Speaker 1: Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 2: Hey, welcome to Stuff to Blow Your Mind. My name
Speaker 2: is Robert Lamb.
Speaker 3: And I'm Joe McCormick, and we're back with part three
Speaker 3: in our series on the theme of being upside down.
Speaker 3: In part one of this series, we talked about a
Speaker 3: scene in Dante's Inferno in which the world suddenly seems
Speaker 3: to be upside down while the poet is crawling down
Speaker 3: the body of Satan, and we talked about how different
Speaker 3: cosmological models apply to that scene. After that, we talked
Speaker 3: about adaptations to upside down living in mammalian biology, particularly
Speaker 3: in bats and tree slots. And then in part two,
Speaker 3: we talked about inverted vampires and other beasts and monsters
Speaker 3: of folklore, things that are said to hang from the
Speaker 3: ceiling or dwell upon the ceiling. And then we talked
Speaker 3: about the physiology and psychology of spaceflight and how in
Speaker 3: microgravity astronauts sometimes they're subject to a number of cognitive
Speaker 3: and perceptual illusions that can make them suddenly feel like
Speaker 3: they're hanging upside down, or can cause the astronauts' subjective
Speaker 3: sense of up and down to switch places, and so
Speaker 3: we are back today to talk about more.
Speaker 2: Yeah, and one place I want to start out with
Speaker 2: here is this kind of goes back to something we
Speaker 2: were talking about. I think maybe in the first episode.
Speaker 2: We're talking about how sometimes the idea of an upside
Speaker 2: down world is not necessarily a bad thing. You know,
Speaker 2: It's not necessarily the Stranger Things model where the upside
Speaker 2: down is a nightmare, shadow realm, or you know, some
Speaker 2: sort of illogical world that is ruled by chaos. Turning
Speaker 2: things on their head can of course reveal truth. That's
Speaker 2: how we use the phrase, and it's actually one of
Speaker 2: the key ideas bound up in the Tarot card, the Hangedvan.
Speaker 2: I think most of you have probably seen some version
Speaker 2: of this, even if you're not familiar with taro He's
Speaker 2: He is in general revealed as an individual who is
Speaker 2: of course hanging upside down one leg by one leg,
Speaker 2: with the other leg crossed behind him, like he's doing
Speaker 2: an inverted yoga pose of some sort, but hanging from
Speaker 2: like the branch of a tree or some sort of
Speaker 2: a cross like structure, hands behind the back. But generally
Speaker 2: he is not depicted as being in distress. Most depictions
Speaker 2: of the hanged Man have kind of a voluntary feel
Speaker 2: to them, and the idea I'm to understand within the
Speaker 2: Tara tradition is that he is seeing the world from
Speaker 2: a new angle.
Speaker 3: That's not what I would have assumed based on the
Speaker 3: name the hang demand sounds like a character being portrayed
Speaker 3: in a kind of execution or crucifixion or something. But
Speaker 3: the idea here is more that this is a figure
Speaker 3: assuming a pose or assuming a new perspective.
Speaker 2: Yeah. Yeah, some more things going on with other tarot
Speaker 2: cards as well, where what it might seem to be
Speaker 2: about is not the full story, and then you have
Speaker 2: interactions and so forth. But you know, there's also some
Speaker 2: connection here to the idea of the inverted cross, which
Speaker 2: is often today popularly employed as an unholy symbol particular bands. Yeah,
Speaker 2: metal bands and the sort of the sort of horror
Speaker 2: movies that you and I navigate to and sometimes discuss
Speaker 2: in weird house cinema and thinking about like a lacarda
Speaker 2: and so forth. So you know, that's what I think
Speaker 2: of when we think about an inverted cross. But of course,
Speaker 2: traditionally within Catholic tradition, this is also the cross of
Speaker 2: Saint Peter, who, according to tradition asked to be crucified
Speaker 2: upside down because he felt unworthy to die in the
Speaker 2: normal position, the way that Christ died. So it's bound up.
Speaker 2: The symbol is bound up with ideas of humility. Now
Speaker 2: we can't be completely certain about the historic Peter here.
Speaker 2: You know, this might just be a story with him
Speaker 2: ordering off the menu when it comes to this crucifixion.
Speaker 2: But we do have passing references to inverted crucifixions or
Speaker 2: perhaps to inverted crucifixions by such first century historians as
Speaker 2: Seneca the Younger and Flavious Josephus, to suggest that the
Speaker 2: acts were sometimes committed in this fashion and in other fashions.
Speaker 2: Now there's no real archaeological evidence, but then again, archaeological
Speaker 2: evidence for crucifixion is extremely rare. You know, just think
Speaker 2: about the elements involved here. And there were also, to understand,
Speaker 2: no manuals on how to do it, So it's not
Speaker 2: like there was a laminated card that crucifixion. Roman crucifixion
Speaker 2: grunts referred to and decided how they were going to
Speaker 2: torture people to death. There was, you know, it seems
Speaker 2: to be kind of like a traditional way to do it.
Speaker 2: And then sometimes they did other things out of their
Speaker 2: you know, cruelty and horror.
Speaker 3: Yeah, that is an interesting thing. I've come across this
Speaker 3: historical fact before that while there are tons of references
Speaker 3: to crucifixion in ancient literature and stuff people were writing
Speaker 3: during the Roman Empire, there's no like canonical source from
Speaker 3: Roman authorities on how you did it or what it is. Instead,
Speaker 3: it's just something that people are writing about, assuming everybody
Speaker 3: else already knows exactly what they're talking about.
Speaker 2: Yeah, yeah, And it can be easy to assume this
Speaker 2: as well. If you again, if you grow up in
Speaker 2: in certain you know, church environments where a lot of
Speaker 2: emphasis is placed on the the you know, gritty specifics
Speaker 2: of crucifixion, you might think, oh, we got it all
Speaker 2: figured out, but there are you know, a number of uh,
Speaker 2: there are a number of questions that still remain regarding
Speaker 2: what was done and indeed, like exactly how people would
Speaker 2: die under these circumstances. I will admit I did not
Speaker 2: have a strong enough stomach to really go any further
Speaker 2: in that direction for this episode, But there are plenty
Speaker 2: of papers out there that discuss these various ideas. But
Speaker 2: I just didn't have the stomach for it myself.
Speaker 3: Well, I don't want to go into too much detail either,
Speaker 3: but I'll just say generally, outside of Roman Crucifixion, the
Speaker 3: possible instances of upside down Roman Crucifixion, there are some
Speaker 3: other cases in world history of torture methods that involve
Speaker 3: being put upside down.
Speaker 2: Yeah.
Speaker 3: I'm thinking about some Japanese examples that I know of.
Speaker 2: Yeah. Yeah, and again I didn't have the stomach to
Speaker 2: do and all that, but they exist. There's a whole
Speaker 2: world of that if anyone is interested. The next thing
Speaker 2: that I want to talk about concerns the antipodes, or
Speaker 2: well antipode. The singular is antipode, the plural is antipothies. Yeah.
Speaker 2: So every position on our planet has an antipode. That's
Speaker 2: a position on the exact other side of the globe.
Speaker 2: So if you could tunnel from one point to another,
Speaker 2: you could travel from say Madrid, Spain to Weber, New Zealand,
Speaker 2: or from Formosa, Argentina to tan and Taiwan. A lot
Speaker 2: of notable locations on our planet do not have an antipode.
Speaker 2: On dry land, you know, it would just if you
Speaker 2: were to tunnel straight through it would spit you out
Speaker 2: in the middle of a body of water, you know,
Speaker 2: probably in the ocean. But these are a few key
Speaker 2: surface to surface examples.
Speaker 3: I don't know, but i'd imagine our antipode is somewhere
Speaker 3: in the Pacific Ocean.
Speaker 2: I think, so. Yeah. I was looking around at a
Speaker 2: few and I was like, oh, well, there's not one there. Well,
Speaker 2: there's not one there. And then I was like, okay,
Speaker 2: what are what are the main ones that people point to?
Speaker 2: And generally it's you know, tunneling from you know, somewhere
Speaker 2: in Europe to somewhere Australia and New Zealand. We actually
Speaker 2: heard from a listener about this, reminding us that that
Speaker 2: Total Recall remake that came out several years ago involves
Speaker 2: a plot line about some sort of a crazy elevator
Speaker 2: that go straight through the center of the planet. I
Speaker 2: guess it lines up a little bit with the Dante
Speaker 2: thing We're just got thing previously.
Speaker 3: Several years ago on that Total Recall remake. I think
Speaker 3: that was like twelve years ago, now, wasn't it.
Speaker 2: Yeah, probably that's the way it goes. I still feel
Speaker 2: like it just came out, but it's you know, it's
Speaker 2: a classic film.
Speaker 3: Now Time, gotcha?
Speaker 2: Yeah yeah, Time treats everyone like fool. All right, well, okay,
Speaker 2: what does all this mean? What means that you could
Speaker 2: have a person in Madrid and that person in weber
Speaker 2: Is on the other side of the globe is upside
Speaker 2: down from the Spanish perspective and vice versa. Of course,
Speaker 2: you know it's it's feet to feet And indeed, the
Speaker 2: word antipode comes from the Greek antipotis, which means with
Speaker 2: feet opposite.
Speaker 3: Mmmm. Oh yeah, oposing feet. That that is interesting, and
Speaker 3: you know that fact actually connects to one thing I
Speaker 3: was reading about, which is the the upside downness of
Speaker 3: astronomical references depending on which hemisphere of the Earth you're in.
Speaker 3: So maybe people don't think about this very often, but
Speaker 3: if if you're in the northern hemisphere, you know, the
Speaker 3: moon looks a certain way to you, but if you
Speaker 3: go to the southern hemisphere, the moon will now be
Speaker 3: upside down from your familiar reference point because now you're
Speaker 3: on the opposite side of the sphere looking up at it.
Speaker 2: Oh wow, I wonder if it affects like wherewolf transformations
Speaker 2: like in Australia, wherewolves transform from the feet up or
Speaker 2: something I don't know instead of mouth first.
Speaker 3: Interesting, but you can imagine that it is save for
Speaker 3: ancient writers who did. By the way, you know, there's
Speaker 3: a common misconception that, like, you know, everybody used to
Speaker 3: think the Earth was flat. In history. There was some
Speaker 3: flat Earth consciousness, but there was also a lot of
Speaker 3: round Earth consciousness. So like ancient writers think understanding that
Speaker 3: the geometry of the earth roughly understanding that it must
Speaker 3: be round, and thinking about beings on the opposite sides
Speaker 3: with their feet facing our feet and their heads going
Speaker 3: in the opposite direct action. What kinds of beings must
Speaker 3: those be?
Speaker 2: Yeah, and it's interesting to look at this. This generally
Speaker 2: boils up in discussion of like the monstrous races, the
Speaker 2: monstrous people's the ideas that, yeah, they're humans all over
Speaker 2: the world, but man, they take some weird forms. They
Speaker 2: might have like a mouth in their stomach. They might
Speaker 2: hop around on one foot and then laid back and
Speaker 2: position that foot over their head to provide shade, that
Speaker 2: sort of thing, you know. And a big part of
Speaker 2: this is that you would have writers such as Roman
Speaker 2: historian Plenty the Elder, who've talked about many times in
Speaker 2: the show with someone like Plenty. You know, Plenty was
Speaker 2: I'm to understand more of an empiricist concerning things closer
Speaker 2: to Rome and things that he was able to witness
Speaker 2: first hand in his own personal travels. But he is
Speaker 2: in the Natural History attempting to write about the known world,
Speaker 2: and so he has to depend on a lot of
Speaker 2: far flung and sometimes fringe accounts from things much farther
Speaker 2: out from secondhand and then third hand sources, you know,
Speaker 2: from sailors and that traveled far or historians were reporting
Speaker 2: as well on something that they receive second or third hand.
Speaker 3: Yeah, and so you get interesting things when you read
Speaker 3: Pliny's Natural History. Again, this is a first century Roman
Speaker 3: source that's trying to create a kind of encyclopedia of
Speaker 3: all knowledge at the time, and you get this weird
Speaker 3: mix of like, oh, wow, you know, they they understood this.
Speaker 3: They actually it's kind of surprising that they would have
Speaker 3: certain understandings and knowledge that are to some degree correct
Speaker 3: much earlier than you might think people did. And then
Speaker 3: on the other hand, you will get bizarre, fantastical accounts
Speaker 3: that are obvious and like scientific explanations that are obviously wrong.
Speaker 2: So here's an example of the outrageous. That is obviously
Speaker 2: wrong concerning an antipode. And yeah, so there's essentially there's
Speaker 2: a mythical race of people connected with the idea they
Speaker 2: referred to, I believe as the Abaraman, which Plenty writes
Speaker 2: of here He discusses this and other opposite peoples in
Speaker 2: book seven of the Natural History. I'm going to read
Speaker 2: a quote. But beyond the other Scythian Cannibals, in a
Speaker 2: certain large valley of the Immavas Mountain, there is a
Speaker 2: region called Aberaman, where are some people dwelling in forests
Speaker 2: who have their feet turned backward behind their legs, who
Speaker 2: run extremely fast and range abroad over the country with
Speaker 2: the wild animals. It is stated by Baton, Alexander the
Speaker 2: Great's route surveyor on his journeys, that these men are
Speaker 2: unable to breathe in another climate, and that consequently none
Speaker 2: of them could be brought to the neighboring kings, or
Speaker 2: had ever been brought to Alexander. According to Isaginus of Nicea,
Speaker 2: the former cannibal tribes whom we stated to exist to
Speaker 2: the north ten days journey beyond the river bor Sithonians
Speaker 2: sorry Bori Scynthienes drink out of human skulls and use
Speaker 2: the scalps with the hair on as napkins hung around
Speaker 2: their necks. The same authority states that certain people in
Speaker 2: Albania are born with keen gray eyes and are bald
Speaker 2: from childhood, and that they see better by night than
Speaker 2: in the daytime.
Speaker 3: Now, wait a minute, are any of these peoples said
Speaker 3: by plenty to be Antipodean or these are just generally
Speaker 3: like descriptions of peoples that are probably way off base.
Speaker 2: Yeah, mostly this is just people far away, essentially on
Speaker 2: the other side of the earth, are remarkably different, like
Speaker 2: to the point where they might not be able to
Speaker 2: breathe the same air. Or yeah, they see better at
Speaker 2: night than in the day. You know, obviously we know
Speaker 2: that this is not the case with human beings. There
Speaker 2: are differences with you know, among different peoples in different
Speaker 2: parts of the world, but they're not this pronounced, not
Speaker 2: at all. And there are some other creatures and monstrous
Speaker 2: races that pop up in other medieval bestiaries, such as
Speaker 2: the Newly I think they're also sometimes described as being
Speaker 2: an antipode race. But yeah, I think, you know, I
Speaker 2: think that you know, despite all of this being, you know,
Speaker 2: being quite incorrect. You can imagine that there's a pervasive
Speaker 2: idea here from antiquity through medieval bestiaries, that humans that
Speaker 2: lived on the other side of the planet or sufficiently
Speaker 2: beyond our horizon might be fundamentally different in key biological ways,
Speaker 2: almost like their aliens from an entirely different planetary ecosystem.
Speaker 2: At the same time, it's worth noting again that Plenty
Speaker 2: very much believed that the entirety of the round Earth
Speaker 2: was populated with people, and so like that's the deeper
Speaker 2: truth here, Like he's getting a lot of things wrong,
Speaker 2: but he's also saying here and elsewhere that the world
Speaker 2: is round and there are people all over it. And
Speaker 2: he discusses this in the section chapter sixty five that
Speaker 2: is titled whether there be antipodes or antipodies? On this
Speaker 2: he writes, quote, on this point there is a great
Speaker 2: contest between the learned and the vulgar. We may maintain
Speaker 2: the learned that there are men dispersed over every part
Speaker 2: of the Earth, and they stand with their feet turned
Speaker 2: toward each other, that the vault of the heavens appears
Speaker 2: alike to all of them, and that they all of
Speaker 2: them appear to tread equally on the middle of the Earth.
Speaker 2: If anyone should ask why those situated opposite to us
Speaker 2: do not fall, we directly ask in return whether those
Speaker 2: on the opposite side do not wonder that we do
Speaker 2: not fall. But I may make a remark that will
Speaker 2: appear plausible even to the most unlearned, that if the
Speaker 2: Earth were of the figure of an unequal globe like this,
Speaker 2: like the seed of a pine, still it may be
Speaker 2: inhabited in every part. Hmm.
Speaker 3: Okay, I don't want to overstep, because I don't know
Speaker 3: for sure here, but I would guess then that Plenty
Speaker 3: has basically is. Obviously this is going to be incorrect
Speaker 3: in big ways that come into focus when you think about,
Speaker 3: like the other planets in the stuffs. But that he
Speaker 3: can have basically the right idea about Earth's gravity even
Speaker 3: without having an idea of gravity, just the idea that
Speaker 3: all around the surface of the Earth everything would be
Speaker 3: attracted toward the center. And he could have that idea,
Speaker 3: possibly based on the same kind of Aristotelian model of
Speaker 3: heaviness and lightness that Dante was probably using a thousand
Speaker 3: years later, more than you know, twelve hundred thirteen hundred
Speaker 3: years later.
Speaker 2: Yeah. Yeah, So I think it's interesting to sort of
Speaker 2: focus in on this because, yeah, we sometimes we give
Speaker 2: Plenty up a bit of a hard time based on
Speaker 2: some of the more outrageous things in the natural history.
Speaker 2: Though we often highlight what Plenty has to say in
Speaker 2: that it shows how much was known at the time.
Speaker 2: And to be clear, he was one of the most
Speaker 2: learned men of his day and a titan of knowledge,
Speaker 2: and that's why we keep referring back to him. You know.
Speaker 2: It's whatever Plenty had to say about something or didn't
Speaker 2: have to say about something informs us about just what
Speaker 2: was known during this time period, you know, during the
Speaker 2: first century.
Speaker 3: See, yeah, gives you a good snapshot of what generally
Speaker 3: educated romans on a particular subject probably thought.
Speaker 2: Yeah. Now, the the idea of of of of there
Speaker 2: being an antipode for every point and for there being
Speaker 2: people on the other side of the earth. Again, I
Speaker 2: think on the whole, you know, this was considered settled
Speaker 2: among most of the learned, but you at least, you know,
Speaker 2: a couple of centuries after Plenty's time, you did have
Speaker 2: some folks who were a little bit more grumpy about
Speaker 2: the concept and uh and and disagreed with it, and
Speaker 2: even found the idea of people on the other side
Speaker 2: of the earth of as being a clear counter to
Speaker 2: the notion of a spherical earth. So probably the most
Speaker 2: outrageous example of this is like Tensious Uh. He was
Speaker 2: a later early Christian author and advisor to Roman emperor
Speaker 2: Constantine the First. He lived two fifty through three twenty
Speaker 2: five CE. To put that in comparison to plenty live
Speaker 2: like twenty three to seventy nine. See so anyway, this author,
Speaker 2: this later Christian author, in his work Divine Institutes Rites,
Speaker 2: Is there anyone so foolish as to believe that there
Speaker 2: are people living on the other side of the earth
Speaker 2: with their heels upward and their heads hanging down, Or
Speaker 2: that things that lie flat with us hangs suspend it there,
Speaker 2: that crops and trees grow downward, that rain and snow
Speaker 2: and hail fall upwards upon the earth.
Speaker 3: Wait a minute, I can't tell which way this is going.
Speaker 3: Is this mocking people who don't understand that gravity would
Speaker 3: be attracted the opposite way on the other side of
Speaker 3: the earth, or mocking just the belief in people and
Speaker 3: things on the opposite side of the Earth.
Speaker 2: He's basically taking a shot at the understanding of the
Speaker 2: world that Plenty really represents. So yeah, he was a
Speaker 2: pretty famous attachs was a pretty famous critic of the
Speaker 2: notion of around earth at the time, and though his
Speaker 2: was not the predominant way of thinking, even certainly among intellectuals.
Speaker 2: So the notion of around earth had again been settled
Speaker 2: science essentially for centuries, as mentioned by Plenty, but the
Speaker 2: secular world was sold on a spherical Earth, though the
Speaker 2: issue remained a sort of nuisance discussion in the church.
Speaker 2: Like at times there were people in the Christian Church
Speaker 2: were like, can we maybe just shut up about this
Speaker 2: because this really has nothing to do with salvation or anything.
Speaker 2: It's just a senseless argument that probably makes people look stupid. Yeah.
Speaker 3: Yeah. And by the way, if you're wondering, like, wait,
Speaker 3: how did people in the ancient world know that the
Speaker 3: Earth was round before they had, say, traveled all the
Speaker 3: way around it, it circumnavigated the globe. There are all
Speaker 3: kinds of experiments you can do and even just observations
Speaker 3: you can make that inform you that the Earth is round.
Speaker 3: You are being critical and you're scrutinizing the idea. You
Speaker 3: can think about simple things like ships disappearing over the
Speaker 3: horizon as they travel farther and farther away. That's one
Speaker 3: pretty clear indication that, over long enough distances, the surface
Speaker 3: of the Earth is curved. But then there are also
Speaker 3: even going back into antiquity geometry experiments, you can do
Speaker 3: with say the angle of a shadow cast by a
Speaker 3: sun dial, and you can measure those angles at the
Speaker 3: same time of day at different latitudes and notice that
Speaker 3: there are differences, and that gives you indications that wait
Speaker 3: a minute, the surface of the Earth is curved. And
Speaker 3: then if you extrapolate from the degree of that curve,
Speaker 3: you can see that actually we're living on a ball.
Speaker 2: Yeah, And so as bal dwellers that we are, there
Speaker 2: are those who live right side up and those who
Speaker 2: live upside down. And at the same time, nobody is
Speaker 2: right side up and nobody is upside down.
Speaker 3: It's true.
Speaker 2: So I want to turn now to the realm of optics,
Speaker 2: and I think this is pretty much where we're going
Speaker 2: to stay for the duration of this episode. So here
Speaker 2: here is something that we take for granted, Okay, a
Speaker 2: basic statement that will probably feel true to most of
Speaker 2: you at least until you begin to analyze it, and
Speaker 2: that is we perceive the world right side up.
Speaker 3: Yeah, that seems right up, looks up down, looks down right.
Speaker 2: But what if, to borrow a comparison from David Eagleman,
Speaker 2: previous guest on the show and also fellow podcaster, what
Speaker 2: if we were to flip our eyes upside down, you know,
Speaker 2: like mister potato head style. What if we took them out,
Speaker 2: flipped him upside down, stuck him back in? What would happen?
Speaker 3: So here, we're not considering putting them in the slot
Speaker 3: where the ears go or where the mouth goes. We're
Speaker 3: just talking about flipping the eye, just.
Speaker 2: Flipping the eyes. Okay, Now, for starters, we should point
Speaker 2: out that this would be quite difficult to pull off
Speaker 2: in reality because you can't just say, pull the eye out,
Speaker 2: twisted around and put it back in without severely damaging
Speaker 2: the bundled optic nerve, which would cause blindness Surgically. You'd
Speaker 2: also have to contend with these six extra ocular muscles
Speaker 2: surrounding the eye. There's a lot of stuff holding stuff
Speaker 2: in place, so you know, beyond what you might have
Speaker 2: seen in a mad magazine or something with somebody's eyeball
Speaker 2: hanging out on, you know, on a single thread. There's
Speaker 2: a lot of stuff in there, and it's very delicate
Speaker 2: if you start messing with it.
Speaker 3: Actually, in the very next weird House Cinema movie we're
Speaker 3: going to be doing, there is a pretty pretty awesome
Speaker 3: cyborg cyborg eyeball removal and maintenance scene.
Speaker 2: Oh well, well, now cyborg's can do it. They're different. Yeah,
Speaker 2: But as a side note, there is I was looking
Speaker 2: into this. There is actually a procedure called macular translocation
Speaker 2: by which retina is detached and shifted away from less
Speaker 2: healthy eye tissue, and then the extra ocular muscles are
Speaker 2: also adjusted to prevent a perceived tilt in vision. So
Speaker 2: there is something to that. But of course we don't
Speaker 2: have to dream up mad science surgeries to flip the
Speaker 2: vision of a human being. We don't actually have to
Speaker 2: take the mister Potato eyes out, flip them and reinsert them. Instead,
Speaker 2: we can achieve this optically or visually. Ahead of the eye.
Speaker 2: Don't flip the receptors, flip the input, Flip the incoming media.
Speaker 3: Okay, yeah, so you flip the image of the world
Speaker 3: before it hits the eyes.
Speaker 2: Right, and so In this we turn to a particular
Speaker 2: American psychologist by the name of George M. Stratton and
Speaker 2: his amazing upside down goggles.
Speaker 3: This is a famous experiment in the history of vision studies,
Speaker 3: and it's really interesting, I think.
Speaker 2: Yeah, absolutely so. He lived eighteen sixty five through nineteen
Speaker 2: fifty seven, and around eighteen ninety six he set out
Speaker 2: to study the way that we perceive the right side
Speaker 2: up world. Because here's the mind blowing thing that Stratton
Speaker 2: knew very well and I think was probably popping into
Speaker 2: a number of your minds as you were contemplating whether
Speaker 2: we see a right side up world, and that is
Speaker 2: that we don't exactly see the right side up world
Speaker 2: at all. If you think back to our episode of
Speaker 2: stuff to blow your mind on the Camera Obscura, which
Speaker 2: you can find in the archive wherever you get the
Speaker 2: audio version of this podcast, or any or if you
Speaker 2: think on any experience you have with these optical devices,
Speaker 2: because you can find Camera Obscura is set up at
Speaker 2: various museums and events, but light passes through a small
Speaker 2: aperture of a dark chamber and projects a scene from
Speaker 2: the outside world a projection, but the resulting image is
Speaker 2: inverted upside down and reversed left to right. The term
Speaker 2: camera obscura, by the way, was coined by Johannes ke
Speaker 2: Bler in sixteen oh four, and he made the connection
Speaker 2: that our eye works much the same way with an
Speaker 2: image of the outside world inverted and reversed on the
Speaker 2: retina of the eye. The camera obscura and the human
Speaker 2: eye share the same fundamentals of optics here. But yeah,
Speaker 2: the what enters our eye is then it placed on
Speaker 2: the retina upside down.
Speaker 3: But the cool thing is that that's okay because it's
Speaker 3: not the retina that sees, it's the brain that sees.
Speaker 2: Absolutely, that's the amazing thing here. Our eyes receive an
Speaker 2: upside down version of the right side up world, and
Speaker 2: then the brain flips it without our realizing it. And
Speaker 2: I think this alone is pretty amazing.
Speaker 3: Absolutely, yes, especially the fact that you don't have to
Speaker 3: think about doing it. You're not conscious of this flipping.
Speaker 3: The world just looks right to you.
Speaker 2: Yeah, It's like it's like our brain is a plumber,
Speaker 2: and we have a toilet set up to flush with
Speaker 2: hot water, and then the plumber sneaks in and re
Speaker 2: and does it, and it adds an additional twist around
Speaker 2: to make sure that our toilet flushes with cold water.
Speaker 2: I don't know, this is a terrible comparison, but at
Speaker 2: any rate, it's amazing what's happening here. So, coming back
Speaker 2: to Georgia M. Stratton, he wanted to know how we'd react,
Speaker 2: how our brains would deal with it if, via special goggles,
Speaker 2: we received a pre flipped vision of the world which
Speaker 2: then gets flipped right side up in our retinas and
Speaker 2: then flipped upside down once more via the brain. His
Speaker 2: theory was that the brain didn't really need an upside
Speaker 2: down retinal image and that it could make do with
Speaker 2: whatever it had.
Speaker 3: Okay, so the idea is where these goggles that flip
Speaker 3: the image of the world upside down before it reaches
Speaker 3: your eyes, and figure out how does how do the
Speaker 3: eyes and the brain react to this?
Speaker 2: Right, So this is what happened. Stratton experimented on himself
Speaker 2: wearing a special glass over his right eye, and he
Speaker 2: covered his left eye with an eye patch, and then
Speaker 2: he wore like a blindfold or two eye patches when
Speaker 2: he slept at night. So via this special goggle, he
Speaker 2: perceived an upside down world that was initially highly disorienting
Speaker 2: because the brain, to be clear, the brain didn't do
Speaker 2: anything with this information right away. Is just highly disorienting.
Speaker 2: It's like seeing the world upside down through a crazy
Speaker 2: goggle strapped to your eye. As you can imagine, it
Speaker 2: was a lot. But by around day three things begin
Speaker 2: to even out and to be clear. And this is
Speaker 2: something that has to be driven home regarding this and
Speaker 2: other experiments using this sort of thing. It's not that
Speaker 2: the brain ends up flipping the image again, because it
Speaker 2: does not. It's not like, oh, by day three I
Speaker 2: just saw everything right side up again. No, but he
Speaker 2: was able to. He found himself adapting to this inverted
Speaker 2: feed and was able to effectively move through environment again,
Speaker 2: you know, interact with things I believe. In this or
Speaker 2: other experiments, the users have been able to read again
Speaker 2: that sort of thing. And then upon taking the goggles off,
Speaker 2: there's another period of readjustment which is interesting to think about,
Speaker 2: Like your brain has adapted to an upside to the
Speaker 2: upside down feed, and then when it gets the right
Speaker 2: side up feet again, you again have to sort of
Speaker 2: recombobulate yourself. He wrote. Initially all the images were inverted.
Speaker 2: Things were seen in one way and thought about it
Speaker 2: in a different way because of memory and past experience. However,
Speaker 2: with practice, the subject and he's preferring to himself here,
Speaker 2: learned to adapt to the new visual field. On removal
Speaker 2: of the glasses, normal vision was restored. Concluded that difficulty
Speaker 2: in seeing things upright due to upright retinal images is
Speaker 2: due to previous experience. And so this brings me back
Speaker 2: to the true example of the mister potato head that
Speaker 2: David Eagleman brought up that he's discussed on his most
Speaker 2: recent appearance on our show a few years back, and
Speaker 2: that is this idea that our brain will make use
Speaker 2: of whatever sensory information is plugged into it, mister potato
Speaker 2: head style. So it might be site, It might be smell,
Speaker 2: It might be taste. It might be something entirely new,
Speaker 2: such as like stock information or some you know, heightened
Speaker 2: awareness of electromagnetism. It might be again to come back
Speaker 2: to the specifics here, it might be vision, but that
Speaker 2: is flipped. It might be say, smell that is different
Speaker 2: like I don't know if you were somehow able to
Speaker 2: you know, put the plug the nose of a dog
Speaker 2: onto us and gift us with like the scent abilities
Speaker 2: of a dog, that sort of thing. The brain would
Speaker 2: just make use of it. It would stitch together an
Speaker 2: understanding of the outside world that we can use. If
Speaker 2: the world is flipped to the upside down, the brain adjusts.
Speaker 3: This reminds me of what we talked about in the
Speaker 3: last episode actually with astronauts in microgravity. You know, when
Speaker 3: you arrive in microgravity, a lot of astronauts are going
Speaker 3: to have problems related to the brain continuing to try
Speaker 3: to establish a subjective vertical where the kind of information
Speaker 3: that it's normally getting from the vestibular system to supply
Speaker 3: that is not present, or the vestibular system is just
Speaker 3: being you know, stimulated to the point of haywireness, Like
Speaker 3: it's getting confusing information and that's conflicting with visual information.
Speaker 3: So it causes all these problems initial but it doesn't stay,
Speaker 3: or at least for most astronauts, does not stay like
Speaker 3: that forever. There is an adjustment period, and then eventually
Speaker 3: the brain starts to get used to the new environment
Speaker 3: and adapt essentially to the idea that I now live
Speaker 3: in a place where there's no necessary up and down.
Speaker 2: Yeah. Yeah, So there have been some other studies involving
Speaker 2: goggles like this or goggles that carry out some more functions.
Speaker 2: There is the Ensbruk goggle experiment of the fifties and sixties,
Speaker 2: carried out by Austrian psychologist Theodore Heersman who lived eighteen
Speaker 2: eighty three through nineteen sixty one and Ivo Kohler who
Speaker 2: lived nineteen fifteen through nineteen eighty five, involving prism equipped goggles,
Speaker 2: colored goggles, and other designs that distorted perception in one
Speaker 2: way or another, including flipping things upside down, but also
Speaker 2: stuff like making the wear see only through the back
Speaker 2: of their head via a retroscope, and so you know,
Speaker 2: they were really sort of getting into the nitty gritty
Speaker 2: of well, what if we did this, what if we
Speaker 2: did this? And these experiments were again more focused on
Speaker 2: particular effects, and they often lasted for extended periods of time,
Speaker 2: like they would have subjects wearing these things for weeks,
Speaker 2: and you know, ultimately these various studies were further revealed
Speaker 2: the power of neuroplasticity in the brain when it comes
Speaker 2: to visual sensory input and regarding the upside down world.
Speaker 2: These experiments also found that people adapted after a period
Speaker 2: of days psychologist Hubert Dolzel also conducted a rigorous long
Speaker 2: term study published in the book Living in a World
Speaker 2: Transformed in eighty two, and he found that while the
Speaker 2: upside down visual sensations never fully disappeared again, the world
Speaker 2: still looks flipped and your brain does not flip things
Speaker 2: back for you said that the appropriateceptive since the internal
Speaker 2: map of where your limbs are it completely reorients. And
Speaker 2: then it's worth noting that fMRI assisted studies have also
Speaker 2: shed additional light on all of this, and the basic
Speaker 2: experimental findings seem to have remained the same. Subjects adapt
Speaker 2: to move and even read, but they don't experience a
Speaker 2: true reversal. Things remain flipped. But i F MRI has
Speaker 2: revealed increased activity in the parietal cortex responsible for spatial
Speaker 2: processing and the motor And basically the idea here is
Speaker 2: that motor response seems to essentially be corrected to work
Speaker 2: with the new data. So you know, to think in
Speaker 2: terms of like you know, sci fi, if aliens strapped
Speaker 2: weird goggles to our head or some sort of bizarre
Speaker 2: you know, mutagen from another world suddenly flipped all of
Speaker 2: our visions and made us see like this, it would
Speaker 2: be greatly disorienting, but we would all adapt within a
Speaker 2: matter of days and weeks to this new way of
Speaker 2: seeing and moving through the world, and it would just become.
Speaker 2: It would just become how it is.
Speaker 3: Yeah, totally. Now, we might not all adapt at the
Speaker 3: same to the same degree or at the same rate, right,
Speaker 3: I don't know this actually, but for some reason, I
Speaker 3: would guess kids would probably adapt easier than older than
Speaker 3: older adults, and that I.
Speaker 2: Don't recall it being specifically pointed out, but in general,
Speaker 2: we know that neuroplasticity is higher in younger humans, so
Speaker 2: that would make sense.
Speaker 3: So yeah, I don't know that, just speculating on my part,
Speaker 3: but generally there would be a pattern of adaptation, even
Speaker 3: to things that you just wouldn't imagine that we could
Speaker 3: get used to. We can't. Okay, we've already been to
Speaker 3: hell once in this series. You want to go to
Speaker 3: hell again?
Speaker 2: Sure? Why not? So?
Speaker 3: I want to explore a different topic in upside down perception,
Speaker 3: specifically in how our brains process faces when they're upside down.
Speaker 3: This is a subject that I think is both funny
Speaker 3: and mysterious, fascinating and mysterious. It is known as the
Speaker 3: Thatcher effect or the Thatcher illusion, so named because it
Speaker 3: was first demonstrated with photos of the at the time
Speaker 3: of this paper newly elected British Prime Minister, Margaret Thatcher,
Speaker 3: so this was the year nineteen eighty. But the effect,
Speaker 3: to be clear, is in no way specially related to
Speaker 3: Margaret Thatcher or to the appearance of her face. It's
Speaker 3: about how we perceive general human faces under strange circumstances.
Speaker 3: So this is one where it really benefits to see
Speaker 3: this for yourself. If you were able to look up
Speaker 3: imagery right now, you can understand the effect immediately by
Speaker 3: doing a search for Thatcher illusion, or if you go
Speaker 3: to one of the web pages that people have set
Speaker 3: up to demonstrate it. I found one at Thatcher effect
Speaker 3: dot com.
Speaker 2: But it is worth noting that it's gonna make more
Speaker 2: sense to you and be more effective. It is if
Speaker 2: it's a face you're familiar with, then Margaret Thatcher obviously
Speaker 2: a pretty famous international figure, but also one that people
Speaker 2: don't see every day in today's media environment, so you
Speaker 2: might be better off looking at some other celebrity or something.
Speaker 3: People do this with other celebrities as well. In fact,
Speaker 3: I've got some in the outline for you to look
Speaker 3: at here rob In fact, for our video viewers on Netflix,
Speaker 3: could we just briefly throw up an image of the
Speaker 3: Thatcher effect to demonstrate Ah, so do explain what it
Speaker 3: is here. Imagine you take a photo of a face,
Speaker 3: any face, especially a smiling face. So I'm personally going
Speaker 3: to be thinking about Christopher Lambert here, christof Lambert doing
Speaker 3: like a big you know, grinning Raiden and Mortal Kombat
Speaker 3: the movie, that kind of thing. So you take a
Speaker 3: pritted out photo of face and carefully you use a
Speaker 3: razor to cut out the mouth, like cut out a
Speaker 3: little rectangle around the mouth, and cut out the eyes,
Speaker 3: and then keeping the picture otherwise the same, you flip
Speaker 3: just the mouth and the eyes upside down. You leave
Speaker 3: them where the mouth and the eyes go, but you
Speaker 3: invert them. Okay, so now you've got regular face upside
Speaker 3: down mouth, upside down eyes. The magnitude of the effect
Speaker 3: can vary, but on average this tends to create a grotesque,
Speaker 3: hilarious image that is immediately recognizable as absolutely cursed. And
Speaker 3: there are differences depending on like on a facial expression
Speaker 3: is a big thing. Like I think a very flat
Speaker 3: closed mouth makes the effect less noticeable, but especially when
Speaker 3: there's like a smile or something, this effect is not subtle.
Speaker 3: It looks like something from the pit of hell that
Speaker 3: has come out to suck your soul. And based on
Speaker 3: looking at a lot of these, I think it is
Speaker 3: the big smile, especially that inevitably creates great terror and anguish.
Speaker 3: So I've got some more examples for you to look
Speaker 3: at in the outline. Here rob one that actually doesn't
Speaker 3: have a big toothy smile but does still look pretty cursed.
Speaker 3: Is an image that was going around of Adele with
Speaker 3: thatcherized mouth and eyes. It looks something about that image
Speaker 3: looks a little bit cabinet of doctor Kaligari. There's just
Speaker 3: I don't know.
Speaker 2: It's evil. It is, but you wouldn't necessarily if you
Speaker 2: saw upside down face Adele. You know, if you saw
Speaker 2: that your face Adele on the street, you wouldn't think, oh,
Speaker 2: there is a denizen of Hell. It's like there is
Speaker 2: a lady. I don't know. It doesn't look bad crazy
Speaker 2: at least at first glance.
Speaker 3: Really wow, Okay, I don't know, I'm seeing something different.
Speaker 2: I don't know. Of course, with the Adele image, are
Speaker 2: the lips flipped.
Speaker 3: Yeah, yeah, you're not noticing. Wow, you're not noticing.
Speaker 2: No, no, no, clip, I'm looking at like where is the
Speaker 2: larger lip? And yeah, yeah, I mean I guess yeah.
Speaker 2: As we'll discuss, like this is part of what's going
Speaker 2: on in the mind. The way it's you know, stitching
Speaker 2: things together but not seeing her teeth. I think is
Speaker 2: very clear here because the toothy images are the ones
Speaker 2: that turn a toothy smile into a grimace of hell.
Speaker 3: Yes, like I said, yeah, the big the big toothy
Speaker 3: smile is like the most extreme, hell infernalizing of the images.
Speaker 3: But still something typically looks wrong when you see the
Speaker 3: head right side up and the eyes and mouth upside down.
Speaker 3: So you know, in a sense this might not be
Speaker 3: surprising you screw around with human facial features. You flip
Speaker 3: people's eyes and mouth upside down, keep the rest of
Speaker 3: the face right side up, it is probably going to
Speaker 3: look to some extent wrong and grotesque. But here's the
Speaker 3: psychologically interesting thing. If you take one of these hilarious
Speaker 3: cursed faces and you simply turn the whole image upside down,
Speaker 3: the effect becomes, to many observers almost completely invisible, or
Speaker 3: at the very least significantly more difficult to detect. So
Speaker 3: a thatcherized face turned upside down just looks like a
Speaker 3: normal face turned upside down. You don't see the grotesque
Speaker 3: inversions unless you're really taking your time and looking for them,
Speaker 3: or unless you rotate the image right side up again,
Speaker 3: and then you recognize the horror immediately. So isn't that
Speaker 3: interesting an upside down face? Just turning a head upside
Speaker 3: down obscures otherwise comple completely obvious mutilations of the image.
Speaker 2: Yeah, what is going on here? Yeah?
Speaker 3: So this effect was originally discovered by a British psychologist
Speaker 3: named Peter Thompson working at the University of York in
Speaker 3: nineteen eighty. It was published in a very short paper
Speaker 3: in the journal Perception with the title Margaret Thatcher a
Speaker 3: New Illusion. So the paper is just a few paragraphs
Speaker 3: and an accompanying image Thompson, And in fact there's no
Speaker 3: experiment in the paper at all, I think, because the
Speaker 3: strength of the effect is immediately apparent to anybody who
Speaker 3: just looks at the image and flips the paper upside
Speaker 3: down and right side up, Like, you don't really need
Speaker 3: an experiment to see something interesting is going on here.
Speaker 3: So in a very brief background section. It's like one
Speaker 3: paragraph long. Thompson refers to previous researchers who had proposed
Speaker 3: that upside down faces are more difficult to recognize, perhaps
Speaker 3: because within them it is harder to recognize facial expressions.
Speaker 3: That was kind of a strange claim to me. Maybe
Speaker 3: I admit that maybe I don't understand something about what's
Speaker 3: being positive there, But I was thinking, why would it
Speaker 3: be expressions that make that make it harder to recognize
Speaker 3: upside down face? And again, maybe I admit there's something
Speaker 3: I don't understand. But Thompson says that it says that
Speaker 3: since the eyes in the mouth tend to convey the
Speaker 3: most information about emotional state through facial expression, quote, it
Speaker 3: seems possible that an inverted face in which the eyes
Speaker 3: and mouth remain the normal way round might preserve the
Speaker 3: facial expression better than a truly inverted face. So he
Speaker 3: decided to try it out, and in another source in
Speaker 3: a minute, he's going to give a different kind of
Speaker 3: explanation for his inspiration to create this image. So there
Speaker 3: might be multiple reasons this.
Speaker 2: This I don't know.
Speaker 3: Early photoshopping experiment actually came together, but for whatever reason,
Speaker 3: he did to try out the mouth and eyes in version.
Speaker 3: So he cut out the eyes and mouth of a
Speaker 3: photo of Margaret Thatcher that he got from a poster
Speaker 3: from a student organization, and he flipped him upside down
Speaker 3: relative to the rest of the head. And he observed that, strangely,
Speaker 3: when you are looking at the whole image upside down,
Speaker 3: it doesn't really seem to change her expression.
Speaker 2: Quote.
Speaker 3: However, Figure two, which can be viewed by rotating the
Speaker 3: page one hundred and eighty degrees, reveals that we have
Speaker 3: been cruelly deceived by the smiling mis Thatcher of figure one.
Speaker 3: Her two faces are now dramatically different. Returning to figure one,
Speaker 3: meaning flipping the page right side up again, it is
Speaker 3: still very difficult to perceive the eyes and mouth rotated
Speaker 3: version as we now know it to be.
Speaker 2: And looking at an example of this, it is crazy.
Speaker 2: I know that I should, or I know that I
Speaker 2: should expect to see some different you know. Yeah, but
Speaker 2: the two images really like match up pretty well. The
Speaker 2: only thing that really jumps out at me is just
Speaker 2: the obvious place where you can tell that something had
Speaker 2: been cut and yeah, pasted, you know.
Speaker 3: Yeah, I would not looking at the thatcherized version of
Speaker 3: the of the face upside down, I would not notice
Speaker 3: anything was weird about it. It is not until you
Speaker 3: rotate it that you start to see the way something's
Speaker 3: wrong and then oh, oh, okay, yeah that's totally wrong.
Speaker 3: And I guess it's like a partially dawning awareness, like
Speaker 3: as you turn it around. But so you've got the
Speaker 3: core components here. You got the face editing, which is
Speaker 3: immediately overwhelmingly apparent when the face is right side up,
Speaker 3: but then it mostly vanishes and looks normal when the
Speaker 3: picture is upside down. There's also I think a bit
Speaker 3: of dry political humor in this short paper. It's so
Speaker 3: dry you can't even really explain it. But just one
Speaker 3: example is the acknowledgment section of the paper for where
Speaker 3: Thompson says, quote, I thank the your Conservative Association for
Speaker 3: supplying the stimulus material.
Speaker 2: This being the post organization that provided the poster. Ok.
Speaker 3: Yeah, the conservative organization that gave the political poster. Yeah.
Speaker 3: I don't know, maybe I'm reading into that, but that
Speaker 3: was a funny sentence to me.
Speaker 2: So this was going up on like college students' walls,
Speaker 2: like conservative college students walls.
Speaker 3: No, I don't think it was a poster like, oh,
Speaker 3: I have a Batman poster in my room, or it
Speaker 3: wasn't like the Einstein with the tongue out poster. I
Speaker 3: think this is more like a campaign poster, political poster
Speaker 3: for the you know, for the political organization for conservative students.
Speaker 2: Okay.
Speaker 3: So, in the years since Thompson first discovered this, there
Speaker 3: have been many experiments demonstrating versions of the Thatcher effect
Speaker 3: with human subjects. It has proven especially in interesting as
Speaker 3: a way of exploring how humans recognize the faces of
Speaker 3: other humans. So experiments will often take the form of
Speaker 3: tasks where subjects have to look at pictures of faces
Speaker 3: upside down and right side up and judge as quickly
Speaker 3: as they can whether faces have normal features or whether
Speaker 3: the face has been thatcherized. And as you just imagine
Speaker 3: trying to do one of these tasks, it would probably
Speaker 3: be almost infuriating how difficult it is to figure out
Speaker 3: whether the upside down face is altered or not. I
Speaker 3: was reading a bit more about the history of the
Speaker 3: Thatcher effect in an entry in the Oxford Compendium of
Speaker 3: Visual Illusions edited by Shapiro and Todorovich, and this entry
Speaker 3: on the Thatcher effect called about face is actually by
Speaker 3: Peter Thompson, the same guy who discovered it, and he
Speaker 3: tells a story here that's kind of interesting. He gives
Speaker 3: a slightly different account of exactly how he first discovered this,
Speaker 3: how he ended up at the photo editing task. Here
Speaker 3: he says what he was really trying to do was
Speaker 3: demonstrate something for his students. The idea was that at
Speaker 3: a distance, some fine details of an image, like a
Speaker 3: human face, would be undetectable, but then as you came closer,
Speaker 3: the details would become clear. And so he originally made
Speaker 3: the he says here he made the altered Thatcher face
Speaker 3: with the eyes and mouth inverted to show this principle.
Speaker 3: I think the idea was you'd hold it far away
Speaker 3: and students would be like, ah, yeah, that's just a
Speaker 3: picture of Margaret Thatcher. But then you would come closer
Speaker 3: and be like, oh, something is wrong. But he says,
Speaker 3: it just so happened that in the process of doing
Speaker 3: of making these materials, he happened to see the thatcherized
Speaker 3: image upside down, and he realized that when they were
Speaker 3: upside down, these images looked the same. The thatcherized and
Speaker 3: unthatcherized version looked the same, despite how obviously disgustingly different
Speaker 3: they were when oriented normally. So I love when you
Speaker 3: get these little accidents.
Speaker 2: Just because he happened to post it down on the
Speaker 2: on the desk upside down, and then then you got
Speaker 2: the deeper revelation about what's going on here.
Speaker 3: Yeah. Thompson also points out some interesting historical forerunners, not
Speaker 3: to the Thatcher effect, but just to differences in face
Speaker 3: perception based on vertical orientation. So in this century, he
Speaker 3: cites the work of the sixteenth century Italian painter Giuseppe Arcimbaldo,
Speaker 3: who live fifteen twenty seven to fifteen ninety three. This
Speaker 3: guy was a court painter and a master of festivals
Speaker 3: for three Holy Roman emperors. You have probably seen his
Speaker 3: paintings before. He likes to, or I guess liked long ago,
Speaker 3: liked to make images of people or humanoid figures out
Speaker 3: of assemblages of smaller inanimate objects like food items or books.
Speaker 3: So some of these composite images, you have somebody who
Speaker 3: is one level of resolution, it's like a you know,
Speaker 3: a jurist or a barrister or something. But then you
Speaker 3: zoom in it's like the face is a roast chicken.
Speaker 3: And then there's a you know, and the ear is
Speaker 3: a clam or something. It's just a bunch of food.
Speaker 2: Yeah. I long loved these images. Yeah, yeah, they there's
Speaker 2: a surreal nature to them that you're just like, wow,
Speaker 2: this is like this, this is such a singular vision.
Speaker 3: But some of these playful images are clearly supposed to
Speaker 3: be up down reversible. So there's one called the vegetable gardener,
Speaker 3: and there's another one called reversible Head with a basket
Speaker 3: of fruit, and they are only really recognizable as human
Speaker 3: portraits when oriented one way. You flip them around vertically
Speaker 3: and they don't look like humans anymore. They just look
Speaker 3: like bowls of produce. Rob I don't know if you
Speaker 3: can tell that. I've got examples for you to look
Speaker 3: at in the outline here. I would say, both of
Speaker 3: these immediately look like people upside down. Flip them right
Speaker 3: side up, and I don't see the face anymore. It's
Speaker 3: just a bowl of fruit and vegetables.
Speaker 2: They're The crazy thing is, if you're looking at the
Speaker 2: both versions side by side, it's hard to not see
Speaker 2: the face in the version in which the bowl is
Speaker 2: right side up and the face is upside down. Because
Speaker 2: of this effect.
Speaker 3: Yeah, so again that's not quite Thatcher effect, but that is, like,
Speaker 3: there's something weird going on when we're trying to process
Speaker 3: faces upside down or things that look like faces upside down,
Speaker 3: And Thompson goes on to note that before he discovered
Speaker 3: the Thatcher effect, it was well known in psychology that
Speaker 3: the recognition of faces in particular paid an especially high
Speaker 3: penalty for up down inversion. Experiments show that basically every
Speaker 3: type of image with a regular updown orientation takes people
Speaker 3: longer to identify when it's upside down. So whether it's
Speaker 3: a dog breed or a vehicle like a car, or
Speaker 3: an airplane or a building, any of these things that
Speaker 3: are normally vertically oriented one way in the world, it's
Speaker 3: harder and takes people longer to recognize them and say
Speaker 3: what they are when they're upside down. But the point is,
Speaker 3: so that's not abnormal. It's true for all up down
Speaker 3: objects basically, But the point is that the gap between
Speaker 3: how easy faces are to identify normally versus how much
Speaker 3: harder they are to identify when upside down is especially large.
Speaker 3: Faces in particular pay a special inversion penalty, and Thompson
Speaker 3: argues that we still actually don't fully understand the cause
Speaker 3: of the Thatcher effect, but I thought i'd run through
Speaker 3: a few common interpretations, partial explanations, and subsequent findings. One
Speaker 3: thing is that a widely cited at least partial explanation
Speaker 3: of the Thatcher effect goes something like this. It is
Speaker 3: differences in human faces are actually quite small. In one sense,
Speaker 3: all human faces look basically the same, but they look
Speaker 3: very different to us because we are highly sensitive to
Speaker 3: tiny differences in human faces, because we need to be.
Speaker 2: We need to.
Speaker 3: Use that information to recognize identity, who is this and
Speaker 3: expression how are they feeling? This is extremely important information
Speaker 3: to us, often life and death information, literally, to know
Speaker 3: who you're looking at and know how they're feeling.
Speaker 2: Yeah, yeah, I mean we've all been in that situation
Speaker 2: where you see someone out in a public setting and
Speaker 2: you have that moment where you're like, is this person
Speaker 2: the person? I think? It is? Like they look up
Speaker 2: just enough like someone you used to know, and then
Speaker 2: you feel that kind of like social pressure whether you
Speaker 2: should acknowledge this or not or keep it to yourself,
Speaker 2: and you know, social pressure is no small thing for
Speaker 2: the human animal.
Speaker 3: Yeah yeah, Oh, I mean I would say in our
Speaker 3: ancestral environments, that social record ignition and recognition of feelings
Speaker 3: probably literally was a difference between you know, it could
Speaker 3: be difference between meeting a friend and having a deadly encounter,
Speaker 3: or navigating tense social situations if you were not accurately
Speaker 3: recognizing other people's emotions, that can be very dangerous. Yeah,
Speaker 3: So in order to recognize faces quickly and accurately, our
Speaker 3: brains have special adaptations. We humans tend not to look
Speaker 3: at faces feature by feature, but in a holistic way,
Speaker 3: taking in the whole thing, the whole face at once,
Speaker 3: and recognizing it based on a sort of at least
Speaker 3: in part on the spatial relationship between all of the
Speaker 3: features put together, kind of the total map. And this
Speaker 3: is what experts call, I think, the configural information view
Speaker 3: of the face. But the configural representations is only works
Speaker 3: when the face is in its normal orientation, or it
Speaker 3: only works fully when the face is in the normal
Speaker 3: updown orientation. When you turn the face upside down, configural
Speaker 3: recognition fails or is impaired, and then we have to
Speaker 3: fall back on other systems to try to understand the
Speaker 3: face we're looking at. So we might have to fall
Speaker 3: back on looking at the face feature by feature to
Speaker 3: try to make sense of it. You look at the eyes,
Speaker 3: and then you look at the mouth, you look at
Speaker 3: the nose. You're trying to piece it together, one thing
Speaker 3: at a time, and in this feature by feature system,
Speaker 3: it is harder to notice that the mouth is turned
Speaker 3: grotesquely upside down relative to the nose and the chin. Instead,
Speaker 3: you're going feature by feature and you're like, yep, that's
Speaker 3: a mouth. Everything checks out.
Speaker 2: Yeah, this is fascinating because this is exactly what you
Speaker 2: can kind of feel this happening when you have that
Speaker 2: moment where you think you recognize someone. Your brain is like,
Speaker 2: we have a holistic match, and then we're like, okay,
Speaker 2: on to the next level of analysis here, what does
Speaker 2: the mouse look like? And so forth.
Speaker 3: Yeah, so regarding the Thatcher effect, you know, yeah, so
Speaker 3: you're maybe going more feature by feature when a head
Speaker 3: is upside down, But then you rotate the image and
Speaker 3: then it's like the configural processing comes back online again.
Speaker 3: It becomes easier at least, and then you see, oh, oh,
Speaker 3: things are not fitting together.
Speaker 2: Something's wrong.
Speaker 3: And Thompson seems to think this explanation is not completely correct.
Speaker 3: It may be partially correct, but Thompson thinks it still
Speaker 3: doesn't explain everything, and there are mysteries that remain about
Speaker 3: the Thatcher illusion, like some results don't fully match up
Speaker 3: with that broad story about what's going on there. But
Speaker 3: there are other interesting things. One is that, strangely, the
Speaker 3: Thatcher effect seems to be not always, but often reduced
Speaker 3: or atypical in people with the condition known as prosopagnosia
Speaker 3: or face blindness. Yes, the term face blindness. We've talked
Speaker 3: about this on the show before, though it's been a while.
Speaker 3: It can sometimes give people the wrong idea about what
Speaker 3: prosopagnosia is. So to understand face blindness, do not picture.
Speaker 3: Do not picture people with their faces blurred out or invisible.
Speaker 3: People with face blindness can actually see faces just fine.
Speaker 3: They have normal visual processing and normal ability to see,
Speaker 3: so faces probably look the same as they do to us.
Speaker 3: The problem is that people with face blindness do not
Speaker 3: recognize familiar faces, sometimes even including their own face in
Speaker 3: the mirror as easily as people with typical face recognition.
Speaker 3: And for people with face blindness recognizing faces, it's just
Speaker 3: not easy and automatic like it is for most people.
Speaker 3: It often requires effortful attention and deliberate memorization of specific
Speaker 3: facial features, so people with face blindness have to make
Speaker 3: a mental map like Jim is the guy who has
Speaker 3: brown hair and a mole beside his left eye, and
Speaker 3: they can remember based on the individual feature processing. Face
Speaker 3: blindness is most often associated with dysfunction in a region
Speaker 3: of the brain known as the fusiform gyros or the
Speaker 3: fusiform face area. The FFA could be a dysfunction in
Speaker 3: the FFA or within a broader network of brain regions
Speaker 3: that work together to process faces. So a network of
Speaker 3: regions that include the FFA and this FFA based network
Speaker 3: is what we use to engage the holistic or configural
Speaker 3: processing a near instant recognition of faces. Dysfunction anywhere in
Speaker 3: this system or in the fusiform face area can lead
Speaker 3: to prosopagnosia and can be caused by either congenital disorder
Speaker 3: or by brain injury can be acquired later in life.
Speaker 3: But the interesting thing is people with face blindness, on average,
Speaker 3: are less subject to the Thatcher effect than people with
Speaker 3: typical face perception, so the thatcherized faces are sometimes easier
Speaker 3: for people with face blindness to see as grotesque even
Speaker 3: when upside down. And this fact, which is strange to imagine,
Speaker 3: but this is part of the evidence for the idea
Speaker 3: of holistic or configural processing being key to the Thatcher effect,
Speaker 3: because you know, people on face blindness have to fall
Speaker 3: back on featural processing to identify faces anyway.
Speaker 2: Oh wow, So yes, yes, they don't have the pronounced
Speaker 2: like first pass recognition ability. They're not cost they're not
Speaker 2: caught by like first pass recognition illusions.
Speaker 3: Yes, interesting, but from what I've read, it's not like
Speaker 3: it's not as simple as it just just Thatcher effect
Speaker 3: turned on for typical face recognition and turned off for
Speaker 3: people with brosopagnotia. Instead, it's more on average it's reduced
Speaker 3: for people with face blindness, so you know, some individual
Speaker 3: results vary, so anyway, that's your effect. I think is
Speaker 3: a great subject because of not only how hilarious and
Speaker 3: cursed these images look, but it really does raise interesting
Speaker 3: questions about how our brains work the way they do.
Speaker 3: And you know, mysterious process is like recognition, Like when
Speaker 3: you really start to think about what recognition is, the
Speaker 3: sense of familiarity we get when we identify an image,
Speaker 3: and like how that sense is generated in the brain.
Speaker 3: It becomes a more and more fascinating and mysterious process.
Speaker 2: Yeah. Absolutely, all right, well, at this point I think
Speaker 2: we can acknowledge, let's see, everything is upside down, but
Speaker 2: there's also no upside down. Things that you think are
Speaker 2: right side up are actually upside down, and things that
Speaker 2: you think are upside down or actually right side up.
Speaker 2: I think that about covers it.
Speaker 3: I think that's right. And when things are upside down,
Speaker 3: you might not notice things about them. There might be
Speaker 3: a i don't know, hidden alterations slipping beneath the detection level,
Speaker 3: so you know, scrutinize those upside down images.
Speaker 2: Yeah, yeah, I'd love to hear back from anyone who
Speaker 2: who after listening to this, or just outside of the
Speaker 2: experience of listening to this, I have tinkered around with
Speaker 2: like these stature images, thatcherized images, or if you've ever
Speaker 2: experimented with some sort of perception altering goggles, you know,
Speaker 2: some of this will also venture into the world of VR,
Speaker 2: I know, in which you were essentially putting on some
Speaker 2: sort of goggles that are giving you an augmented or
Speaker 2: completely different visual feed of what the world is. Yeah,
Speaker 2: all right, well we're going to go and call it there,
Speaker 2: but yeah, we'd love to hear from everyone out there.
Speaker 2: Just a reminder that Stuff to Blow Your Mind is
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Speaker 3: Huge thanks as always to our excellent audio producer JJ Posway.
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