land just to
beat after yours. That little leg wouldn't feel negligible. It
would be what yourself distressing. And similarly, in Julio's lab,
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you'd have the sensation that this robot arm behind you
is controlled by you in real time. It's a simple
reflection of your movements. Like a shadow. You are the
only agent in command until that little leg, and then
all of a sudden it feels like, maybe you're not
entirely in control. So if not, you who About one
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third of Julio's research participants on prompted reported feeling a presence.
What did they actually say? There was like fence. Somebody said, oh,
I feel like there was somebody behind me touching me
it was not me, or he felt creepy. Oh. A
guy said, oh, I felt like that there was a
monkey replicating my movements on my back. But typically it
(13:34):
was reported like as if there was somebody watching them
and then replicating what we're doing, and that it didn't
feel like it was them doing it at all. Successfully
inducing feeling of presence. In this way, I can help
explain how the phenomenon occurs outside the lab. Two did
anybody say ghosts? No, they didn't say ghosts. I think
(13:56):
I don't know. I have not really big experiences with ghosts, honestly,
But you get touched by ghosts, I don't know. I
don't know. You know what, I don't know if you're
supposed to get by ghosts, but is going absolutely not? Okay,
yeah you see so that that would make sense? Then yeah, okay,
I'm you know what, I'm sorry you were like, does
(14:17):
that's a breach of scientific protocol ghost don't type. Well,
there you go, so don't say you didn't learn anything
from this rigorous science based program. Someone who knows more
than me about ghost dues and don't is Bruce Hood.
(14:38):
He's the director of the Cognitive Development Center in the
School of Psychological Science at Bristol University in the UK,
and he wrote a book called super Sense that investigates
white people believe in ghosts and stuff like past lives.
In telepathy, Bruce explains that humans are designed to be
sensitive to other social creatures, were always scanning our environments
for other animals like us. So one of the really
(15:01):
interesting phenomenon is that people see faces all over the place,
and so we seem to have a face detecting system.
It just looks for a couple of eyes and anything
that looks like a mouth. So that leads to that
really interesting phenomenon called paradilia, where people see faces in
the most weird, wonderful things like slices of pizza or
you know, a coffee stain or a water stain on
(15:21):
the wall. What do you mean to Bruce's writing was
this fascinating explanation of hyperactive agency detection, a term I've
never heard before. What's hyperactive agency detection? Okay, So within
the human brain, we have specialized systems for detecting other
social animals, and we have, if you like, dedicated mechanisms
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for identifying others and their form and their shapes and
their movements. And what's going on with a hypersensive agency
detector is that you're attributing or anthropomorphizing things which aren't alive.
So you're actually over interpreting things. Okay, Then, once we
categorize something as a living thing, what kind of assumptions
do we make about it? Well, we we see it
(16:06):
as having gold directed movement or intentions. Agency detection isn't
something we're learning from our parents. Bruce thinks it's probably
an innate faculty we've developed to keep us safe from threats.
We have a perceptual system which is hyper sensitive to
the possibility of there being another being out there, hiding
in the trees or amongst the woods. And we think
(16:27):
it's probably that sensitive because that's the way it evolved,
because it is better to assume that there's a possible
another agent hiding out there rather than just to ignore it.
So your systems was biased to see these patterns and structures.
Let's say you're a cave person sitting in the firelight
beside your special someone on a romantic evening. You're interrupted
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by a nearby rustling of the high grass, and you
don't know for sure if it's a lion or if
it's just a breeze. Well, people who presume it's a
lion grab a spear and then find out it's just
the wind are gonna look dumb in front of their dates.
But people who presume it's just the wind continue making
(17:11):
out and then find out it's a lion are going
to be eaten in front of their dates. So the
idea here is that evolution would favor the folks with
the hair trigger, who readily perceived the presence of another agent.
But again, our brains aren't foolproof. We're prone to false positives,
to thinking someone's there even when we're alone. Our brains
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are always looking for patterns in the chaos. We see
human faces in the knotted bark of a tree, we
presume it must have been a footfall that snapped a twig.
And that's partly because we can't really perceive randomness. Our
brain always imposes a degree of structure or we can't know,
you can't. It's really tough. I mean in talking to friends,
(17:54):
I don't you know the kind of talk that you
do after like two cocktails, when you're solving none of
the world's problems. But it was just like pattern junkies, like,
we just gotta have it, you know, and we see
it where there are patterns, and we see it where
there are no noise. If you're having a couple of cocktails,
you'll see more patterns because of course, what happens there
is you're deactivating the frontal lobe systems. So these are
(18:15):
the areas in the front of the brain, and that's
how alcohol works as a depressed and it turns this
off and then suddenly you see connections and you become
more creative. And I'm writing off every bar tab on
my taxes this year. Um, you've done a lot of
work that investigates how hyperactive agency detection, among other things,
might relate to our superstitions. Yeah. I wrote a book
(18:39):
trying to give a scientific account for why people believe
in the unbelievable, and at that time, there was a
lot of talk about religion and how people are indoctrinated
to believe in ghosts and spirits and stuff like that,
And I was just trying to address the balance and say, well, actually,
you don't have to be religious to sort of infer
that there's all this agency in the world. I argued that, actually,
you know, people who are secular or even atheists will
(19:01):
have exactly the same sort of misconceptions and beliefs, which
are tanned amount to supernatural thinking. I'm generally a secular
kind of gal, but I still cross all the fingers
on both hands when I'm waiting for good news, and
I sometimes knock on wood in business meetings. I don't
actually think those behaviors will change the outcome of events.
(19:22):
I just feel better to do. Like, our habits of
mind don't always neatly align with our carefully considered world views.
So all I think religions have done is they've built
upon our tendency to see structure and agency and essences
and causality. All these things pre existed religion. Our cave divers.
Stephanie seems to hold a pretty similar position. I don't
(19:45):
believe in God, I don't believe and uh, you know,
our ghosts or anything like that. But I do recognize
that some of the things that we do experience, certainly.
I mean, when we look at our ancestors so long
ago that tried to explain light ng and thunder and
things like that, you try to find a way to
explain things, and that's perfectly normal. Bruce wages that if
(20:06):
you could start a human society from scratch on an
island somewhere far removed from our existing traditions, my bed
is they would soon come up with their own demons,
their own gods, and their own explanations of the world,
which are equally the same sort of supernatural beliefs that
we have in the case of conventional religion. So I
think it's a natural consequence of the way that we
(20:27):
have evolved systems to kind of respond to threats, to
try and control the world around this to see the
whole being grand and the sums that were all of
these things I think are just part and parcel of
the way we interpret the world. When I was tiny,
my mom was on to put me to bed, and
she used to freak me out by doing this puppety
(20:49):
thing with her right hand. It was just a bare
hand like rings and everything, but her long brown fingers,
and her thumb would be pointed at me like a beak,
and she'd slowly advance this little creature towards me, and
every night I swore I wasn't gonna fall for it
this time, but then she'd start doing the voice, which
went he and I couldn't help it. Like all of
(21:16):
my attention turned towards this hand because it was alive.
It was getting closer to my face. And I can
still remember the shape of her bunched finger tips, which
seemed so clearly a snout, with her thumb as the
working jaw. And even now when I look at my
own hand in that position, the bedtime animal is resurrected
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at the end of my own wrist. We can be
spooked by the features of our own design, even just
sensing our own bodies. If something goes wrong and we
can't differentiate what's happening inside from what's happening outside, the
results aren't just distressing. They could feel paranormal. And even
when our brains and bodies are humming along and working order,
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we look for signs of life so vigilantly that we
perceived hidden agents in the rustling grass. We find faces
in our snack foods. Even when we were alone. We
see creatures everywhere, friends, foes, gods, or even just fingers
and thumbs. I think, well, at our next team meeting,
(22:39):
Deeply Human will be talking menopause. Why do both women
and whales go through it? Deeply Human is a co
production of the BBC World Service in American public media
with I Heart Media, and it's hosted by me, Tessa. Okay, buddy,
let's get you out of that chair. Huh h man
(23:02):
running through your own neighborhood with a microphone and you
freaks people out.